Decision-making special issue in Science

This week’s Science has a special selection of papers on the psychology and neuroscience of decision making. While most of the articles are closed-access, one on how game theory and neuroscience are helping us understand social decision-making is freely available.

It is a great introduction to ‘neuroeconomics’, a field that attempts to work out how the brain supports cost-benefit type decisions.

This can be directly applied to financial decision-making, but also to other types of situations where weighing possible gains and losses is important, whether the gains and losses are in the form of money, time, social advantage or status – to name just a few.

One of the crucial discoveries of recent years is that people do not act as rational maximisers – making individual decisions on how to get the most benefit out of each choice. In fact, social influences can be huge and often lead people to reject no-risk economic gains when then feel it is socially unjustified.

This had led the field into interesting territory, both informing models of the economy, and illuminating how we make social decisions.

As part of the neuroeconomic approach, researchers have begun to investigate the psychological and neural correlates of social decisions using tasks derived from a branch of experimental economics known as Game Theory. These tasks, though beguilingly simple, require sophisticated reasoning about the motivations of other players. Recent research has combined these paradigms with a variety of neuroscientific methods in an effort to gain a more detailed picture of social decision-making. The benefits of this approach are twofold. First, neuroscience can describe important biological constraints on the processes involved, and indeed, research is revealing that many of the processes underlying complex decision-making may overlap with more fundamental brain mechanisms. Second, actual decision behavior in these tasks often does not conform to the predictions of Game Theory, and therefore, more precise characterizations of behavior will be important in adapting these models to better fit how decisions are actually made.

Link to Science special issue on decision making.
Link to article ‘Social Decision-Making: Insights from Game Theory and Neuroscience’.
Link to previous Mind Hacks post on game theory and (ir)rationality.

The deadly South American arrow poison

I’ve just found a fantastic article on the history of curare, the powerful Amazonian arrow poison that causes paralysis and death. It’s from a 2005 edition of the Journal of the Royal College of Physicians Edinburgh and is available online as a pdf.

The article tells the story of how the New World poison came to be known to the West, and how explorers, researchers and ‘gentleman scientists’ attempted to work out how it had its deadly effect.

Curare can be extracted from several plants but the active ingredient is d-tubocurarine.

It has its effect by blocking the effect of the neurotransmitter acetylcholine at the neuromuscular junction. In other words, it blocks the chemical signals that allow nerve signals to activate the muscle.

You may be interested to know that Botox works in an almost identical fashion. It is used in in very small doses in plastic surgery to supposedly ‘smooth’ wrinkles.

Actually, the main ‘smoothing’ effect is due to the fact that the underlying muscles are paralysed and so cannot move to cause creases in the skin.

In larger doses it is also very dangerous. The name is a clue – Botox is short for ‘botulinum toxin’.

The article on curare also has some fascinating asides about the myths associated with the compound, and some curious historical incidents associated with it – such as its role in a plot to assassinate the British Prime Minister during World War One.

pdf of article ‘Curare: the South American arrow poison’.

Faces, genetics and addiction

BBC Radio 4’s science programme Material World just had an interesting edition on the links between face structure, psychological attributes and genetics, as well as a discussion on the science of addiction.

It is well known that certain genetic disorders that affect brain development can also lead to differences in facial structure (the most well-known example being Down Syndrome) owing to the fact that the brain and face develop from closely related groups of cells during embryogenesis.

One interesting example mentioned by medical geneticist Dian Donnai is the link between having a single incisor (‘front tooth) and possible problems with brain development.

It’s now being found that differences in the face, even in people without genetic disorders, reflect aspects of growth and development that can be linked to psychological attributes (or just as interestingly, are reliably linked to perceived psychological traits).

Psychologist Anthony Little is one of the guests on the programme and, with a number of colleagues, has done some fascinating work in this area (often using morphed or averaged faces like the one on the left) with many of the research articles available online.

The second part of the programme discusses the science of addiction in terms of both its psychology and neurobiology, but also in terms of its place in our culture as a concept that is applied to patterns of excessive behaviour.

