January 31, 2005

People hacking for women:

A research team led by Simon Chu from the University of Central Lancashire have found that a woman's height can significantly effect how they are perceived by others.

The researchers found that taller women are perceived by both men and women as more intelligent, assertive, independent, ambitious, richer and more successful, regardless of how the person really is.

In contrast, shorter women are perceived as more considerate and nurturing, but only by men.

Unfortunately, the scientific paper isn't out yet, as it would be interesting to calculate the strength of the effect per inch or centimetre lost or gained.

However, women should be able to encourage people to form particular first impressions by influencing the height they are perceived to be, either by the use of heels, meeting on uneven surfaces, or even carefully selecting the surrounding environment to fool our brain's size-estimation process.

This process is known as size constancy and allows us to understand that objects tend not to expand when they come towards us, even though they take up more room on our retina.

Size constancy can be easily fooled though, as the Ames room demonstrates, although standing next to shorter people (to seem taller) or taller people (to seem shorter) is likely to have some effect, as the system partly works by relative comparisons.

Link to summary of research via independent.co.uk

—Vaughan.

Liecatching:

Since we've been hitting lie detection recently, I thought I'd point out that according to a brief communication in a 2000 volume of Nature (May, vol 405, abstract here, full text here if you can access it), people who have acquired aphasia (an impairment in the processing of others speech, leading to difficulties in comprehending spoken language) are better at detecting lies. The case the authors make is that the brain redresses damage to the circuitry that underpins language ability by boosting the recognition of non-verbal behaviour. This more sensitive detection (which isn't merely better processing of the information in the voice, but depends on using facial cue information) allows a superior level of 'lie-detection' - which in this study was confined to recognising emotions that models (the people being viewed - effectively the stimuli for this kind of study) are trying to conceal.

Using patients as some kind of high-falutin sniffer dog isn't particularly appealing. But the finding lends itself to some great hard-boiled noir...

"I don't know what the hell he's talking about. But this guy's a liar."

It's also a fun conundrum for philosophers of semantics, no? An entity that can evaluate whether something is true or false without accessing its content. And they're a bit more real than zombies.

—Alex.

January 28, 2005

The Noonday Demon:

Andrew Solomon, author of the award winning book on depression, 'The Noonday Demon', is interviewed on BBC Radio 4's 'Taking A Stand'.

Solomon wrote the book after suffering from an intense clinical depression and managed to convey not only his own personal experiences, but much of the science and history of the disorder as well.

Approaches to depression vary, but Solomon believes that both medication and psychotherapy are worthwhile approaches.

He occupies the middle ground between Lewis Wolpert, the Nobel Prize winning biologist who wrote of his own depression in the book Malignant Sadness, and Pulitzer Prize winning novelist William Styron who recounted his experiences in Darkness Visible.

Perhaps unsurprisingly, Wolpert tends towards an almost exclusively biological view of depression and treatment with anti-depressants, whereas Styron is less convinced by the physical explanations and medical treatments. Solomon however, maintains a strong belief in the biological reality of depression, but does not suggest that life events and emotional turmoil are unimportant either as a cause or a focus for treatment.

Either way, it's an important debate which is shaping both how society understands depression and the most appropriate forms of care for people with mental illness.

All three books come highly recommended and Solomon is always worth listening to, as he is an articulate and knowledgable part of an ongoing discussion.

Link to 'Taking a Stand' webpage and audio archive (looks like the audio will be available until Tue 1st Feb)

Other links:

Realaudio stream or transcript of ABC Radio 'All in the Mind' show on evolutionary approaches to depression.
Link to excerpt of Malignant Sadness.
Link to review of little known but excellent book on depression called 'Speaking of Sadness' by David Karp.
Link to Mind factsheet on depression.

—Vaughan.

2005-01-28 Spike activity:

Quick links from the past week in mind and brain news:

A study finds significant differences in the structure of male and female brains related to IQ. However, an insightful article from the NYT seems to cut through a lot of the crap and looks at the implications and (mis)interpretation of such findings in the age old debate about male-female psychological differences.

'Bad driving' may be related to hormones. Best read with the previous link in mind.

Developments in 'gene chip' technology look likely to push forward the understanding of genetic influences on brain development.

Recent brain scanning work has examined the brain functions responsible for looking someone in the eye. Studying this simple action may result in a better understanding of how volutary actions are controlled by the brain.

More research on the contentious area of the genetic contribution to homosexuality has just been published. Don't be fooled by the title of the article though. Anything which claims that the "gene(s) for x have been identified", where x is a complex behaviour, is almost certainly marketing or bad journalism rather than informed scientific conclusion.

—Vaughan.

New Scientist on sensation:

The 29th September issue of New Scientist is a particularly good one if you're interested in the mind and brain.

It has a number of articles on sensation and the senses, and particularly challenges the idea that there are five 'classical' senses. Recent research suggests this may be a fairly artificial division, and more subtle distinctions, as well as cross-overs are common.

Unfortunately, New Scientist have been steadily making less and less of their content freely accessible, but there is an outline of the issue at the link below.

Nevertheless, it's well worth a read, either if you grab a copy at the newsagents or pop into your local library for a browse.

Link to contents for 29th September issue of New Scientist.

UPDATE: One of the articles from the current edition ("The art of seeing without sight") has appeared online.

—Vaughan.

January 26, 2005

Blind people can use the visual cortex to locate sounds:

A study just published in the open access journal PLoS Biology has reported that blind people might be able to use parts of the brain for locating sounds that sighted people normally use for vision.

Frédéric Gougoux and colleagues asked participants who had been blind from early life and who had previously demonstrated superior listening skills to try and judge the source of certain sounds while they were being brain scanned.

Unlike the normally-sighted participants, they showed activity in the occipital lobe, an area of the brain usually dedicated to processing visual information.

This suggests the brain of the blind participants had reorganised, or had organised differently, demonstrating how the brain can alter its structure depending on the demands placed on it.

This is a process known as neural plasticity and is known to be important in both early brain development and ongoing adult learning.

