Encephalon #3 arrives

Issue 3 of neuroscience writing carnival has just been published on Thinking Meat and contains articles on everything from whether video games desensitise us to violence to whether spindle neurons will be the next fashionable thing after ‘mirror neurons’ have lost their media sparkle.

See the complete issue for a raft of other commentaries on current mind and brain issues.

Link to Encephalon #3.

What do antidepressants do?

grey_shadow_pills.jpgThere’s a thought-provoking piece in the latest issue of open-access medical journal PLoS Medicine on whether antidepressants ‘correct’ a problem in the brain, or just create an altered state that may be useful for people with low-mood problems.

It is notable that the way psychiatric drugs are described is usually because of marketing. For example, SSRIs are classed as ‘antidepressants’, dopamine agonists and ‘antipsychotics’ and drugs like sodium valproate as ‘mood stabilizers’.

These terms have been promoted by drug companies in an effort to establish a market for particular compounds and imply that they directly affected these conditions. Often, they have been invented to replace previous labels which were no longer useful in marketing the drug.

The authors of the PLoS Medicine paper argue that trials have shown that, for example, opiates and amphetamine-like drugs can have beneficial effects in depressed patients but are not considered ‘antidepressants’.

The paper also tackles the idea that depression is ’caused by low serotonin’ in the brain and that antidepressants ‘correct’ this problem.

The low serotonin theory of depression must rank as one of the most widely known and least supported scientific theories, as there is comparatively little evidence that backs this explanation.

The authors argue that instead of trying to explain the action of a drug in terms of a disease it is meant to ‘correct’, it is more accurate to describe the drug in terms of its general actions in the brain which could be coincidentally useful in treating certain conditions.

I suspect, this is what inevitably happens anyway, owing to the needs of marketing.

Typically, when a drug is discovered, it is targeted at a condition which is likely to be profitable (depression being the classic example). At this point, it is usually marketed as an anti-something-or-other.

Later, when the profits begin to come in, the pharmaceutical company looks to widen the market and tests it on other, less prevalent, but hopefully still profitable conditions (e.g. social phobia).

For example, SSRI drugs (such as Prozac) are now indicated for depression, PTSD, obsessive-compulsive disorder, eating disorders and panic disorder to name but a few.

The marketing then begins to place less emphasis on its original label, so it is seen as more wide acting.

Have a look at the archives of the front page of the Seroquel website before and after it gained approval for the treatment of bipolar disorder and notice how the term ‘antipsychotic’ is suddenly not so prominent.

Perhaps to put the paper in context, psychiatrist Dr Joanna Moncrieff, one of the authors of the PLoS Medicine paper, is co-chair of the Critical Psychiatry Network – a group of psychiatrists who dispute the predominance of biological models of mental disorder and campaign for a less coercive psychiatry.

Link to PLoS Medicine article ‘Do Antidepressants Cure or Create Abnormal Brain States?’

Psychology Wiki on recovery from brain injury

neuron_magnified_brown.jpgThe Psychology Wiki is a wide-ranging Wikipedia-like resource that is edited by psychology professionals and students. It focuses on the mind and brain and contains a number of fantastic articles.

They’ve just announced their first ‘featured article’, an comprehensive piece on the science of Recovery from Acquired Brain Injury.

The article examines the neuroscience of brain injury and the mechanisms that support subsequent recovery. It also looks at practical steps and the experience of the recovery process.

There’s plenty more fantastic material on the wiki, and if you want to share your knowledge I’m sure they’d be pleased to have you pitch in.

Link to Psychology Wiki.
Link to article ‘Recovery from Acquired Brain Injury’.

Dennett interviewed on explaining religion

candle_black_bg.jpgABC Radio’s All in the Mind sees the return of long-time presenter Natasha Mitchell with an interview with philosopher and cognitive scientist Daniel Dennett on a scientific approach to understanding religion.

Dennett is tackled on some of the issues raised in his recent book Breaking the Spell (ISBN 0713997893) and particularly on his reliance on the controversial theory of memes to back up his arguments:

Mitchell: Many would argue that the idea of memes is a seductive idea, others would say, ‘pseudo-scientific wordplay Dan Dennett, this is no more scientific than religion’.

Dennett: Memetics has not been turned into a science yet and it may not be turned into a science, except insofar as we come to understand that if you’re going to do a scientific study of culture you have to keep the space open for cultural themes to change without being changed deliberately by anybody.

Regardless of your views on any of Dennett’s points, he is always an engaging speaker and well worth listening to.

Link to audio and transcript of All in the Mind.

