November 03, 2009

Rare 'shell shock' footage online:

One of the most important films in the history of psychiatry, depicting treatment of 'shell shocked' British soldiers during World War One, has just been made freely available online by UK medical charity the Wellcome Trust who are currently releasing lots of their archive footage.

The film was made by Sir Arthur Hurst in 1917 when large numbers of soldiers with 'shell shock', later to be called 'war neurosis', were returning from the front - in this case to a make-shift military hospital in South Devon, England, which was previously an agricultural college.

Time and time again you'll read in news articles that post-traumatic stress disorder (PTSD) is the new name for what used to be called 'shell shock' but this is false and you can easily see why in the film.

The most prominent symptoms of the World War One patients are 'hysterical' symptoms. These are symptoms that appear to be due to nervous system damage (such as paralysis, tremor or blindness, to name but a few) despite the fact that it is possible to demonstrate that the parts of the nervous system involved in the seemingly impaired ability are working perfectly fine.

A long-standing idea is that these impairment are caused by the subconscious mind 'converting' emotional distress into physical symptoms, but there is little good evidence to say whether this is likely or not.

These conditions are now diagnosed as 'conversion disorder' or 'dissociative disorder' and, while it is accepted that trauma may play a role in triggering them it is not a requirement.

This makes it quite different from PTSD, which requires the patient to have experienced a traumatic event and that includes symptoms of hyperarousal (feeling 'on edge'), having intrusive memories of the event, and avoiding reminders of the trauma.

As we've discussed before on Mind Hacks, PTSD was a direct result of the Vietnam war (indeed, it was originally called 'post-Vietnam' syndrome) and was partly introduced as a way of allowing veterans to get treatment for their war-trauma-related psychiatric difficulties.

The 1917 film was hugely important because it unequivocally showed to a wide audience that mental stress could lead to dramatic physical difficulties, highlighting the importance of psychiatry which was often considered to be a 'second rate' medical speciality.

It is also an important historical document because it shows some dramatic symptoms that rarely appear in such a stark form and also outlines the treatments of the day.

The first patient seen is Pte. Meek, age 23. He has complete retrograde amnesia, hysterical paralysis, contractures, mutism and universal anaesthesia. There is a shot of him in a wheelchair with a nurse, and the intertitles explain that he is completely unaware of the efforts to overcome the rigidity of his ankles, and a man is seen trying to bend his feet. He had a sudden recovery of memory nine months later, with gradual recovery of body functions. Seven months after this we see him teaching basket-making, which was his peacetime job. Two and a half years after onset he makes a complete recovery, and there is a shot of him running up and down stairs waving his arms.

The next patient is Pte. Preston, who has amnesia, word blindness and word deafness, except to the word 'bombs', and his response to this is shown. When a doctor says 'bombs', he dives under a bed. Pte Ross Smith is also seen, who has a facial spasm. The spasm ceases under hypnosis, but return on waking. He has a lateral tremor of the head, treatment being relaxation and passive movements. There is a shot of him lying in bed having his head moved around.

You can watch the film at the Wellcome website, or they've uploaded it as five parts to YouTube. The first part is here and you can click through the rest.

Link to film and info from the Wellcome Trust.
Link to first part on YouTube.

—Vaughan.

October 29, 2009

Apply a female pigeon:

The first neurology book printed in English was called 'De Morbis Capitis' and appeared in 1650. An old article from the Archives of Neurology discusses the book and has a lovely excerpt where it discusses numerous bizarre-sounding cures for brain diseases.

The full title of the book is the wonderful "DE MORBIS CAPITIS; Or, Of the chief internal Diseases of the HEAD. With Their Causes, Signes, Prognosticks, and Cures, for the benefit of those that understand not the Latine tongue".

It was written by the country physician Robert Pemell who outlines the best rural neurological knowledge of the time.

This part from the Archives of Neurology article that discusses some of the 'cures' is both delightful and frightening in equal measure:

Ingredients in other remedies are marjoram, hyssop, lavender (a stimulant), rosemary, thyme, cinnamon, and nutmeg. Animal extracts included the brain of a hare, "much commended as having a peculiar property for the Paralyticall." Diet is an important component in both the treatment and prevention of disease. Patients with paralysis, a disorder caused by an overabundance of thick humors, are counselled to "abstain from all gross and flegmatic meat..."

Physical remedies are also described by Pemell. Some are simple. "Make a noise in the ears of the (epileptic) party; for hereby the faculties are more stired up." "Let the soles of the feet be well rub'd, and bathed with salt and vinegar." Some are more elaborate. Apply "a female pigeon (the fethers being first leptick; for hereby the fit is abated, and the venomous vapours are drawn away."

Link to PubMed entry for Archives of Neurology article.

—Vaughan.

October 23, 2009

A poster to remember:

While strolling through town the other day, I came across this fantastic memory and brain-themed poster.

It's from the University of Antioquia's museum who are holding an art and literature competition to celebrate 200 years of Colombian independence.

Click the image for a bigger version or hit the link below if you want to see it in all its glory.

Link to bigger version.

—Vaughan.

October 22, 2009

Size zero culture in Ancient Rome:

We often think that pressure on young women to be thin is a modern phenomenon, but a fascinating letter to the Journal of the American Academy of Child and Adolescent Psychiatry published in 2000 noted that this is not a new development. The authors cite evidence from Ancient Rome showing a similar cultural pressures were widespread:

Garner et al. (1985) wrote about the present “unprecedented emphasis on thinness and dieting” which is one factor responsible for the increase in anorexic and bulimic disorders. It is generally believed that dieting in pursuit of a thinner shape and slimness as a standard for feminine beauty are modern attitudes. However, a clear account can be found in the ancient comedy Terence’s Eunuchus.

Terence (Publius Terentius Afer) (c. 190–159 BC) was a Roman comic poet. His 6 surviving comedies are Greek in origin but describe the contemporary Roman society. Eunuchus was probably presented in 161 BC. In this comedy, a young man named Chaerea declares his love for a 16-year-old girl whom he depicts as looking different from other girls and he protests against the contemporary emphasis on thinness: “haud similis uirgost uirginum nostrarum quas matres student demissis umeris esse, uincto pectore, ut gracilae sient. si quaest habitior paullo, pugilem esse aiunt, deducunt cibum; tam etsi bonast natura, reddunt curatura iunceam. itaque ergo amantur.” (She is a girl who doesn’t look like the girls of our day whose mothers strive to make them have sloping shoulders, a squeezed chest so that they look slim. If one is a little plumper, they say she is a boxer and they reduce her diet. Though she is well endowed by nature, this treatment makes her as thin as a bulrush. And men love them for that!) Then he describes the girl he loves: “noua figura oris . . . color uerus, corpus solidum et suci plenum” (unusual looks . . . a natural complexion, a plump and firm body, full of vitality). So he opposes vividly the typical thinness of the girls of these times to the blossomed body of the girl he loves.

This Roman pressure on girls to diet to meet the social expectations for thinness represents a clear precedent for the current emphasis on thinness. It is clear that in Ancient Rome, as in today’s society, there were multiple factors related to the development of body image concerns which today are often a precursor to eating disorders. These include cultural pressures to strive to develop and maintain a particular body shape in order to be considered attractive and then valued as a woman. Here, Terence mentions Chaerea’s preference for a plumper girl, while mothers usually wished their daughters to be thinner. Although the media influences that today are critical in influencing images of a perfect body were not present in Ancient Rome, it is clear from this part of the text that pressures concerning appearance existed long before the 20th century.

Link to PubMed entry for letter.

—Vaughan.

August 18, 2009

Booze memory of waiters in Buenos Aires:

The Guardian's Improbable Research column covers a clever study on the incredible memory of waiters in Buenos Aires who can take orders from a large table of customers without writing anything down.

Instead of coming up with some abstract computerised lab task, the researchers tested their drink ordering skills and then swapped places to test how they were remembering all the orders.

Eight customers sat at a table, and ordered drinks. When the waiter brought the beverages, the scientists tallied up how many were served to the people who had ordered them, and how many delivered to someone else. All the waiters performed admirably.

The customers later ordered more drinks, then switched seats before the waiter returned. This produced dreary results. The scientists tried this on nine waiters, only one of whom consistently delivered drinks to the right people.

Interviewed afterwards, waiters said they generally paid attention to customers' locations, faces and clothing. They also disclosed a tiny trick of the trade. They "did not pay attention to any customer after taking a table's order, as if they were protecting the memory formation in the path from the table to the bartender or kitchen."

Link to Improbable Research column on the study.
pdf of scientific paper.
Link to PubMed entry for same.

—Vaughan.

August 02, 2009

Like running through hell:

The Neurocritic covers some fascinating research on how marathon runners could be a scientific window into the neuropsychology of trauma owing to the fact that they experience extremely high levels of the stress hormone cortisol.

In their study, psychologists Teal Eich and Janet Metcalfe note that cortisol levels recorded 30 minutes after a marathon have been found to be similar to those in soldiers during military training and interrogation, rape victims just after the attack, severe burn injury patients and first-time parachute jumpers.

This suggests that marathon runners could be studied in a more systematic way than would would be ethical with victims of trauma, giving an important insight into the brain under extreme stress.

Eich and Metcalfe were particularly interested in the effect of stress on memory and wanted to see if there were any differences between explicit memory - memories that you can consciously call to mind, and implicit memory - the influence of past information on a task even if you're not aware of doing any remembering.

They tested a group of runners about half an hour after they completed a marathon and a group who were just about to run a marathon.

In comparison to the about-to-runs, those who had completed the marathon had worse explicit memory but better implicit memory. In other words, their conscious memory was reduced but their unconscious memory seemed to be sharper.

This is interesting because chronically high cortisol levels from trauma are thought to affect the hippocampus, a brain area known to be key in conscious memory. The researchers suggest that a similar process may be temporarily reducing explicit memory in runners.

The authors are a little more cautious in suggesting why implicit memory may have been improved, but one possibility is that cortisol is known to affect fear conditioning - the unconscious linking of fright with the situation it occurred in.

Interestingly, this is known to work differently in men and women. Cortisol boosts unconscious fear learning in men, but not women. The researchers didn't compare male and female marathon runners directly, but it would be interesting to know whether general unconscious learning that wasn't associated with fright was also sex-specific in their study.

There's more on the research over at The Neurocritic and the full text of the study is available online as a pdf if you want an in-depth look at the experiment.

Link to great write-up from The Neurocritic.
pdf of study.
Link to PubMed entry for same.

—Vaughan.

July 09, 2009

Brand new second hand :

Newsweek has an interesting article about the reality of unconscious plagiarism - otherwise known as 'cryptomnesia'.

The article describes apparently genuine cases in terms of source memory - the ability to not only to remember information but also where it came from. When you remember a great idea, was it one of yours, it did you read it in a book, or hear it from a friend?

In the lab this has usually been tested by relatively simple experiments where participants are asked to read out words, imagine themselves reading out words and hear words being read out.

They're then shown another list, and they have to say whether they've encountered the word before and, if so, did they hear it, read it or imagine it.

There are many variations on this simple idea, but all of which show that we routinely mistake information from other people as something we generated ourselves.

Psychologist Marcia Johnson has done a huge amount of work on how we monitor the source of our memories and how distortions affect what she calls 'reality monitoring'.

It turns out that memories don't have a specific source tag, like a mental label. We infer where they came from based on their content. There are many things have been found to be important, but even something as simple as the sensory vividness of the memory is known to have a big effect.