In fact, this isn't the first study to show that the brain of blind people might be organised differently. Research published in 1993 showed that braile reading abilities can be impaired by using magnetic stimulation to disrupt the activity of the occipital lobe.

The researchers suggested that this area had been recruited for touch and language skills, rather than vision.

Synopsis or full text from PLoS Biology.
Link to story on nature.com.

—Vaughan.

On orgasms, epilepsy and the lack of sexual neuroscience:

Recently published results report the first reliable link between brain activity and levels of sexual desire. Yoram Vardi from Rambam Hospital in Israel has reported an association between an electrical brain signal (known as P300) and libido.

The fact that such a straightforward link is both important and newsworthy may be surprising for people who aren't aware of the state of scientific research into the neuroscience of sex.

Considering that sex is one of the most important human activities, and the current findings have been thrilling to say the least, why is it that we know so little about how the brain handles sex ?

A case study published by a team of Taiwanese neurologists reported a most unusual set of circumstances.

One of their 41 year-old female patients, diagnosed with epilepsy, had a seizure every time she brushed her teeth. Seizures in response to external stimulation are not unusual - flashing lights are a well known source - and other sorts of stimulation are not uncommon triggers. A recent case-report even involved seizures induced by vacuum cleaner use.

So the unusual aspect for the Tiawanese case was not the trigger, but the effect of the seizure. The woman had seizures when she brushed her teeth, and had an orgasm every time she had a seizure, shortly before losing consciousness.

Although probably doing wonders for her dental health, the condition has left neurologists rather puzzled. Because so little is known about sex and the brain, her doctors had very little to go on when they tried to explain what was happening.

Sexual neuroscience is one of the most under-researched areas in the human sciences. A quick search of PubMed (the international database of medical research) shows that we know more about the neuroscience of hiccups than we do about orgasm.

Part of the problem is practical. fMRI scanners, some of the most useful and popular tools in cognitive neuroscience, involve lying in a tube while scanning takes place and need the head to be completely still. Add the fact that you're being watched by neuroscientists and none of this makes for relaxed coupling, or even self-stimulation.

Nevertheless, pioneering researchers have tried to tackle the problem with other methods. A Dutch team led by Gert Holstege used an alternative form of brain scanning, known as Positron emission tomography or PET, to study orgasm in men. PET doesn't have the same cramped conditions as fMRI allowing for a bit more sexual freedom in the lab.

They still had some considerable problems to overcome though, not least of which was timing an orgasm to occur during a predefined time-slot, during which brain activity could be monitored. PET requires a radioactive tracer to be injected into the bloodstream, and although the radiation is very weak, it's best to use only as much as necessary. This means the intuitive approach of continuous scanning and waiting for the pop of the cork is just not feasible.

Instead they asked couples to practice at home. The participant's partner (who had the more difficult task by far) needed to be be able to make her partner ejaculate - while he was standing, being injected by radiation, watched by neuroscientists and, most importantly, during a precise 50 second time-slot.

With all credit to the women involved, 8 ejaculations were recorded from the eleven men who volunteered.

The research team found that brain activation is not dissimilar to the effects of certain drugs (the authors mention heroin), showing greatly increased activation in a deep midbrain area called the ventral tegmentum, an area linked to reward, desire and pleasurable experiences.

In contrast, comparitively little cortex activity is involved in the male orgasm. The cortex is typically considered the source of complex thought and mental co-ordination, and Holstege's team put most of the activity here down to erection and sensations in the penis. Men it seems, are more than capable of thinking with their dicks, even when being injected with radioactive tracer.

Sadly, even less is known about the neuroscience of female sexuality and orgasm. Not least because, as many men (and I'm sure women) will testify, the female orgasm is sometimes difficult to predict.

But a far greater problem is the perception of this sort of research. It's exactly the sort of science that the press loves to go giggly about. News stories tend to be gleefully reported, virtually free of any actual news. "Sex researchers study sex" seems to make headlines where "hiccup researchers study hiccups" seems to barely raise a byline.

This type of reporting tends to put off scientists, who want to be seen as serious researchers, and funders, who want to be seen as supporting important research. Science marches on however, and luckily for us all, some scientists are not disuaded by the accompanying media circus.

But if it takes your fancy, you could always volunteer as a participant yourself. Neuroscience studies take various forms, and many involve nothing more than having a few electrodes stuck to your head.

Importantly, participation is confidential and you would be contributing towards progress in neurology and neuroscience, but most deliciously, it's a fantastically unusual way to spice up your sex life.

—Vaughan.

January 25, 2005

Morph your personality:

I recently attended the annual meeting of the Experimental Psychology Society in London and equipped with my PAA (personal analogue assistant, i.e. paper + pencil) got busy sucking up what was said. This is the first of a few posts looking at some of the new research presented there. Since much of this is genuinely new, it won't have jumped through all the hoops normally traversed by science printed in a journal or re-reported in the media. But it's sound stuff from respected researchers, and I figure all of you are as eager as me to get the news before it's news. Right? Today I'll be working from a talk given by Ian Penton-Voak called "Personality dimensions in the social face". I hope you'll understand the title I've given presently.

Stereotyping is a big interest of social psychologists, and it's long established that we make judgments about the personality of strangers based on their appearance. These judgments are reliable - that is to say, that people tend to agree about what personality a face represents, at a level higher than chance would allow. An interesting issue with these kinds of phenomena is how they get started: is there a 'kernel of truth' that tipped judgments one way or the other, resulting in the far more sweeping and gross generalisations that now exist? We should bear in mind that in previous times, the idea that elements of personality persist in the face wasn't just a scientific question, it was a presupposition: The art of physiognomy, or reading faces, was employed as far back as the ancient Greeks, as recently as Schopenhauer (see here for some of his thoughts on the issue) and has been popular between the two. In the present day, people still attribute the same kinds of traits to the same faces, and perhaps more surprising, they explicitly believe that the appearance of the face reveals personality.

However, it is up to the research to show that this reliability among viewers of a face has any correspondence to the genuine trait exhibited. I should note that one doesn't need to be a hardline nativist (someone certain that traits are innate, genetically determined and fairly resistant to change) to consider this hypothesis. Activity affects physiology, so in principle personality, by affecting your activities, could affect how you look. And how you look may shape your personality. So is there anything to this? A kernel of truth, a whole lot of truth, or no truth to speak of?