Me and My Memory

oanas_face.jpgAs part of the BBC Memory Season, BBC Radio 4 are running a series of programmes on people with unique memories – either because of disorder or because of remarkable talents.

The series is called Me and My Memory and started last Wednesday.

All the programmes are archived online, and the first was on prosopagnosia – the condition where people are unable to recognise others by their faces.

In this case, the programme talks to a woman who developed prosopagnosia after viral encephalitis, a brain infection that damaged parts of the brain involved in face recognition.

Future programmes will be on developmental amnesia, a memory champion, confabulation and mild cognitive impairment.

Link to homepage for Me and My Memory series.

Mind-reading competition

brain image interpretation.jpgDon’t worry, this isn’t about telepathy and doesn’t involve Uri Gellar.

No, it’s about a team of three Italian researchers who won $10000 in a brain-activity interpretation competition organised by the University of Pittsburgh earlier this year.

Entrants were provided with the fMRI data and behavioural reports recorded when four people watched two movies. The competitors’ task was to create an algorithm that could use the viewers ongoing brain activity to predict what they were thinking and feeling as the film unfolded. The crunch test came from a third film. This time the competing researchers were shown the viewers’ brain activity only, and they had to predict the behavioural data – what the viewers had reported seeing and feeling during the film on a moment-by-moment basis. The full rules are here.

The Italians – Emanuele Olivetti, Diego Sona, and Sriharsha Veeramachaneni were the most accurate, achieving a correlation of .86 for basic features, such as whether an instant of the film contained music. The full results are here.

I heard about this from the latest Nature Neuroscience editorial. They discuss the competition in the context of the increasing trend for researchers to see if they can predict what people are thinking based on their overall brain activity (this often gets discussed in relation to lie detection), rather than the more traditional correlational/localisation approach of seeing what brain activity occurs where, when people are thinking certain things.

The Nature Neurosci. editors welcome the shift:

Neuroimaging’s obsession with localization has often led to accusations that it is little more than phrenology. By using population responses across the whole brain to ask how rather than where information is processed, neuroimaging may be starting to come of age.

Link to the competition website.

Amateur psychiatry is booming

World of Psychology has a short but interesting article on the increasing trend for people to order unprescribed psychiatric medication as a form of self-treatment or simply to get their kicks.

The trend is being fuelled by ‘no prescription’ web sites that will deliver drugs to anywhere in the world and online instructions of dubious origin.

Link to article ‘Self-medicating Online’.

Manic exhilaration

car_speed_tracers.jpgThere’s a wonderful piece in yesterday’s British Medical Journal by Raquel Duarte, a fourth year medical student at Edinburgh University, on the sheer exhilaration of being with a manic patient.

She describes the first time she interviewed a manic patient during her attachment to a psychiatric ward.

…my patient sat down in the family room of the inpatient ward, and I proceeded to obtain a full, detailed psychiatric history‚Äîor rather, I tried to. The truth is, she just talked‚Äîabout everything from art, to politics, to literature. Because of my complete inability to direct the interview, I let her carry on. “Been here almost three hours already… Damn, shouldn’t have giggled at the SHO. Never mind, I’ll just have to come back again tomorrow.” Resigned to the fact that I’d have to meet this patient many times before I could get all the relevant facts, I relaxed and was surprised to find myself enjoying all the irrelevant bits of the conversation.

We both laughed and chuckled like a couple of schoolgirls, me and this 65 year old woman, as I got caught up in her contagious joy and boundless energy. Amid deliberations on Monet and reflections on the situation in the Middle East, she told me about her experience of terrible confusion that somehow, like in a dream, makes perfect sense. I heard about her tragic losses and deep despair, about the havoc this disease can wreck on a family and about how her faith had sustained her throughout. “Mania… psychosis… depression.” She didn’t just give me a history of bipolar illness, she told me a story and took me on a journey to discover a person struggling with a disease but who, in spite of or perhaps because of it, was a whole and wonderful human being.

Unfortunately, the whole piece is not freely available available online, but for those who can access the BMJ, you can read it here.

2006-07-28 Spike activity

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


Research in PLoS Biology reports that functional connections in the brain transform experience into memory.

Some researchers still not disclosing their conflict of interest in key studies, reports AADT Blog.

BBC Radio 4 programme Leading Edge discusses body clock genes and mind reading machines.

Metapsychology has an in-depth review of Nancy Andreasan’s book on the neuroscience of genius (via 3Q).

New autism study shows differences in brain structure.

Seed Magazine reports that brain scanning research that suggests that we can process social outsiders as less than human.

