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.

Continue reading “Size and selection times: Fitts’s Law”

Oxford Companion To The Mind, 2nd Edition

companiontothemind.gifThe 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.

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).

Ones to watch

Two blogs I’ve just discovered and will be keeping an eye on are <a href="http://mixingmemory.blogspot.com/
“>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)

Spike activity

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

spike.jpg

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.

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.

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.

ballet_dancer.jpg

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.

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….

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.

Forest Fire

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.

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).

Continue reading “No uniqueness in the speed of the brain’s evolution?”

Eyes wide with fear

fearful_eyes.jpg

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.

Continue reading “Eyes wide with fear”

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.

Continue reading “Multi-tasking”

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.

feareyes.jpg

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

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.