vaughanbell

Does your neighbourhood cause schizophrenia?

The results of two new studies suggest that the neighbourhood you live in affects your chance of developing schizophrenia. Surprisingly, neighbourhood seems to have no effect on your risk of bipolar disorder.

The received wisdom says that schizophrenia affects 1% of the population worldwide, with little variation between race, country and area.

The trouble is, the received wisdom is wrong. We now know that the prevalence (total amount of cases) and incidence (amount of new cases per year) varies globally, nationally and locally.

These two new studies, led by Dr James Kirkbride, investigated whether street-by-street differences also have an effect.

The research team examined every person who was treated by mental health services in South East London for a first episode of psychosis over a two-year period.

Psychosis involves delusions and hallucinations and most often leads to a diagnosis of schizophrenia or bipolar disorder, bipolar being most associated with mood problems such as soaring highs followed by crashing lows.

South East London is notable for many things, not all of them positive. It’s a high poverty, high crime, highly urbanised inner-city area.

We know that one of the single largest environmental risk factors for schizophrenia is living in an urban area, and, unsurprisingly, this corner of the UK’s captial has one of the highest rates of psychosis in the world.

The team looked at all the areas, and, controlling for the effects of age, sex and ethnicity, used statistics to test whether any differences between areas were likely to due to chance, or whether they varied enough to be confident that the critical influence was the neighbourhood.

The map on the left shows the variation between neighbourhoods. If you know South East London, click on the map to see how it relates to specific areas.

You”ll notice that the toughest, poorest areas tend to have a higher rate of schizophrenia. In comparison, the rates for bipolar disorder were largely the same wherever the team looked.

Even if you don’t know the area at all, the amount of neighbourhood variation is quite startling. In some cases, moving just a few streets could dramatically affect your mental health.

In a second study, the team looked at characteristics of the area to try and see what risk was linked to.

Some main influences stood out: poverty, ethnic fragmentation, and, surprisingly, local election voter turnout.

In fact, a 1% increase in the number of voters in local elections was linked to a 5% reduction in new cases of schizophrenia.

Voter turnout itself is hardly likely to affect mental health, but the researchers suggest it might reflect the sense of community in the neighbourhood: the more you’re concerned about your neighbourhood the more likely you are to vote on issues affecting the area.

Ethnic fragmentation is a measure of how many people of your ethnic background live in your neighbourhood.

Immigrants are known to be at greater risk of schizophrenia than other people in the country, and South East London has a large immigrant population.

This might mean that contact with a community of people who share your cultural experiences may be protective against mental illness, perhaps again suggesting that ‘community spirit’ is key for mental health.

So why do all these things affect schizophrenia and not bipolar disorder? The researchers don’t discuss it in detail probably because it’s a bit puzzling.

The truth, of course, is just outside the front door.

Link to abstract of ‘Neighbourhood variation in the incidence of psychotic disorders in Southeast London’.

Link to abstract of ‘Neighbourhood-level effects on psychoses: re-examining the role of context’.

Striking perspective shift illusion

I’ve just stumbled across a remarkably simple yet fiendishly effective visual illusion that seems to give flat images the illusions of 3D depth. It works by quickly shifting between two images of the same scene taken from slightly different perspectives.

As we’ve noted when discussing other illusions, our brain generates the experience of seeing a 3D world by making the best it can out of the two fairly poor quality flat images that fall on the back of the retina.

Visual illusions usually have their effect by taking advantage of the brain’s processes for inferring visual features.

These processes are really nothing more than educated guesses, and illusions essentially give the brain red herrings, misleading it to guess in the wrong direction, so we experience one visual feature in a context where it wouldn’t normally appear.

In this case, the illusions give the misleading impression of depth in the context of an entirely flat image.

One clue the brain uses to infer depth is occlusion – things that are near the front of a visual scene will block those at the back. They just get in the way.