For example, people who have very vivid mental images have been found to be more likely to misattribute the source of memories for this reason.

So the idea is that sometimes we present other people's ideas as our own, not because we're being deliberately dishonest, but because we genuinely think we came up with it in the first place because of source memory failure.

The Newsweek article covers how this applies to writers and journalists and some of the recent research which tackles exactly these sort of memory distortions.

However, it doesn't mention perhaps the most famous of cryptomnesia - where a judged ruled that ex-Beatle George Harrison had unconsciously plagiarised the Chiffons' He's so Fine in his own track My Sweet Lord.

And this is exactly where it gets a bit murky, because it's never clear whether someone has unconsciously plagiarised, or just plagiarised, because it relies on making a judgement about someone else's intentions.

Link to Newsweek article on cryptomnesia.

—Vaughan.

April 11, 2009

The future of targeted memory manipulation:

Wired Science has an interesting interview with Oxford neuroethicist Anders Sandberg about the future of drugs that can reduce the emotional impact of traumatic memories.

The interview uses the term 'memory editing' which is not a great label for these drugs, such as beta-blocker propranolol, which largely work by reducing the emotional 'kick' stored with a memory of a painful or traumatic experience when taken after the experience or during recall.

This is something that is often misreported by the mainstream media who often starting going off on one about 'memory erasing' drugs and the like.

However, it is also not true that propranolol solely effects the emotional aspects. Careful reading of the studies show that people treated with the compound do typically show a slight reduction in their actual memory for traumatic events.

But the interview makes the interesting point that maybe we're a bit too focused on removing or reducing memories, the problem of inducing false memories is probably more serious:

Wired.com: I've asked about memory removal — but should the discussion involve adding memories, too?

Sandberg: People are more worried about deletion. We have a preoccupation with amnesia, and are more fearful of losing something than adding falsehoods.

The problem is that it's the falsehoods that really mess you up. If you don't know something, you can look it up, remedy your lack of information. But if you believe something falsely, that might make you act much more erroneously.

You can imagine someone modifying their memories of war to make them look less cowardly and more brave. Now they'll think they're a brave person. At that point, you end up with the interesting question of whether, in a crisis situation, they would now be brave.

Link to 'The Messy Future of Memory-Editing Drugs'.

—Vaughan.

March 31, 2009

Symbol of remembrance triggers mass false memory:

There's an interesting short research report in Cortex about how a national symbol adopted in Italy after the 1980 terrorist bombing of Bologna train station likely instilled a false memory about the following 16 years.

On the morning of August 2nd, 1980, at 10.25, a bomb exploded in Bologna Centrale station, killing eighty-five people wounding over 200.

The blast also stopped the large station clock on the side of the building at the moment of the explosion, freezing the hands in the 10.25 position. Shortly afterwards, the clock was repaired and it continued to function normally for 16 years.

However, when it broke in 1996, it was decided to leave the clock in its broken state and permanently set the hands at 10.25 in remembrance of the tragedy, owing to the fact that the image of the frozen clock had been widely used in commemorations during the intervening years.

A group of Italian psychologist were aware that repetition tends to cause false memories and decided to test residents of Bologna, all familiar with the station, for their memory of the clock.

What they found was that the majority of people falsely remembered that the clock had been frozen since the bombing and never worked since, despite the fact that this was never the case.

This included those who had regularly seen the clock working fine, presumably on a daily basis, owing to the fact that they worked at the station during the 16 intervening years.

Of the 173 participants who knew that the clock is now stopped, 160 (92%) stated that the clock has always been broken. 127 (79%) further claimed to have seen it always set at 10.25, including all 21 railway employees. Most interviewees did not know that the clock had been working for over 16 years and stated that it had always been broken.

From the 173 people who knew that at the time of testing the clock was stopped, a subgroup of 56 citizens who regularly take part in the annual official commemoration of the event has been further considered: only six (11%) of them correctly remember that the clock had been working in the past.

The findings are an interesting parallel to a study published last year on the London bombings. The researchers asked participants about their memories of seeing TV footage of the bus exploding in Tavistock Square.

Despite the fact that no such footage exists and no reconstruction was ever shown on TV, 40% of British participants 'remembered' seeing it and produce 'details' of the coverage when asked.

Link to study on Bologna bombings.
Link to PubMed entry for same.
Link to summary of London bombings study.

—Vaughan.

March 26, 2009

Where time becomes a loop:

New Scientist has an excellent article on the neuroscience of deja vu, tackling how our brain can generate the anomalous feeling that we are reliving an event when it has happened for the first time.

The article tackles both experiments that try to trigger and measure deja vu in healthy participants, as well as in people who experience, sometimes permanent, deja vu because of epilepsy of brain injury.

There is one slightly awkward bit in the article however.

One possibility is that déjà vu is based on a memory fragment that comes from something more subtle, such as similarity between the configuration or layout of two scenes. Say you are in the living room of a friend's new house with the eerie feeling that you have been there before, yet knowing you can't possibly. It could be just that the arrangement of furniture is similar to what you have seen before, suggests Cleary, so the sense of familiarity feels misplaced...

Although the familiarity idea appeals to many, Moulin, for one, is not convinced. His scepticism stems from a study of a person with epilepsy that he conducted with Akira O'Connor, now at Washington University in St Louis, Missouri. This 39-year-old man's auras of déjà vu were long-lasting enough to conduct experiments during them. The researchers reasoned that if familiarity is at the root of déjà vu, they should be able to stop the experience in its tracks by distracting the man's attention away from whatever scene he was looking at. However, when he looked away or focused on something different, his déjà vu did not dissipate, and would follow his line of vision and his hearing, suggesting that real familiarity is not the key. The fact that an epilepsy aura can cause déjà vu at all suggests that it is erroneous activity in a particular part of the brain that leads to misplaced feelings of familiarity, suggests Moulin.

This dichotomy is interesting because it implies that 'brain activity' and 'misplaced familiarity' are somehow separate, when we know each can just be descriptions of the same thing on different levels of interpretation.

However, it also implies that deja vu can only be caused in one particular way, when it could be caused by many different processes.

For example, think about trying to understand why someone got angry. We could be studying one person who gets angry when his football team loose, another when he is wrongly accused and another when he has a seizure in his limbic system.

You could use each one of these explanations to say that the other explanation is wrong if you believed that anger could only be caused in one way.

However, if we accept that it is an experience described at the level of psychology or behaviour there could be many ways of explaining it, and many paths that lead to the same experience, each cause does not cancel the other out.

Like deja vu and probably many other experiences, there are many causes and ways of explaining causes for the same phenomena.

Link to NewSci article 'Déjà vu: Where fact meets fantasy'.

—Vaughan.

February 16, 2009

The scientific legacy of HM's missing memories:

The latest edition of Neuron has a fantastic tribute to the recently departed amnesic Patient HM, "probably the best known single patient in the history of neuroscience", covering the scientific work he participated in and what it has told us about the structure of memory.

The piece is by respected memory researcher Larry Squire and he tackles HM's personal history while also reviewing his contributions to science through numerous landmark studies.

It can be said that the early descriptions of H.M. inaugurated the modern era of memory research. Before H.M., due particularly to the influence of Karl Lashley, memory functions were thought to be widely distributed in the cortex and to be integrated with intellectual and perceptual functions.

The findings from H.M. established the fundamental principle that memory is a distinct cerebral function, separable from other perceptual and cognitive abilities, and identified the medial aspect of the temporal lobe as important for memory.

The implication was that the brain has to some extent separated its perceptual and intellectual functions from its capacity to lay down in memory the records that ordinarily result from engaging in perceptual and intellectual work.

The article is fascinating not least because it dispels a few common myths about HM - such as the original study showed the hippocampus was necessary for memory when HM also had the amygdala and parahippocampal gyrus removed and so it wasn't possible to say which were most important.

It also notes that the original studies over-stated how much brain was removed owing to the basic knowledge of neuroanatomy that existed at the time.

Link to 'The Legacy of Patient H.M. for Neuroscience'.
Link to PubMed entry for same.

—Vaughan.

September 11, 2008

The amazing technicolour dream hoax?:

Dream researchers in the 1950s concluded that people typically dreamed in black and white whereas modern dream research reports most people dream in colour. Philosopher Eric Schwitzgebel discusses this curious finding in a 2002 article, arguing that it is unlikely dreaming has changed so radically and that this is likely evidence of how bad we are at introspection into our dream lives.

Schwitzgebel discusses a whole range of theories and ideas, but begins by summarising the evidence from a time when it was largely assumed that people dream in monochrome:

In 1951, Calvin S. Hall announced in Scientific American that 29% of dreams are either entirely colored or have some little bit of color in them (Hall, 1951). He called such dreams ‘technicolored’, thereby explicitly comparing them to the colored movies that were becoming increasingly prevalent in the 1940s and ’50s, and implicitly contrasting them with lower-tech black and white movies and dreams.

Some of Hall’s contemporaries might have thought him too generous in his estimation of the proportion of colored to black and white dreams. Tapia, Werboff and Winokur (1958) found that only about 9% of a sample of people reporting to the hospital at Washington University in St. Louis for non-psychiatric medical problems reported having colored dreams, compared with 12% of neurotic men and 21% of neurotic women. Middleton (1942) found that 40% of his college sophomores claimed never to see colors in their dreams, 31% claimed rarely to do so, and only 10% claimed to do so frequently or very frequently.

The first objection you might think of is that perhaps these results are accurate, owing to the fact people watched lots of black and white TV and films.

But in an age when people still spent a relatively small proportion of their time in the cinema or in front of the TV (which only had restricted broadcasts) it is unlikely to account for the virtual 'absence' of coloured dreaming, especially considering that 'real life' is experienced in colour.

One of the most interesting hypothesis tackled by the article is that dreams are like narratives, and do not necessarily have colour, but black and white media might just have led people to interpret their dreams in this way.

Consider, as an analogy, a novel. While novels surely are not in black and white, it also seems a little strange to say that they are ‘in color’. Certainly novels make fictional attributions of color (‘she strode into the room in a dazzling red dress’) and refer to objects that normally have a particular color (‘she promptly chopped a carrot’). Maybe it makes sense to describe such fictional claims as ‘in color’ or partly in color. However, most elements of most scenes in novels do not have determinate colors in that way...

If you find yourself disinclined to think that novels, or the images evoked by novels, are properly described as being either in black and white or in full color, then you might likewise find yourself hesitant to apply the terms ‘black and white’ or ‘colored’ to dreams. Perhaps dream-objects and dream-events are similar to fictional objects and events, or to the images evoked by fiction, in having, typically, a certain indeterminacy of color, neither cerise nor taupe nor burnt umber, nor gray either.

The article goes on to suggest that this reconstructive aspect is a core feature of consciousness and that is further evidence that we are just not very good at introspecting our own minds because as soon as we do, we alter the contents of what we're attempting to experience.

pdf of 'Why did we think we dreamed in black and white?'

—Vaughan.

June 02, 2008

What the tip of the tongue tells us about the brain:

The tip-of-the-tongue state is a common experience where you know you know something but can't quite bring it to mind. This everyday experience has told us a great deal about how the mind and brain work, as explored in an article for the Boston Globe.

It's a paradoxical experience if you think about it. You know something, but you can't remember it.

