February 28, 2005
Research Digest blog:
Mind Hacks contributor Christian Jarrett [Hacks #18, #62, #66] has started a blog for the British Psychological Society's Research Digest. Writes the BPS:
Each fortnight we send out an email full of fun, engaging accounts of the most exciting new research, together with invaluable syllabus advice. This unmissable service is aimed primarily at undergraduate and A-level students, but academics have been signing up too, either to help with their teaching or simply to keep abreast of the best research outside of their specialist area.
So now you can get via blog rather than via email - and contribute comments back on papers Christian has summarised.
—tom.
The science and curiosities of psychology:
Professor Anthony Walsh has compiled a comprehensive guide to psychology, full of curiosities, images and tutorials.
Some of my favourites include images of trepanning devices from the middle ages, a case study of Mollie Fancher, a curious patient from the 19th century and a Dr Walsh's own guide to classroom decorum!
This is one of the most comprehensive online psychology resources I've discovered as yet, and certainly one of the most fun to browse through.
Good starting points are his pages on:
* Introduction to Psychology
* Abnormal psychology
* Statistical methods in behavioural science
—Vaughan.
February 27, 2005
better to light a candle?:
She says: It's better to light a candle than to curse the darkness
He says: I wouldn't be so sure, maybe a candle would destroy your night-vision - without the candle your eyes could adjust to the lowered light levels (a process called adaptation, [Hack #26])
She says: But if you're in total darkness, there's no light at all to adjust to seeing
He says: Good point, so maybe it should be "It's better to wait for a bit, then, if your eyes don't adjust, you should light a candle rather than curse the darkness"
She says: How long do you have to wait until you know?
He says: Ah well, the cone receptors in the eye - which let you see colour - adapt fully after about 5 minutes. But it takes about 30 minutes for the rod receptors to fully adapt. These are the important ones for night vision, since they are specialised in detecting light or dark - which is presumably the fundamental information you are interested in.
She says: Okay. So it should be "It's better to sit in the dark for up to 30 minutes doing nothing, then light a candle rather than curse the darkness"?!
He says: Oh, you don't have to do nothing. Adaptation happens at the retina. You can prove this to yourself by adapting to the dark and then looking at a light with only one eye. One eye will adjust to the light, and the other (which you kept closed) will keep it's dark adaptation. Now if you go back to darkness you can switch between being blind (in your light adapted eye) and being able to see (in your other eye), just by openning and closing your eyes alternately. So, you can do anything you want with the rest of your brain, it shouldn't matter.
She says: So talking would be okay?
He says: Talking would be fine. Or whistling.
She says: So "It's better to wait in the dark to see if your eyes dark adapt (you can do anything you want while you're waiting) and only then, if they don't, light a candle rather than curse the darkness"
He says: You could even curse the darkness while you're waiting and get it out of the way. And really a red light would be better than a candle, because red spectrum light doesn't affect your dark adaptation (which is why cabin lights in aeroplanes and ships are red).
She says: "It's better to wait in the dark to see if your eyes dark adapt (you can do anything you want while you're waiting) and only then, if they don't, light a candle rather than curse the darkness. But it would be better if you had a red light rather than a candle for preference"
He says: That's it
She says: Snappy. I like it
He says: Someone should tell Amnesty
—tom.
February 25, 2005
2005-02-25 Spike activity:
Quick links from the past week in mind and brain news:
An area of the brain may be responsible for warning us of risky outcomes and the possibility of making future mistakes.
New Scientist publishes a lead article on the use of psychedelic drugs for treating mental distress online.
Recent evidence suggests that some migraines may be linked to heart minor heart problems.
The relationship between distance and clarity of vision in face recognition research leads to important evidence for a murder trial.
Research shows that men are more committed to 'e-relationships' than women and internet dating relationships are generally more successful than previously thought.
A detailed diary kept by a mother of an autistic child leads to important insights into the development of play and social skill in autism. Other research shows that autistic people may have better visual skills than others.
Researchers measure the change to visual perception in a particular area of space when we focus our attention without moving our eyes.
—Vaughan.
February 24, 2005
New series of BBC 'All in the Mind' online:
'All in the Mind', BBC Radio 4's programme on the mind, brain and mental health starts a new season this week.