In fact, the lines in cartoons or diagrams are often just a representation of the occlusion contours – the edges of where one surface hide another.

However, although we can see that a cartoon drawing of a head is a 3D representation, we don’t experience it as actually having depth. It doesn’t seem to stand out from the page.

The perspective shift illusion flips between two images taken from slightly different perspectives and this seems to add a dynamic aspect – the illusion of movement.

Movement is often crucial for determing something’s depth. Have you ever moved your head side-to-side when you see a puzzling sculpture to try and better understand its shape?

This allows us to see the relative depth of each of the occlusion contours by experiencing how much the foreground moves in relation to the background. Things nearer the front seem to ‘move quicker’ – something known as motion parallax.

I’m guessing by adding an impression of movement – some motion parallax – to a detailed photograph that already has other depth cues from the natural environment, the perspective shift illusion produces an impression of real depth.

If you want to know more about the cognitive science of 3D shape perception, there’s a great review article by available Dr James Todd available online as a pdf file.

Otherwise, just spend a few minutes checking out the impressive visual effect.

Link to perspective shift visual illusion.

Duped: Brain scan lie detection

There’s been quite a bit in the news recently about ‘brain scan lie detection’, but The New Yorker magazine have just published possibly the best article I’ve read so far on this intriguing but still-not-very-accurate technology.

It not only looks at the current technology, but also explores the dubious history of lie detection technology from times past.

The article is also remarkably well researched and level-headed, a balance that many stories about the technology sorely lack.

It points out some of the drawbacks of the technology, and some of frankly bizarre pitches being made by commercial companies.

One company recommends brain scans to help with “risk reduction in dating” and “trust issues in interpersonal relationships”!

Don’t get me wrong, people with brain scanners are sexy, but as with many things in life, it’s not what you have but what you do with it. Being shoved in a ‘fMRI lie detector’ by a potential lover would be a definite turn off.

The article is delightfully wide-ranging and talks to plenty of senior psychologists about their views on the technology and why we’re so attracted to brain scan evidence despite its drawbacks.

Really, an excellent piece. Well done New Yorker.

Link to New Yorker article ‘Duped: Can brain scans uncover lies?’.

Dreaming of the dead

The New York Times has an eye-opening article on research that has looked at how contents of dreams can be linked to emotional concerns – particularly when they relate to lost loved ones or turbulent life events.

‘Dream interpretation’ has got a bad name, partly due to the proliferation of books that claim to ‘decode’ dreams on a seemingly random basis (e.g. lemon = unrequited love), and partly because of its importance in the history of Freudian psychotherapy, which is now deeply unfashionable in some quarters.

Unfortunately, this has meant that research on the content of dreams has also fallen out of favour, despite the fact that it remains an interesting scientific topic and is still of clinical concern.

Modern psychotherapists will occasionally get into discussions about dreams, but, these days, will tend to avoid a strictly Freudian approach of trying to ‘interpret’ them.

Instead, they might use them as a point of discussion to make sense of real life concerns.

For example, if you’ve been particularly disturbed by a dream about work, it might be an opportunity to reflect on how you’ve been dealing with work-related stress, particularly if your reaction to the dream was quite a surprise in itself.

The NYT article looks research on the content of dreams, particularly ‘big dreams’: those of a more profound nature, often concerning deaths or other significant losses.

“Back to life” or “visitation” dreams, as they are known among dream specialists and psychologists, are vivid and memorable dreams of the dead. They are a particularly potent form of what Carl Jung called “big dreams,” the emotionally vibrant ones we remember for the rest of our lives.

Big dreams are once again on the minds of psychologists as part of a larger trend toward studying dreams as meaningful representations of our concerns and emotions. “Big dreams are transformative,” Roger Knudson, director of the Ph.D. program in clinical psychology at Miami University of Ohio, said in a telephone interview. The dreaming imagination does not just harvest images from remembered experience, he said. It has a “poetic creativity” that connects the dots and “deforms the given,” turning scattered memories and emotions into vivid, experiential vignettes that can help us to reflect on our lives.