Both are engaging discussions and are well-worth a listen.

Link to Material World with permanent audio archive.
realaudio of programme.

Neurology in the UK

I’ve just found this on the announcements for the Wellcome Trust’s Small Arts Awards grant scheme. It’s a proposed art / science project that combines neurology, computational modelling, robots and punk rock!

“Neurotic” by Fiddian Warman

Neurotic questions the neurology associated with the essential human experience of pleasure, learning, taste and aging in the context of the instinct to dance. The project, which involves a collaboration between a neurologist, a computational biologist, punk musicians and a robotics artist, culminates in a live performance at the ICA. Punk band Neurotic will play to an audience of both humans and a group of robots whose cognition is modelled on brain function. The human-sized robots will ‘pogo’ alongside the human audience when their neural networks, modelled on real neural pathways, are appropriately stimulated by the music. The event will be accompanied by discussions on the role of memory, emotion and cultural context in the development of taste in humans and a website which explores neuroscientific issues raised by the research and performance.

Rock on! I can’t wait to see it completed. The full list includes many more innovative art / science collaborations.

Link to full list of Wellcome Trust Small Arts Awards funded projects list.

Full disclosure: I’ve been involved in Wellcome funded art / science projects and am an occasional grant reviewer for the scheme.

My brain made me do it

Gerontologist and all-round skeptic Raymond Tallis has written an article for The Times where he laments the rise of ‘neurolaw’ where brain scan evidence is used in court in an attempt to show that the accused was not responsible for their actions.

Tallis cites the example of the trial of Bobby Joe Long where his lawyers tried to argue (unsuccessfully as it turned out) that he wasn’t responsible for his crimes because brain scan evidence showed that he had an overactive amygdala (supposedly suggesting increased aggression) and underactive frontal lobes (supposedly suggesting reduced ability to inhibit aggression).

This, Tallis argues, is hardly evidence for diminished responsibility because it assumes that our brain is some sort of separate ‘alien force’ that is somehow not ‘us’, when we generally think of the brain as being synonymous with the self.

However, he goes on to cite the example of an epileptic seizure and argues that this is an example where we definitely can’t say the person is responsible for twitching or losing consciousness.

Tallis aims to make a clear cut distinction between these different sorts of action and how we attribute responsibility for them, but he is perhaps relying on the extremes when reality can be full of grey areas.

Each of us has a propensity or threshold for violence, so some people will have aggressive urges more easily than others.

One way of looking at the question is ‘how responsible is the person for their actions’, but another is ‘what strength of urge do we think it is reasonable for a person to inhibit’.

Life experience, genetic factors, brain injury or any forms of neurological disturbance may make urges stronger or reduce our ability to inhibit them.

Some epileptic seizures may be ‘irresistible’ in this way of thinking (although interestingly, some seizures may cause thoughts or urges that are resistible to varying degrees), whereas other patterns of brain activity will produce desires or intentions that can be more easily suppressed.

A serial killer may genuinely have reduced ability to inhibit violence urges, but at what point do we say that the effort they would have to make to stop them reacting violently is beyond what is considered reasonable or possible.

Link to Times article ‘Why blame me? It was all my brain’s fault’.

All in the Mind blog launches

ABC Radio National’s ever-excellent radio programme All in the Mind has just launched a blog.

It has the latest on issues arising from the programme as well as other interesting snippets from the world of psychology and neuroscience.

The blog will also clue us into forthcoming editions, and there’s also a chance for you to comment, discuss and suggest ideas on anything that comes to mind.

And there’s even a scan of Natasha Mitchell’s brain. What more could you ask for?

As for the programme itself, tomorrow’s edition will feature Steven Pinker discussing ideas from his latest book.

Link to ABC Radio National’s All in the Mind blog.

2007-10-26 Spike activity

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

BPS Research Digest has an article on the secret to remembering material long-term.

Dennis Brain has a posse, sorry, orchestra.