Previous research showed that people were better at chance at at least some of the personality judgments they made about faces. However this was marred by the common use of full-face photographs, which provide cues such as haircuts, jewellery and the like. Even a cropped photo may contain scars and other unique markers. This also doesn't tell you very much about whether there are types of face that correspond to types of personality.

Penton-Voak's work addressed this using interesting methods and providing exciting results. The first part of the method was fairly standard: they took 300 students and photographed their faces with neutral expressions, and asked them to complete a 40-item questionnaire which was designed to tap into the 5 factors of personality. Then, 100 participants rated the faces on each characteristic - e.g. agreeableness - one at a time. As expected, these rating were reliable. Also, they correlated with some of the questionnaire measures: Extraversion, and also male Neuroticism and Openness to expression.

So far, so expected. Here comes the geek bit: concentrate. For each personality factor, Penton-Voak took the faces of the people who rated themselves as highest on that factor (the top ten percent) and used them to create a personality composite. This was achieved by overlaying each face, preserving their commonalities but gradually smoothing out the differences to arrive at some kind of 'platonic ideal' of the face for that factor. The same was done with the bottom 10 percent on each scale. Would candidates just presented with this averaged information still be able to discern which was the agreeable and which the unagreeable ideal?

Turns out they could, for the following dimensions: Agreeableness, Extraversion, and Neuroticism. So, if anything, the composites stripped of individual social cues such as distinctive haircuts, allowed better perception of the personality trait that underlay them. Penton-Voak suggests that this may be because if the face does carry personality information, a single face is carrying information from multiple, independent sources (as there are proposed to be 5 independent personality measures) and this muddies the waters, as we find it difficult to ignore information and tend to incorporate it into our judgments, even when it isn't helping.

They also made another kind of composite: the product of those faces high or lowly rated on a dimension by the viewers. It would seem trivial to say that these composites continued to be rated as high or low on the scale, just as their components were, but remember that this suggests that some component of personality stereotyping has roots in across-face averages, rather than picking and operating on idiosyncracies. Moreover, using a form of statistical investigation termed discriminant analysis, they revealed that underlying those judgments made upon women was a reliance on their level of perceived attractiveness - their agreement was based not on a shared impression of what constitutes agreeableness in a female face, but a shared supposition that attractive faces are more agreeable. This is termed a halo effect - where perception of one feature determines another one.

In what for me is the most exciting aspect of the research, Penton-Voak took this yet further. If these composites really were ideals, then it should be possible to apply them to fresh data and in effect, produce a transformation along that dimension. He took his strongest candidates - the high and low Agreeableness composites - and applied them to new faces, morphing them towards those common aspects the composite held. These faces, both unknown and famous, were then rated on all dimensions. As hoped for, those morphed towards the high-Agreeable composite were judged more agreeable, and those towards the low judged less. But the most impressive finding was that there was no effect of the morphing on any of the other personality dimensions - they were not rated as more or less extraverted, neurotic etc. It was totally specific to one - in effect, isolating the 'agreeableness' transformation.

This seems compelling evidence that this method has locked on to a proto-face structure that communicates information about one personality dimension only, and promises a method of interrogating whether multiple personality dimensions can be communicated this way, and whether they map onto the classic Big-5 measures. Penton-Voak thinks not - not all the distinctive personality differences that are researched in people will be coded in any sense in the face - but thinks he can find at least one or two more using this method. It also holds out the possibility that, in images at least, we may be able to morph our personality.

I can't resist spelling out the applications of this kind of work in true Mind Hacks fashion...actually, I'll let Ian do it for me:

...the computer graphic faces generated by this project will be useful in an applied setting, as they will allow controlled alterations of perceived personality in faces. The use of computer generated characters (avatars) that successfully elicit personality judgements of the designer’s (or user’s) choosing may increase the usability of, and satisfaction with, computer interfaces. With the increasing use of avatars in many forms of human computer interaction, the current project has value as a first step towards the principled use of facial characteristics in computer graphic avatar design...

As a coda, I should add that the possibility I held out above, that it's personality that is presently morphing our faces is stronger than mere conjecture; studies from the 80s show that couples grow more alike over time in physical appearance, and it's no great step to say that those that smile together wrinkle together in the same way.

—Alex.

January 22, 2005

Alex:

Hello to Tom, Matt, Vaughan and the Mind Hacks viewing community. I'm Alex Fradera, and you may remember me from such hacks as Fake Familiarity, Make Yourself Happy and other fond favorites. If not, we can get acquainted, as I'll be posting here for the foreseeable future.

In a cavernous nutshell:
I'm on the home stretch of a PhD on Time and Memory, which I've been studying at University College London in, well, London. I'm interested in a stack of mind/brain topics, but at least for now don't intend on a high output of link-laden entries. I figure that this kind of format works best when everyone plays to their strengths and complement one another,and frankly I'm too verbose.

Instead, I'm going to pick some topics that I rate as particularly Mindhackish and go to town on them. I'm also going to have my roving reporter hat on, and give you research straight from the cows udder whenever I can. It's the biggest perk of working in an academic environment that you get to hear research before it hits the journals, and invariably before it hits the press, so I'm going to pay my share forward. One drawback is that piping hot research hasn't yet been peer reviewed, which means a lick of scepticism should be applied where appropriate (though on the plus side you do get to see scientists asked the one killer question they were hoping not to get). So I'll apply that warning where appropriate. Now back to your scheduled programming.

—Alex.

January 21, 2005

2005-01-21 Spike activity:

Quick links from the past week in mind and brain news:

More news on developments in 'lie detector' technology - a mix of informed journalism and wild speculation.

A journalist's personal experience of synaesthesia, the experience of having information in one sense, cross over to another (tasting words, for example).

A recent study suggests a drink a day seems to be protective against mental decline in older women.

Howard Rheingold on the psychology of texting.

—Vaughan.