Link to article ‘Winding Through ‚ÄòBig Dreams‚Äô Are the Threads of Our Lives’.

Best of the Brain

A book called Best of the Brain from Scientific American (ISBN 1932594221) turned up unannounced the other day, and so far, I’m very impressed with it.

It’s a collection of twenty one of the most notable mind and brain articles from past issues of SciAm collected in a single volume.

I feel a bit reticent about waxing lyrical about a free book I’ve been sent, but I have to admit, I quite a fan of SciAm and SciAmMind, not least because they always make two feature articles from every issue freely available online which allows you judge the quality for yourself.

In fact, several of the articles from the book have already been made available online:

The Addicted Brain

Unleashing Creativity

Decoding Schizophrenia

Treating Depression: Pills or Talk

Controlling Robots with the Mind

Thinking Out Loud

Unfortunately, it doesn’t seem if the book’s a table of contents is online, as you could get a better idea of the diversity of topics that are covered.

Essentially, if you’re a fan of SciAm psychology and neuroscience writing, you’ll probably like this book. It’s really a greatest hits collection.

As this is the first unsolicited book I’ve been sent, a couple of clarifications. Readers: I’ll always say if a book I mention has been sent to me for free. Publishers: I won’t mention your book just because you’ve sent it to me.

Link to more info on the book.

Drug reduces the impact of traumatic memories

BBC News has a story with the headline ‘scientists can erase bad memories’, which is, at best, nonsense. What has been found is still an important discovery: a drug given during the recall of a traumatic memory can reduce its long-term emotional impact.

The drug is propranolol, a ‘beta-blocker’ that dampens down the sympathetic nervous system.

One of the roles of this system is to prepare the body for ‘flight or flight’ during stressful situations, by, among other things, releasing adrenaline, increasing blood pressure, and upping anxiety.

The drug has been used for years to help people with high blood pressure and heart conditions, so when they get stressed, it doesn’t put such a strain on their heart.

It’s been known for a while that starting a course of propranolol shortly after a traumatic event reduces the chance of people developing post-traumatic stress disorder – a condition that involves intrusive traumatic memories and hyper-arousal.

This new study is important, because it recruited people who had been traumatised a long time ago – an average of ten years earlier.

The participants were asked to recall what happened. Half were given propranolol and half were given placebo.

A week later, the participants were asked to recall the same memory while the researchers measured heart rate, sweating and muscle tension in the face – all of which are measures of bodily stress.

The participants who had been given the propranolol showed significantly less arousal than those who were given the placebo, suggesting the emotional impact of the memories had been reduced.

The fact that this can have an effect ten years after the event, if used when the memory is recalled, is an interesting finding.

Memory is a reconstructive process – in other words, our brain recreates the best estimation of an event each time we recall it. This might be slightly different each time and, importantly, each time we recall something the ‘store’ of information is changed.

It would be like if a CD remembered the other sounds in the room each time it was played, and included some of them when you listened to it again.

Propranolol might work by reducing the stress associated with the memory by influencing the ‘rewriting’ process.

The study is only a clue though. What it didn’t show is that this selectively reduced the arousal associated with that memory (maybe it affected other traumatic memories which weren’t recalled) and there was no group who were only given the drug and weren’t asked to recall anything.

It’s unlikely that the drug can reduce traumatic memories if just given at any time, but its something that needs to be explored to be sure we know how the treatment is working.

UPDATE: The Beeb have changed their headline to the slightly more sensible ‘Drug can dampen down bad memories’.

Link to abstract of scientific paper.

Swarm intelligence and group synchronicity

National Geographic has just published an article on swarm behaviour in animals and how this is being applied to understanding human behaviour and improving complex systems.