Each week's edition is archived on the programme's website, so you can listen in to the latest. The website also has a comprehensive archive of previous shows, so you can revisit any programme from the last few years.
Link to BBC 'All in the Mind' website
—Vaughan.
February 23, 2005
'Mirror neurons' track thoughts and intentions:
In research published in PLoS Biology, scientists led by Marco Iacoboni discovered that the brain's "mirror neurons" are active when we are trying to work out other people's thoughts and intentions.
'Mirror neurons' are a set of cells in the frontal lobe of the brain, named because as well as being active when we execute actions, they are also active when we observe the actions of someone else.
Iacoboni and his colleagues asked participants to watch various movie clips of actions and related scenes in a fMRI scanner. In their analysis, they contrasted the brain activity from actions where their was an obvious intention (like picking up a sandwich) with actions where no obvious intention was implied.
They discovered that part of the activity in the 'mirror neuron' system was specifically related to perceiving intentions, rather than watching actions in general.
The ability to understand other people's intentions is known as "theory of mind" and is considered one of the building blocks of social interaction. This is the first study to show how the 'mirror neuron' system may be involved in reading others' intentions and desires, and is an important step in understanding how the brain supports social functioning.
This is part of an increasingly popular area of science known as social cognitive neuroscience, which aims to understand the psychology and neuroscience of person-to-person interaction.
Synopsis of study, and a news story discussing it.
Full text of the study from PLoS Biology.
—Vaughan.
February 22, 2005
The one hundred most influential works in cognitive science:
The Cognitive Science society has voted on The one hundred most influential works in cognitive science from the 20th century. Although we have tended to refer to the contents of Mind Hacks as 'cognitive neuroscience', much of what we've written about is classic cognitive science material. It was this discipline that first aimed to use a information processing view of mind to synthesise work in linguistics, artifical intelligence, ethology, biology and experimental psychology (and I'm sure a few others). The relevance to the more recent 'cognitive neuroscience', and to the spirit of 'Mind Hacks', should be obvious. So have a browse of the top 100. There's quite a few that get cited here and there in the book, and lots of other gems that might catch your interest.
—tom.
Book links:
Already own Mind Hacks? You'll know that there are many links to demos on the Web, and in the End Notes. So you don't have to type these in, we've put all the book links on a single page. Keep it handy! We'll be updating that page to give replacements for dead links as-and-when they happen.
(Still undecided? The book page now excerpts some of our reviews too.)
—Matt.
February 21, 2005
How to open the brain to everyone:
The development of science needs the free flow of information, so scientists can both build on and test the work of others, and so the public can make informed democratic decisions about the role of science in society.
Most scientific journals are run by publishing companies that own the articles they publish. In fact, the results from the majority of publically funded science appears in these journals.
Why is so much science owned by private companies ? Part of the reason is that scientists jobs often depend on how many publications they produce, and there is a hierarchy of journals, so publishing in some journals (typically the more established and privately owned ones) counts for more in a scientist's career.
Many scientists would like to publish in open access journals but don't want their careers to suffer or to be out of a job.
The following suggests some ways in which you can support open access journals to boost their value in the science community, prevent career dilemmas, and help open up scientific research for the benefit of all.
The main aim of these points is to make sure the work in open access journals is high quality, and that the science community is aware of the results published in them.
Ways to share the love:
1) Check out open access journals regularly and be aware of the work published there. Word of mouth is one of science's best methods of communication. Check that the journal is peer reviewed if you want to make sure that it meets accepted academic standards.
2) Cite open access papers where relevant. Individual papers are often rated on how many times they are cited by other papers, so by referencing a paper, you are increasing its visibility to other researchers.
3) Encourage your local library to list open access journals under their electronic resources listings. Many libraries do not list extremely high quality open-access journals like PLoS Medicine in their resources list, making them invisible to some students.
4) Contact open access journals and, if they aren't already, encourage its editors to apply to have their articles listed on a major database such as PubMed, or other relevant resource. This will make the articles visible to most students and scientists working in the area.
5) If you are a qualified scientist or academic, think about volunteering for the board of editors of an open access or free online journal. Journals are often judged on the quality of their editorial board, so the better editorial board they have, the more respected the journal will be. This will also look great on your CV.
6) Support organisations such as the Public Library of Science, that campaign for open science and publish high-quality open access journals.
