In the eye of the swarm

The Economist has a great article on how computer models of how bees, ants and birds operated in swarms, are being deployed as ‘artificial intelligence’ systems to solve previously unassailable problems.

To be honest, the premise of the piece is a little too grand to be plausible: the introductory paragraph announces “The search for artificial intelligence modelled on human brains has been a dismal failure. AI based on ant behaviour, though, is having some success.”

This is really not true, as artificial intelligence has actually been a great success when applied to limited and well-defined problems. The article really just explains how the study of swarm intelligence has allowed us to tackle a new set of limited and well-defined problems that were previously out of easy reach.

However, it does give some fantastic examples of how swarm behaviour, where the combination of simple individual behaviours can solve complex problems, can be applied to a range of problems:

In particular, Dr Dorigo was interested to learn that ants are good at choosing the shortest possible route between a food source and their nest. This is reminiscent of a classic computational conundrum, the travelling-salesman problem. Given a list of cities and their distances apart, the salesman must find the shortest route needed to visit each city once. As the number of cities grows, the problem gets more complicated. A computer trying to solve it will take longer and longer, and suck in more and more processing power. The reason the travelling-salesman problem is so interesting is that many other complex problems, including designing silicon chips and assembling DNA sequences, ultimately come down to a modified version of it.

Ants solve their own version using chemical signals called pheromones. When an ant finds food, she takes it back to the nest, leaving behind a pheromone trail that will attract others. The more ants that follow the trail, the stronger it becomes. The pheromones evaporate quickly, however, so once all the food has been collected, the trail soon goes cold. Moreover, this rapid evaporation means long trails are less attractive than short ones, all else being equal. Pheromones thus amplify the limited intelligence of the individual ants into something more powerful.

 

Link to Economist article ‘Riders on a Swarm’.
Link to Wikipedia article on swarm intelligence.

2010-08-20 Spike activity

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

New Scientist has a good feature article on how ‘crossing the senses‘ can help blind people ‘see’ with sounds and the like.

There’s good update on the biology and effects of the recently ex-‘legal high’ mephedrone over at DrugMonkey.

NPR has been running a good series on ‘How Evolution Gave Us The Human Edge’ that has lots of interesting psychology segments.

fMRI analysis in 1000 words. Awesome guide to the multiple complex steps involved in turning a brain scan into a scientific data point from the top-notch Neuroskeptic.

The Guardian asks stupid question ‘The internet: is it changing the way we think?’ (everything we interact with does) but it turns out to be a thoughtful discussion on the impact of technology on our lives from a number of contributors.

Biologist PZ Myers says that transhumanist and brain simulation enthusiast Ray Kurzweil ‘doesn’t understand the brain’. Kurzweil responds.

Case Study, the excellent series looking at the background of famous psychology case studies on BBC Radio 4 is still ongoing. Because the BBC live in the dark ages, you can only listen to a streamed version for 7 days before the latest episode disappears. Be quick, worth catching.

The number of books in the house predicts child success at school and work better than parent’s education and occupation in countries around the world, according to a study covered by Evidence Based Mummy.

The New York Times has an extended article on the psychology of 20-Somethings and the whether the period is becoming a life-stage categorised as ’emerging adulthood’. Slate takes a critical look at the piece.

Like it or not, parents shape their children’s sexual preferences. The latest Bering in Mind column covers how sexuality develops in childhood. Not a wealth of data but an interesting take.

Wired UK starts the first in a series of monthly ‘Lab Notes’ columns on quirky psych studies. It kicks off a piece on the science of positive thinking.

There’s been a fantastic series on how kids understand numbers over Child’s Play. The latest piece about the neuropsychology of numbers and numeracy is a good starting place.

Newsweek has a brilliant article on why cholesterol levels seem to have a stronger genetic basis than personality. Great introduction to understanding the challenges and trials of genetics for thought and behaviour.

Forensic psychology blog In the News has been at the American Psychological Association annual conference and has sent back some great dispatches.

Slate takes a skeptical look at the claims that adolescents are reaching puberty at and earlier and earlier age.

Innovative philosophers Eric Schwitzgebel and Joshua Knobe mull whether studying ethics makes you more ethical and tackle the studies that suggest the opposite in a great video discussion over at The Splintered Mind.

Scientific American Mind has an article discussing evidence that the cholesterol lowering drugs statins may impact on memory.

The chaps over at Neuroanthropology have written a couple of brilliant pieces that take a look at the assumptions behind the ‘scientists go rafting’ tech and the brain piece that ran recently in The New York Times.

The Fortean Times has considers why the CIA became interested in the ‘LSD in the water supply’ idea.