Researchers identify what are possibly the first neurons in the development of the human cortex.

Nature Reviews Neuroscience has an in-depth article on molecular and genetic approaches to brain asymmetry and handedness.

The Psychiatric Times explores the link between conduct problems in adolescence and personality disorders in adulthood.

Nature vs nurture via neuroscience


For those of who you particularly enjoyed the Prospect article on the interaction between environment and genetics in promoting certain mental states and behaviours, Nature Reviews Neuroscience has an in-depth review article on how neuroscience is helping understand this complex process.

If you haven’t got time to get down and dirty with a full-on review article though, Brain Ethics has a fantastic summary that captures the main points.

Link to full text of Nature Reviews Neuroscience article.
Link to Brain Ethics article.

Reflected glory

new_hair_mirror.jpgThere have been some critical commentaries recently that suggest that the hype over mirror neurons has become unbearable and a backlash is about to begin.

Mirror neurons are cells in the brain that are active both when a person is performing an action, or when they see someone else perform an action, and have been hypothesised to be involved in perceiving and comprehending others’ actions.

Worryingly, this system has been proposed as the basis of everything from empathy to appreciation of art, with very little supporting evidence.

Both Mixing Memory and Neurotopia have sceptical commentaries on mirror neurons and doubt whether they have been consistently demonstrated in humans in anything other than correlational brain scanning experiments.

This is probably a little unfair, as evidence for ‘mirror neurons’ in humans has been found using subdural (brain surface) electrodes, transcranial magnetic stimulation, fMRI, magnetoencephalography, EEG and when studying patients with action production and recognition problems after brain injury.

That’s quite a lot of converging evidence for the existence of an equivalent human system.

What is a little misleading is that the original studies measured the responses of single neurons in monkeys, whereby the human studies have all been using techniques that measured activation from a group of neurons.

This, and the fact that the recognition and generation of actions also relies on other brain areas, has led some to use the more accurate term ‘mirror system’ in preference to ‘mirror neuron’.

What most of the recent articles seem to be criticising, however, is that the concept is being used as a convenient ‘just so’ story for explaining almost any sort of complex human behaviour, usually by people with a fairly poor grasp of the existing evidence.

It’s easy to see why the idea is attractive. A system that is both involved in producing our own movements and becomes active when we see others moving leads some to infer (perhaps falsely) that we encode others’ behaviour into our brains in quite a direct way.

Even worse, in some retellings of the story, behaviour can include almost anything you care to think of.

As noted by Frontal Cortex, this concept, although flawed, is easy to grasp and user-friendly, making almost anyone an instant ‘expert’ on how the brain supports human interaction.

The reality will probably turn out to have too many qualifications to allow the media obsession with mirror neurons to continue forever, but in the mean time, don’t get put off by the hype.

The findings are fascinating and the mirror system will surely play an important role in our future understanding of human neuropsychology, even if this won’t exactly match how the media portrays it the moment.

Link to Mixing Memory article.
Link to Neurotopia article.

The intelligent environment

school_student.jpgContinuing our IQ theme, the New York Times has a fascinating article on the contributions of genetics and environment to IQ and argues that the effect of the environment becomes much more crucial for those from low-income backgrounds.

[Psychologist Eric Turkheimer] has a reputation as a methodologist’s methodologist. In combing through the research, he noticed that the twins being studied had middle-class backgrounds. The explanation was simple – poor people don’t volunteer for research projects – but he wondered whether this omission mattered.

Together with several colleagues, Turkheimer searched for data on twins from a wider range of families. He found what he needed in a sample from the 1970’s of more than 50,000 American infants, many from poor families, who had taken I.Q. tests at age 7. In a widely-discussed 2003 article [pdf], he found that, as anticipated, virtually all the variation in I.Q. scores for twins in the sample with wealthy parents can be attributed to genetics. The big surprise is among the poorest families. Contrary to what you might expect, for those children, the I.Q.’s of identical twins vary just as much as the I.Q.’s of fraternal twins. The impact of growing up impoverished overwhelms these children’s genetic capacities. In other words, home life is the critical factor for youngsters at the bottom of the economic barrel. “If you have a chaotic environment, kids’ genetic potential doesn’t have a chance to be expressed,” Turkheimer explains. “Well-off families can provide the mental stimulation needed for genes to build the brain circuitry for intelligence.”

This interaction between economic background and mental functioning has now been replicated in a number of studies looking at everything from mental illness to criminal behaviour (e.g. see Christian’s previous post).

