Dr Ginger Campbell’s Brain Science Podcasts

I’ve been listening to some of Dr Ginger Campbell’s brain science podcasts recently and am thoroughly enjoying them.

Campbell has been broadcasting for a fair while now (she’s just put her 31st podcast online) but these latest editions are particularly good.

I caught a few of the early ones and found them a little rough around the edges to be honest. I have only recently revisited to discover I’ve been missing out on some great discussions.

Not tied down by the dictates of a radio schedule, the programmes are often wonderfully satisfying and in-depth. She doesn’t like Chomsky’s theories very much though as you’ll discover in a recent edition on the evolution of language!

Campbell has obviously also put a lot of hard work into getting neuroscientists on the show to be interviewed, which make for some of the most interesting exchanges.

Link to Dr Ginger Campbell’s Brain Science podcast.

Maths and the numbers game in the brain

Frontal Cortex has alerted me to a wonderful article in The New Yorker about Stanislas Dehaene’s work on understanding the neuropsychology of number sense.

Like written and spoken language, human numerical abilities are quite astonishing for how they are organised in the brain.

After brain injury, various maths or numerical abilities can be shown to ‘doubly dissociate‘, meaning that parts of the ability can be independently damaged and so it can be inferred that they rely on independent (but, of course, interacting) brain systems.

The surprise comes from the fact that as a species, abilities like complex language, writing and maths are relatively recent cultural innovations.

While some of the core abilities may be inherited, there must be some aspects of the more complex skills which become tied up with the development of brain structure as we grow to account for the way in which they break down in very selective ways after brain damage.

Dehaene is one of the key researchers in understanding the neuropsychology of numerical ability and what he calls ‘number sense’ – a more general intuitive perception of quantity and number.

It has been suggested that this is also linked to other ways of perceiving the world, as can be seen from some strange interactions between number and space that can be seen in experiments:

But the brain is the product of evolution—a messy, random process—and though the number sense may be lodged in a particular bit of the cerebral cortex, its circuitry seems to be intermingled with the wiring for other mental functions. A few years ago, while analyzing an experiment on number comparisons, Dehaene noticed that subjects performed better with large numbers if they held the response key in their right hand but did better with small numbers if they held the response key in their left hand.

Strangely, if the subjects were made to cross their hands, the effect was reversed. The actual hand used to make the response was, it seemed, irrelevant; it was space itself that the subjects unconsciously associated with larger or smaller numbers. Dehaene hypothesizes that the neural circuitry for number and the circuitry for location overlap. He even suspects that this may be why travellers get disoriented entering Terminal 2 of Paris’s Charles de Gaulle Airport, where small-numbered gates are on the right and large-numbered gates are on the left. “It’s become a whole industry now to see how we associate number to space and space to number,” Dehaene said. “And we’re finding the association goes very, very deep in the brain.”

The article is a great read and a useful introduction to some of the key findings in the field, as well as containing a whole load of eye-opening findings about number and the brain.

Link to New Yorker article ‘Numbers Guy’.

Autism reconsidered

Wired covers the beginning of a possible revolution in how we understand autism from both a humanistic and a scientific point of view.

The article starts by discussing Amanda Baggs who is a non-speaking but incredibly articulate young woman with autism.

We discussed her video previously on Mind Hacks which remains a remarkably inspiring challenge to how we understand and value people who experience the world differently.

This alternative view of autism as a variation rather than a disorder in human neurology has been taken up by some researchers, and the article also looks at how recent neuropsychology research is starting to reframe the condition.

The first test, known as the Wechsler Intelligence Scale, has helped solidify the notion of peaks of ability amid otherwise pervasive mental retardation among autistics. The other test is Raven’s Progressive Matrices, which requires neither a race against the clock nor a proctor breathing down your neck. The Raven is considered as reliable as the Wechsler, but the Wechsler is far more commonly used…

What the researchers found was that while non-autistic subjects scored just about the same ‚Äî a little above average ‚Äî on both tests, the autistic group scored much better on the Raven. Two individuals’ scores swung from the mentally retarded range to the 94th percentile. More significantly, the subset of autistic children in the study scored roughly 30 percentile points higher on the Raven than they did on the more language-dependent Wechsler, pulling all but a couple of them out of the range for mental retardation.