The article looks at how whole groups of animals seem to have intelligence, while individually they only seem to be able to perform very simple actions.

One of the big discoveries in this area is that complex problem solving behaviours can emerge from a group of individuals who each follow simple rules.

The article also mentions Craig Reynolds, a computer scientist who has been working on computer simulations of flocking behaviour.

He has a fantastic page with animated demonstrations and explanations of his work if you want to see how it all fits together.

This technology was used to simulate flocks in Hollywood movies like Batman Begins but is also being used by everyone from the military to internet technology companies in an attempt to develop distributed but efficient problem solving systems.

Link to National Geographic article ‘Swarm theory’.
Link to Craig Reynolds ‘boids’ page.

Neuropsychology of hypnosis at Dublin science cafe

I shall be giving a talk at the Dublin science cafe on Thursday 12th July on the neuropsychology of hypnosis. Come along if you’re in the area and would like to join the discussion.

The talk will happen at The Mercantile on Dame Street. We’ll kick off at 7.45pm, it’s free to attend and everyone is welcome.

I’m relatively new to hypnosis research, having started working with a research team investigating the psychology and neuroscience of hypnotisability about a year ago, but am completely fascinated by this intriguing process.

Susceptibility to hypnosis differs between individuals, is stable across the lifespan, and is known to be partly inherited and has been linked to a specific dopamine modulating gene. In addition, structural and functional brain differences have also been found between people who differ in hypnotic suggestibility.

As well as discovering more about the intriguing process of hypnosis, this sort of research is helping us make sense of poorly understood disorders such as conversion disorder – where patients might experience paralysis despite having no detectable physical problems.

For example, one study found that similar brain areas are involved in paralysis linked to conversion disorder, and paralysis caused by hypnosis, perhaps indicating that suggestion plays a powerful role in conversion disorder syndromes.

Other studies have used hypnosis to investigate brain areas linked to experiences of external control in psychosis, pain relief and control of attention in healthy individuals.

I’ll be looking at some of these areas, and others, in the talk, but if you can’t make it, Dr Matt Whalley’s website on the science of hypnosis is probably the single best resource on the net.

Link to talk details.
Link to Dr Matt Whalley’s Hypnosis and Suggestion site.

Encephalon 26 – one year birthday

Issue 26 of psychology and neuroscience writing carnival Encephalon has just been published on the Neurophilosophy blog, returning to where it first started for its first anniversary.

It also coincides with the blog joining the ScienceBlogs fraternity and what better way to celebrate its new home.

A couple of my favourites include an 1880 article from The New York Times which claims that the right hemisphere of the brain is less developed than the left because babies tend to squash the brain by sleeping on their right sides, and one on the recent publication of the ‘cognitive health roadmap‘.

There’s a whole range of other articles, so check it out to see what else is on the menu.

Link to Encephalon 26.

Unconscious inspiration

I’ve just found an article from The Psychologist that examines historical accounts of sometimes world-changing ideas which have seemed to arrive during sleep or dreaming.

The article looks at inspirational slumber which has inspired everything from sewing machine designs to the theory of relativity.

The author, psychologist Josephine Ross, has discovered some great examples. My favourite being from horror writer Stephen King on how the plot for his novel Misery came to him when he fell asleep on a plane.

Ross notes that people’s own insight into whether the dream was genuinely the inspiration may not be entirely accurate.

They may just have been ‘incubating’ the idea (having it ‘at the back of the mind’) and because we sleep so often, it might be easy to attribute it to last night’s dreaming.

However, a study published in Nature in 2004 suggested that sleep might genuinely help in problem solving.

The researchers found that volunteers asked to complete maths problems were three times more likely than sleep-deprived participants to figure out a hidden rule for solving the problem if they had eight hours of sleep.

Link to Psychologist article ‘Sleep on a problem… it works like a dream’.

