A multitude of phantoms

A fascinating paper in the neuroscience journal Brain looks at artistic depictions of phantom limbs – the feeling of the physical presence of a limb after it has been damaged or removed – and gives a wonderful insight how the brain perceives non-functioning or non-existent body parts.

In fact, most people who have a limb amputated will experience a phantom limb, although they often fade over time.

However, the feeling is usually not an exact representation of how the actual limb felt before it was removed, but can involve curious and sometimes painful ‘distortions’ in its perceived physical size, shape or location.

The Brain article looks at the diversity of phantom limb ‘shapes’ through their visual depictions.

The image on the left is from a 1952 case report where an amputation involved a ‘Krukenberg procedure‘.

This operation is rarely performed in the modern world but it involves the surgeon splitting the stump to allow pincer movements – and in this case it left the patient with the feeling of divided phantom hand.

In other cases, without any out-of-the-ordinary surgical procedure, patients can be left with a phantom that feels like the middle parts of their limb are missing while they still experience sensations in phantom extremities.

The drawing on the right was completed by a patient in a medical case study to illustrate their experience of a post-arm-amputation phantom limb.

In this case, the person experienced the feeling of a phantom hand on their shoulder stump, but had no experience of an intervening phantom arm.

While phantom limbs are usually associated with amputations, the phenomenon is actually caused by the mismatch between the lack of sensory input from the limb and the fact that the brain’s somatosensory map of the body is still intact and trying to generation sensations.

This means that any sensory disconnection, perhaps through nerve or spinal damage, can cause the experience of a phantom limb, even if the actual limbs are still there.

In the drawing on the left, a patient who suffered spinal damage that caused a loss of sensation in their limbs, illustrated how their phantom legs felt.

Although their own legs were completely ‘numb’ the phantom legs felt like they were bent at the knee, regardless of where their actual legs were positioned.

Normally, feedback from real world actions and sensations keeps the somatosensory map tied to the genuine size and shape of the body, but these sensations can begin to generate distorted sensations when this connection is broken through damage.

However, the stability of our experience of body size, shape and position is remarkably flexible in everyone as the rubber hand illusion shows.

Link to locked Brain article on depictions of phantom limbs.

The most accurate psychopaths in cinema

The most accurately depicted psychopaths in cinema have been identified by a study that has just been published in the Journal of Forensic Sciences.

The study specifically excluded films that weren’t intended to be realistic (involving magical powers, fantasy settings and so on) but still examined 126 characters from 20th and 21st century movies.

It’s worth noting that the clinical definition of psychopathy is not what most people think – it’s not necessarily someone who is a knife wielding maniac – but suggests someone who has poor empathy, little remorse, and is impulsive and manipulative.

Needless to say, psychopathy is more common in people who are persistently violent, but you don’t need to be violent to be a psychopath.

After conducting the analysis the authors note which films they feel have most accurately captured the characteristics of the psychopath.

Among the most interesting recent and most realistic idiopathic psychopathic characters is Anton Chigurh in the 2007 Coen brothers’ film, No Country for Old Men. Anton Chigurh is a well-designed prototypical idiopathic / primary psychopath. We lack information concerning his childhood, but there are sufficient arguments and detailed information about his behavior in the film to obtain a diagnosis of active, primary, idiopathic psychopathy, incapacity for love, absence of shame or remorse, lack of psychological insight, inability to learn from past experience, cold-blooded attitude, ruthlessness, total determination, and lack of empathy. He seems to be affectively invulnerable and resistant to any form of emotion or humanity. Having read and studied [serial killer] Richard Kuklinski’s case, Chigurh and Kuklinski have several traits in common. In the case of Chigurh, the description is extreme, but we could realistically almost talk about “an anti-human personality disorder”.

Another realistic interesting example is Henry (inspired from [real life serial killer] Henry Lee Lucas) (Henry-Portrait of a Serial Killer, 1991). In this film, the main, interesting theme is the chaos and instability in the life of the psychopath, Henry’s lack of insight, a powerful lack of empathy, emotional poverty, and a well-illustrated failure to plan ahead. George Harvey is another different and interesting character found in The Lovely Bones, 2009. Harvey is more ‘adapted’ than Chigurh and Henry. He has a house, is socially competent and seems like ‘the average man on the street’. Through the film, we learn that he is in fact an organized paraphilic SVP [sexually violent predator]. Here, the false self is well illustrated.

In terms of a ‘successful psychopath’, Gordon Gekko from Wall Street (1987) is probably one of the most interesting, manipulative, psychopathic fictional characters to date. Manipulative psychopathic characters are increasingly appearing in films and series. Again, we observe the same process, as observed and explained before, with antisocial psychopaths. For the past few years, with the world economic crises and some high-profile trials (such as the Bernard Madoff trial), the attention of the clinicians is more focused on ‘successful psychopaths’, also called corporate psychopaths by Babiak et al. Films and series presenting characters such as brokers, dishonest traders, vicious lawyers, and those engaged in corporate espionage are emerging (e.g., Mad Men, The Wire) and are generally related to the global economy and international business. Again, we see a strong parallelism between what happens in our society and what happens in film.