While the majority of autism research is very much disorder based, the article is a wide-ranging look at the autism spectrum and a great review of some of the new thinking that beginning to challenge the status quo.

Link to article ‘Scientists Reconsider What They Think They Know’.

Fragments of consciousness

Dana’s online neuroscience magazine Cerebrum has a fantastic article on trauma and dissociation – the splitting of consciousness that apparently makes some aspects of the mind inaccessible to others.

Dissociation is a term that’s used rather loosely in modern psychology and psychiatry. It is sometimes used to be synonymous with derealisation or depersonalisation, describing a feeling of being detached from reality or not being ‘grounded’ in your usual sense of self.

However, in its original and most interesting formulation by the French psychiatrist Pierre Janet, it describes the splitting of consciousness so one part of conscious experience is compartmentalised, becomes inaccessible, is literally ‘dis-associated’ from the rest.

Its not clear why it occurs, but Janet’s theory (often erroneously ascribed to Freud) suggests its a defence against psychological distress. Like the mental equivalent of brushing something under the carpet until you’re unaware it existed or you even did the brushing.

Regardless of whether it is genuinely a ‘defence’ in this sense, it is thought to be at play in conversion disorder, where a person might experience paralysis despite having no damage to the muscles or nervous system (so called ‘hysterical paralysis’).

There is now growing evidence that the high level control systems in the brain deliberately inhibit the movement in the immobile limb, outside the conscious control of the patient.

It is also thought to be the mechanism by which hypnosis has its effect on those susceptible to it. In this case, however, it is a form voluntary dissociation guided by suggestion – meaning someone can have the experience of, for example, limb movement without the associated sense of having willed the action.

One of the most striking demonstrations of this form of dissociation is where some people can be hypnotised not to be bothered by pain, despite the fact they can report on its intensity – even to the point of surgical operations being possible without anaesthetic in some rare cases.

Perhaps it’s not surprising then that dissociative disorders, where patients are seemingly permanently dissociated from their memory (dissociative amnesia) or dissociated from their senses or actions (conversion disorder) are particularly linked to trauma.

The most controversial of these syndromes is what used to be called ‘multiple personality disorder’, but is now called ‘dissociative identity disorder’ to suggest that the patient’s very personality structure has become dissociated from itself, seemingly leading to several identities or ‘alters’.

It’s partly controversial because it was so obviously over-diagnosed in a period of 1950s and 60s American psychiatry that was seemingly drunk on Freudian theory without recourse to the strong coffee of scientific testing.

But its also controversial because its so rare despite still being in the diagnostic manuals. For example, I’ve never met a patient with the condition, and I’ve never met anyone who’s met a patient with the condition, whereas I’ve seen many patients with dissociative amnesias and conversion disorders.

The Cerebrum opens as if it’s about ‘multiple personality disorder’ but don’t be fooled – it’s actually a really good review of what cognitive science has told us about how trauma might cause dissociation (almost all the research mentioned is on memory rather than ‘multiple personalities’).

This is still a controversial area but the article gives the case for the link. The article presents evidence that experience of childhood abuse, both physical and sexual, may be particularly linked to dissociation, perhaps suggesting that it arises from an attempt at a ‘defence’ in some cases.

Cognitive scientists are now increasingly interested in dissociation and hopefully this new level of interest should unlock some of the its mysterious secrets.

Link to article ‘Coming Apart: Trauma and the Fragmentation of the Self’.

2008-02-29 Spike activity

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

“Chewing gum and context-dependent memory: the independent roles of chewing gum and mint flavour”: A lovely forthcoming paper from The British Journal of Psychology.

Bloggingheads.tv has a video debate on natural *cough*, sorry, experimental philosophy.

Pure Pedantry investigates the neurological basis of the “runner’s high“.

Have you been in psychotherapy doctor? The New York Times has an article on the dying tradition of psychiatrists being in therapy.

A new book on ‘neuroarthistory‘ is picked up by My Mind on Books.

Bolding going back to 1962. The Sunday Herald reports on a recently discovered neuroreceptor link found between psychosis and effects of LSD.

Parapsychologist Dean Radin is interviewed by the San Francisco Chronicle.

We respond differently to babies’ faces within 150 milliseconds. Cognitive Daily covers a MEG study of face recognition responses in the brain.

BBC News reports that poor diet is linked to bad behaviour in children.