7) If you have to publish in closed access journals, put a pre-print version of the paper on the web. It doesn't have to be fancy (the word processor document would do), but it's often useful to include the full reference to the published version for those who do have access.
This is a list of open access journals in psychology and neuroscience. Enjoy your discoveries and share the science!
* Directory of open access Journals: Psychology
* Open access neuroscience journals on the internet
* Directory of open access / free journals on mental health
—Vaughan.
February 20, 2005
History of neuropsychology: Guaranteed safe!:
Professor Derek J. Smith has a detailed and comprehensively annotated neuropsychology timeline on his website.
For those of you who are worried that this thorough review of the history of brain science is just a honeypot, filled with fake links to gambling and porn sites, you may be rest assured that:
The remote hyperlinks have been selected for the academic appropriacy of their contents; they were free of offensive and litigious content when selected, and will be periodically checked to have remained so.
There's other excellent writing and reviews by Professor Smith linked from his homepage. Explore in safety!
—Vaughan.
February 19, 2005
Brain candle:
A candle in the shape of a brain. Say no more... (except perhaps, that the cerebellum seems rather squashed).
Link to catalog item from naturestore.com
—Vaughan.
February 18, 2005
'A Genius Explains':
There was an interesting piece in last weekend's Guardian (A Genius Explains) about a high-functioning autistic who is also a savant (i.e. he's got amazingly intellectual abilities - he can recall pi to 22,514 decimal places for example). Autistic savants are more common than non-autistic savants, but usually they aren't able to quite so lucidly explain how they manage to do the things they do.
The article left me curious, and a little jealous ("It's mental imagery", he said "It's like maths without having to think.") and makes me feel like we're in for some interesting times ahead as research into savantism, synthesia, developmental cognitive neuroscience and mental imagery converges.
—tom.
2005-02-18 Spike activity:
Quick links from the past week in mind and brain news:
A recent study shows that the preference for side of body used to cradle infants is linked to the dominant hemisphere of the mother's brain. Another example of how observing simple behaviours (like kissing) can show underlying brain structure.
Alphabets and writing may have been shaped by the constraints of our visual system.
For those who consistently over-commit themselves, research suggests it maybe because we are excessively optimistic about time for future tasks.
An article from Scientific American on what we do and don't know about how anesthetics work.
Research challenges the idea that the visual system must separate objects from background before they are classified (PDF of full article).
Psychoanalyst Adam Phillips discusses his new book on sanity. A sign of the growing trend for a focus on positive psychology?
A gene known as ApoE, known to be involved in Alzheimer's disease, has been linked to poorer memory even in healthy individuals. Part of ongoing push to understand the genetics of psychological abilities.
—Vaughan.
February 17, 2005
What you lookin' at?:
The eyes are the primary social signal. It's the eyes we spend most of the time looking ("To See, Act" [Hack #15]). Even when the other person is talking, we look most at the eyes, not the mouth. We use them to signal turn-taking in conversation, to read emotions from, like fear...and we use them to work out what another person is looking at.
It's this - gaze perception - that I've been getting interested in. How accurately can we tell where someone is looking? How accurately can we tell if someone is looking at us, or not? I've been looking out for some actual figures here, basic parameters on how small a difference we can detect in where someone is looking, either when they are looking at us, or at someone else.
Obviously, to be able to answer this question with actual parameters would have all sorts of implications. For, say, the design & manipulation of pictures showing people looking at things, for VR interfaces and, also, I guess it might give a better idea of when someone can tell i'm looking at them, and when they just can't know I am for sure. You know, just as a sort of side benefit...
One of the great things about science, is that if you have a question you can usually be pretty sure that someone, somewhere, has asked the same question and done some experiments to find out the answers. If I'm able to be curious about something it's pretty much a dead cert that someone else already did. So - I figure - time to dip into the back catalogue of psychological research.