The paper also has a short section on the how the movies portray psychopathatic mental health professionals, which were apparently more common in cinema from the 1980s.

It describes how psychiatrist Hannibal Lecter is an ‘extraordinarily astute clinician’ who can diagnose Agent Starling’s psychological conflicts by identifying her perfume and assessing her shoes and clothing, while also being invulnerable.

They authors dryly note that these seem to be abilities “that are not generally found in everyday clinical practice”.

Link to locked study in Journal of Forensic Sciences.

2013-12-27 Spike activity

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

Mother Jones reports on a new study finding that political beliefs interfere with logical reasoning.

Space in the brain: how the hippocampal formation supports spatial cognition. Excellent video introduction to Royal Society special edition.

The New York Times discusses the science of depression and what we still need to acheive.

The Inaccuracy of National Character Stereotypes. Neuroskeptic covers a wonderful study. British people apparently not universally humorous, dashingly good looking and modest.

The Brain Bank blog collects the best neuroscience images of 2013 for your viewing pleasure.

Remember that neurosurgeon who had a near death experience and claimed he had proved the existence of heaven? OK, Mind Hacks readers probably don’t but lots of other folks will. Esquire has an in-depth expose on him. That heaven thing was apparently unlikely.

Cracking the Enigma discusses the latest research on autism and asks whether ‘autistic brains’ are under- or over-connected.

The mysterious nodding syndrome – a crack of light

Two years ago we discussed a puzzling, sometimes fatal, ‘nodding syndrome‘ that has been affecting children in Uganda and South Sudan. We now know a little more, with epilepsy being confirmed as part of the disorder, although the cause still remains a mystery.

The condition affects children between 5 and 15 years old, who have episodes where they begin nodding or lolling their heads, often in response to cold. A typical but not exclusive pattern is that over time they become cognitively impaired to the point of needing help with simple tasks like feeding. Stunted growth is common.

Global Health News have a video on the condition if you want to see how it affects people.

In terms of our medical understanding, a review article just published in Emerging Infectious Diseases collates what we now know about the condition.

Firstly, it is now clear that epilepsy is part of the picture and the nodding is caused by recurrent seizures in the brain. This is a bit curious because this type of very specific ‘nodding’ behaviour has not been seen as a common effect of epilepsy before.

Also, knowing that it is caused by a seizure just pushes the need for explanation further down the causal chain. Seizures can occur through many different forms of brain disruption, so the question becomes – what is causing this epidemic form of seizure that seems to have a very selective effect?

With this in mind, a lot of the most obvious candidates have been ruled out. The following is from the review article, but if you’re not up on your medical terms, essentially, tests for a lot of poisons or infections have come up negative:

Testing has failed to demonstrate associations with trypanosomiasis, cysticercosis, loiasis, lymphatic filariasis, cerebral malaria, measles, prion disease, or novel pathogens; or deficiencies of folate, cobalamin, pyridoxine, retinol, or zinc; or toxicity from mercury, copper, or homocysteine.

Brain scans have been inconclusive with some showing minor abnormalities while others seem to show no detectable damage.

There have been some curious but not conclusive associations, however. Children with the nodding syndrome are more likely to have signs of infection by the river blindness parasite. But huge swathes of Africa have endemic river blindness and no nodding syndrome, and some children with nodding syndrome have no signs of infection.

Furthermore, the parasite is not thought to invade the nervous system and no trace of it has been found in the cerebrospinal fluid from any of the people with the syndrome. The authors of the review speculate that a new or similar parasite could be involved but hard data is still lacking and the typical signs of infection are missing.

A form of vitamin B6 deficiency is known to cause neural problems and has been found in affected people but it has also been found in just as many people untouched by the mystery illness. One possibility is this could be a risk factor, making people more vulnerable to the condition, rather than a sole cause.

One idea as to why it is so specific relates to the increasing recognition that some neurological conditions are caused by the body’s immune system erroneously attacking very specific parts of the brain.

For example, in Sydenham’s chorea antibodies for the common sore throat bacteria end up attacking the basal ganglia, while in limbic encephalitis the immune system attacks the limbic system.

This sort of autoimmune problem is a reasonable suggestion given the symptoms, but in the end, it is another hypothesis that is awaiting hard data.

Perhaps most mysterious, however, is its most marked feature – the fact that it only seems to affect children. At the current time, we seem no closer to understanding why. Similarly, the fact that it is epidemic and seems to spread also remains unexplained.