To the bunkers! $24 billion spend predicted to developed autonomous robot armies. You have 20 seconds to comply!

The first human nerve tissue transplant has been completed. Next step, Robocop (we hope).

Wired reports on a psychologist leading the competition to develop a film recommendation algorithm and win the Netflix Prize.

How do psychologists study what we know about ourselves? Psychologist Virgina Kwan writes a guest article for the BPS Research Digest

Against compulsory happiness: The LA Times discusses the miracle of melancholia and BBC News asks is depression good for you?

First Monday ponders whether whether the increasingly media obsessed world needs to be understood as an attention economy.

Deric Bownd’s has a primer on executive function in the prefrontal cortex.

The normality of strangers

“The only normal people are the one’s you don’t know very well.”

A quote from the Austrian psychologist Alfred Adler. Not sure exactly where this quote comes from, but it’s widely quoted on the net.

Adler was hugely influential in the early Freudian circle and coined the term ‘inferiority complex’ to describe what he thought was the innate sense of inferiority we are all born with and need to learn to manage as part of our development.

He believed that this developmental process shaped the personality and was reflected in each person’s individual personality traits.

UPDATE: I’ve just noticed that there don’t seem to be any photographs of Alfred Adler Smiling. Cheer up Dr Adler.

Medicated Americans

Scientific American Mind has a fantastic article on the endemic use of antidepressant drugs in the United States. It starts with some surprising statistics: 11 percent of American women and 5 percent of men are on antidepressants.

Serious clinical depression is devastating, and if ever you needed convincing that mental illness should be taken as seriously as physical illness, you only need to meet someone suffering in the depths of a mood disorder.

In contrast, the article notes that the modern concept of depression and the diagnostic criteria have been increasingly widened to cover states of low mood or disinterest that would previously have never been thought of as a medical problem.

It’s full of interesting snippets from the scientific literature to suggest the pervasive influence of this new broader ‘depression’ on society.

For example, a 2007 study found that 1 in 4 people treated for depression have recently experienced a major emotional setback, such as a marriage break-up, a job loss or a financial crisis – suggesting the emotional difficulties may be part of a normal reaction to a serious life event.

A 2006 study found that three-quarters of people prescribed antidepressants receive them for a non-licensed or ‘off label’ reason – for a purpose that there is no strong evidence for.

Furthermore:

If statistics serve, we know a number of things about the Medicated American. We know there is a very good chance she has no psychiatric diagnosis. A study of antidepressant use in private health insurance plans by the New England Research Institute found that 43 percent of those who had been prescribed antidepressants had no psychiatric diagnosis or any mental health care beyond the prescription of the drug. We know she is probably female: twice as many psychiatric drugs are prescribed for women than for men, reported a 1991 study in the British Journal of Psychiatry. Remarkably, in 2002 more than one in three doctor’s office visits by women involved the prescription of an antidepressant, either for the writing of a new prescription or for the maintenance of an existing one, according to the ­Centers for Disease Control and Prevention.

This is not to dismiss the suffering of those who have less disabling mood problems – each of which can be a torment in itself.

The key question though, is should it be the responsibility of medicine to prevent these unpleasant mood states, and if so, is medication the answer?

Psychological therapies are known to be effective treatments when depression first occurs and better than drugs in preventing relapse, and for much mild – moderate depression increasing activity levels and light exercise can be strikingly effective.

For more serious cases, a combination of drugs and psychological treatment is the most effective treatment.

The boundaries of illness say as much about our society as they do about our medical advances because it is impossible to define illness without making a value judgement about what point normal variation becomes a pathology.

Depression and antidepressants and complicated because there are many interests – individual, professional, scientific and financial – all shaping how we detect and treat ‘it’.

Over these last few months it has become clear that medication is not as effective as the published evidence has led us to believe, and that we need to radically rethink how we understand mood problems and help those who suffer them.

While the SciAm article focuses on the US where the problem is most apparent, it is clear that this is an issue facing many countries in the West.

Link to SciAm article ‘The Medicated Americans’.

The metaphysics of a Jazz Thing

A fantastic study has just been released by open-access science journal PLoS One that investigated the neuroscience of jazz improvisation.

Jazz musicians were put inside an fMRI brain scanner and were asked to do complete a number of different musical exercises using a specially adapted magnet-friendly keyboard.

