Month: January 2009

Shattered delusions

I’ve just found a fascinating article in the History of Psychiatry about a type of delusion that was widely reported in the 15th to 17th centuries but rarely occurs in modern times. The reports were of patients who believed that they were made of glass and thought they might shatter if they suffered even the lightest of knocks.

In some of the more unusual forms, people struck with this form of madness might even consider themselves to be an oil lamp, a drinking vessel or even trapped in glass bottle.

The belief could even be specific to certain parts of the body:

Reports of glass bones, arms, and legs appeared much later, but Early Modern accounts were particularly rich in allusions to glass hearts/chests, and fragile heads. Tommaso Garzoni, an Italian monk,wrote a series of character sketches of mentally-disturbed people in 1586. In one of these cameos, drawn from Galen, the fragile delusion presents as a man who thought that his body consisted of only a large head, which he protected from injury by avoiding all contact with his fellows.

The delusion was reported in medical and the proto-scientific literature of the time, but also shows up in plays and literature.

Reportedly, one famous sufferer was King Charles VI of France, who allegedly refused to allow people to touch him, and wore reinforced clothing to protect himself.

While we tend to be most interested in how new delusional themes arise in response to cultural developments, we pay much less attention about delusions which were once common but now rarely occur.

This is a lovely example of a very well researched look at the history of no-longer popular delusions.

It’s also worth noting that Wikipedia has a page on the delusion where someone has briefly summarised some of the main points of the article.

Link to ‘Reflection of the Glass Delusion of Europe’.
Link to DOI entry for same.
Link to glass delusion page on Wikipedia.

Legal threat for criticising neurobabble ‘lie detector’

Francisco Lacerda is a professor of phonetics and the author of an academic article criticising the use of the unproven voice analysis ‘life detector’ technology in the legal system. He highlighted “discrepancies between the claims the producers and vendors make and what their products are capable of delivering” and as a result, is now being threatened with a libel suit by a company that makes these devices.

The academic journal received similar threats and, rather disappointingly, has now taken the article offline.

But have no fear, a copy was grabbed from the International Journal of Speech Language and the Law before it disappeared and is now available online for all to read.

The article makes for interesting reading, as it looks at the claims and scientific basis of both specific products and the whole project of using voice stress for ‘detecting’ lies.

The company concerned are Nemesysco, who manufacture devices that supposedly detect lies by analysing speech patterns, despite the fact that there is no conclusive peer-reviewed evidence that the devices reliably detect untruths.

The company claim that their products works like this:

The technology detects minute, involuntary changes in the voice reflective of various types of brain activity. By utilizing a wide range spectrum analysis to detect minute changes in the speech waveform, LVA detects anomalies in brain activity and classifies them in terms of stress, excitement, deception, and varying emotional states, accordingly. This way, LVA detects what we call ‘brain activity traces,’ using the voice as a medium. The information that is gathered is then processed and analyzed to reveal the speaker’s current state of mind.

If that made no sense to you, read it again. It won’t make any more sense but it does get funnier.

Rather than presenting data showing that their devices work, the company is resorting to legal action to silence their critics.

UPDATE: Grabbed from the comments:

The article is quite unusual for a scientific article. For example, it has a section titled “who is Mr. Liberman?” addressing a private person and claiming that he is a charlatan based on a visit by a friend made to a private company.

Link to report of legal threat from Stockholm University.
Link to copy of pulled article.

2009-01-30 Spike activity

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

The BPS Research Digest reports on how the weather can affect our memory.

Hallucinations, psychosis found as rare side-effect of ADHD drugs in children, reports The Washington Post. Study abstract here.

The New York Times reports that coffee intake is associated with a lower risk of developing <a href="Coffee lower dementia risk
http://www.nytimes.com/2009/01/24/health/research/24coffee.html?em”>dementia.

The neuroscience of acalculia, an impairment in understand number and calculation, is discussed in a feature article from New Scientist.

The LA Times reports on a new study finding children who had thimerosal based vaccines are cognitive and neurologically normal later in life. Study abstract here.

There’s a great article over at Computer World on building better CAPTCHAs. Sort of an anti-AI science as it has to require something that computers can’t easily do.

New Scientist reports that video game conditioning spills over into real life, although actually, it would be much more surprising if it didn’t.

Two teenage boys singing about CBT on YouTube. History now officially complete.