Polygraph hacking:

A report on the deception of polygraph tests (commonly called "lie detector tests") has just been released by the British Psychological Society.

The section that most caught my eye was the discussion of polygraph countermeasures, and particularly a section on a fellow, who after being wrongly convicted for murder on polygraph evidence, took it on himself to hack the polygraph test to help prove his innocence, all while being wrongly imprisoned.

The most famous countermeasures test was probably conducted by Floyd 'Buzz' Fay, a man who was falsely convicted of murder in the USA on the basis of a failed polygraph examination. He took it on himself to become a polygraph expert during his two-and-half years of wrongful imprisonment. He coached 27 inmates, who all freely confessed to him that they were guilty, in how to beat the control question polygraph test. After only 20 minutes of instruction, 23 of the 27 inmates were successful in defeating the polygraph examination.

The report discusses empirical evidence on how well these tests detect potential mistruths (not brilliantly it seems) and contains summaries of research which shows the percentages of hits and misses each sort of test is likely to make.

For example, in a form of polygraph test known as the Control Question Test (where responses to direct questions about the crime are compared to responses to indirect questions) over 26% of innocent suspects were scored as lying, although in the Guilty Knowledge Test (where responses to items of information only a guilty person would know are compared to responses to other information) only 4% of innocent suspects were wrongly scored as lying, but guilty suspects were correctly identified only 59% of the time.

Link to BPS report on 'Polygraphic Deception Detection'.

—Vaughan.

January 20, 2005

Size and selection times: Fitts's Law:

Oo Oo - Just when I thought I was settling down to do some of the work i'm actually paid to do, I discovered a bit of psychology that is relevant to interaction design:-
Did you know that the time it takes you to point your mouse, or your finger, at something is predictable from the size and distance of the object using an equation known as Fitts's Law?

Nope, neither did I till today. But if you apply it right it shows how you can get a big gain in how quick and easy it is to select something with just a small change in the selection interface.

First, the maths. Quoting, Fitts's Law at a glance (lecture notes):

Fitts discovered that movement time was a logarithmic function of distance when target size was held constant, and that movement time was also a logarithmic function of target size when distance was held constant. Mathematically, Fitts' law is stated as follows:

MT = a + b log2(2A/W)

where

MT = time to complete the movement

a,b = parameters which vary with the situation ('regression coefficients')

A = distance of movement from start to target center

W = width of the target along the axis of movement (also equivalent to the degree of permissible error in movement target)

Fitts's Law is an example of a principle in psychology which was developed from information theory (you can read more about this here [1]). Although the basic message is obvious (big things are easier to select) it is the precise mathematical characterisation that is exciting, and that this characterisation includes a logorithmic function - which means that the shape of relationship between size and reaction time is curved so that small increases in size for small objects result make it much easier to select them (whereas small increases in size for big objects don't make that much difference). And the same applies for changes in target distance.

AskTog.com defines Fitts's Law as "The time to acquire a target is a function of the distance to and size of the target" and has some pleasingly opinionated notes on the application of Fitts's Law to interaction design:

While at first glance, this law might seem patently obvious, it is one of the most ignored principles in design. Fitts's law dictates the Macintosh pull-down menu acquisition should be approximately five times faster than Windows menu acquisition, and this is proven out. Fitt's law dictates that the windows task bar will constantly and unnecessarily get in people's way, and this is proven out. Fitt's law indicates that the most quickly accessed targets on any computer display are the four corners of the screen, because of their pinning action, and yet they seem to be avoided at all costs by designers.

Use large objects for important functions (Big buttons are faster).

Use the pinning actions of the sides, bottom, top, and corners of your display: A single-row toolbar with tool icons that "bleed" into the edges of the display will be many times faster than a double row of icons with a carefully-applied one-pixel non-clickable edge along the side of the display.

AskTog also has this quiz for interaction designers, all of the answers to which are based on some application of Fitts's Law.

Now for a typical GUI interaction lets suppose that the width of the thing you want to click on is about a ten times smaller than the distance you need to move to click on it. What is the effect of making the object closer, compared to making it bigger (and vice versa)?

Well for a range of distances (1 to 10) and a range of widths (0.1 to 1.0) the surface of the time-taken-to-move space looks like this:

If the 3D version is a little hard to understand, here's a flat version, with the same colour coding (red = longer time, blue = shorter time)

From this, I suggest that these things are true:

Decreasing the size/width of your target, if compensated for by an equivalent decrease in the distance of the target, won't have any effect on ease of selection. This is just moving along the leading diagonal space shown above.

but this is only true as long as the changes are equivalent percentages. The same absolute change to both target size and target distance could have a big effect on ease of selection

If selection is very slow, the most gains in ease of selection will first be made by making the target nearer (ie you start at the highest point of the movement time surface, the gradient is steepest along the 'distance' axis)

Then you will enter a region of the parameter space where equivalent (percentage) changes in distance and size will have comparable effects (ie the middle bit).

The final increases in ease of selection (ie decreases in movement time) will only be got by increasing target size.

Obviously, for any particular design problem you are working on the maths won't tell you which part of the parameter space you are operating in - but Fitts's Law does give you a model to start thinking about it

Refs

1. MacKenzie, I. S. (1989). A note on the information-theoretic basis for Fitts' law. Journal of Motor Behavior, 21, 323-330. (Online here)

2. Wikipedia article on Fitts's Law

—tom.

January 19, 2005

Oxford Companion To The Mind, 2nd Edition:

The second edition of The Oxford Companion to the Mind has been published and I didn't even notice. It's been ten years since the first edition, and I'm sure that for the second editon editor Richard Gregory has preserved and nurtured all the breadth and good humour of the first. The book has it's own site here, along with some sample PDFs of entries on everything from tickling to memes to attachment theory. This book will keep you company with wit and information as you explore all the myriad shores that make up psychological science. At £40 it's not cheap, but if you've got the money spare it is truly worth it.

—tom.

January 17, 2005

Successful psychopaths at work:

If you suspect your boss is a psychopath, you may be onto something.