Mixing Memory discusses the psychology of women in maths, science, and engineering.

A transcript of R.D. Laing interviewing Van Morrison in 1986. Personally, I’m still waiting for Thomas Szasz to interview the Spice Girls.

Why do some babies talk sooner than others? The mighty Cognitive Daily investigates.

The Washington Post reports on a US Government committee who have concluded that only exposure therapy is known to be effective in treating PTSD. Presumably the Cochrane report on psychological treatments for PTSD escaped them at the time.

Newsweek has a report and video on a case of ‘multiple personality disorder’ which is remarkable largely for the fact that it tells us our concepts about the condition have barely moved on since the famous cases in the 70s.

The ‘source of optimism’ has not been found in the brain, but two brain areas have been identified which are relatively more active when positive events are imagined.

Furious Seasons notes the curios yoga-themed advertising campaign for antipsychotic ziprasidone (aka Geodon).

Lack of sleep makes it more difficult to manage negative emotions. This story got mangled by much of the press. BBC News did the best job, but it’s probably best to read the original abstract.

PsyBlog reviews The Most Dangerous Animal, a book on war and human behaviour.

Lovely Francis Crick quote: “Any theory that fits all the facts is bound to be wrong since some of the facts will be misleading”. James Watson is probably wishing he remembered this before putting his foot in his mouth about race and intelligence and subsequently losing his job.

The Phineas Gage Fan Club discusses a wonderfully clear schematic map of the visual cortex.

Just beautiful, if not slightly surreal. Neurophilosophy finds an online exhibition of photos from an abandoned soviet brain research lab.

Who’s afraid of Kanye West?

Jonah Lehrer is a neuroscientist, blogger, editor and now author of a new book on what neuroscience can learn from art and literature. Wired has a brief Q&A with him, where he discusses Virginia Woolf, cognitive science and Kanye West.

Actually, this just serves as a brief introduction to some of Lehrer’s thoughts, as he’s promised to talk to Mind Hacks in more detail about art, the cutting edge of brain research and his new book Proust was a Neuroscientist.

We’ll post the interview shortly, but in the meantime Wired has a brief introduction to some of the key ideas.

Link to Wired Q&A with Jonah Lehrer.

The psychological hazards of war journalism

Harvard journalism magazine Nieman Reports has a brief 2004 article (pdf) by psychiatrist Anthony Feinstein on how war journalists respond to what they witness and why they return to cover traumatic situations.

The article briefly summarises some of Feinstein’s research on war journalists, and also notes the results on an interesting study that looked at differences between final year journalism students who wanted to become war journalists, and those who did not.

Given the dangers confronted, the high mortality, and increased risk of developing PTSD and depression, what motivates journalists to return repeatedly to war zones?

The journalists in my study spent, on average, 15 years covering war. Those I interviewed spoke of factors such as the importance of bearing witness, keeping the public informed of important events, having a ringside seat as history unfolded, and personal ambition. Yet there seems to be another pivotal factor that may override all of these. There is evidence that individuals who are attracted to risky and dangerous professions are to a high degree biologically primed for this type of activity…

Preliminary data from a recently completed study in my laboratory demonstrate that final year Canadian journalism students who propose following a career in foreign lands not only have a fundamentally different personality profile from their peers who wish to remain at home, but also possess different cognitive attributes. This last point refers to a certain pattern of thinking and approach to problem solving that correlates with well-defined neural networks.

Feinstein has written a book on the subject called Dangerous Lives that apparently explains his work in more detail.

pdf of ‘The Psychological Hazards of War Journalism’.

Philosophy and cognitive science archive launches

Two important new cognitive science resources have just been launched: Online Papers on Consciousness is a huge database of full-text papers and articles on consciousness and the philosophy of mind, and MindPapers is a much larger index that contains entries for both open and closed access work.

The impressive project has been a joint venture between two tech-savvy philosophers: David Bourget, who is both a computer scientist and a philosopher of mind, and David Chalmers, who has been a beacon of philosophy information on the net for many years, alongside his notable achievements in consciousness studies.

