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’.