Psychologists accused of Geneva violations

Salon claims to have uncovered evidence that two psychologists have been involved in developing military and CIA interrogation techniques “which likely violated the Geneva Conventions on the treatment of prisoners”.

The online magazine has been investigating the role of psychologists in ‘war-on-terror’ interrogations for some time.

Last year they broke the story that the American Psychological Association endorsed the participation of psychologists in military interrogations when American medical associations had explicitly banned their members from taking part as they considered it against their ethical code.

The article caused a storm of controversy among psychologists, not least because the committee that drafted the guidelines had a majority of members with direct ties to the military.

Despite protests from members, the APA still fell short of bringing their code of conduct in line with their medical colleagues, although they did require their members to intervene and report abusive practices.

Now, Salon claim that two psychologists have been involved in a joint US military / CIA project to develop potentially abusive interrogation techniques by ‘reverse engineering’ a training programme to help special forces troops resist abusive interrogations.

There is growing evidence of high-level coordination between the Central Intelligence Agency and the U.S. military in developing abusive interrogation techniques used on terrorist suspects. After the Sept. 11 attacks, both turned to a small cadre of psychologists linked to the military’s secretive Survival, Evasion, Resistance and Escape program to “reverse-engineer” techniques originally designed to train U.S. soldiers to resist torture if captured, by exposing them to brutal treatment. The military’s use of SERE training for interrogations in the war on terror was revealed in detail in a recently declassified report. But the CIA’s use of such tactics — working in close coordination with the military — until now has remained largely unknown.

Furthermore, APA members have now written an open letter claiming that another psychologist has been involved in similar practices.

If the accusations turn out to be true, it makes for truly grim reading for a profession that usually prides itself on its ethical standards and robust code of conduct.

Link to Salon article ‘The CIA’s torture teachers’.

Shapes of thought

Neurofuture has picked up on a fantastic science-art project that is creating beautiful ‘thought images’ by visualising EEG readings in 3D.

The project is part of the Einstein’s Brain collaboration which involved two artists, Alan Dunning and Paul Woodrow, and medical researcher Morley Hollenberg.

The image on the left is the visualisation of anger. The image is described:

The shape of anger. Hypnotised participant’s thought form emerges as she recalls an incident in which she became uncontrollably angry. In this visualisation the elements are separated to show background of beta activity from 15 to 25 Hz from which emerges a dynamic form generated by wild swings between beta and alpha activity in the range 4 – 30 Hz, as she oscillated between meditative recall and consciousness.

Link to Neurofuture on the project.
Link to more ‘Shapes of Thought’.

The Brain That Wouldn’t Die!

The classic 1960’s B-movie The Brain That Wouldn’t Die has fallen into the public domain and is now available to download or to watch online.

It’s another classic story of boy meets girl, boy loses girl in terrible car crash, boy keeps girl’s head alive in neuroscience lab while looking for attractive new body.

Needless to say, it all ends in tears, but not before a journey that takes us from the lab, to a cat fight in a strip bar, and back again.

All in the best possible B-movie taste of course with some er… ‘unique’ dialogue that should give any experimental scientist cause for thought:

“The paths of experimentation twist and turn through mountains of miscalculations and often lose themselves in error and darkness!”

Wise words indeed.

Link to download from the Internet Archive.
Link to stream from Google Video.

Inside the psychotic world of Grand Theft Auto

A brief article published in the Journal of the Royal Society of Medicine in 2001 reported the case of a young man who suffered delusions that he was a player inside a computer game.

The game isn’t mentioned by name, but it seems to be Grand Theft Auto.

The authors of the case study point out that they’re not suggesting that computer games cause psychosis, but they comment on how it’s a somewhat unusual illustration of how ideas from a person’s life get incorporated into the themes of psychosis.

A young man was admitted from prison to a psychiatric facility after reports that he had been acting in a bizarre manner. He had been arrested for stealing motor vehicles and assaults with weapons. At interview he was found to be experiencing the delusion that he was a player inside a computer game (adult-certificate game, widely available) in which points are scored for stealing cars, killing assailants and avoiding police vehicles.