The site also uses an interesting mechanism to classify papers:

…entries are categorized along two dimensions. First, all newly harvested entries are evaluated for their relevance to MindPapers. Second, those entries which have a sufficiently high likelihood of being relevant are assigned categories from the directory. Both of these steps make use of a specially developed Bayesian categorization program. In a nutshell, this program assigns probabilities to entry-category pairs based on heuristics and statistics drawn from training sets. The training set for the first categorization step was derived from the Stanford Encyclopedia of Philosophy… The training set for the second categorization stage is MindPapers itself.

It’s a lovely computational approach to making sense of huge amounts of work in this area. Perhaps this is the birth of a new field – computational philosophy?

Either way, both sites are going to be hugely valuable resources for philosophy and cognitive science alike.

Bravo!

Link to Online Papers on Consciousness (thanks Katerina!).
Link to MindPapers.
Link to more from Neurophilosophy.

The beauty of false depth

The image is one of many beautiful street art images from artist and architect Kurt Wenner who uses false perspective to give the images an impression of a 3D structure when viewed from a certain angle.

Wenner uses the same optical manipulation as Julian Beever, whose work we covered previously on Mind Hacks.

It takes advantage of the fact that we use visual features such as relative sizes to infer the depths of objects in the visual field.

When this is manipulated, we can be fooled into thinking that a depth is present in spatial dimensions where it can’t possibly exist – like in this case, where it seems as if the paintings represent ‘holes’ in the floor.

However, because in reality, these are flat images, the effect is lost when viewed from an alternative angle.

There are many more stunning images on Wenner’s website.

Link to Kurt Wenner’s street art portfolio (thanks Ceny!).
Link to previous post on Julian Beever’s optical street art.

Strobing numbers show saccadic vision

This week’s New Scientist has a brief letter which describes an elegant demonstration of visual processing during eye movements.

When you move your eyes (known as a saccade), visual input is suppressed, so less information is processed by the brain during the move.

This can be easily demonstrated, as described in one of the hacks in the Mind Hacks book (pdf).

An earlier article in New Scientist suggested that visual perception shuts down completely during the move, and someone wrote in with an elegant demonstration to show that this isn’t the case.

It is not strictly true that your visual perception mechanism shuts down completely during a rapid eye movement (22 September, p 34). This can easily be confirmed by flicking your eyes across a digital clock running off an alternating-current power supply, whose figures are luminous and flash at 100 or 120 hertz. You may see a line of images of the numbers, spaced out in proportion to the speed of your eye movement.

The same applies to a TV image: flicking your eyes to the right or left produces a succession of lozenge-shaped images, whereas flicking up or down results in a series of images respectively drawn out or squashed. If you flick your eyes down fast enough you can reduce the picture to a single bar, and if you flick your head down at the same time you can even manage to invert the picture, though you have to be very quick. Do not attempt this, however, if anyone is watching you.

Link to NewSci letter ‘Saccade effects’.
pdf of hack to demonstrate visual suppression during saccade.

Hypermemory and amnesia in National Geographic

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

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

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

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

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

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

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

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

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

I ask you a question, I wanna know why

Dr Lolita Shant√© Gooden is New York-based psychologist with a block rockin’ background. Under the stage name Roxanne Shant√© she revolutionised hip-hop at the age of 14 when she recorded a direct reply to a popular hip-hop track which became a hit in its own right.

This was one of the first rounds in an avalanche of subsequent musical responses, dis records, and on-air replies – a phenomenon now known as the Roxanne Wars.

She was famously dissed in Boogie Down Production’s track The Bridge is Over but she always gave as good as she got and, over the next decade, defined herself as one of the strongest female MCs in rap music.

Nevertheless, at the age of 25 she decided to go to college and study psychology. She describes in a video how she was funded by a clause in an early record contract that promised to pay for her education.