The musicians were asked to demonstrate musical scales, a pre-practised fixed piece, and an improvisation exercise while their brains were scanned.

A summary of the study by the John Hopkins medical school team gives the main results:

The scientists found that a region of the brain known as the dorsolateral prefrontal cortex, a broad portion of the front of the brain that extends to the sides, showed a slowdown in activity during improvisation. This area has been linked to planned actions and self-censoring, such as carefully deciding what words you might say at a job interview. Shutting down this area could lead to lowered inhibitions, Limb suggests.

The researchers also saw increased activity in the medial prefrontal cortex, which sits in the center of the brain’s frontal lobe. This area has been linked with self-expression and activities that convey individuality, such as telling a story about yourself.

Some years ago, psychiatrist Sean Spence suggested that Jazz music may have been born owing to the ‘the father of Jazz’, Buddy Bolden, having schizophrenia and suffering from associated frontal lobe impairments.

Spence argued that reduced frontal lobe function meant that Bolden could only improvise, as he didn’t have the cognitive control to stick to pre-learnt pieces.

At the time improvisation was considered a sign that you couldn’t play ‘proper music’ well enough, but Bolden took improvisation to a new level with wondrous flights of fancy and, as the legend goes, jazz was born. That’s not the whole story of course, but it’s possibly an ingredient.

While these new findings don’t give us much of a lead on whether this might have been the genuine beginning of jazz music, it’s interesting that the idea that reduced frontal lobe function ‘frees up’ the over-inhibited playing of set pieces, is consistent.

Link to PLoS One article on the cognitive neuroscience of Jazz.
Link to study summary.
Link to BBC News on Spence’s theory.

Behavioural Obamanomics

Theories are made great by those whom they inspire. Perhaps then, it is not surprising that the fresh new face of the US presidential race has been inspired by behavioural economics, one of the fresh new faces of cognitive science.

The New Republic magazine has an article on how the Obama campaign have adopted behavioural economics – the science of how people actually reason about money, as opposed to how they should – as their mainstay of economic policy.

Unsurprisingly, The New Republic, generally a centre-left publication, hold out great hope for the partnership of this new science and an Obama government.

You can find subtle evidence of this influence across numerous Obama proposals. For example, one key behavioral finding is that people often fail to set aside money for retirement even when their employers offer generous 401(k) plans. If, on the other hand, you automatically enroll workers in 401(k)s but allow them to opt out, most stick with it. Obama’s savings plan exploits this so-called “status quo” bias.

What is more interesting though is that cognitive science is starting to make inroads into policy development outside the traditional area of defence (where psychology, and more recently neuroscience, have traditionally been key in driving defence spending).

Link to The New Republic article ‘The Audacity of Data’.
Link to intro to behavioural economics (both via MeFi).

Chuck Close and perceptual Science

I just discovered the wonderfully perceptive artist Chuck Close did a cover for Science magazine back in 1999.

Close was renowned for doing huge super-realistic paintings of portrait photographs that seem more real than real. When you get up close you notice that he’s painted in insanely small details, like individual hairs that stretch into the background and blur as they become out of focus in the original photograph.

Painting this sort of detail on such a huge scale makes you question how real photographs really are, as it gives them an surreal quality despite looking like wonderful likenesses. It’s an uncanny perceptual effect.

In 1988, Close suffered a stroke in his spinal artery, restricting his movement and confining him to a wheelchair.

Close was determined to continue painting and thought about how he could still paint with his inability to do fine detail because of his damaged nervous system.

His later paintings, like the one featured on this cover, break down images almost into perceptual units. As you move away from them, they coalesce into photorealistic images.

His paintings lose a lot when you can’t see them in their original towering sizes, so if you ever get the chance to his work ‘live’, don’t miss it.

He’s a wonderful ‘perceptual explorer’ and a wry commentator on our photo obsessed age.

Link to BBC News article on Chuck Close cover.
Link to search of his pictures (just stunning).

The 7even sins of memory

PsyBlog has just finished its series on the ‘seven sins of memory’ that fade and distort what we try to remember, based on memory researcher Dan Schacter’s book on the same name.

The ‘seven sins’ are:

1. Transience
2. Absent-Mindedness
3. Blocking
4. Misattribution
5. Suggestibility
6. Bias
7. Persistence

And PsyBlog looks at each one, discussing what research has told of us about this particularly memory difficulty and how it affects our record of things past.