Psychotic symptoms had emerged slowly over two years. His family had noticed him becoming increasingly withdrawn and isolated from social activities. He developed delusions that strangers were planning to kill him and also experienced auditory hallucinations, constantly hearing an abusive and derogatory voice. Previously a computer enthusiast, he began to play computer games incessantly. He felt that the games were communicating with him via the headphones.

In a complex delusional system he came to believe he was inside one of these games and had to steal a car to start scoring points. He broke into a car and drove off at speed, believing he had `invulnerable’ fuel and so could not run out of petrol. To gain points he chose to steal increasingly powerful vehicles, threatening and assaulting the owners with weapons. Later he said he would have had no regrets if he had killed someone, since this would have increased his score.

After arrest and while in prison he continued to believe he was in the game, despite initial medication. When he was admitted to hospital six weeks later, part of ward management was to deny him access to computer games. Nothing abnormal was found on physical examination, blood investigations, drug screen, electroencephalography or a computed tomographic brain scan. Paranoid schizophrenia was diagnosed and he responded well to further treatment with antipsychotic medication.

Similarly, ‘rock and roll delusions’ have occasionally been reported in the medical literature (David Bowie seems to be a favourite).

Link to JRSM full-text article ‘Computer Game Delusions’.

Can’t compute the wood for the trees

Computer scientist David Gelernter has written an in-depth article for Technology Review where he criticises the possibility of creating artificial consciousness, but has high hopes for unconscious artificial intelligence.

My case for the near-impossibility of conscious software minds resembles what others have said. But these are minority views. Most AI researchers and philosophers believe that conscious software minds are just around the corner. To use the standard term, most are “cognitivists.” Only a few are “anticognitivists.” I am one. In fact, I believe that the cognitivists are even wronger than their opponents usually say.

But my goal is not to suggest that AI is a failure. It has merely developed a temporary blind spot. My fellow anticognitivists have knocked down cognitivism but have done little to replace it with new ideas. They’ve showed us what we can’t achieve (conscious software intelligence) but not how we can create something less dramatic but nonetheless highly valuable: unconscious software intelligence. Once AI has refocused its efforts on the mechanisms (or algorithms) of thought, it is bound to move forward again.

Gelernter is a a great writer and an interesting guy, not least because of his brush with death, courtesy of disturbed anti-technologist Ted Kaczynski aka ‘The Unabomber’.

Link to TechReview article ‘Artificial Intelligence Is Lost in the Woods’.

2007-06-29 Spike activity

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

Couple of good radio shows on philosophy: In Our Time on the history of ‘common sense philosophy’ and The Philosopher’s Zone has a special on the late Richard Rorty.

When do children think wishes can come true? Mixing Memory examines a psychology study that aimed to find out.

Scientific American investigates the neuroscience of irrationality and economic decision-making.

New Hitachi ‘brain-machine interface’ uses infrared light to read brain activity.

Prospect Magazine has a short article on the psychology of suicide bombers.

Experts say video games are not an addiction. Pope still catholic.

Why do we find it harder to recognise faces of other races than our own? Cognitive Daily looks at the influence of experience.

Supporters of ‘child bipolar disorder’ champion write to the Boston Herald with a strong defence of his work.

New Scientist covers a virtual world that can be explored through the power of thought (with video).

Wired looks at some of the revelations about behavioural control studies from recently de-classified CIA documents.

When brain damage helps. Developing Intelligence looks at a study that found that patients with frontal lobe damage actually do better on some reasoning tasks.

If there such a thing as photographic memory? Scientific American ‘asks the expert’.

The excellent NYC radio show RadioLab has a <a href="http://www.wnyc.org/shows/radiolab/episodes/2007/06/08
“>special on Memory and Forgetting, featuring a well-known science blogger.