Just this tells us that the storage of information and the ability to access it are distinct in the brain.

It also tells us that the brain must have ways of monitoring itself and communicating how successfully it carries out its operations to the conscious and unconscious mind.

This is known as 'metacognition' and is one of the most important concepts in modern psychology.

The Boston Globe article (by Jonah Lehrer of the Frontal Cortex blog) is a remarkably lucid exploration of exactly this topic, looking at how it has been studied in everything from lab studies to people with brain injury who suffer near permanent tip-of-the-tongue states.

Link to Boston Globe article 'What's that name?'.

—Vaughan.

May 15, 2008

The secret family life of a false memory :

Thanks to Aaron and Frontal Cortex for simultaneously alerting us to this fantastic animation that recounts a charming real life case of a false memory.

Families are like incubators for false memories because each family has its favourite stories, anecdotes and foundational myths that get passed on, retold and molded in the retelling, like an intergeneration game of Chinese whispers.

I have many early memories that I simply don't know whether I genuinely remember, or I just think I do, because I've heard stories or seen the photos so many times.

I love listening to families talk about memories, because its fascinating to hear how recollections can vary, each highlighting a different aspect, as well as how they resolve conflicting accounts.

The animation shows exactly this process in action, showing us that remembering is more than just an individual process, it's often a group activity.

Link to This American Life animation on memory.

—Vaughan.

May 08, 2008

Warping court memories with subtle suggestions:

The legal system works on a principal of innocent until proven guilty by the evidence presented in court, but Cognitive Daily covers several studies that shown our memory of the evidence is affected by moral judgements of the person in question.

With their trademark clarity, CogDaily discuss a study [pdf] by psychologist David Pizarro that found if participants were told about man leaving a restaurant without paying, they remembered the unpaid bill being more expensive if they were told he treated the waiters rudely, than if they were told he was generally a responsible person.

The study is reminiscent of a famous experiment by a young Elizabeth Loftus called Reconstruction of Automobile Destruction.

It was simple but elegantly designed. Groups of people were shown clips of cars crashing and then asked how fast the cars were travelling, but with different verbs in the question.

For example, some people were asked how fast the cars were travelling when they "smashed" into each other, others how fast when they "bumped" into each other, others how fast when they "contacted" with each other, and so on.

Loftus found that simply asking the questions with a different verb altered people's memories of the speed of the crash - like so:

"smashed" : 40.8 miles per hour
"collided" : 39.3 miles per hour
"bumped": 38.1 miles per hour
"hit" : 34 miles per hour
"contacted" : 31.8 miles per hour

Needless to say, these sorts of tricks have been used by lawyers ever since.

Link to CogDaily on moral blame can change the memory of a crime.
pdf of full-text paper.
Link to Wikipedia page Loftus's car crash study.

—Vaughan.

April 17, 2008

Does Freudian repression exist?:

Psychologist Yacov Rofé has written a damning article in the Review of General Psychology summarising the evidence from studies on the cognitive science of memory and arguing that the repression of memory, as described by Freud, doesn't exist.

Rofé is careful to point out that Freud's ideas about the repression of memory were not that we can deliberately forget or ignore traumatic experiences (as is often assumed by both professionals and lay people), but that process is supposedly unconscious (and so not deliberate) and that it was 'pathogenic' - in other words, a cause of mental distress and mental illness.

Rofé also notes that psychoanalysis was assumed to make people better by uncovering and lifting repression to make people better adjusted (although this has largely been rejected by modern therapists).

In contrast to these theories, Rofé cites evidence that people tend to remember rather than repress traumatic experiences, that banishing unpleasant memories tends to be a useful way of coping for many people (although interestingly, probably bad for physical health), that there is no evidence for unconsciously motivated forgetting, and that psychoanalytic therapy doesn't seem to work by 'lifting repression'.

In the article, Rofé has a bit of a tendency to suggest that supporting evidence that can be equally explained with a non-Freudian theory is evidence against Freud, when it fact it's likely to support both explanations equally.

Nevertheless, he makes a strong case, largely based on the limited amount of supporting evidence that does actually exist.

However, I suspect this won't be the end of the argument, as most debates concerning Freud centre as much around agreeing on what the terms mean, as applying data to their truth.

Link to abstract of scientific article.
pdf of full-text article.

—Vaughan.

February 26, 2008

The 7even sins of memory:

PsyBlog has just finished its series on the 'seven sins of memory' that fade and distort what we try to remember, based on memory researcher Dan Schacter's book on the same name.

The 'seven sins' are:

1. Transience
2. Absent-Mindedness
3. Blocking
4. Misattribution
5. Suggestibility
6. Bias
7. Persistence

And PsyBlog looks at each one, discussing what research has told of us about this particularly memory difficulty and how it affects our record of things past.

If you're interested in reading more, Schacter's 1999 book comes highly recommended.

Link to PsyBlog on the 'Seven Sins of Memory'.

—Vaughan.

February 01, 2008

Deep brain stimulation opens memory floodgates:

Neurophilosophy has a great write-up of the recent finding that deep brain stimulation boosted memory function in a patient undergoing brain surgery to treat morbid obesity.

I've only just got round to having a look at the scientific paper myself, and the summary on Neurophilosophy captures the main themes beautifully, and is some of the best coverage I've read so far.

A couple of things stand out for me.

Firstly, the patient was given a last-ditch experimental treatment for obesity by having an electrode planted in the ventral hypothalamus, a deep brain structure, to try and reduce his appetite.

The hypothalamus is involved in regulating a number of essential bodily functions and most pertinently, contains glucoreceptors - cells that detect levels of glucose in the body to regulate feeding and appetite.

A lot has been written about the role of 'mechanical' models of the mind and brain in undermining our sense of free will and responsibility for our actions.

This case suggests that we've now got to the stage where an inability to control a biological urge which negatively affects few people except the patient himself, is reason enough to consider neurosurgery.

I wonder whether deep brain stimulation for people who can't give up cigarettes, alcohol or self-harm will be next.

Secondly, the immediate effect of the stimulation on the patient, who was flooded with numerous vivid memories, is quite striking:

Unexpectedly, the patient reported sudden sensations that he described as déjà vu with stimulation of the first contact tested (contact 4: 3.0 volts, 60-microsecond pulse width [pw], and 130Hz). He reported the sudden perception of being in a park with friends, a familiar scene to him. He felt he was younger, around 20 years old. He recognized his epoch-appropriate girlfriend among the people. He did not see himself in the scene, but instead was an observer. The scene was in color; people were wearing identifiable clothes and were talking, but he could not decipher what they were saying. As the stimulation intensity was increased from 3.0 to 5.0 volts, he reported that the details in the scene became more vivid.

This is a strikingly similar experience to the memories triggered by electrical stimulation of the surface of the temporal lobe reported by legendary Canadian neurosurgeon Wilder Penfield in the 50s and 60s:

The other response is an activation of the stream of past experience. This is what the patient often refers to as a 'flash-back' to his own past. When the electrode is applied, he may exclaim in surprise, as the young secretary, M M, did: 'Oh, I had a very, very familiar memory, in an office somewhere. I could see the desks. I was there and someone was calling to me, a man leaning on a desk with a pencil in his hand.' Or the patient may call out in astonishment, as J T did (when the current was switched on without his knowledge): 'Yes, Doctor, yes, Doctor! Now I hear people laughing - my friends in South Africa ... Yes, they are my two cousins, Bessie and Ann Wheliaw.'

However, despite testing over 600 patients in this way, less than 8% had the experience of electrically triggered memories, and the effect has not been reliably replicated by modern researchers.

This suggests that the flood of memories triggered by stimulating the hypothalamus in this new study, perhaps may not happen in all people.

Of course the big finding in this new study was not the triggered memories, but that when the stimulation was switched on for longer periods, the patient did much better in memory tests.

It will be interesting to see whether this general effect on memory is perhaps as unpredictable across individuals as electrically evoked memories have proved to be in the past.

Link to Neurophilosophy post on the new study.
Link to abstract of scientific paper.
Link to Penfield's paper (with evoked memory memory examples).

—Vaughan.

January 23, 2008

The resistence of memory in hypnotic amnesia:

Research just published in neuroscience journal Neuron has discovered some of the brain networks behind post-hypnotic amnesia. Importantly, the study might give us an insight into how memories are repressed from consciousness.

Psychogenic amnesia is a type of memory disorder where there is no brain damage to explain the memory loss. Unlike amnesia after brain injury, which usually causes an inability to form new memories, psychogenic amnesia typically results in the person being unable to remember past events.

Most memory research involves comparing how well people recognise or recall information that they've been shown earlier.

One of the difficulties in studying psychogenic amnesia is that you're never sure whether the memories you're asking about were taken in, but are inaccessible, or whether the person simply didn't register the information in the first place.

Amnesia caused by hypnosis is remarkably similar to psychogenic amnesia in many ways, but has the advantage of being temporary and reversible.

This is important because it allows researchers to show people information, then induce hypnotic amnesia and check memory, and then reverse the effects and check memory again.

The final memory check shows that the person genuinely took the information in to start with, so you know that the amnesia was for memories that were definitely there already.

Post-hypnotic amnesia is where a suggestion is given during hypnosis that the person won't remember a specific event after the hypnosis is over. Because hypnotisability varies between individuals, it doesn't work for everybody, but for those who experience this type of temporary memory loss, the effect can be quite dramatic.

In an initial session, researchers showed high and low hypnotisable participants a 45 minute film which they were told to remember.

A week later, they were put in an fMRI scanner, hypnotised and told to forget the film when the hypnosis was over. Crucially, they were told that their memories would return when given a specific command.

They were then scanned while being asked "yes/no" questions about both the film itself and other details about the initial session (such as whether the door to the testing room was open).

Unlike facts about the film, the participants were never told to forget these other details, allowing the researchers to test how specific the amnesia was.

The 'hypnosis resistant' low hypnotisable participants were equally good at recalling facts about the film and the testing session.

For high hypnotisable participants, although they were good at remembering session details, they were no better than chance at answering the questions about the film. In other words, they would have got the same number of questions right if they flipped a coin - suggesting their memory was quite impaired.

When given the command to remove the amnesia, the high hypnotisable participants could then recall the film as well as the others.

(Partly owing to the scepticism about hypnosis, the researchers also tested another group of people who were told just to pretend to be hypnotised. They performed quite differently - vastly exaggerating their memory difficulties - indicating that the high hypnotisable participants weren't faking or 'conforming').

When trying to recall information when post-hypnotic amnesia was in effect, activity in the temporal lobes and occipital lobes was reduced, while activity in part of the frontal lobes increased.

The areas of the temporal and occipital lobes are known to be involved in dealing with factual and visual information, while the frontal lobes are known to be involved in coordinating other brain areas.

In this case, they seem to be inhibiting the function of other areas, perhaps preventing recall and explaining the amnesia.

Interestingly, when the amnesia was reversed, brain circuits involved in long-term memories became more active as the participants were able to answer questions.

This study might explain how psychogenic amnesia works. Perhaps this syndrome results from the same brain mechanism being 'locked' in place, persistently 'repressing' memories.

In fact, there's a whole range of apparently neurological problems but where the person has no recognisable brain damage. These usually get diagnosed as conversion disorder and can involve everything from blindness to paralysis.

Two studies have just come out which point in the same direction as this hypnosis study.

In one, several patients with structurally normal brains were found to have under-activation in certain areas corresponding to their conversion disorder paralysis.