Belinda Board and Katarina Fritzon of the University of Surrey compared personality traits of successful business managers and patients at Broadmoor Hospital, one of Britain's highest security psychiatric hospitals.

The researchers found that the business managers scored, on average, more highly on measures of histrionic, narcissistic and compulsive personality than samples of former and current patients. These personality traits are thought to reflect characteristics such as superficial charm, lack of empathy and perfectionism. All of which could be potentially useful in the cut-throat business world.

However, unlike the Broadmoor patients, the business managers scored lower on antisocial, borderline and paranoid personality traits, reflecting lower levels of aggression, impulsivity and mistrust. Exactly the sort of personality traits that are likely to cause problems with senior managers and the law.

The authors of the study suggest that the business managers may be examples of 'successful psychopaths' - "people with personality disorder patterns, but without the characteristic history of arrest and incarceration".

Link to study summary (via BPS research digest).

—Vaughan.

January 16, 2005

Review in The Guardian:

We've had our first review (that I'm aware of, at least), in The Guardian

It's not long, but it's very favourable - here it is:

—tom.

Ones to watch:

Two blogs I've just discovered and will be keeping an eye on are Mixing Memory (who has recently done an excellent post on time perception, in two parts!) and Circadiana who has just started and promises:

'This blog will be dedicated to tracking and commeting on the advances in the study of biological time, mainly circadian rhythms, but also other aspects of temporal biology, e.g., developmental timing.'

And to wet your appetite is this post Everything You Always Wanted To Know About Sleep (But Were Too Afraid To Ask)

—tom.

January 14, 2005

Spike activity:

Quick links from the past week in mind and brain news:

More on the proposed project to study the pain-killing effect of religion - a continuation of the research on the pain-reducing effect of soft porn perhaps ? Only seems to work for men though, sorry girls.

Lovers are worse at spotting other people in love. Truly, love is blind.

fMRI study shows that the brain is connected as a small-world network. Like actors, mathematicians and even the internet.

Exploding the self-esteem myth - a critical article on the concept of self-esteem from Scientific American.

Research shows passive smoking can have significant negative effects on reading, math, and logic and reasoning, in children and adolescents.

—Vaughan.

Are friends electric ?:

The latest edition of the BBC Radio 4 programme In Our Time was a discussion on the mind-body problem.

This is a problem which has taxed thinkers for millenia, and concerns the relationship between our thoughts and experiences, and the biology of the brain. Thinkers have questioned whether mind and brain are distinct in any sense, or whether the we should ultimately reject all talk of the mind and purely describe experience and behaviour in terms of the biology.

Biology, of course, breaks down to physics, and if we believe that all physical outcomes are determined by the prior state of the world, where does free-will come from ? Perhaps it is only an illusion and thoughts are simply unable to cause any biological changes. Thoughts may be like the squeak of a bicycle wheel - certainly produced by the system - but playing no causal role in its function.

Needless to say, the mind-body problem has implications for the understanding of consciousness and other important applications in day-to-day neuroscience.

Link to In Our Time webpage, with realaudio stream and mp3 download of the programme.

—Vaughan.

January 12, 2005

Ballet and the mirror system:

Beatriz Calvo-Merino and researchers from University College London have been investigating how the brain understands other people's movements with the help of professional ballet dancers and experts in capoeira.

It is thought that the human brain has a 'mirror system', that simulates the actions of others as we observe them. This might be the basis of a number of important skills such as observational learning and communication.

This system seems particularly tuned to biological motion, as it doesn't seem to activate when mechanical motion is viewed, or, for example, when an obviously artificial hand is watched while it moves.

Calvo-Merino used the brain scanning technique fMRI to investigate whether the mirror system of expert dancers would react differently when watching their own dance style, when compared to a dance style they didn't know.

They found that when dancers viewed moves which they were expert in, their brains were more active in areas associated with action planning, body image, motion perception and, unexpectedly, and reward and social behaviour.

The results suggest that the mirror system is involved in understanding the movement of others by combining it with our own repertoire of skills and experience, and that this may be a crucial part of our social interaction.

Link to story from sciencedaily.com
Link to the abstract of the study from the journal Cerebral Cortex.

—Vaughan.

Hacking Consciousness:

Susan Greenfield was on BBC Radio 4's Today programme this morning, talking about a new 'centre for the mind' at Oxford (apologies if i've got the exact name wrong, but i can't find a web reference) which she will be directing. The centre will carry out cross-disciplinary research into topics like consciousness, and Prof. Greenfield has some well put things to say about the whole topic - you can hear her again here.

Cross-disciplinary studies of consciousness must be a good thing - in the book see "Talk To Yourself" [Hack #61] for an example of some good work done by a philosopher (Peter Carruthers at The University of Maryland), based on the work of psychologists (most notably Elizabeth Spelke at Harvard)

One phrase Susan Greenfield used a couple of times jumped out at me: 'hacking'! "You can't just hack into someone's consciousness", she said. Well, maybe not in the sense she meant it....

—tom.

January 10, 2005

Inside the mind of an arsonist:

Rebecca Doley, an Australian doctoral student has been studying the forensic psychology of recurrent arson. Particularly, she's been interested in being able to 'profile' or identify common behaviours or experiences that are distinctive of people who set fires.

Profiling usually hits the headlines when applied to murderers or sex offenders and is often used to narrow the number of suspects in a criminal investigation.

It is also used to look at 'risk factors' in certain sorts of criminal behaviour, to allow policy makers and community leaders to make social changes to reduce the risk of criminal behaviour in the community.

Doley has found that serial arsonists often have a sense of excitement or pleasure seeing the damage done by their fires, although their background is not necessarilly very different from the troubled histories of other persistent criminals.

If you're interested in profiling, forensic science or forensic psychology, it's often worth checking your local adult education college who often run short courses or talks on these topics.

Link to write-up of Doley's research via ABC Southwest.
Audio of streamed interview with Doley in Real Audio format.

—Vaughan.

January 08, 2005

No uniqueness in the speed of the brain's evolution?:

Reports (eg) of genetic evidence that the human brain evolved usually fast may be exaggerated - see this very thorough post at language log (thanks to Cosma for the heads up).