Neurophilosophy discusses a lovely study finding that touches to the face when we’re trying to understand speech can affect how we perceive what is being said.

An in-depth article on the ‘connectome‘ and the quest to understand the brain’s wiring appears in Nature.

American Psychologist published the first replication of the Milgram conformity experiments for 30 years and has lots of commentary.

Nintendo brain-trainer ‘no better than pencil and paper’, reports The Times.

Neuroanthropology has a brilliantly written piece on veteran’s experiences of PTSD and combat trauma.

Reviews of books on AI morality and embodied cognition appear in this week’s Nature.

New Scientist reports that overweight seniors who consume fewer calories show improved memory.

An interview with Edward Vul of the ‘voodoo correlations’ controversy is on SciAm Mind Matters. The latest reply from some of the ‘red list’ researchers is now online as a pdf.

The Economist reports that we are more like to procrastinate when asked to think in the abstract.

Pharmacy students also have a negative attitude towards mental health patients, reports Dr Shock MD.

Science News reports on a neuroimaging study finding that key emotion areas are involved in empathetic understanding of others’ pain.

The neuroscience of legal and courtroom decision making is discussed on SciAm Mind Matters.

ABC Radio National’s Ockham’s Razor discusses the neurological impact of viral diseases and the history of rabies vaccination.

The Seattle Times reports on the US Army’s highest suicide rate since records began.

A new paper that might give a ‘theory of everything’ for memory is discussed by Developing Intelligence.

Furious Seasons reports on a new head-to-head metanalysis of which are the best antidepressants.

New SciAmMind on play, placebo, lies and illusion

The new edition of the excellent Scientific American Mind has just hit the shelves and several of the feature articles are freely available online – covering the psychology of play, some fascinating new research on the placebo effect, the quest to build a brain scan lie detector and several other fantastic reports.

I found the article on the cognitive benefits of free play particularly interesting. In this instance ‘free play’ is where kids are playing without set rules or requirements, as are needed when playing structured games or doing tasks.

The article is full of intriguing studies that indicate the immediate and long-term benefits of imaginative play. Even rough-and-tumble seems to be associated with better social skills:

Play fighting also improves problem solving. According to a paper published by Pellegrini in 1989, the more elementary school boys engaged in rough-housing, the better they scored on a test of social problem solving. During the test, researchers presented kids with five pictures of a child trying to get a toy from a peer and five pictures of a child trying to avoid being reprimanded by his mother. The subjects were then asked to come up with as many possible solutions to each social problem; their score was based on the variety of strategies they mentioned, and children who play-fought regularly tended to score much better.

As well as checking out the latest issue of SciAmMind, you may also want to have a look at a fantastic online gallery they’ve put together which captures numerous visual illusions that have been realised as 3D sculpures, some of epic proportions.

If you want to see some of M.C. Escher’s impossible staircases rendered in lego, or several impressive sculptures that change depending on the light or viewing angle, do have a look.

Link to Feb 2009 SciAmMind with plenty of freely available articles.
Link to visual illusions sculpture gallery.

‘Internet addiction’ lacks validity finds another study

Dr Shock covers a new study examining the validity of one of the most popular methods for diagnosing ‘internet addiction’, Young‚Äôs Diagnostic Questionnaire, finding it lacks even the most basic ability to distinguish between frequent and infrequent net users.

Validity is one of the essential components of a psychological measure. It refers to whether it is actually measuring what it says it’s measuring.

One of the most common ways of testing validity is to see whether the scale predicts other aspects of behaviour or psychological functioning that we would expect would go along with the target behaviour.

In this case, we would expect ‘internet addicts’, as identified by a cut-off score on the Young’s Diagnostic Questionnaire, to spend more time on line than ‘non-addicts’, have greater levels of mental distress or behavioural impairment and would be more focused on specific internet activities.

Two psychologists, Nicki Dowling and Kelly Quirk, set out to test this on over 400 students – a group who have been previously highlighted as likely to be vulnerable to excessive internet use.

They found that those students who were clearly identified by the questionnaire as ‘internet addicts’ were no different in time spent online or psychological dysfunction from those students who were just below the cut-off.

What they did find, however, is those students who ticked zero to two items, the lowest ‘risk’ category, on the 8-item questionnaire typically used the internet for fewer hours and were likely to be depressed or anxious than the people who scored above the ‘addiction’ cut-off.

However, as three of the diagnostic items specifically refer to spending longer time online, and three specifically refer to low mood, anxiety or preoccupation, this is hardly surprising.