In another, when a patient with conversion disorder was asked to recall the traumatic event which triggered her paralysis, brain activation suddenly dropped in the brain areas that controlled movement in her immobile limbs.

What these studies are suggesting is that problems can arise in the operation of seemingly intact brains that can lead to what appear to be neurological problems.

An analogy might be that while the roads are intact, traffic jams can still bring a city to a standstill. The trick, of course, is to get the traffic flowing again.

The more we understand about how the flow gets disturbed, the more likely we are to help patients get things running smoothly again.

Link to abstract of post-hypnotic amnesia study.
Link to write-up of study from Science News.

—Vaughan.

January 02, 2008

Are repressed memories a product of culture?:

Harvard Magazine has an interesting article on whether it is possible to repress memories to force them into the unconscious.

As well as discussing the phenomenon, it also updates us on the challenge put forward by the McLean Hospital Psychiatry Lab: find a single account of repressed memory, fictional or not, before the year 1800 and win $1000.

It turns out, the $1000 dollars has just been awarded, although the account only sneaked past the post - it was from 1786.

The point of the challenge was because the McLean lab suspect that repressed memories, also called 'dissociative amnesia', are a 'culture bound syndrome' - in other words, they're so heavily influenced by cultural ideas that they are not a universal feature of the human mind and brain.

If they are a universal human feature you'd expect them to be reported throughout history, but it turns out that there are no clear reports of anyone repressing a memory, either in historical writing or in fiction, until the late 1700s.

Their paper [pdf] on culture, dissociative amnesia and their challenge, was published just before they awarded the prize, so doesn't include the winning account, but discusses the cultural influences on this controversial concept.

As well as being enormously good fun, their challenge is an interesting way of gathering date to inform a hot topic in psychology.

Link to Harvard Magazine article on repressed memory and culture.
pdf of paper 'Is dissociative amnesia a culture-bound syndrome?'.
Link to McClean Psychiatry Lab challenge page with entries.

—Vaughan.

November 28, 2007

Ministry of Memory Distortions:

In George Orwell's dystopian novel, 1984, Winston Smith works in the Ministry of Truth retouching photographs to remove people from the record of history. A recent psychology study suggests that these manipulations may change more than the historical record, they could affect our collective memories of what actually happened.

In the study, led by Italian psychologist Dario Sacchi, participants were shown two photographs; one from the 1989 Tiananmen Square protests and another from a 2003 protest in Rome against the Iraq war.

What they didn't know was that some participants saw doctored versions of either one or both of the photographs. The image on the left demonstrates that a crowd was added to the Tiananmen Square image. With the Rome photo police and aggressive-looking demonstrators were added to the image of peaceful protesters.

To test whether people perceived the photos as genuine or not without giving the game away, the researchers asked participants how familiar they were with the image.

Both groups rated the Tiananmen Square photo as equally familiar, suggesting few picked up on the changes.

Interestingly, participants rated the altered Rome photo as less familiar, but when given a chance to comment, no-one suggested it was fake, with some suggesting that their memory of the protest being peaceful, rather than the photo, must be mistaken.

The participants were then asked to answer questions about the events from their memories of what happened.

Those who saw the altered Tiananmen Square image remembered more people being there, those who saw the Rome image remembered it as more violent, more negative, and recalled more property being damaged and confrontations with the police.

When the experiment was run again, participants additionally rated themselves as less likely to attend a demonstration in future.

The study has obvious implications for propaganda and the paper spends much time discussing the possible impact of doctored photos on public opinion.

Combined with some earlier studies that suggest that people often believe initial false news reports even when they're aware of them being falsified, you can see how the media has a powerful influence over our remembered realities.

Link to study abstract.
Link to write-up from LiveScience.

—Vaughan.

October 24, 2007

Hypermemory and amnesia in National Geographic:

Neurophilosophy has alerted me to the fact that National Geographic magazine has a fantastic cover feature on memory, forgetting, amnesia and hyper-recall in this month's issue. It's both freely available online and is accompanied by an interactive 3D brain map of the key memory structures.

The article discusses some of the extremes of memory that have been reported in the neuropsychology literature and describes an encounter both with EP, a patient with profound amnesia after suffering an HSE infection, and AJ, a woman who seemingly has an almost 'perfect' memory for her past.

As well as tackling some of the neuroscience of memory, the piece does an excellent job of communicating the characters and frustrations of the people with these remarkable memories

It also contains some wonderful asides about the place memory has in our society, and how that has changed significantly since the advent of technologies such as disposable writing tools that have allowed us to artificially 'extend' our memories.

Before that time, the act of remembering was, in itself, a hugely significant skill and quite literally in some cases, the stuff of legend.

It's hard for us to imagine what it must have been like to live in a culture before the advent of printed books or before you could carry around a ballpoint pen and paper to jot notes. "In a world of few books, and those mostly in communal libraries, one's education had to be remembered, for one could never depend on having continuing access to specific material," writes Mary Carruthers, author of The Book of Memory, a study of the role of memory techniques in medieval culture. "Ancient and medieval people reserved their awe for memory. Their greatest geniuses they describe as people of superior memories."

Thirteenth-century theologian Thomas Aquinas, for example, was celebrated for composing his Summa Theologica entirely in his head and dictating it from memory with no more than a few notes. The Roman philosopher Seneca the Elder could repeat 2,000 names in the order they'd been given to him. A Roman named Simplicius could recite Virgil by heart—backward. A strong memory was seen as the greatest of virtues since it represented the internalization of a universe of external knowledge. Indeed, a common theme in the lives of the saints was that they had extraordinary memories.

After Simonides' discovery, the art of memory was codified with an extensive set of rules and instructions by the likes of Cicero and Quintilian and in countless medieval memory treatises. Students were taught not only what to remember but also techniques for how to remember it. In fact, there are long traditions of memory training in many cultures. The Jewish Talmud, embedded with mnemonics—techniques for preserving memories—was passed down orally for centuries. Koranic memorization is still considered a supreme achievement among devout Muslims. Traditional West African griots and South Slavic bards recount colossal epics entirely from memory.

Link to National Geographic article 'Remember This'.
Link to interactive 3D brain map of the key memory structures.

—Vaughan.

September 20, 2007

Gone, and yet forgotten:

An interesting section from neuropsychiatrist Michael Kopelman's 2002 review article on the neuropsychology of memory disorders where he tackles transient global amnesia - a form of brief, severe, but mysterious amnesia that resolves in a few hours. No-one really knows what causes the majority of cases.

Transient global amnesia (TGA) most commonly occurs in the middle-aged or elderly, more frequently in men, and results in a period of amnesia lasting several hours. As is well known, it is characterized by repetitive questioning, and there may be some confusion, but patients do not report any loss of personal identity.

It is sometimes preceded by headache or nausea, a stressful life event, a medical procedure, intense emotion or vigorous exercise. Hodges and Ward (1989) found that the mean duration of amnesia was 4h and the maximum 12h. In 25% of their sample, there was a past history of migraine, which was considered to have a possible aetiological role.

In a further 7%, the patients subsequently developed unequivocal features of epilepsy in the absence of any previous history of seizures. There was no association with either a past history of or risk factors for vascular disease, nor with clinical signs indicating a vascular pathology. In particular, there was no association with transient ischaemic attacks.

In 60-70% of the sample, the underlying aetiology was unclear.

Link to full-text of paper 'Disorders of memory'.

—Vaughan.

September 18, 2007

Patient HM marks 50 years in science with new study:

A new study has been published on Patient HM, marking fifty years of participation in neuroscience research since the first study was published in 1957.

HM was suffering from incapacitating epileptic seizures that were not helped by any of the medications of the 1950s.

As a last resort, neurosurgeon William Scoville tried an experimental operation to remove 8cms of tissue on both sides of the inner parts of his temporal lobes, including both hippocampi, hopefully also removing the source of his seizures.

Neurosurgery to treat otherwise untreatable epilepsy is still common and highly effective, although this type of operation isn't used any more.

This is largely because HM's seizures reduced considerably, but he was left with a severe amnesia, meaning he couldn't seem to lay down any new conscious memories, although could remember things that occurred before his surgery.

Because of his seemingly unique memory impairment and an exact knowledge of which brain areas were missing, he has become a regular in neuroscience research that has aimed to understand what his impairment tells us about how normal memory is supported by the brain.

This new study is no exception. The researchers, Profs Veronique Bohbot and Suzanne Corkin, guessed on the basis of the existing evidence that the right parahippocampal cortex would be enough to support spatial learning and navigation.

The right side of the brain is known to be specialised for understanding 3D space and some of the parahippocampal cortex, an area adjacent to the surgically removed hippocampus, remained in HM's brain.

So the researchers used a task where a sensor is hidden under a section of carpet in a room which beeped when it was stepped on.

The participants were asked to find it just by exploration, and subsequently, they were taken to different parts of the room and asked to re-find it.

Despite having no conscious memories of previous tries, HM began to find the sensor quite accurately, much more accurately than if he was just stumbling across it by chance alone.

This suggests that his remaining part of HM's parahippocampal cortex was enough to support spatial memory, and importantly, that the brain areas missing in HM, although they would help, are probably not essential for navigation.

HM has participated some key studies through the decades and has outlasted many in the field. He probably doesn't realise it, but he's been one of the most important people in neuroscience.

Link to abstract of scientific study.
Link to NPR radio show on HM and memory.
Link to Wikipedia entry on HM.
pdf of 1957 study on HM.

—Vaughan.

August 03, 2007

Gene may influence traumatic memory impact:

The Science website is reporting on a study that has found that people with a variant of the ADRA2B gene, which regulates the effect of key memory neurotransmitter norepinephrine, are more likely to have enhanced memory for emotional and traumatic events.

A strong emotional response at the time of an event is known to make the event more memorable, and the neurotransmitter norepinephrine, also known as noradrenaline, has been found to be a key player in this process.

The researchers, led by neuroscientist Prof Dominique de Quervain, wondered whether a version of the ADRA2B gene, that codes for the alpha-2b norepinephrine receptor, would influence emotional memory recall.

One of the defining features of post-traumatic stress disorder or PTSD is that distressing memories of the original trauma intrude into everyday life.

People differ in their tendency to remember emotional memories, so understanding the factors behind this difference might help us better understand why some people can survive trauma with little long-lasting disturbance, while others are seriously affected.

The team determined the genotype (gene version) of 435 young Swiss adults and 202 refugees from the Rwandan civil war.

The Swiss volunteers were shown a series of pictures from the International Affective Picture System, a series of photos that range from the pleasant (e.g. sunsets) to the disturbing (e.g. mutilated bodies) that have been rated for their emotional impact.

Participants with a common variant of the ADRA2B gene were more significantly more likely to recall the emotional, but not the neutral pictures.

The refugee participants were asked to recall memories from their time in Rwanda during the civil war.

Participants with the same gene variant that was linked to an increase in emotional picture recall in the Swiss participants, recalled significantly more traumatic incidents than others.

However, the rate of PTSD in the refugee sample did not depend on gene version.

This is possibly because a diagnosis of PTSD requires three things: intrusive traumatic memories, hyperarousal (a feeling of being 'on edge' all the time) and avoidance of the reminders of the trauma.

The gene variant was only linked to the likelihood of re-experiencing traumatic memories, and not the other symptoms, suggesting that the effect is specific to memory and not trauma in general.