And here it is. Argyle & Cook's (1976) Gaze and Mutual Gaze. Notable not just for the fact that it's a book about experimental psychology that quotes Sartre, but it also contains summaries of experiments from the sixties looking into just the questions i'm interested in. Here's my summary of what I found:
First, some ball-park figures, from two experiments:
Imagine two people, 80 cm apart. The 'sender' looks at one of seven points near the 'receivers' face. The points are about 2.4 cm apart and two of them are the reciever's eyes. The receiver's job is to judge where the other person is looking. By chance you'd get this right about 14% of the time (1 in 7). Actually, people get it right about 35%. At 2 m people perform at chance. [full details in ref 2]. Moral: At normal conversational distances, people might be able to tell where on your face they are looking, but more likely they'll get it wrong (so if you don't want to look people in the eyes look at the bridge of their nose and unless they're very close they won't be able to tell that you're not looking them in the eye.
Now imagine two people, one being looked at, one looking, at either 1.5 m or 3 m apart. A third person, next to the 'looked at' (let's called them the 'observer') is trying to tell where the looker is looking. It's a bit like sitting on a train next to your friend and trying to work out who someone a few rows in front is looking at. I won't go into the details of the points the looker had to focus on, but they were either on the person, or up to about two persons widths either side of them (so imagine five people sitting in a row). At 3 meters the observer only correctly judged the lookers gaze about 50% of the time, which isn't much above chance. And most of these judgements were found to be based on the direction of the lookers head, not the direction their eyes were pointing. At 1.5 m the observer was right for about 65% of the times the looker's gaze was straight at the looked at. [full details in ref 3]
So maybe it seems like you can pretty much get away with looking at whoever you want at around 3 m, and they'll be none the wiser. But, before jumping to conclusions, some other results of the experiments
Eye directed gaze is overestimated, for someone looking at the face. In other words, if you look at someone's face they are likely to assume you are looking at their eyes.
For gaze targetted near the face, face directed gaze is overestimated. (In other words, if someone is looking roughly at you, you are likely to assume they are looking directly at you).
Head angle biases judgement of gaze direction. We tend to assume that people are looking mostly the way their head points. Even if we can see the eyes, head angle affects where we think they are looking. Gibson & Pick (1963) found that a 30 degree turn of the head shifted judgements of where someone was looking by an average of 3 degrees in that direction
As distance between looker and lookee increases, head angle become more and more influential on the judgement of the looker's gaze
Horizontal discrimination is better than vertical discrimination. We're more accurate judging where someone is looking left-to-right than up-to-down.
So, it seems, we can't very accurately detect gaze (at least at distance beyond the normal conversational), but we have biases to assume that if it's possible, someone probably is looking at us.
If you've got this far, I hope you've enjoyed the journey along the back-shores of psychology research (before electronic abstract indexing!). I couldn't find any information on depth-of-gaze perception (i.e. can we tell at what distance from their face someone is focusing?) so if anyone knows any leads on this send them along.
1. Argyle, M., & Cook, M. (1976). Gaze and Mutual Gaze. New York: Cambridge University Press.
2. Kruger & Huckstedt (1969), cited in Argyle & Cook (1976).
3. Von Cranach and Ellgring (1973), cited in Argyle & Cook (1976).
4. Gibson, J.J. & Pick, A.D. (1963). Perceptions of another person's looking behavior. American Journal of Psychology, 76, 386-94
—tom.
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.
February 16, 2005
Abstract structure need not be based on language:
Grammar-impaired patients with problems in parsing sentences can parse sums. This weighs against the argument that language underpins our capacity for abstract thought: these individuals have problems with telling "dog bites man" from "man bites dog" but no similar problems with 112-45 vs 45-112.
Aphasia and other language problems stemming from brain damage can indeed lead to calculation problems, but this study suggests that they are not necessarily intertwined. As the authors put it, the performance of their subjects is "incompatible with a claim that mathematical expressions are translated into a language format to gain access to syntactic mechanisms specialized for language."
The same issue is also discussed in a recent Trends in Cognitive Science article by Rochel Gelman and Brian Butterworth. They survey the claims made about the need for counting words to do counting, and arithmetic facts to be stored verbally, and find them wanting. The imaging data does not give a decisive picture, as is often the case, but it is certainly true that numerosity appears to depend in large part on areas in the parietal lobe (top-back of the head) which are some way from language areas.