It’s like finding out people who say they are sad are more likely to be depressed.

What the study did clearly show, however, is that the criteria for distinguishing ‘addicts’ from ‘non-addicts’, which has been the basis of the majority of ‘internet addiction’ research, doesn’t even reliably distinguish between amount of use and psychological distress.

This is important, because the criteria have been offered by proponents as the basis of a possible ‘internet addiction’ diagnosis in the forthcoming updated psychiatric diagnostic manual, the DSM-IV.

This comes only a few weeks after a recent study reported the damning conclusion that previous studies used “inconsistent criteria”, where subject to “serious sampling bias” and usually reported associations rather than doing any sort of work on causal influences.

Link to Dr Shock internet addiction post ‘Garbage In, Garbage Out’.
Link to study.
Link to DOI entry for same.

The economics of crack hustling

I just found this fascinating TED lecture by economist Steven Levitt on the social structure and economics of ghetto crack dealing. What’s surprising is that hustling rocks is a below-minimum-wage occupation with a 7% per annum employee death rate – despite the hype, a very shitty job.

Levitt is famous for being one of the co-authors of the book Freakanomics but is mostly known in the academic world for his research on the economics of crime and the underworld.

His lecture recounts some of the findings of a 10-year research project into the economics of a crack-dealing gang from an inner city US housing project.

Unsurprisingly, being a hustler is incredibly dangerous, but perhaps more of an eye-opener is that the business is run very much like a franchise and that most street dealers had second jobs, moonlighting in the mainstream economy, because dealing crack pays below the minimum wage.

The career prospects are slightly better higher up the ladder, but are still surprisingly modest in the grand scheme of things.

In other crack news, The New York Times recently published an article discussing research on ‘crack babies’, now many children whose mothers were addicted to crack while they were pregnant have grown up to be adolescents.

During the 1990s, a huge fear was that the children of ‘crack moms’ would be neurologically impaired, as when born they tend to be smaller in body and head size.

Although there are detectable differences in the teenage years, these aren’t as bad as expected, and it seems that being a ‘crack baby’ isn’t a life sentence as it was once thought.

Link to Steven Levitt on sociology and economics of crack dealing.
Link to NYT on ‘The Epidemic That Wasn’t’.

War trauma and brain impact

Although much of The Telegraph’s science coverage seems to have gone down the pan recently, they’ve just published a remarkably well balanced and informative article on war trauma and how it is associated with measurable changes in brain structure.

Brain imaging studies have found that people with post-traumatic stress disorder tend to have smaller hippocampi, an area known to be key for emotional memory.

But it’s not clear whether this is a direct consequence of PTSD, or simply that people with smaller hippocampi are more likely to develop the disorder after trauma.

The article does a fantastic job of presenting a balanced look at the causality hypnotheses, and quotes psychiatrist Simon Wessely, known for his research on the psychology, neuroscience and history of combat trauma.

But Prof Wessely has found that the very thing that exposes soldiers to PTSD might also help them deal with it: their job. According to his research at King’s, group cohesion and firm leadership are critical in reducing the impact of psychological distress.

“You have to remember we are talking about professional soldiers who have been highly trained,” he says. “Their training is designed to harden them against the unpleasant nature of war. The military is actually very effective at reducing the risk of PTSD with their training, their professionalism, esprit de corps and morale. War is a stressful business and this all prepares soldiers for that.”

The flip side is that the memories that provoke trauma are not necessarily those of gruesome battles or injuries. “The kind of events that affect them are not simply seeing bad things and coming under fire ‚Äì it is when the rules they have come to expect are somehow broken. It is when errors of omission or commission lead to the feeling they have been let down, or that they have let their comrades down, that mental health problems occur. This is why ‘friendly fire’ incidents are so psychologically damaging ‚Äì it violates the soldiers’ rules of who is supposed to be shooting at them. They will feel anger at those responsible.”

The only bizarre bit is the second to last paragraph where it mentions “new treatment is being developed, drawing on neurolinguistic programming, relaxation techniques and even Eye Movement Desensitisation Therapy”.

It mentions EMDR as if it is something unusual, when it is an increasing well researched evidence-based treatment, and NLP as if it is nothing out-of-the-ordinary, when it is largely pseudoscience that lacks even the most basic empirical support.

Link to ‘How brain scans show the trauma of war’.