Link to write-up from Science.
Link to abstract of scientific paper.

—Vaughan.

July 29, 2007

Goodbye Fair City:

I leave Dublin today after working in the Fair City since spring.

Many thanks to the psychologists I've worked with and learnt so much from, and the people of Dublin for their kind hospitality.

The picture is taken from Sandycove Harbour, looking out across Dun Laoghaire and Dublin Bay.

Only a few hundred yards from where this photo was taken is a tower where James Joyce stayed for several nights until his medical student housemate, Oliver Gogarty, shot at him with a gun.

The tower sets the scene for beginning of Joyce's novel Ulysses, known for its 'stream of consciousness' narrative - a technique first borrowed from psychology by writer May Sinclair.

—Vaughan.

July 18, 2007

Remembered spaces:

A poignant short essay from The New York Times on locations that only live in our memories.

It has the lovely image of cities that exist only in our minds, after buildings we knew so well have since been replaced.

Sort of nostalgic landscapes that we carry with us, long after the actual places have ceased to exist.

I’d might as well be looking at the people on the street and imagining all the buildings that have passed through them — places we knew almost by intuition until they vanished, leaving behind only the strange sense of knowing our way around a world that can no longer be found.

Link to NYT article 'Remembered spaces'.

—Vaughan.

July 03, 2007

Drug reduces the impact of traumatic memories:

BBC News has a story with the headline 'scientists can erase bad memories', which is, at best, nonsense. What has been found is still an important discovery: a drug given during the recall of a traumatic memory can reduce its long-term emotional impact.

The drug is propranolol, a 'beta-blocker' that dampens down the sympathetic nervous system.

One of the roles of this system is to prepare the body for 'flight or flight' during stressful situations, by, among other things, releasing adrenaline, increasing blood pressure, and upping anxiety.

The drug has been used for years to help people with high blood pressure and heart conditions, so when they get stressed, it doesn't put such a strain on their heart.

It's been known for a while that starting a course of propranolol shortly after a traumatic event reduces the chance of people developing post-traumatic stress disorder - a condition that involves intrusive traumatic memories and hyper-arousal.

This new study is important, because it recruited people who had been traumatised a long time ago - an average of ten years earlier.

The participants were asked to recall what happened. Half were given propranolol and half were given placebo.

A week later, the participants were asked to recall the same memory while the researchers measured heart rate, sweating and muscle tension in the face - all of which are measures of bodily stress.

The participants who had been given the propranolol showed significantly less arousal than those who were given the placebo, suggesting the emotional impact of the memories had been reduced.

The fact that this can have an effect ten years after the event, if used when the memory is recalled, is an interesting finding.

Memory is a reconstructive process - in other words, our brain recreates the best estimation of an event each time we recall it. This might be slightly different each time and, importantly, each time we recall something the 'store' of information is changed.

It would be like if a CD remembered the other sounds in the room each time it was played, and included some of them when you listened to it again.

Propranolol might work by reducing the stress associated with the memory by influencing the 'rewriting' process.

The study is only a clue though. What it didn't show is that this selectively reduced the arousal associated with that memory (maybe it affected other traumatic memories which weren't recalled) and there was no group who were only given the drug and weren't asked to recall anything.

It's unlikely that the drug can reduce traumatic memories if just given at any time, but its something that needs to be explored to be sure we know how the treatment is working.

UPDATE: The Beeb have changed their headline to the slightly more sensible 'Drug can dampen down bad memories'.

Link to abstract of scientific paper.

—Vaughan.

May 30, 2007

Memory exploratorium:

San Francisco's interactive science museum Exploratorium has a fantastic online memory exhibit, that includes articles, games, demonstrations and lectures from leading memory researchers.

The exhibit looks at the science of memory, as well as how it is used in art.

There's a great article that explains memory distortions via Philip K. Dick and a try-it-yourself demonstration.

And for some unknown reason there's a slideshow of a sheep brain dissection, when what would be genuinely informative would be to see the memory structures in the human brain.

It's like going to an air show and watching someone take a bicycle apart.

Apart from that, the site's fantastic. The lectures are particularly good. Most cover the science of memory, but one is on ideas of forgetting in myth and story.

Link to Exploratorium memory exhibit.

—Vaughan.

April 18, 2007

I don't know who I am:

The New York Times has just published an article on dissociative fugue, the poorly understood memory disorder where people seem to forget who they are.

It has many similarities to conversion disorder where people seem to experience a disability (such as paralysis) despite having nothing medically wrong with them.

Both conversion disorder and dissociative fugue are often linked to trauma and they are often thought to arise from emotional difficulties being pushed from consciousness and expressed in other ways - all outside the conscious control of the patient.

Brain imaging research has shown that these sorts of states are likely to be different from people purely 'faking' the same thing, but in the clinic, fakers might be still quite hard to detect and extensive neuropsychological testing may be required to do so.

Also, there's always the worry that there is some medical reason for the problem that just hasn't been found yet.

Despite these difficulties, some researchers are investigating these conditions, which may provide vital clues to understanding the conscious mind.

The article discusses some famous cases of dissociative fugue and deal with some of the differences with amnesia after brain injury.

It also mentions that a play about the condition, entitled Fugue, is running at New York's Cherry Lane Theatre until April 22.

Link to NYT article 'When a Brain Forgets Where Memory Is'.
Link to description of dissociative fugue from the Merck Manual.

—Vaughan.

March 13, 2007

Interactive websites make false memories more likely:

Collision Detection has some interesting coverage of recently published research suggesting websites with interactive graphics are more likely to produce false memories about the pictured products than sites with static images.

The article also makes an interesting point about the focus of consumer psychology in this area:

One interesting thing [researcher] Schlosser points out is that market-research folks almost never study the false-memory effects of advertising. Sure, they test to see whether consumers who've looked at promotional material can recall true information about a product. But they rarely check to see whether the consumers also remember false information.

There's more in the Collision Detection article and a link to the full-text of the paper.

Link to Collision Detection article (thanks Katerina!).

—Vaughan.

March 06, 2007

Memory and the parietal lobe:

Science and Consciousness Review has a new feature article by staff writer Alice Kim discussing the role of the parietal lobe in memory.

The parietal lobe is typically linked to the representation of the body, and space in relation to the body, so it might be surprising that this area is being linked to more general memory abilities.

There is now a growing body of evidence for the importance of parietal areas in remembering and the article takes an in-depth look at what the scientific studies are telling us about how it all fits together.

Presumably, the author is not the same Alice Kim who is married to Nicolas Cage, but you can never be too sure.

Link to SCR article 'The potential role of the parietal lobe in episodic memory and other cognitive functions'.

—Vaughan.

Expertise vs Randomness:

A widely cited result asserts that experts superiority over novices in recalling meaningful material from their domain of expertise vanishes when random material is used. A review of recent chess experiments where random positions served as control material (presentation time between 3 and 10 seconds) shows, however, that strong players generally maintain some superiority over weak players even with random positions, although the relative difference between skill levels is much smaller than with game positions

Gobet, F. & Simon, H. A. (1996). Recall of rapidly presented random chess positions is a function of skill. Psychonomic Bulletin & Review, 3, 159-163.

Preprint as Word Doc
Gobet's bibliography here

—tom.

February 05, 2007

Little memory men and spirit voices:

A curious footnote on p183 from Mary Roach's wonderful book on the natural history of the dead body Stiff: The Curious Lives of the Human Cadaver (ISBN 0141007451):

People have trouble believing Thomas Edison to be a loopy individual. I offer as evidence the following passage on human memory, taken from his diaries: "We do not remember. A certain group of our little people do this for us. They live in the part of the brain which has become known as the 'fold of Broca'... There may be twelve of fifteen shifts that change about and are on duty at different times like men in a factory.... Therefore it seems likely that remembering a thing is all a matter of getting in touch with the shift that was on duty when the recording was done."

As well as his idiosyncratic views on memory, Eddison also thought that departed spirits might communicate through electrical equipment. In his writing, he refers to a device he had specifically designed for communicating with the dead.

Later, Dr. Konstantin Raudive, a Latvian psychologist and student of Carl Jung, continued Eddison's work by looking for the apparent voices of spirits that appeared on audio recordings (known as EVP).

Critics suggest that the apparent voices are nothing but our brains trying to making sense out of essentially random data - something known as apophenia.

Raudive is pictured on the right with one of his special devices.

An unusual chapter in the history of psychology.

Link to Fortean Times article on the history of EVP.

—Vaughan.

February 03, 2007

The romantic literature of recovered memories:

The New York Times discusses a recent challenge laid down by psychologists skeptical of claims of recovered memories: find a single account of repressed memory, fictional or not, before the year 1800.

The researchers claim that the earliest account is from the 1782 novel Dangerous Liaisons and have published their findings in the journal Psychological Medicine.

They suggest that the idea of a recovered memory is a cultural invention and people are likely to arrive at the clinic with trauma and memory problems already shaped by these ideas.

The challenge has revisited a long-standing and heated debate over the reality of recovered memories that first exploded in the 1980s.

At the centre of the storm were people who claimed to have recovered memories of childhood abuse, often after hours of unusual or maverick forms of therapy.

The sheer numbers of people claiming to have uncovered repressed memories of abuse led some psychologists to question the reality of many of these memories and doubt that a healthy person could effectively repress whole episodes of their life, only to have them return later.

Researchers began to investigate the psychology of recovered memories in the lab and found evidence that false childhood memories could easily be induced in healthy participants [pdf] but also that memories could be deliberately 'forgotten' to some extent [pdf].

In response to the literary challenge, other researchers have offered earlier examples, but the challengers have dismissed them as not fitting their criteria adequately.

How much culture affects the expression of both normal and disordered thinking is currently a poorly-understood area and will probably become a major force in psychology over the coming decades.

Link to NYT article 'A Study of Memory Looks at Fact and Fiction'.
Link to PubMed entry for the Psychological Medicine paper.

—Vaughan.

January 29, 2007

A visual record of madness in 50s France:

Luminous Lint has published a collection of evocative images by photographer Jean-Philippe Charbonnier who documented French psychiatric hospitals and psychiatric patients in the 1950s.

Some of the most important developments in psychiatry have happened in France.

Physician Phillipe Pinel was one of the first people to advocate humane treatment for patients with mental illness and epilepsy.

A famous painting shows him overseeing the removal of chains from patients at the Salpêtrière Hospital in 1795 Paris.

The photo collection shows French psychiatry in the 1950s and contain both hopeful and desperate scenes.

This sort of historical record is important both to realise how far psychiatry has developed since these bygone days, and to pick up where change still needs to occur.

Link to Jean-Philippe Charbonnier photo collection (via BB).

—Vaughan.

January 17, 2007

Is infantile amnesia a myth?:

There's a great post from Developing Intelligence looking at research on 'infantile amnesia' - the 'amnesia' we have for events that happened before about 3 years of age.

It turns out that studies done on young babies, even babies in the womb, have shown that infants have got surprisingly good memory.

As reviewed by Hayne, 3-day-old infants were capable of distinguishing a particular passage (from Dr. Seuss's "Cat in the Hat") that had been read to them twice daily for the last 6 weeks of gestation from similar passages (matched for word count, length, and prosody). What's more, these infants preferred the familiar passage even if spoken by someone other than their mother, strongly suggesting that they had encoded (and retained) a relatively high-level representation of the passage's auditory content.