There’s a discussion of how one of the most famous cases of demonic possession influenced the history of psychiatry over at Providentia.

The Psychologist September issue is freely available, in full, online. You can read it here.

Six causes of social disinhibition on the internet are discussed by PsyBlog. Oddly, ChatRoulette is not listed.

Nature has a fantastic open article on how neuroscientists are trying to breach the blood-brain barrier to avoid having to pipe new treatments directly into the brain in complex and sometimes risky operations.

How to apologise. The BPS Research Digest has some great coverage of which apologies work best for whom.

National Geographic has an eye-opening piece about the incest taboo has traditionally been suspended for royal families.

The necessity of the vagueness of language is discussed by Mark Changizi. I love the phrase “higher-order vagueness”.

The New York Times has a narrated slide-show by an urban explorer photographer who takes photos of abandoned psychiatric hospitals.

There is a funny and sarcastic analysis of a recent study on whether the toy boy / cougar phenomenon really exists over at The Last Psychiatrist.

The Sun, a popular British newspaper of ill repute, has an unlikely photo mock-up of a girl injecting enough heroin to kill a horse, into her elbow, with the safety cap still on the syringe.

The genetics of cocaine addiction has recently begun to focus on the brain protein MeCP2. Addiction Inbox covers the buzz.

The Atlantic has a fantastic article on the evolution of technology and why the ‘this tech is dead’ approach is far from reality.

Determined to fail: free will and work success

If you want to predict how well someone might perform in a new job, you might want to enquire about their views on whether we are free to choose our own actions.

A delightful study just published in the journal Social Psychological and Personality Science found that belief in free will predicted job performance better than conscientiousness, belief in influence over life events and a commitment to a ‘Protestant work ethic’ where diligent labour is seen as a benefit in itself.

Here’s the summary from the study’s abstract:

Do philosophic views affect job performance? The authors found that possessing a belief in free will predicted better career attitudes and actual job performance. The effect of free will beliefs on job performance indicators were over and above well-established predictors such as conscientiousness, locus of control, and Protestant work ethic. In Study 1, stronger belief in free will corresponded to more positive attitudes about expected career success. In Study 2, job performance was evaluated objectively and independently by a supervisor. Results indicated that employees who espoused free will beliefs were given better work performance evaluations than those who disbelieve in free will, presumably because belief in free will facilitates exerting control over one’s actions.

 

Link to summary and DOI entry for study (via Brain Hammer).

Thumb sucking was a brain disease

I’ve just discovered an astounding article from the journal Medical History that left me, dare I say, open mouthed. It’s about how, in the early 1900s, thumb-sucking in children was considered a neurological disorder that was thought serious enough to justify paediatrics as a separate medical speciality.

It sounds ridiculous now, but at the time these were weighty concerns and thumb-sucking merited a place in medical textbooks where it was thought to be responsible for dental damage – a genuine risk to developing teeth in some cases – but less realistically, it was also cited as a cause of facial deformity and, oddly, masturbation.

Fuelled by the popularity of Freudian concepts, thumb-sucking was seen as infantile form of ‘self-pleasuring’ that had lots of knock-on effects for both child and adult development.

It’s probably worth explaining that, in those less enlightened times, whacking off was not only considered dirty, but a leading cause of insanity and hysteria. So the charge that one activity could trigger self-pleasuring was a much more serious affair.

These are genuine quotes from the medical textbooks of the time:

Many are absolutely incurable and the victim may be compelled to carry the marks of this practice and their accompanying discomforts through a long life.

So hideous is the deformity caused by this habit, that it seems incredible that it should be necessary even to call attention to it, much less to urge that action be taken to put a stop to the evil.

Probably the most pernicious result of sucking is its tendency to develop the habit of masturbation.

No consideration of the nervous and mental derangements of infancy would be complete which omitted the consideration of the curious group of minor psychoses which, for want of a more distinctive name, are usually referred to as “bad habits”.

 

Link to Medical History article on thumb sucking and paediatrics.

A cultured gene

Not Exactly Rocket Science covers an eye-opening study that looked at an interaction between genetics and social behaviour. So far, so normal, except that the researchers found that the gene in question, involved in sensing the hormone oxytocin, had a different effect on social behaviour in Americans and Koreans.

The study looked at how often people will ‘reach out’ to others for help and emotional support when they under stress, something that is more acceptable in the US than in Korea, and how this differs among people with different versions of the OXTR or oxytocin receptor gene.

Oxytocin has been stereotyped as a ‘hug drug’ that promotes positive social interaction but really is just a hormone involved in a range of social behaviours and has been linked to everything from bonding with babies to gloating and envy.