Another claim is that numerical concepts can only develop if language is there to support it, like a virtual scaffolding. This is one aspect of the strong Whorfian claim - that language shapes thought. Number words are acquired in much the same way that we learn to distinguish 'dog' from 'dogs', and then form a shorthand that is expanded into our full abilities. However when you examine tribes with limited number vocabularies (no greater than the value 3 with consistency) you find that they can succeed in tasks that involve values as great as eighty , presented non-verbally. Research into one tribe, the Munduruku, had a deal-closing finding: adults and children from the tribe performed comparably on the tasks, whether they were monolingual or bilingual with Portuguese - a language with the full range of number words. The groups even performed comparably with a French control groups. If number vocabulary is supposed to be crucial for numerosity, one would expect it to, well, actually help in number tasks.
Finally, it seems the idea of 'recursive infinity' - that is, you can keep adding one indefinitely to get larger and larger numbers - comes naturally to us, even when it does not figure in our established systems. A New Guinean group who used body-parts as a fixed counting system quickly adapted the system to a generative counting rule (ie being able to count higher and higher, up 'levels' of magnitude) when times changed and money became introduced to the system. It implies that these key concepts come naturally to us, rather than being imposed as linguistic concepts.
The study I led with, underaken by Rosemary Varley and colleagues, isn't the first to suggest that language deficits need not cause maths deficits - the TiCS survey outlines such work from way back in the 1920s. And dyscalculia is now well-recognised as its own dissociable disorder. The strength of the study is how it systematically matches the demands of the math and language tasks to make a compelling case that the difference in performance must be due to different underlying mechanisms. And it comes, as part of the burgeoning Renaissance in our understanding of numerosity, to query whether language need be the syne qua non of our species, and continue to feed the language-thought debate.
The BBC have an account of the Varley et al paper. Link
Abstract Link
TiCS survey abstract Link
Henschen, S.E. (1920) Klinische und Anatomische Beitrage zu
Pathologie des Gehirns, Nordiska Bokhandeln
Saxe, G.B. (1981) The changing form of numerical reasoning among
the Oksapmin. Indigenous Mathematics Working Paper. No 14,
UNESCO Education
Pica, P. et al. (2004) Exact and approximate arithmetic in an
Amazonian indigene group. Science 306, 499–503
—Alex.
Fodor vs Pinker scrap continues:
Philosopher Jerry Fodor and cognitive scientist Stephen Pinker are continuing their tussle over the structure of the mind in a recently published exchange.
Pinker wrote a book in 1999 entitled 'How the Mind Works' which argues that the mind can be understood as a computational or information processing device. This, he says, consists mostly of independent but co-operating mental modules that can be inherited and selected for by evolution. An approach strongly linked to the new discipline of evolutionary psychology.
Fodor dismissed most of these ideas in 2000 with a book entitled 'The Mind Doesn't Work that Way' and the two have carried on their dispute in a recent edition of the journal Mind and Language.
Pinker argues his latest case in an article entitled 'So How Does the Mind Work?'.
The subsequent commentaries get quite lively with Fodor starting with "If you really must have a defense mechanism, I recommend denial. It's special charm is that it applies to itself, so if it doesn’t work, you can deny that too."
Earning the comeback from Pinker "This kind of language can be paraphrased as, 'I really don't have an argument here, but if I dismiss the opposition with enough confidence, perhaps readers will assume that I'm right'".
Meow!
Link to PDF of Pinker's article 'So How Does the Mind Work?'.
Wikipedia entries for Jerry Fodor and Stephen Pinker.
—Vaughan.
February 15, 2005
An unusual case of a shrinking brain:
A gentleman from Utah has a condition which is baffling brain scientists. The left side of his brain is shrinking, although the right-hand side seems fine.
He is currently being investigated by neurologists at the University of Utah, Brain Institute.
His brain scan is shown in the picture on the left.
NB: brain scans done by radiologists have left and right reversed, as they label their scans as if they were looking at the patient as they lie on their backs in the scanner, so the patient's left is on the viewer's right.
Link to news story from ksl.com
Link to coverage from Daily Times.
—Vaughan.
February 14, 2005
Love looks not with the eyes...:
"Love looks not with the eyes, but with the mind" says Helena in A Midsummer Night's Dream, perhaps explaining the strange behaviour of those in love.
Love has long been linked to madness, and it's easy to see why. People in love tend to hold unlikely and overly positive beliefs about their lovers, show signs of mania, obsessional thinking and experience catastrophic lows when things go wrong.