The post looks at the mystery of how we have such trouble remembering this period, when psychology studies show that infants' memory is actually quite good.

Link to 'The Myth of Infantile Amnesia'.

—Vaughan.

January 16, 2007

waking life crossword experiment:

In Richard Linklater's Waking Life (2001) two of the characters discuss the idea synchronicity. They mention an experiment where people were isolated and given daily crosswords. If the crossword puzzles were a day old, meaning that thousands of people had already completed them, then people found it easier to get the answers - because the answers were already 'out there' in the collective memory of course.

The question is: did anyone ever really do this experiment, or anything like it, and what are the references? I'm not expecting that it would really produce a significant effect, but I'd still love to know if anyone has tried it.

Answers in the comments please

Link: Article on The Baader-Meinhof Phenomenon from damninteresting.com

I've put the relevant except from the script below the fold...

I like that. It's like there's this whole telepathic thing going on that we're all a part of, whether we're conscious of it or not. That would explain why there are all these seemingly spontaneous worldwide innovative leaps in science and the arts, you know, like the same results popping up everywhere independent of each other. Some guy on a computer figures something out, and then almost simultaneously a bunch of other people all over the world figure out the same thing. They did this study where they isolated a group of people over time, you know, and monitored their abilities at crossword puzzles in relation to the general population, and they secretly gave them a day-old crossword, one that had already been answered by thousands of other people, and their scores went up dramatically. Like 20%. So it's like once the answers are out there, people can pick up on them. Like we're all telepathically sharing our experiences.

—tom.

Amnesia affects ability to imagine the future:

There's an interesting New Scientist news report on recent research suggesting that people with amnesia have difficulty imagining the future, suggesting this ability relies on our capacity to remember past experience.

The study was led by Dr Eleanor Maguire and involved five participants with dense amnesia caused by damage to the hippocampus on both sides of the brain.

Researchers asked the participants – and a control group without amnesia – to imagine several future scenarios, such as visiting a beach, museum and castle, and to describe what the experience would be like. They then analysed the subjects' narrations sentence by sentence, scoring each statement based on whether it involved references to spatial relationships, emotions or specific objects.

All but one of the amnesiacs were worse at imagining future events than the participants in the trial who did not suffer from amnesia. Their visualisations of future events were more likely to be disorganised and emotionless. "It's not very real. It's just not happening. My imagination isn't…well, I'm not imagining it, let's put it that way," one patient told researchers during a trial.

Apparently, the research will be published in the science journal Proceedings of the National Academy of Sciences but I'm damned if I can find it at their website or on PubMed, but presumably it will appear shortly.

Link to NewSci story 'Amnesiacs struggle to imagine future events'.
Link to write-up from Nature News.

—Vaughan.

December 06, 2006

Drinking the milk of paradise:

The opening of Samuel Taylor Coleridge's poem Kubla Khan:

In Xanadu did Kubla Khan
A stately pleasure-dome decree :
Where Alph, the sacred river, ran
Through caverns measureless to man
Down to a sunless sea.
So twice five miles of fertile ground
With walls and towers were girdled round :
And there were gardens bright with sinuous rills,
Where blossomed many an incense-bearing tree ;
And here were forests ancient as the hills,
Enfolding sunny spots of greenery.

Coleridge claimed he wrote the poem after experiencing a vision during an opium-induced sleep, but was woken by a 'person from Porlock' before it was complete.

Coleridge's biographer, Richard Holmes, suggests that because we tend to remember dreams best when we're woken in their midst, rather than cutting short the poetic inspiration, the 'person from Porlock' may have actually saved this vision from sinking into the depths of unconsciousness.

However, it's not clear whether the vision genuinely occurred as Coleridge claimed, so this remains speculation.

If you're interested in a more in-depth analysis of this poem that Coleridge called a "a psychological curiosity", there's an excellent article in the PsyArt journal that examines it using a number of cognitive and psychological theories.

Link to full text of Kubla Khan.
Link to article on the poem from PsyArt.

—Vaughan.

October 27, 2006

The madness of King Eadbald:

"A Saxon king of the early seventh century, Eadbald, was described in the language of the early eighth century as troubled by frequent fits of insanity and 'by the attack of a foul spirit' after marrying his late father's second wife.

But he had also rejected Christianity which his father Ethelbert had taken up, and the missionaries in Kent were going through a difficult period; so, apart from the meaninglessness of the description, some character assassination may be involved in the record."

From p48 of Mental Disorder in Earlier Britain (ISBN 0708305628) by Basil Clarke.

—Vaughan.

July 29, 2006

Me and My Memory:

As part of the BBC Memory Season, BBC Radio 4 are running a series of programmes on people with unique memories - either because of disorder or because of remarkable talents.

The series is called Me and My Memory and started last Wednesday.

All the programmes are archived online, and the first was on prosopagnosia - the condition where people are unable to recognise others by their faces.

In this case, the programme talks to a woman who developed prosopagnosia after viral encephalitis, a brain infection that damaged parts of the brain involved in face recognition.

Future programmes will be on developmental amnesia, a memory champion, confabulation and mild cognitive impairment.

Link to homepage for Me and My Memory series.

—Vaughan.

June 18, 2006

Swimming in bottomless lakes:

"Our whole past experience is continually in our consciousness, though most of it sunk to a great depth of dimness. I think of consciousness as a bottomless lake, whose waters seem transparent, yet into which we can clearly see but a little way."

Philosopher Charles Peirce in Vol VII of his Collected Papers.

—Vaughan.

May 23, 2006

Developing Intelligence finishes 'seven sins' series:

Cognitive scientist and owner of the Developing Intelligence blog Chris Chatham has finished his series on memory distortions, arguing that common forms of memory failure can be explained within a concise model of maintenance, search, and monitoring.

The 'seven sins' are a reference to a more complex model put forward by psychologist Dan Schacter, in a well-known book on the subject.

Chatham explains each in turn, and gives details of how he feels they can all be explained by more fundamental functions of the mind.

* The Seven Sins of Memory
* The Transience of Memory
* Lost keys: Memory Search Failures
* Lost in the Network: Failures of Memory Architecture
* Memory's Gates: Failures of Monitoring
* Origins of Memory Distortion

The series has been an engaging look at some of the most important theories in contemporary memory research, as well as highlighting a few curious gems, such as the scientific basis for Freudian-style repressed memories.

Even if you don't entirely agree with Chatham's take on the psychology of memory, there's plenty of food for thought in what has been a lucid series on a mysterious human ability.

—Vaughan.

May 18, 2006

Flash back:

I'm always impressed by the way Cognitive Daily manage to break down sometimes quite complex research into straightforward explanations, and their and try-it-yourself experiment on visual working memory is no exception.

Their article is a wonderful tour through a recent paper that examines visual memory for briefly presented scenes.

—Vaughan.

May 15, 2006

Developing Intelligence on the seven sins of memory:

The first part of a series on memory failures has just appeared on the increasingly compulsive cognitive science blog Developing Intelligence.

The site is run by cognitive neuroscientist Chris Chatham who summarises the 'seven sins of memory' - Daniel Schacter's famous description of the seven ways in which memory can become distorted or degraded.

Schacter first described his ideas in a landmark paper and later in an accessible book of the same name.

Chris has a different approach, however, and will be setting out his alternative views over the coming week:

In contrast to Schacter’s “seven sins of memory” (1999), I argue that all types of memory inaccuracy arise from three distinct types of memory system failure: those of maintenance, of search, and of monitoring. Failures of maintenance include problems involving prospective memory (“forgetting to remember”), rapid forgetting, and absent-mindedness. Failures of search include retrieval-induced forgetting, tip-of-the-tongue phenomena, and amnesia. Failures of monitoring include source misattribution, memory biases, and suggestibility. Finally, other memory inaccuracies may actually result from interactions among multiple sources of failure.

In this week's upcoming posts, I will review each of these categories of memory failure in turn, and describe how they can account for all types of memory inaccuracy when taken together.

Link to post at Developing Intelligence.

—Vaughan.

April 06, 2006

Observation balloons, mental break down, and female hysteria:

"As soon as he started work at the hospital he became...fascinated by the differences in severity of break down between the different branches of the RFC. Pilots, though they did indeed break down, did so less frequently and usually less severely than the men who manned observation balloons. They, floating helplessly above the battlefields, unable to either avoid attack or to defend themselves effectively against it, showed the highest incidence of breakdown of any service. Even including infantry officers. This reinforced Rivers's view that it was prolonged strain, immobility and helplessness that did the damage, and not the sudden shocks or bizarre horrors that the patients themselves were inclined to point to as the explanation for their condition. That would help to account for the greater prevalence of anxiety neuroses and hysterical disorders in women in peacetime, since their relatively more confined lives gave them fewer opportunities of reacting to stress in active and constructive ways. Any explanation of war neurosis must account for the fact that this apparently intensely masculine life of war and danger and hardship produced in men the same disorders that women suffered from in peace".

The thoughts of army psychiatrist W.H.R. Rivers from the novel Regeneration by Pat Barker. In Regeneration, the first of a trilogy, Barker blends fact with fiction in her depiction of the relationship between Rivers and the celebrated poet Siegfried Sassoon, at Craiglockhart during the First World War.

—christian.

February 24, 2006

where do implicit associations come from?:

The Implicit Association Test [1] is a sorting task which reveals something about our automatic, non-deliberate, associations [2].

The part of the test which betrays our automtic associations is a combination of two simpler sorting tasks. Both simple tasks involve sorting words and pictures into categories which are assigned to the left and right (by pressing the E and I keys, which are on the left and right of your keyboard). One task is to sort words (like 'love', or 'failure') into the categories 'good' and 'bad'. The other task varies depending on what you want to detect automatic associations about. In the 'race IAT' the task is to sort pictures of the faces of white americans and the faces of black americans. The race IAT isn't the only version, but it is the most (in)famous (you can also do the IAT on fat vs thin, arab-muslim vs non-arab-muslims, for different US presidents and in many other variations). The compound task involves sorting both words and pictures to the left and right where each side has two categories assigned to it - so 'good' and 'black american' on the left, and 'bad' and 'white american' on the right, for example.

What the IAT test does is compare your times for sorting good words when the 'good' side is also the 'white' side to when the 'good' side is also the 'black' side (and vice versa for sorting bad words, and for sorting white and black faces to the good and bad sides). By doing these comparisons the test can detect any evaluation of 'white' or 'black' as positive or negative that is affecting your time to classify the words or faces to the correct side. So, for example, if you take significantly longer to sort good words to the 'black' side than you do to the 'white' side then the result is an automatic preference for 'white americans' over 'black americans' [3]

What the Racial IAT indicates is that most Americans have an automatic preference for whites over blacks. Two things are important about this. First it isn't really clear what mechanisms lie behind the effects found in the test ('Voodoo' is one suggestion!), nor is it clear what they mean [4]. Second, the automatic preference shows up for most people, even in those who consciously express no race preferences and even in many black americans.

Now where did this automatic preference come from? It certainly can't be deliberate attitudes, since the bias shows up in people (including many black americans) who have explicitly anti-racist attitudes. Some suggestions have been made, like they are the residual of previously held explicit attitudes, or the result of a 'cultural bias' (whatever that means) [5], but I think a strong, and more likely causal [6], possibility is that that these preferences are the result of systematic exposure to particular associations (i.e that white = good and black = bad). Associations can become established in memory merely by the repeated co-presentation of two things (conditioning), there doesn't need to be any logical connection between the two. So if on television the adverts for flash cars and happy domestic scenes always feature white folks and the the crime shows more often have black folks as the bad guys you're going to absorb those associations.