This quote seems pretty typical of the media reports:

Humans went into evolutionary overdrive as their brains developed, sending them on a path that set them apart from other animals, scientists believe

And you can understand the general yearning for signs of human uniqueness. Despite this there is no structure, or chemical, in the human brain that isn't found in other species - and, it seems, even the pace of genetic change associated with human brain evolution isn't unprecentedly fast (languagelog cites a cell adhesion protein in the zebrafish, and the SARS virus as just a couple examples of higher rates of change).

Although it isn't unprecendented, the rate of genetic change in human and primate nervous-system evolution is at least fast - (maybe especially fast for such complex structures? I don't know, I've no expertise in this) - and who would argue that even though there is a continuity in the building-blocks of the human brain there has been some sudden leap in it's emergent properties?

(Terrence Deacon, in his Symbolic Species argues that this is due to co-evolution of the brain and langauge - which is by-the-by mostly except that it allows me to mention a book which I will be compulsory reading when I am king of the world.)

We don't need genetic evidence of human uniqueness (indeed, the way our species behaves it might be more helpful to focus on our similarities to the rest of nature), but it's great to have some qualitive figures on the rate of evolution of the human brain's genetics - and, in a different way, it's equally great to have blogs like languagelog which give such an informed and accessible critique of the research, unlike most of the traditional news media - great stuff!

—tom.

January 07, 2005

Eyes wide with fear:

Here's another story related to Vaughan's post of a couple of days ago about the amygdala and fear perception.

A brain imaging study reported in the journal Science [1] found that showing the silhouettes of fearful eyes for just 17 milliseconds was enough to increase activity in the amygdala's of human subjects - the effect is something like just seeing the whites of someone's eyes in the dark (as shown in the picture, along with the comparison condition - the silhouette of the eyes of someone showing a happy expression).

The two things struck me about this. The first, obviously, is how brief the exposure is. If you are shown something for 17ms you will probably be unable to tell that you've been shown anything at all (you might see a flash), you certainly won't be able to tell what it is. In this study the 17ms picture of eyes was immediately followed by a picture of a normal, expressionless, face - which makes perceiving the eye-silhouettes even harder (and, indeed, none of the participants in the experiment reported that they noticed anything unusual).

But their brains did. The amygdala was already ramping up, ready to signal 'be afraid' to the rest of the brain. And this to something that isn't actually scary in itself - but a social signal that there is something to be afraid of nearby. Social and emotional information is being priority-routed through the brain's processing streams.

If your brain responds to something in 17ms then you know it is priority information - compare with the window of conscious experience (about 200 ms), or the time it would take someone to say if a coloured ball is red or green (nearer 1000 ms). And in general it is emotional information (such as fear) and things for which we have a long-evolutionary legacy of prioritising (danger, food, sex) that we can start responding to so quickly. (There's more about all this stuff in the book, maybe start with "Subliminal Messages Are Weak And Simple", [Hack #82]).

The other thing that struck me about the study was that the fearful eyes, are, well, more eye-like. They look more like cartoon-eyes, an exaggeration of the things that make an eye an eye (what an ethologist might call a super-normal stimulus. Like shoulder-pads are for shoulders, wonder-bras are for breasts and cartoon caricatures are for people - more 'thing-like' than the thing itself). I wonder if being "eyes-wide" with fear is simply a functional reaction which gives us as wide a field-of-view as possible - or if being eyes-wide with fear is a social signal that has evolved to capitalise on an existing human ability to read emotions from the eyes. We know that eyes are the most important part of our social landscape (see, for illustration, the eye-tracking picture of someone looking at a face on page 45 of the book). And we can assume that fear will be one of the more important, or at least more urgent, things to communicate. The fear signal may have evolved to take advantage of where people are already spending a lot of their time looking, and to piggyback on an existing neural-specialisation to respond to eye-like stimuli.

Refs

1. Whalen, P.J. et al (2004). Human Amygdala Responsivity to Masked Fearful Eye Whites. Science, 306, 2061. Discussed here

—tom.

January 06, 2005

Multi-tasking:

A reader writes:

Hi, I've recently discovered that I can play a video game while listening to spoken word audio (podcasts).

The game, AntiGrav, uses the body (via a cam which is interpreted as movements). It's physically demanding and demands quick visual recognition and response-- ie. flailing arms about and generally looking like an idiot. Terrific game.

The podcasts on the other hand are fairly intellectually engaging. However, I find that I cannot just sit and listen to them... I need to be doing something else. I can't do programming work or read blogs/web pages, because I get overwhelmed by the two language-based inputs.

So I'm able to turn off the game music / effects and listen, while playing and do as well as I would listening to the game soundtrack.

This seems a suprising result, and I gather that they use different parts of the brain. Care to comment?

Good question - it is a little suprising that you can do both at once. I think the answer is not so much that they involve different input modalities (one visual, one auditory), but that the two tasks involve different types of processing which do not require a change of the 'representational code' between input and output.

With the game you get visual input and rapidly convert it into movements. With the podcast you're hearing linguistic inputs, and - although you aren't responding in any overt way - you need to understand it and remember what happened over (i presume) a longer space over time than with the game.

As with most real life situations there is a whole bunch of things going on here, but i'll try and break it down a bit.

Cognitive psychologists use simple versions of what you are doing here to find out what kind of mental abilities group together - called a 'dual-task methodology'. There's an example described in "Talk To Yourself", Hack #61 - the experimenters wanted to find out if a certain ability relied on language so they got the participants to continuously repeat a news report what they heard over a loud-speaker. Not a complex task, but one that stopped them using their language faculty. Conversely an equally complex task (clapping their hands in time to a rhythm they heard over a loud-speaker) didn't affect their language faculty, even though it was an equally difficult in itself.

Using this two-things-at-once-and-see-what-happens approach, we know that (not too surprisingly) visual and spatial tasks interfere with each other, as do auditory and linguistic tasks. But visual and spatial tasks don't generally interfere with auditory and linguistic ones (and vice-versa).