This new study adds to the more nuanced view of the hormone, which found a ‘reaching out’ effect only in the group of Americans, indicating that culture was affecting how the gene affected behaviour.

[Psychologist Heejung Kim] compared 134 Korean students with 140 American ones, all with comparable splits of age, gender and background. Using a questionnaire, she measured how stressed each volunteer was feeling at that point in their lives, and how they cope with stress. As with previous studies, Kim found that Koreans are less likely than Americans to turn to their social circle for support and they get less out of doing so; they are more concerned about burdening their friends and straining their relationships.

The OXTR gene exerts its influence against the background of these contrasting cultural conventions. Distressed Americans with one or more copies of the G version were more likely to seek emotional support from their friends, compared to those with two copies of the A version. But for the Koreans, the opposite was true – G carriers were less likely to look for support among their peers in times of need (although this particular trend was not statistically significant). In both cases, the G carriers were more sensitive to the social conventions of their own cultures. But the differences between these conventions led to different behaviour.

The research is a nice counter to a trend in science where studies from the American and European ‘science superpowers’ tend to overgeneralise their results (assuming that they apply universally) where research from smaller countries tends to over-localise their results.

Studies from the US and Europe tend to have titles like “An effect of gene X on ability Y”, whereas papers from smaller countries tend to say “An effect of gene X on ability Y in sample of young people from a small town in the north west of a mountainous region in continental Asia”.

Of course, each are likely to be influenced by culture and have limitations to their generalisability but this doesn’t tend to be equally recognised.
 

Link to Not Exactly Rocket Science coverage.

The brain machine interface of the old ones

Brain-machine interfaces have been of huge interest to the press over recent years, particularly as the technology sparks concerns that have been the subject of numerous science-fiction fantasies.

I found a lovely offbeat example of a fictional brain-machine interface, not from recent high-tech science fiction, but from a H.P. Lovecraft horror story called ‘The Whisperer in Darkness’ – written way back in 1930.

It concerns a race of winged fungi creatures who transport themselves across the space-time continuum as brains-in-cylinders that can be plugged into sensory and speech apparatus where necessary.

There was a harmless way to extract a brain, and a way to keep the organic residue alive during its absence. The bare, compact cerebral matter was then immersed in an occasionally replenished fluid within an ether-tight cylinder of a metal mined in Yuggoth, certain electrodes reaching through and connecting at will with elaborate instruments capable of duplicating the three vital faculties of sight, hearing, and speech.

For the winged fungus-beings to carry the brain-cylinders intact through space was an easy matter. Then, on every planet covered by their civilisation, they would find plenty of adjustable faculty-instruments capable of being connected with the encased brains; so that after a little fitting these travelling intelligences could be given a full sensory and articulate life – albeit a bodiless and mechanical one – at each stage of their journeying through and beyond the space-time continuum.

It was as simple as carrying a phonograph record about and playing it wherever a phonograph of corresponding make exists. Of its success there could be no question.

I also note it’s an early example of the ‘brain in a vat‘ thought experiment used in philosophy of mind.
 

Link to Wikipedia page on ‘The Whisperer in Darkness’.
Link to short story full text.

Flowers, falling maple leaves and wriggling dwarves

I love this summary of a study on unusual hallucinations in an elderly Japanese lady.

The full article is in Japanese but the translation of the abstract and the form of her hallucinations gives it a stylised quality that reminds me of the traditional art from the country.

The last sentence is wonderfully zen-like.

[Formed visual hallucination after excision of the right temporo parietal cystic meningioma–a case report.]

Brain Nerve. 2010 Aug;62(8):893-7.

Yoshimura M, Uchiyama Y, Kaneko A, Hayashi N, Yamanaka K, Iwai Y.

We report the case of a 64-year-old woman with cystic meningioma; this patients was otherwise healthy and experienced formed visual hallucinations after excision of the tumor. She experienced diplopia associated with metamorphopsia, which had persisted for 5 years only when she laid down and turned on her left side.

After the excision of the convexity meningioma located in the right temporoparietal lobe, she experienced several types of formed visual hallucinations such as closet-like pictures, flowers sketched on stones, falling maple-like leaves, and moving or wriggling dwarves.

She was alert and her visual field was normal; further, she did not experience delirium or seizures. She experienced these hallucinations only when she closed her eyes; these hallucinations persisted for 3 days after the operation.

The patient illustrated her observations with beautiful sketches, and the mechanism of visual hallucinations was studied.

If any of our Japanese readers have access to the article I would love to see if it has examples of the patient’s “beautiful sketches”.
 

Link to PubMed entry for study.