The researchers running the project imply as much in an answer in their FAQ

...it is very possible to possess an automatic preference that you would rather not have (and the researchers who developed this test are convinced that they, too, fall into this category). One solution is to seek experiences that could undo or reverse the patterns of experience that could have created the unwanted preference. But this is not always easy to do. A more practical alternative may be to remain alert to the existence of the undesired preference, recognizing that it may intrude in unwanted fashion into your judgments and actions. Additionally, you may decide to embark on consciously planned actions that can compensate for known unconscious preferences and beliefs."
(My emphasis).

The interesting thing for me about the hypothesis that these automatic preferences develope from repeated exposure to particular associations is that you do not need to believe the associations on any deliberate level, nor do you need particularly to pay attention to them, all you need to do is to have them as part of your environment. In that way our Implicit Associations reflect a part of our minds which belongs as much to the environment of our experience as to ourselves - and, additionally, is as much common to everyone who has shared our environment as it is unique to our individual minds.

And this relates to advertising. Adverts are ubiquitious. Advertising shapes the statistical content of the stimuli we are exposed too, however much we decide to give ourselves certain experiences. Does the IAT give us a glimpse of the consequences we reap from an unclean mental environment? [7]

References below the fold

[1] You can get all the research papers here. How wonderful

[2] I nearly used the word 'unconscious' here but couldn't quite bring myself to. I'm afraid that if i say it three times the ghost of Freud will appear!

[3] e.g. here or here

[4] Here's one example of an intepretation

[5] The residual of childhood preferences? discussion at cognitive daily. Review Article Sources of Implicit Attitudes (2004)

[6] That's the problem with much psychology research. You can find factors associated with some phenomenon, but it's far hard to find what is truly causing it

[7] Guardian article about the clean mental environment movement

—tom.

February 06, 2006

music, wine and will:

You go to the supermarket and stop by some shelves offering French and German wine. You buy a bottle of French wine. After going through the checkout you are asked what made you choose that bottle of wine. You say something like "It was the right price", or "I liked the label". Did you notice the French music playing as you took it off the shelf? You probably did. Did it affect your choice of wine? No, you say, it didn't.

That's funny because on the days we play French music nearly 80% of people buying wine from those shelves choose French wine, and on the days we play German music the opposite happens

This study was done by Adrian North and colleagues from the University of Leicester [1]. They played traditional French (accordion music) or traditional German (a Bierkeller brass band - oompah music) music at customers and watched the sales of wine from their experimental wine shelves, which contained French and German wine matched for price and flavour. On French music days 77% of the wine sold was French, on German music days 73% was German - in other words, if you took some wine off their shelves you were 3 or 4 times more likely to choose a wine that matched the music than wine that didn't match the music.

Did people notice the music? Probably in a vague sort of way. But only 1 out of 44 customers who agreed to answer some questions at the checkout spontaneously mentioned it as the reason they bought the wine. When asked specifically if they thought that the music affected their choice 86% said that it didn't. The behavioural influence of the music was massive, but the customers didn't notice or believe that it was affecting them. Similar experiments have shown that classical music can make people buy more expensive wine [2], or spend more in restaurants [3].

Is this manipulation? There's no coercion, all the customers are certainly wine buyers who are probably more or less in the mood to buy some wine. But they have been influenced in what kind of wine they buy and they don't know that they have.

What would be the effect, I wonder, of having someone stand by the shelves saying to the customers as they passed "Why don't you buy a French wine today"? My hunch is that you'd make people think about their decision a lot more - just by trying to persuade them you'd turn the decision from a low involvement one into a high involvement one. People would start to discount your suggestion. But the suggestion made by the music doesn't trigger any kind of monitoring. Instead, the authors of this study believe, it triggers memories associated with the music - preferences and frames of reference. Simply put, hearing the French music activates [4] ideas of 'Frenchness' - maybe making customers remember how much they like French wine, or how much they enjoyed their last trip to France. For a decision which people aren't very involved with, with low costs either way (both the French and German wines are pretty similar, remember, except for their nationality) this is enough to swing the choice.

This priming affect is, I believe, one of the major ways advertising works [5]. Simply by making it more likely for us to remember certain things, we are more likely to make decisions biased in a certain way. There's no compulsion, nobody has their free-will wrenched from their conscious grip. There's just an environment shaped a certain way to encourage certain ideas. And how could anything be wrong with that?

Refs & Footnotes below the fold:

[1] Adrian C. North, David J. Hargreaves, and Jennifer McKendrick? (1997). In-store music affects product choice. Nature, 390, 132.
Adrian C. North, David J. Hargreaves, and Jennifer McKendrick? (1999). The influence of in-store music on wine selections. Journal of Applied Psychology, 84, 271-276.

[2] Areni, C. S. and Kim, D. (1993). The influence of background music on shopping behavior: classical versus top-forty music in a wine store. Advances in Consumer Research, 20, 336-340.

[3] North, A. C., Shilcock, A., and Hargreaves, D. J. (2003). The effect of musical style on restaurant customers’ spending. Environment and Behavior, 35, 712-718.

[4] For 'activates', read 'primes'. See Hacks #38 and #81 in 'Mind Hacks' or look up priming in any cognitive psychology textbook

[5] This is my first-pass conclusion. I'd love to be convinced otherwise. Get in touch if you know of any evidence otherwise.

—tom.

September 01, 2005

Iron Maiden's déjà vu:

Whilst looking for an article in the British Journal of Psychiatry I came across this curious letter, noting an accurate description of déjà vu in the lyrics of an Iron Maiden song.

Sir: Sno, Linszen and De Jonge have reviewed a number of descriptions of déjà vu in poetry and literature (Journal, April 1992, 160, 511-518). There is another particularly striking example. It is the song "Déjà vu" by Dave Murray and Steve Harris (1986) from the album Somewhere in Time by the rock group Iron Maiden. It vividly illustrates many of the points made by Sno et al in their article. The song gives an accurate phenomenological description of déjà vu. It implicitly suggests reincarnation as an explanation and it refers explicitly to precognition ("And you know what's coming next") and to feelings of depersonalisation ("And you feel that this moment in time is surreal"). The full lyrics are reproduced here with the kind permission of Iron Maiden Publishing (Overseas) Ltd, administered by Zomba Musica Publishers Ltd.

When you see familiar faces
But you can't remember where they're from
Could you be wrong?

When you've been particular places
That you know you've never seen before
Can you be sure?

'Cause you know this has happened before
And you know that this moment in time is for real
And you know when you feel déjà vu.

Chorus:
Feels like I've been here before (rpt. four times)

Ever had a conversation
That you realise you've had before
Isn't it strange?

Have you ever talked to someone
And you feel you know what's coming next
It feel pre-arranged.

'Cause you know that you've heard it before
And you feel that this moment in time is surreal
'Cause you know when you feel déjà vu

Chorus

Sno et al suggest that psychiatrists "should be encouraged to overstep the limits of psychiatric literature and read literary prose and poetry as well" because "novelists and poets excel in [the] ability to depict subjective experiences". While agreeing with this point of view, I would go further. Literature and art are capable of an emotional response in the person who experiences them. This can lead to a far deeper empathic or subjective understanding of an experience than is possible from a scientific description. Wide reading and exposure to the arts enables us to share, if only partially and in completely, the experience of our patients. We can understand them better, not just at an intellectual level, but as people like ourselves.

Bill Plummer
Mental Health Advice Centre, Folkstone, Kent.

Rock on Dr Plummer. Even more intriguingly, the following letter in the same issue is about hypnotised lobsters, but I think that will have to wait until another time.

Link to letter's PubMed entry.

—Vaughan.

August 11, 2005

The 2005 World Memory Championships:

This weekend, the World Memory Championships are coming to Oxford University. The event is being hosted by the UK Festival of the Mind, which involves lectures from memory champions and experts on advanced learning techniques.

On the BBC Radio Four Today programme this morning, Dominic O’Brien, eight times World Memory Champion, demonstrated his ability to remember the order of a shuffled pack of cards, after just a few minutes studying them. You can listen to the item again here.

In recent years, psychologists and neuroscientists have begun studying superior memory and memory feats, although the area is relatively neglected compared with the study of memory deficit.

In 2002 Dr. Eleanor Maguire at UCL's Functional Imagaing Lab in London used fMRI scanning to compare the brain structure and function of 10 memory champions with that of 10 healthy controls. To find out what they discovered, read on by clicking below.

Although no differences in brain structure or general cognitive ability (excluding memory) were found between the groups, a difference was found in the distribution and intensity of brain activation during the learning of new information. These differences weren’t just a consequence of the memory champs learning more. Maguire et al. used three item types: digits, faces and snowflakes. The memory champs order- and item-recognition performance was superior to the controls with digits, was less so for faces and equivalent for snowflakes, thus allowing some control for the amount of material memorised.

Some brain areas, like the right cerebellum, were more active in the memory champs regardless of performance. Other areas were active in the champs, but not the controls, contingent on performance. But Maguire et al. drew most attention to those areas that were only active in the memory champs irrespective of item type – left medial superior parietal gyrus, bilateral retrosplenial cortex, and right posterior hippocampus – areas associated with spatial memory and navigation (the right posterior hippocampus was found to be enlarged in a sample of London taxi drivers, Maguire et al. 2000). Maguire et al. concluded this brain activity probably reflected the use by every memory champ, but none of the controls, of the ‘method of loci’ mnemonic, an ancient memory strategy that involves imagining oneself encountering items along a route.

So if the memory champions special memory is due only to their use of a spatial strategy, perhaps there is hope for us all. But therein lies the weakness of this study. As discussed by Jack and Roepstorff (2002), a premise of cognitive mapping is that subjects all perform to the same ‘script’, as derived from experimenters’ instructions. It is little wonder that differences in brain activation were found if the memory champions were reading from a different script; were employing a powerful mnemonic when the controls were not. In this instance functional imaging has served only to support what self-report investigations could have told us. It might be more enlightening to investigate whether differences in brain activity between memory champions and controls persist, even when the latter have been trained to use the champions’ mnemonic strategies.

Abstract of the Maguire Study here.

—christian.

June 23, 2005

Cognitive daily on 'childhood amnesia':

Cognitive Daily has an elegant summary of research on why we don't remember the first years of life. The results suggest that it may be because young children lack the language resources to support the necessary memories.

I would be tempted to quote some of the post here, but its described so succinctly its probably best just to read the original.

Link to 'Why do we forget our childhood?' from Cognitive Daily.

—Vaughan.

June 02, 2005

Are our memories suffering from our reliance on gadgets?:

So I'm in this month's edition of Wired, just a short quote. Since it's here and it's now I've reproduced the full quote I sent them below:

> I'm looking for a response to this question: "Are tools like Google and PDAs
> ruining our ability to remember things?"

So we have this amazing brain which constantly scans our environment and seeks out short-cuts. New bits of tech, like google or mobile phones, stop being strange very quickly (even though, truely, they're just incredible. Unthinkable just a few years ago). They get absorbed, become artifical information-processing prosthetics. Are they making us forget things? Sure, we're forgetting the things they allow us not to have to remember. But when we use something, or design something, we get a choice about what it asked us to remember. My mobile phone means the only numbers i remember are the ones i deliberately haven't put in their so i'm forced to learn them. Not knowing any phone numbers is fine - as long as i don't lose my phone. Then it becomes a bit of a problem.