So one part of the story is that tasks of different sensory forms can often be dealt with similatanously. The next part is that sometimes tasks in different sensory modalities still interfere with each other if their content requires 'strategic' skills - things like complex planning and memory for events longer than a few seconds. Even if the inputs and outputs of both tasks may be being dealt with by modality-specific subroutines (ie one visuo-spatial, one auditory-verbal), they can still interfere with each other if they both call on our modality-general resources (what some psychologists call 'the central executive', which - as far as i can tell - essentially means 'the bit that does all the complex stuff we don't understand': planning, organising timing, attention and memory. And stuff).

I'm guessing that, in your case, only the podcasts put a heavy load on your planning and reasoning abilities, although (and i can't say, because I don't know the game) AntiGrav may require momentary slices of attention. And this leads on to two major caveats about dual-task performance.

With most dual-task experiments performed in the lab, people are made to use all of their capacity to do a particular kind of task, and then psychologists look at what else they can't do. In real life we are often performing under-capacity, and so can dynamically shift our 'mental attention' between the things we are doing. The podcasts may be intellectually demanding, but do you really miss so much if you move your focus to the game for 500 milliseconds? So, often when it looks like you are doing two things at once, you are really doing two things intersliced with each other.

The second, and related, major caveat is that we can often learn to do tasks, or bits of tasks, automatically. As we practice a skill (driving is a good example) we master more and more of the components so that we can do them as one thing, without out needing to deliberately focus our attention to oversee what we are doing. During one of my first driving lessons I was so busy trying to work out what order to check the mirrors in, how to coordinate the accelerator and clutch, and how to avoid steering the car into anything else, that I completely didn't hear the engine complaining as i tried to do 40 mph in first gear. Everything else took up so much of my planning/coordinating resources that I had no spare attention to remember to change gears, or even to notice the ugly noise that resulted because I hadn't (this example may make less sense to drivers of automatics, you lucky things). My instructor angrily pointed out the sound that was obvious to him but I'd completely missed. Now, having learnt to drive, my keeping-in-the-middle-of-the-road, changing gear, checking mirrors, and pedal control subroutines are all solidly over-learnt. Even if i did forget to change gears I would have spare attention to notice the sound of the engine.

I'm guessing there's bits of the AntiGrav game which are similarly automatic for you. Chunks - movements, responses - which you can just decide to do and they happen without much further thought. The wonderful thing about our brains is that the more we do something the more and more of it becomes encapsulated into chunks. There's a seminal cognitive psychology experiment in which typists were asked to touch type one document, while listening to an essay being read over ear-phones (and about which they were asked questions about at the end). At first the typists could do one task or the other, either typing at their normal speed or listening to the essay and answering the questions at the end to 90%-100% accuracy. After enough hours (and hours) of practice they could do both at once!

The last major thing that I think is relevant to this story is the input and output 'codes' of the two tasks. By 'codes' i mean the form that the information is represented in. We know that visual and spatial tasks interfere with each other if they are in conflict, so we infer that there is some single system that is responsible for processing them. Likewise auditory information and spoken outputs. The two tasks have parallel input-output streams which do not cross over between mental modules. I predict that if your game required you to remember verbal labels, or to make responses by saying things aloud, you wouldn't be able to listen to your podcast while playing - nor would you ever be able to learn to do both things at once with the same skill as you could do both seperately.

A similar thing has been shown in a far simpler situation, the Stroop task ("Confuse Color Identification With Mixed Signals", Hack #55). Normally, in this experiment, your ability to name our loud the colour of coloured-inks is confused by the colour-words that the colour-inks spell out [1]. What you have is a visual input (the colour of the ink) which you are trying to convert into a verbal output (the name of the colour). You are translating across representational codes - and it's difficult, people slow down and start making mistakes. If you make it so that the participants indicate their reponse with a movement the task becomes far easier [2]. Now, conversely, the hard task is reading the word - this is normally the easy thing, the skill we've spent thousands of hours practicing, but because it involves translating across representaitonal codes (from the verbally-encoded semantics of the written word into the physical movement) it becomes more difficult.

So these factors, I think, probably explain the suprise that you can play the game and listen to the podcast at the same time.

One final caveat - although you say you play the game just as well when listening to the podcasts, this may not always be true. A close study of your scores might show a small drop when listening to podcasts. There's some similarity here to people using mobile phones when driving (discussed a bit in "Don't Divide Attention Across Locations", Hack #54). Research has shown that in general people are very good at coordinating their driving and phone use, scheduling more attention to driving as it is needed, but if you truly are doing both at once there is a dip in performance, which may be all that's needed to cause an accident.

Apologies if this is a little over-long and involved. I hope it is clear(ish).

refs

[1] Sorry if this is confusing. Look at this and it may help make it clear

[2] I did an experiment that shows this for my PhD thesis (it's discussed in chapter 5, but i wouldn't really recommend anyone reads it )

—tom.

Fear can be found in the eyes:

Neuroscientist Ralph Adolphs has been working with a woman known only by the initials SM. She has damage to the amygdala on both sides of the brain, and although she can recognise emotions such as happiness, anger, surpise, sadness and disgust on people's faces, she can't recognise fear.

Adolphs investigated exactly what SM was looking at when she viewed emotional expressions and found that she rarely looked at the eyes. Most other emotional expressions can be recognised from other parts of the face, but recognising fear seems to particularly involve viewing the eyes.

When prompted to look specifically at the eyes, SM became a lot better at recognising fear, although quickly reverted back to avoiding them if not reminded.

The amygdala has been traditionally associated with emotion, particularly the negative emotions, but Adolphs suggest that maybe it has a wider function, also involving visual attention and analysis.

Why damage to the amygdala might specifically cause problems with viewing the eyes of other people remains to be investigated, as does whether SM's ability to focus in on other parts of the face is entirely normal.

Link to story on nature.com

—Vaughan.

January 05, 2005

Yum:

I'm not sure I can resist this brain gelatin mold:

Fill the plastic brain mold with a customized gelatin mix and a few hours later, out pops a life-size, anatomically correct brain. Delicious! Recipe included.

[Zombie voice:] Braaaains.

—Matt.