In a new book, psychologist Frank Tallis argues that love and lovesickness should be considered more seriously by psychologists and neuroscientists, and that lovesickness can trigger identifiable symptoms of mental illness in some people.
In fact, Dr Tallis is continuing a long tradition of medical enquiry into lovesickness which has been around since the Ancient Greeks (as the history of erotomania shows) although Jacques Ferrand's 1623 A Treatise on Lovesickness probably stands as one of the greatest works in this area (summary, amazon entry with excerpts).
To say that "The course of true love never did run smooth" would be an understatement though, especially if you're investigating love and attraction.
Research has shown that, for some, making love causes amnesia. Luckily though, people are disproportionately more likely to marry others whose names resemble their own, perhaps making the post-coital name guessing a little easier. It seems Cupid has a sense of humour if nothing else.
Link to BBC site on the science of love.
Link to Frank Tallis' site with a sample chapter of his book.
—Vaughan.
February 13, 2005
Male faces with feminine features more attractive:
Recently released results from Dr Tony Little and his team, suggest that males with more feminine features are more widely attractive to women. Women who consider themselves highly attractive however, are more likely to go for classically masculine faces.
Dr Little is interested in identifying the features of attractiveness and explaining why we might have evolved to recognise and seek-out beauty.
The link might be explained by the fact that some physically attractive features are linked to levels of hormones (such as testosterone) that are present during development. These are also known to have an influence on fertility and coupling behaviour.
The researchers based their findings on data gathered from staff and students at the University of Liverpool, but have an online lab where you can take part in similar experiments.
Link to the research team's online lab.
Link to BBC News story on the research findings.
—Vaughan.
February 12, 2005
Fortean Times article on Outsider Art:
The Fortean Times have just put a fantastic article online about Outsider Art.
Although the term 'Outsider Art' is used to describe artists from a number of different backgrounds, the art of people who have been declared insane or mentally ill is especially prominent.
The work can often be intricate, intense, disturbing and delightful, sometimes all at the same time, and is largely produced by people with no formal training or contact with the mainstream art world.
The above image is part of Adolf Wölfli's picture 'Irren-Anstalt Band-Hain'.
Link to Fortean Times article on Outsider Art.
Link to some Outsider artists on wikipedia.org
—Vaughan.
February 11, 2005
2005-02-11 Spike activity:
Quick links from the past week in mind and brain news:
Previously it was known that higher IQ predicts longer life, but it was not known exactly why. A recent study suggests that faster reaction times, which are known to be linked to higher IQ, may be one of the key factors.
Recent research suggests that some aspects of visual function actually improve with age, particularly some motion perception skills (story 1, story 2).
The ability to make sense of 'wholes' rather than 'parts' (and vice versa) seems to rely on areas on the opposite sides of the brain in right and left handers.
An in-depth article from this month's Scientific American on the neuroscience of memory is available online.
Bad news for smokers: Tobacco smoking can cause memory and cognitive impairment in adolescents, and smoking marijuana can have long-term effects on the brain's blood flow.
A brain scanning study finds that when information is stored, activity in parts of the brain can predict whether it will be recalled accurately or form a false memory.
—Vaughan.
February 10, 2005
Psychopharmacology of emotion processing:
Some more stuff I learned about at the EPS meeting below the fold.
As before, caveats apply: this includes as-yet-upublished work, so things may not be quite as straightforward as put here; also, it's possible for me to miss, or even misunderstand, what the speaker is saying.
Catherine Harmer and her colleagues have been looking at the effects of serotonin on fear perception, as part of ongoing investigations into its role in this area. They make a persuasive case that these effects are genuine and are independent of the subjective level of anxiety the recipient feels. That is, the drug isn't just 'calming you down' and making you less jumpy: in addition, your cognitive system is oriented away from processing fear. The evidence that it influences cognition in the absence of anxiety changes comes from studies in which a single dose of a seretonergic agent is given; they found a cognitive effect of the dose even though subjective anxiety was unaltered, although interestingly the effect was that of a heightened response to fear stimuli.
In another experiment repeated sub-chronic doses were administered, and the effect reversed - fear was more poorly recognised - and was extended to other some other emotions, of which particular emphasis were given to Anger and Disgust. The most common kind of errors that were made were incorrect selections of happiness. In the talk, the findings were characterised as a decrease in negative processing; whilst I like the coherence this brings - antidepressants make you see the bad things in life more positively - I've been turning over an alternative hypothesis. What wasn't discussed in the talk, but was apparent from the figures, was the effects of chronic dosage on a couple of other emotions, surprise and sadness.