But phone numbers are hard to learn anyway - a hang-up from an old technology. The situation is completely reversed for getting in touch with people through the web. Knowing the URL or email isn't so useful - it might change. But with Google, knowing a person's name (exactly the piece of information you store in your phone to allow you to forget their number) means you can find their details on-line in seconds. The technology lets us forget an implementational detail, and allows us to concentrate on remembering a versatile, tech-enabled, solution.

—tom.

May 07, 2005

Control context to aid memory:

Reader Matt Doar writes in with this Mind hack which uses our brain's natural ability to encode context as an aid to writing code:

My hack/tip/thing that makes people look at me oddly, useful for when I'm working on a large piece of software, an activity which involves holding a lot of related abstract information in your head. Here it is:

1. Pick one tune or one album that you like.

2. Listen to it while you develop the code. Over and over, on repeat. Listen to no other music. Headphones are a must for the office!

3. Don't listen to it again until ...

4. You need to work on the same code, then listen to it.

Lots of context returns with the tune and helps to write better code. One colleague suggested using scents too. Other colleagues (and my wife) just stared at me, then shook their heads sadly ;-)

I think this is great. By training in a tune-as-context you can then use it as a trigger to help recall everything else that was on your mind at that time. And the idea of using scents instead of tunes might work well - smell and memory are famously intertwined, and there may be a neuroanatomical basis for this: the nerves from the nose enter the brain next to the areas associated with storing memories for episodes. The only drawbacks are that you may not get as many distinct smells as distinct tunes, and tunes come with headphones to stop you distracting your colleagues - there's no such device for smells (although maybe the message is that smells should be used for pair-programming or group projects).

—tom.

April 11, 2005

subbliminal messages in music 2:

Federico

Just a short note about subliminal messages placed backwards in music - a reply to your questions about what I wrote to you the other day. Hope this helps, and I'm sorry i don't have time to write more right now.

> When I listen to an album I spend hours looping it. This means that for
> _hours_ my brain and ears will be open to sounds from it. Let's say that our
> inconscious mind has limited skills, couldn't it understand a simple message
> like "drink coca-cola" after being exposed to it for so long ?

The unconscious mind probably doesn't understand anything. Most likely after hearing "drink coca-cola" this thought is more likely to come to your conscious mind, where you decide to act on it.

This, as you point out, is just like advertising and it also suggests why advertising coca-cola (which people are already disposed towards drinking) is easier than advertising behaviours people don't already want to do (paying taxes for example).

Plus, if the message is hidden, the unconscious mind isn't going to decode it to be influenced by it. There's no evidence that we can understand backwards messages embedded in music, consciously or unconsciously.

> Second thing, but strictly related. What type of reactions would be caused by
> listening for hours at a simple recorded voice saying "drink coca-cola" ?
> After all, isn't what radio and tv spots are all about (writing in our mind a
> brand names) ?

Bordom! And probably an aversion related to coca-cola because of that. But if you repeated the words "drink coca-cola" over the course of years, and with interesting visual and background music, that would make people more likely to choose a coke when given the option (which is advertising, and what happens).

Does that make sense and sound fair enough?
Tom

—tom.

April 10, 2005

Subliminal mesages in music:

Federico

Here we go. I'm no expert on subliminal messages, but I did some research on it a few years ago, and again recently for the book. The title of the section in Mind Hacks should give you a good clue as to scientific opinion "Hack #82: Subliminal Messages Are Weak and Simple". Even that may be an exaggeration.

Although you can measure the effects of subliminal stimuli (e.g. pictures not seen consciously, words not heard consciously) the effects are always statistical and small. This means that if you show a cinema audience of 1000 people, say, a 20 ms exposure of a Mars Bar and then measure how many more Mars Bars are sold in the foyer 10 minutes after the film you might find a 1% increase in Mar Bar Sales. (this experiment hasn't been done, but it sounds plausible to me). But two points: Firstly, these people were going to buy confectionary after the film anyway - you already had people ready to spend money on chocolate. The subliminal picture probably just made the idea of 'Mars Bar' come to mind for some people a couple of seconds earlier as they stood wondering about what selection to make. If you'd had shown a picture of a oysters, i don't think anyone would have been at the popcorn-stand demanding to buy edible molluscs. Secondly, the effect of subliminal messages (in this case mars bar sales) is usually less that the effect of superliminal messages. In other words if you had told everyone "Mars Bars taste great, buy a mars bar when you leave the cinema!!" you would have got many more sales.

So that is the weak (second point) and simple (first point) of the section title. You can see that not only are subliminal messages weak in size, they have to operate on something someone is already doing, or has the mental structures for doing already. Another thing is that research shows that if you tell someone about the expected effect of something subliminal the effect is cancelled out - people use conscious deliberation to monitor their behaviour and the automatic processes that are guiding them. (On a side note i think there is probably a deep relation to the way hypnotism works here).

You asked specifically about subliminal messages in music. There was a case in the eighties where a heavy metal band got sued for (it was alleged) putting subliminal suicidal messages in their songs. Nonsense of course. There was no voice - people who thought they could hear something had just been fooled by the electronic voice phenomena (i.e. wishful thinking). Anyway the band got sued and there was a court investigation into the reality of subliminal messages in music. You may be interested to get hold of it and read it. Conclusion: not possible.

The idea was that Judas Priest (they were the band i think) had inserted the words "Do it" backwards into the song, and that this had convinced two fans to kill themselves. Apart from the idiocy of supposing that a hidden message would overcome a normal conscious aversion to suicide and posssess people, there is no reason to believe that backwards messages (especially hidden backwards messages) can be automatically decoded by the brain.

So the probable reason that some professors you mailed said that this was not a topic of research is that all the research on subliminal messages shows that hidden messages in songs don't work - it would be no easier than getting someone to do something by putting the message in plain view in the lyrics. And millions of people listen to heavy metal lyrics without following the instructions therein (my favourite album when i was younger was called "Kill 'Em All" and i seemed to have survived without embarking on a spree of indiscriminate slaughter). Have you heard to remark that if you play a heavy metal album backwards, you hear a satanic message - backwards!

Does that help answer your questions? Sad to say the reality is less exciting that what rumour and stories seem to say. The interesting thing for me is what how being able to subliminally (and superliminally) prompt people's automatic behaviours says about the nature of our minds and what this means for our theories of individual free will, the self and the responsibility of people like advertisers and film-makers. But this is not specifically about subliminal images - it's about all input our brain takes in. Subliminal messages have no special power - no more than messages we do see but don't think about (like a lot of advertising). But that's another discussion.

—tom.

March 20, 2005

Reviewing the brain on film:

Movies often borrow themes from psychology and neuroscience, although only a few have the compliment returned by scientists in the field. Two recent films however, have sparked engaging commentaries from a number of scientists, owing to their accurate depiction of brain function.

Eternal Sunshine of the Spotless Mind was praised by Kirk Jobsluder for eschewing the clichés of a linear 'videotape' memory, and Steven Johnson for accurately capturing the role of emotion in memory.

Johnson's article also touches on another highly regarded film, Memento, but is surprisingly critical, despite the lead character displaying almost identical memory problems to famous cases in the medical literature. One of the most notable is Patient HM, although there are several well-known cases with similar impairments.

Rashmi Sinha further discusses the influences of clinical neuroscence in Memento with some insightful comments, but my favourite has got to be this wonderfully geeky review from a team at Rutgers University:

Unlike patient HM, Shelby acquired his anterograde amnesia through an accidental brain injury. This does happen, but it's much more common for people to develop anterograde amnesia from a stroke, viral encephalitis, chronic epilepsy, or the interruption of the brain's oxygen supply due to near-drowning or strangulation (hypoxia or anoxia).

Nevertheless, the prize for the most popcorn consumed in the service of science undoubtedly goes to neuropsychologist Sallie Baxendale, for her comprehensive reviews of movies about epilepsy and amnesia. Surprisingly, animated movie Finding Nemo is rated as a particularly accurate portrayal of amnesia.

Personally, I'm a big fan of The Man with Two Brains, but I think that's just wishful thinking.

Spare popcorn ? Check out some videos from PBS on amnesic patients EP and 'Chuck', and the neuroscience of memory.

—Vaughan.

March 02, 2005

Gay men and maps:

Gay men seem to read maps in a similar way to women. Although this seems like an insigificant finding, it may help uncover some of the neural functions that are related to sexual preference, as these abilities are known to involve specific areas of the brain.

In fact, this isn't the first study to find a similarities between gay men and women in spatial abilities. Result published in 2003 showed that both women and gay men performed better on a memory test for locations than straight men.

These sorts of abilities are known to rely heavily on area of the brain known as the hippocampus and differences in these abilities are likely to reflect differences in how these brain structures process information.

What is not clear however, is how much these differences can account for individual sexual behaviour. This is because sexual behaviour can be motivated by a wide range of different desires and motivations, all of which may be supported by complex network of brain structures. Few of these are currently known about or understood.

Link to story from New Scientist.
Link to story from The Telegraph.

—Vaughan.

February 17, 2005

Déjà vu: Overdrawn at the memory bank:

Déjà vu is one of the most fascinating of experiences and, until recently, was thought of as an interesting anomaly but virtually impossible to study scientifically.

This has recently begun to change. Psychologist Alan Brown is one of a number of scientists who have begun making considerable headway in researching this curious but fleeting state.

In Brown's recent book (The Deja Vu Experience; ISBN 1841690759) he notes some interesting facts gleaned from research in this area, for example:

About two thirds of people experience it. It is more likely to occur indoors, while relaxing and in the company of friends. It occurs more often in the afternoon or evening, and towards the end of the week. It is more common in those who travel and remember their dreams. It is less common in people with conservative politics and fundamental religiosity. It decreases with age.

Exactly why the experience is linked to these things is not altogether clear, although research has made some progress in understanding which brain areas might be involved.

One clue has been from temporal lobe epilepsy, in which people can have intense feelings of déjà vu, either as the main part of the seizure, or as a pre-seizure experience (called an 'aura'). These studies have suggested that an area of the brain called the hippocampus and nearby area known as the parahippocampal gyrus (both strongly linked to the temporal lobes) are a likely source.

These areas are strong candidates for the source of déjà vu, as they have also been identified as involved in recognition and producing feelings of familiarity by previous research into memory function in healthy volunteers.

Link to excellent article on the science of déjà vu from The Chronical.
Link to NYT article on déjà vu.
Link to transcript of ABC Radio National programme on déjà vu.
Link to list of different types of déjà vu.

—Vaughan.

December 01, 2004

Caffeine rituals:

Ah, this is good to see. There's a hack in the book about the rituals around coffee and tea. It's on the O'Reilly catalog page for Mind Hacks as a free sample, Hack 92: Make the Caffeine Habit Taste Good. It's like Pavlov and his dogs. He conditioned them to associate a noise with food so that they started salivating when they heard the noise. As with that, the ritual of making coffee gets associated with the caffeine high, and so the ritual becomes part of the buzz.

Anyway, here's someone who has found the same thing.

My particular ritual seems to be boiling the kettle, putting the teabag and water in the mug to brew, and then forgetting about it for the next 20 minutes as I suddenly get back into work again.

—Matt.