Face recognition might be innnate:

Researchers from the Universities of Queensland and Denver have found that newborn babies preferentially look at human faces, but not human body shapes in general. This seems to suggest that face recognition might be innate in some way and might be one aspect of our genetic inheritance which promotes social interaction and allows us to develop subtle social communication skills needed for the complexity of human interaction.

A study published in 2004 suggested that this is more than just a simple preference for any face-like shape, but that newborn babies prefer attractive rather than unattractive faces. It is still unclear why this might happen, although it perhaps hints that attractive faces may seem more attractive because they more closely match a configuration passed down to us via our genes.

The excuse "Sorry honey, I was just looking to see if their face matched my genetic template of innate face shapes" is of course unlikely to get you out of trouble, regardless of your ability to describe the science behind it.

—Vaughan.

Waving, not designing:

I got a wave messaging power-up cover for my Nokia 3220 phone. It's got a line of LEDs along the back of the phone, and when you wave it, you can spell out messages in the air. Check this out:

(That's me, by the way. I posted more about this to my other weblog, if you're interested, but I'm going to continue here about embodied interaction and visual affordances.)

This phone is a pointer to something much larger: Embodied interaction is an up-and-coming trend in product and interaction design at the moment--why use just your fingers to select what's on a display when you can use your whole body? It's often easier, and makes more sense. Like, when you use a hammer, you don't key into system to say "hit at point X with force F" and then stand back and let it happen, you just pick up the hammer and hit with it, using your body to judge strength and your eyes to judge position.

Modern technology has always acknowledged the constraints of the mind and body, of course, but always implicitly. The keyboard works because the keys don't move around in function (the letter "B" is always the letter "B"), and because there aren't too many: that works well with our memory. The keyboard isn't too large, and that works well with the physics of how fast our hands can move, and what our handspan is. The icons on the screen feel like objects because we can move them round independently and they're outlined, and that's because of our built-in object recognition abilities. Windows on-screen can go behind one another because we realise that objects still exist when occluded by other objects, and buttons work well with shades of grey around them because we interpret shading and shadows and so the buttons look pressable.

Some bits of the computer interface take even more for granted. Imagine an alien using a laptop trackpad. They'd say "what? This is weird, you have to move a substance of a particular conductive property over this surface to make the cursor move round"--and that particular conductive property is that of our fingers, of course. (Try using your trackpad with a piece of plastic, it won't work. It's tuned to human flesh.)

Embodied interaction design does two things: It asks how we can have a more general interaction with our technology, so that instead of having to encode everything we do in terms of mouse movements and key presses, we can just do what we usually do. Also it asks: Just as we know the span of the hand to make a usable mouse or keyboard, what's the handspan of the brain so we can make an interface which takes advantage of that?

One great example of this in action is the iPod scrollwheel. You move round it with your thumb (it's a trackpad) to scroll, but actually it doesn't move--unlike the earliest iPods which did actually move. There's an interesting interaction design product there: With the early iPods, the moving scrollwheel was coloured white, the same as the rest of the mp3 player. You'd discovere the wheel moved just by picking up the device and touching it, the surface would yield. But with these new iPods, the scrollwheel doesn't move, so how should the designers advertise this capability?

The answer takes into account affordances (term coined by J J Gibson, used by the designer Don Norman, and in the book in "Objects Asked to be Used" [Hack #67]. When you see a coffee mug, you don't just see its colour, its shape, and the fact the handle is on the left, you see the possibilities of using it: immediately you see the mug, you left hand prepares to pick it up. By seeing the possibility of use, that action is represented in your brain, and because it's represented/encoded in your brain, you become more likely to perform that action. (This is just the same as when you scratch your nose. Somebody talking to you will have that action of "nose scratching" encoded in their brain. Just having that encoding active makes them more likely to perform that same action subsequently - scratching their own nose in turn - without realising it.)

Well, what does the scrollwheel need to do? It needs to visually advertise the fact that you put your fingers on it, grip, and pull round. We usually use rubber for grips, and we usually make it grey (people's fingers are carry a little dirt and with a lot of use the rubber gets grubby. Make the rubber grey to begin with, and the dirt doesn't show up). The fact that you don't actually grip the scrollwheel with your thumb is irrelevant. All the designers have to do is make you touch it once, and then the response of the interface will give you the feedback to confirm you made the right choice.

So that's what the designers have done: The scrollwheel is a dirty grey. It looks like it has been touched a lot. It looks rubbery (although it's not). It communicates the affordance of doing something when touched and dragged. And so, as a first-time user, that affordance gets encoded in your brain, and you have the bright idea of touching the iPod there, and: ta-da, you've done the right thing.

That's what easy-to-use interfaces are all about, and that - in a small way - is what embodied interaction is about too: understanding what the brain does (looks for visual affordances) and making use of that knowledge to transform a non-moving piece of plastic into something which begs to be used.

Now, how did I get to iPods and affordances from wave-in-the-air phones? Ah, doesn't matter, they're all part of the same design trend.

—Matt.

January 04, 2005

EVP: Voices from the other side or the inside ?:

Electronic voice phenomena or EVP is the appearance of mysterious voices on tapes or recordings. They are usually hard to make out, ambiguous and hidden among the static, although some claim they are voices of spirits trying to communicate with the living.

Others claim this is a result of apophenia, a psychological tendency to see meaning in noise where there is none.

There's been quite a bit of interest in this lately, probably spurred by the upcoming release of the movie White Noise, which has EVP recordings as its major plot device.

The Scotsman has an article exploring the phenomena from several angles, including quotes from a psychologist and parapsychologist on approaches to understanding these puzzling communications.

—Vaughan.

The High Street persuaders:

The online version of the Telegraph has an article on how psychology is used in shops to persuade us to part with our hard earned cash and lists some common tricks and techniques.

"The most important rule as a shopper is to keep your wits about you," Karl says. "If you enter a retailer's property, in one sense, you lay yourself open to any tricks or techniques that they might want to spring on you. The best armoury you can have is to keep your eyes open and your ear to the ground and see what's going on."

Link to article (via metafilter.com).

—Vaughan.