It seems that the simple summing of genetic and environmental effects is no longer a valid way of understanding how we develop, as the duration, quality and frequency of different life experiences seem to have unique influences on the expression of our inherited traits.

Link to New York Times article ‘After the Bell Curve.
pdf of Turkheimer’s paper.

Born to be bad?

criminal personality.jpgThe latest issue of Prospect magazine features a fresh in-depth analysis of whether there is such a thing as a criminal personality. The author David Rose of the Observer notes that contemporary politicans have tended to focus on the social causes of criminality – think of Blair’s ‘tough on the causes of crime’ speech. But he points to new research showing that genetic factors are also key, in particular he highlights research by Terrie Moffitt and colleagues at the Institute of Psychiatry, including a study showing that whether childhood maltreatment leads to later increased risk of criminality depends in part on the variant of the MAOA gene that a person has. The gene codes for the enzyme monoamine oxidase A, and is involved in the regulation of neurotransmitter levels. A person with a low activity variant of this gene who is maltreated is far more likely to develop antisocial behaviour.

Link to Prospect article (open access).
Link to the Dunedin Study.

Happiness is an impossible dream

adam_phillips_guardian_pic.jpgPsychoanalyst Adam Phillips is interviewed in The Guardian about the paradox of chasing happiness and the negative effects of emotional idealism.

Phillips argues that trying to eliminate all sources of stress in your life is a pointless exercise and we should become better at tolerating difficult situations if we are to be become fully content.

I tell Phillips that at my workstation books with the word happiness in the title arrive unbidden by the hour. They include: Daniel Gilbert’s Stumbling on Happiness, Richard Schoch’s The Secrets of Happiness, Darrin McMahon’s The Pursuit of Happiness, Richard Layard’s Happiness: Lessons from a New Science and Jonathan Haidt’s The Happiness Hypothesis. Do you read these books? “I’ve looked at them. They seem to me to be the problem rather than the solution.”

Phillips also gives his take on the current focus on CBT as the psychological therapy of choice and the use of psychoanalysis as a long-term therapy for people with socially turbulent modern lives.

Link to article ‘Happiness is always a delusion’.

The Flynn effect is reversing

rubix_cube_solved.jpgAmerican Scientist discusses the trend for changes in how well people score on intelligence tests and notes that the Flynn effect, whereby the population has been scoring increasingly well on intelligence tests over time, seems to be slowing down or reversing in some places.

It is well-known is psychology that performance on cognitive tests changes over time and across populations, which is why the most widely used tests (particularly the Wechsler series) have different versions for different countries, and are re-released every few years with new comparison data.

An IQ score is always relative to the average performance of the rest of the population, so an IQ of 100 always means you score the same as the average of the population on a current test.

As new tests are released, this average may shift, so it is difficult to directly compare IQ results from previous versions of a test.

On old tests, however, it was noticed by Flynn that people were scoring better by about 3 points per decade. The American Scientist article notes that this effect is starting to slow down or reverse in some places though.

Does this mean we’re becoming less intelligent? Probably not. It likely reflects the fact that the skill set of population is changing and that we become practiced at different tasks at different rates as modern life develops.

As an aside, IQ tests considered trustworthy by psychologists rarely go above 160, so anyone quoting a 160+ IQ is likely to be talking nonsense.

Link to article ‘Smart as We Can Get?’.
Link to Wikipedia article on the Flynn effect.

The science and culture of hallucinated voices

hearing_phrenology.jpgThis week’s ABC Radio All in the Mind had an edition on auditory hallucinations that discusses the experience of ‘hearing voices’ as well as the neuroscience that might explain them.

Hallucinatory voices are still largely mysterious to science. Originally they were linked to psychotic mental illness and particularly schizophrenia, but it later became known that only about 30% of people who hear voices ever become psychiatric patients.

Furthermore, for some people who hear voices, they can seem to exist as separate conscious entities with their own personalities. Someone may experience a number of voices each with a distinct age, sex and accent.

Research has suggested some explanations for why voices occur (it is know that the auditory cortex is activated with hallucinated voices are heard, suggesting that they may be internal thoughts experienced as sound) but many of these other issues are still unresolved.

The programme discusses the current state of research, as well as talking to two voice hearers about the experience itself, including campaigner Ron Coleman who has been particularly active within the Hearing Voices Network.

The network has taken an alternative view to the medical model, which assumes that voices are a symptom of mental disturbance, and encourages hearers to understand their voices in whatever way best promotes successful living.

Link to ABC Radio All in the Mind on hearing voices.
Link to Wikipedia article on hearing voices movement.