Surprise is as un-valenced(neutral) as an emotion can get, to the extent that many people are dubious about it being an emotion at all. Nevertheless, the drugs lead to worse accuracy on surprise expressions. Meanwhile, sadness is clearly a negative emotion - arguably the emotional state with the closest correspondence to depressive mood (though I stress they are not the same thing) - and recognition of sad faces is not affected by the drugs. This leaves the findings open to a different interpretation, I think, being that seretonergic drugs lead to a decrease in processing of urgent stimuli. Fear, disgust, surprise and anger all triggered by a cue that needs to be responded to, whilst happiness and sadness much more enduring states that are not initiated by an urgent situation. It seems plausible, and while I suspect the explanation presented is likely to be right, this objection would need to be countered first.
For those of you fans of what is happening inside the brain, an fMRI study showed less activation of the amygdala (implicated in the processing of a number of emotions, most notably fear) in subjects taking citalopram rather than placebo, when they were subliminally presented with fearful stimuli (meaning faces showing fear, rather than images of your parents discovering your stash).
In any case, the evidence that anti-depressants have a role in mediating our experience of emotional (or potentially stressing) elements in the environment casts an interesting perspective on what may be lifting the mood of the medicant.
Links: Earlier work showing the effects of a serotonergic agent on fear perception
Also, this looks spot on, but I can't source it in the journal, so it's probably been miscited in some way:
Harmer CJ, Bhagwagar Z, Cowen PJ, Goodwin GW. Acute administration of citalopram in healthy volunteers facilitates recognition of happiness and fear. J Psychopharmacol 2001a; 15 Suppl: A16.
—Alex.
February 09, 2005
Coma and the tyranny of mental life:
A research team led by neurologist Nicholas Schiff has recently published a brain scanning study on two patients who may show evidence of an internal mental life, despite being in a coma-like "minimally conscious state".
MCS usually occurs after severe brain damage and is a condition where patients seem to be unconscious, but show intermittent awareness of the self or the environment, although they are not able to communicate or maintain this awareness for pronlonged periods of time.
It is thought to be 'less severe' than coma, where patients are entirely unresposive, or persistent vegetative state, where patients are unconscious but may show simple automatic functions such as the sleep-wake cycle or eye-tracking.
Schiff's study found that an area of the temporal lobe, known to be involved in language comprehension, was activated when the two unconscious patients were played recordings of a friend or relative recounting a familiar event.
These responses were remarkably similar to the responses recorded from healthy participants used as controls. This surprised the researchers, who expected far less brain activity in the MCS patients.
One further result they describe as "haunting" was finding activity in the patients' occipital lobe. The researchers speculate that activity in these areas may reflect memories and mental images triggered by the recordings and the sound of their family member's voice.
Little is known about the functioning of the brain during these coma-like or miminally conscious states, and medical science is often surprised by the recovery of function even after prolonged periods of unconsciousness.
Terry Wallis, the subject of a recent Channel 4 documentary, regained consciousness after a record 19 years in a coma.
Link to abstract of Schiff study.
Link to news story about the study from Yahoo News.
Link to information on Terry Wallis, his recovery and the documentary about him ("The Man Who Slept for 19 Years").
—Vaughan.
February 04, 2005
2005-02-04 Spike activity:
Quick links from the past week in mind and brain news:
An article on Alexander Shulgin chemist and author of PiHKAL, a book about the chemistry, pharmacology and experience of psychedelic drugs.
Scientists unlock the secrets of sleep and elsewhere report that listening to relaxing music before going to bed can help with sleep problems.
When we make slips of the tongue it may be our language skills which are at fault rather than our intentions, suggests recent research which showed that people often correctly look at an object they incorrectly name.
The large number of young people involved in car crashes may be partly explained by the frontal cortex not being fully mature until the mid twenties. This area of the brain is involved in a number of driving-relevant skills, such as attention, multi-tasking and decision making.
—Vaughan.