If you’re interested in reading more, Schacter’s 1999 book comes highly recommended.

Link to PsyBlog on the ‘Seven Sins of Memory’.

New antidepressants all bark and no bite?

The new generation antidepressants are no better than placebo in mild-moderate depression according to a new analysis of published and unpublished trials that were submitted during the drugs’ approval.

The study is published in PLoS Medicine and despite the huge headlines it has generated, is not entirely surprising.

Psychologist Irving Kirsch, who led this new research, has conducted several previous studies looking at the effectiveness of SSRI antidepressant drugs and found similar results, although this is the first time that the study has factored in the severity of depression.

This study focused on the drugs fluoxetine (Prozac), venlafaxine (Effexor), nefazodone (Serzone), and paroxetine (Seroxat or Paxil) and used the US Freedom of Information Act to request data on (mainly) negative trials that haven’t been published to complement the data set from published trials.

In this new analysis, only in severe depression did these medications show a distinct improvement over placebo, and this, the authors suggest, is because of the reduced placebo effect in the severely depressed, rather than than the fact that the medication has a differential effect in those most affected by mood disorders.

It’s important to note that the study didn’t show that the drugs had no effect in mild-moderate depression. They were all associated with an improvement in depression, but this was no different from placebo (a powerful effect in itself).

It’s also important to note that this finding doesn’t apply to all antidepressant drugs, and that it doesn’t apply to the use of these four drugs in all situations. They are also commonly prescribed for anxiety disorders which weren’t investigated in this study.

However, this is another example of how drug companies’ attempts to obscure data from negative trials are coming back to haunt them.

The Times has one of the best write-ups but as usual, the PLoS article has a jargon-free summary included so you can get the findings from the source even if you’re not familiar with scientific writing.

UPDATE: An important clarification from PJ, taken from the comments:

I think that by saying “this was no different from placebo” you are being misleading. Strictly speaking it was statistically different from placebo but did not reach the NICE criteria for a clinically significant difference:

“a three-point difference in Hamilton Rating Scale of Depression (HRSD)scores or a standardized mean difference (d) of 0.50”

Thanks PJ!

Link to full-text of PLoS Medicine paper.
Link to Times write-up.

Psychosis and the coming glutamate revolution

Dopamine has been the big player in understanding schizophrenia since antipsychotic drugs were discovered. All current antipsychotics have their main effect by blocking dopamine function in the mesolimbic pathway and there’s now significant evidence that this is the location of one of the major dysfunctions.

It’s been clear for a while that this isn’t the whole story though. Ketamine and PCP, two glutamate-focused drugs that barely touch the dopamine system directly, are heavily linked to schizophrenia and can intensify psychotic symptoms.

Findings such as these have sparked a flurry of interest in understanding the role of glutamate in psychosis, and there’s now an intense interest in developing drugs that might target this system.

One of the key hopes is that these newer drugs will have fewer side-effects, as, in some, antipsychotics are have unpleasant and unhealthy adverse consequences.

The New York Times has just published a great article on the development of these new drugs, just in mid-testing stage, and on the neuroscience that motivates them.

People who use PCP often have the hallucinations, delusions, cognitive problems and emotional flatness that are characteristic of schizophrenia. Psychiatrists noted PCP’s side effects as early as the late 1950s. But they lacked the tools to determine how PCP affected the brain until 1979, when they found that it blocked a glutamate receptor, called the NMDA receptor, that is at the center of the transmission of nerve impulses in the brain.

The PCP finding led a few scientists to begin researching glutamate’s role in psychosis and other brain disorders. By the early 1990s, they discovered that besides triggering the primary glutamate receptors — NMDA and AMPA — glutamate also triggered several other receptors.

They called these newly found receptors “metabotropic,” because the receptors modified the amount of glutamate that cells released rather than simply turning circuits on or off. Because glutamate is so central to the brain’s activity, directly blocking or triggering the NMDA and AMPA receptors can be very dangerous. The metabotropic receptors appeared to be better targets for drug treatment.

The article talks about some of the new drugs in development, and the fact that this is where drug companies are placing their (quite substantial) bets at the moment.

Link to NYT article ‘Daring to Think Differently About Schizophrenia’.