The record company obviously didn’t think that the young MC, who was already a teenage mother, would amount to much at school.

However, she used the contract to her advantage, applied herself with enthusiasm to her studies, and eventually earned a PhD in psychology.

She now practices in Queens, New York.

Link to Wikipedia page on Roxanne Shanté.
Link to video of Roxanne Shanté explaining how she got her PhD (via MeFi).
Link to MySpace page with audio of key tracks.

Psychic studies may be influenced by suggestion

The BPS Research Digest has discussed a recent study that analysed recordings of parapsychology experiments and has found that some of the positive findings may be due to experimenters unconsciously prompting the participants as they gave their answers.

The experiments used the Ganzfeld technique where one participant has diffuse white light and auditory noise played to them, effectively blocking the key senses, while another tries to ‘send’ images to them through mental projection.

Afterwards, the ‘receiver’ tells the experimenter what images came to mind and the research team see if it matches what the ‘sender’ was trying to transmit.

Taken as a whole, these sorts of experiments show a weak but positive evidence for extra-sensory perception (ESP), but it’s not clear whether this isn’t just due to a tendency for some negative trials not being reported.

In this new study, psychologist Robin Woofit analysed the tapes of Ganzfeld experiments from the mid-1990s and found that experimenters were more likely to respond decisively to correct responses but give subtle cues (such as saying ‘mm hm’) to give more information when the response wasn’t initially accurate.

This suggests that some of the positive findings may be due to this subtle prompting which is known as the Clever Hans effect, after a horse who was thought to be able to do amazing calculations, until it was later discovered that he was simply clopping his hoof until his trainer responded in a positive way.

However, this also highlights another aspects of parapsychology – they do some of the most thorough experiments in psychology.

This new study was only possible because the researchers keep archived audio recordings of every experimental session, something that almost never happens for other psychology studies.

It could be that other experimental findings in psychology are influenced by the Clever Hans effect, but we’ll never know, because few labs keep such thorough records.

Try asking for the audio recordings of decade-old experimental sessions from other areas of psychology if you’re not convinced.

It sometimes strikes me as ironic that some scientists consider academic parapsychologists to be unscientific when they do often some of the most carefully designed studies in the literature.

The fact that these studies typically find no evidence of ESP doesn’t mean they’re not doing science, and in fact, they’re provided some of the best evidence against airy fairy notions of ‘psychic powers’.

UPDATE: This is an important clarification on the study from Christian, which puts a different spin on it:

The observed interaction effect occurred during the review phase, where the researcher goes through the images the receiver spoke out loud earlier as the the ‘sender’ watched the video clip. This is prior to the receiver’s attempt to choose the correct video clip from a few distractors.

The review generally follows the pattern of the researcher saying ‘you said you saw x’, the receiver say ‘yes’ or ‘no’ or maybe elaborates. It was those times the receiver elaborated, that experimenters appeared to have an influence – if they said ‘okay’ and moved onto the next item, then that was that, but if they went ‘hmm mm’ with an enquiring tone, then the receiver tended to ramble on a bit more and lose confidence in their imagery.

I don’t think it is clear that this would make positive results more likely, and could even make a negative result more likely. Remember too that these were double blind experiments, so it is not a case of the experimenters directing the receivers towards the correct imagery. It is possible though that a sceptical researcher could be more prone to the ‘hmm mm’ noises, and therefore would make their receivers less confident.

Link to BPSRD on parapsychology and suggestion.
Link to abstract of scientific study.

Encephalon 34

The 34th edition of the psychology and neuroscience writing carnival Encephalon has just arrived with the best in the last fortnight’s mind and brain writing.

On this occasion it’s hosted by the Distributed Neuron blog, which is part of an ambitious project to create biologically inspired neural network technology.

A couple of my favourites in this edition of Encephalon include depictions of Alice in Wonderland syndrome in migraine-inspired art and an article that considers claims that differences in executive function are almost entirely inherited.

Needless to say, there’s much more in the complete edition.

Link to Encephalon 34.