February 03, 2005
New Scientist review:
New Scientist reviews Mind Hacks:
Which is nice. I'm pleased they picked up on all the links and references we give if you want to explore the phenomena further. Like another (very favourable) review said:
"Mind Hacks" is helpfully structured to take you just as deep as you want to go.
From bookzen.blogspot.com which also contains this interesting suggestion:
[Mind Hacks] is totally overflowing with examples and simple exercises -- the "hacks" -- that you can do by yourself or with friends. Better yet, buy the book and give a "Mind Hacks" party! Ask your guests to open the book randomly, exclaim on the particular mental characteristic explained on that page, and then put everyone through the exercise or group discussion implied.
If you do have a Mind Hacks party and manage to get a group of people all doing one of the demos (I think some of the mood induction ones like "Make Yourself Happy" [Hack #95] would serve well for this) then make sure you take pictures and let us know how it goes!
—tom.
Alan Turing and the lusty robots:
A news story in the online edition of the Guardian is reporting that a Korean professor has developed 'artificial chromosomes' that will allow robots to fell 'lusty' and have their own emotions and personality.
It sounds like some good PR for what seems to be nothing more than a genetic algorithm approach to artificial intelligence. Certainly interesting, but not new and hardly likely to lead to machine lust or emotion.
Nevertheless, Professor Kim Jong-Hwan would not be the first computer scientist to get a little overexecited about the possibilities of AI.
A certain Alan Turing suggested his 'mechanical brain' might eventually produce some fairly unusual things way back in 1949...
The following is an excerpt from the 1950 Whitaker's Almanack (p1023), the annual reference and micro-encyclopaedia of the past year's happenings.
I have no idea what the "300 year-old sum" was, but it's good to see the art of unlikely optimism has a long and proud tradition.
—Vaughan.
February 02, 2005
Vive la difference:
A news story about a recent meeting on bioethics in neuroscience reports that brain abnormalities are, well, not that abnormal:
Judy Illes, a senior research scholar at the Stanford Center for Biomedical Ethics, said that she and others have found that 18 percent of healthy volunteers had some kind of brain anamoly. While only 2 percent to 8 percent have required clinical follow-up, these incidental findings have raised concerns among scientists who are using the newest technology to unravel the mysteries of the brain.
Ethical issues in neuroscience and neuroimaging research (often called 'neuroethics') are becoming increasingly important as previously expensive and exclusive scientific tools (such as fMRI) are becoming widely used.
One important issue of debate is the ethics of informing someone if a brain abnormality is detected, when they have volunteered to take part in a research study as a healthy participant.
Link to story from newsday.com
Link to recent article on neuroethics from Trends in Cognitive Sciences.
—Vaughan.
February 01, 2005
Ivan Noble, dies at 37:
BBC science writer Ivan Noble, who has been charting his battle with neurological illness since being diagnosed with a malignant brain tumour in 2002, died yesterday.
His online diary gathered thousands of readers as he recorded an ongoing and moving account of the personal, medical and emotional aspects of living with brain cancer.
The diary documented a personal journey not often reflected in the scientific and medical literature.
Thanks Ivan.
Link to announcement on BBC News.
Link to tribute and interview from BBC News.
—Vaughan.
Chimps fair or foul:
I went to a conference a few years ago at the LSE; if you look at the speakers you'll see why. Although it proved to be patchier than I'd hoped, I was captivated by Frans de Waal's contribution, outlining some wonderful research on the social behaviour of apes. One highlight, which is now finally coming to publication, was the finding that chimpanzees judge reward not just on its instrumental value, but whether it is even-handed or otherwise. They reject a moderate reward if they see an unfamiliar ape get a better one. Good to know that apes throw their toys out of the pram as well.
The explanatory gloss on this is that apes have a 'sense of fair play'. Another angle that comes to mind is that preferential reward may be seen as the forming of a dominance hierarchy, and the smart ape should make it clear that it's not going to acquiesce -a nuclear threat to dissuade a minor loss.
Possibly this is merely talking at different levels of causation - the monkeys may have such a sense due to the need to hold their own in a fluctuating dominance hierarchy. It's also very possible that my thought doesn't fit with chimpanzee social structure at all. Regardless, it keeps the mind sharp to explore the gloss at least as much as the nuts and bolts of a study. Simian Cold War, or chimp village cricket: can you find a better tack?
—Alex.