If you’re used to scientific articles, do check out the Emerging Infectious Diseases paper because it reads like a as-yet-unsolved detective story.

Either way, keep tabs on the story as it is something that needs to be cracked, not least because the number of cases seems to be slowly increasing.

Link to update paper in Emerging Infectious Diseases.

Why Christmas rituals make tasty food

All of us carry out rituals in our daily lives, whether it is shaking hands or clinking glasses before we drink. At this time of year, the performance of customs and traditions is widespread – from sharing crackers, to pulling the wishbone on the turkey and lighting the Christmas pudding.

These rituals might seem like light-hearted traditions, but I’m going to try and persuade you that they are echoes of our evolutionary history, something which can tell us about how humans came to relate to each other before we had language. And the story starts by exploring how rituals can make our food much tastier.

In recent years, studies have suggested that performing small rituals can influence people’s enjoyment of what they eat. In one experiment, Kathleen Vohs from the University of Minnesota and colleagues explored how ritual affected people’s experience of eating a chocolate bar. Half of the people in the study were instructed to relax for a moment and then eat the chocolate bar as they normally would. The other half were given a simple ritual to perform, which involved breaking the chocolate bar in half while it was still inside its wrapper, and then unwrapping each half and eating it in turn.

Something about carefully following these instructions before eating the chocolate bar had a dramatic effect. People who had focused on the ritual said they enjoyed eating the chocolate more, rating the experience 15% higher than the control group. They also spent longer eating the chocolate, savouring the flavour for 50% longer than the control group. Perhaps most persuasively, they also said they would pay almost twice as much for such a chocolate.

This experiment shows that a small act can significantly increase the value we get from a simple food experience. Vohs and colleagues went on to test the next obvious question – how exactly do rituals work this magic? Repeating the experiment, they asked participants to describe and rate the act of eating the chocolate bar. Was it fun? Boring? Interesting? This seemed to be a critical variable – those participants who were made to perform the ritual rated the experience as more fun, less boring and more interesting. Statistical analysis showed that this was the reason they enjoyed the chocolate more, and were more willing to pay extra.

So, rituals appear to make people pay attention to what they are doing, allowing them to concentrate their minds on the positives of a simple pleasure. But could there be more to rituals? Given that they appear in many realms of life that have nothing to do with food –from religious services to presidential inaugurations – could their performance have deeper roots in our evolutionary history? Attempting to answer the question takes us beyond the research I’ve been discussing so far and into the complex and controversial debate about the evolution of human nature.

In his book, The Symbolic Species, Terrance Deacon claims that ritual played a special role in human evolution, in particular, at the transition point where we began to acquire the building blocks of language. Deacon’s argument is that the very first “symbols” we used to communicate, the things that became the roots of human language, can’t have been anything like the words we use so easily and thoughtlessly today. He argues that these first symbols would have been made up of extended, effortful and complex sequences of behaviours performed in a group – in other words, rituals. These symbols were needed because of the way early humans arranged their family groups and, in particular, shared the products of hunting. Early humans needed a way to tell each other who had what responsibilities and which privileges; who was part of the family, and who could share the food, for instance. These ideas are particularly hard to refer to by pointing. Rituals, says Deacon, were the evolutionary answer to the conundrum of connecting human groups and checking they had a shared understanding of how the group worked.

If you buy this evolutionary story – and plenty don’t – it gives you a way to understand why exactly our minds might have a weakness for ritual. A small ritual makes food more enjoyable, but why does it have that effect? Deacon’s answer is that our love of rituals evolved with our need to share food. Early humans who enjoyed rituals had more offspring. I speculate that an easy shortcut for evolution to find to make us enjoy rituals is by connecting our minds to that the rituals make the food more enjoyable.

So, for those sitting down with family this holiday, don’t skip the traditional rituals – sing the songs, pull the crackers, clink the glasses and listen to Uncle Vinnie repeat his funny anecdotes for the hundredth time. The rituals will help you enjoy the food more, and carry with them an echo of our long history as a species, and all the feasts the tribe shared before there even was Christmas.

This is my latest column for BBC Future. You can see the original here. Merry Christmas y’all!

Whatever happened to Hans Eysenck?

Psychologist Hans Eysenck was once one of the most cited and controversial scientists on the planet and a major force in the development of psychology but he now barely merits a mention. Whatever happened to Hans Eysenck?

To start off, it’s probably worth noting that Eysenck did a lot to ensure his legacy would be difficult to maintain. He specifically discouraged an ‘Eysenck school’ of psychology and encouraged people to question all his ideas – an important and humble move considering that history favours the arrogant.

But he also argued for a lot of rubbish and that is what he’s become most remembered for.

He did a lot of work on IQ but took a hard line of its significance. Rather than thinking of it as simply a broad-based psychological test that is useful as a clinical measure of outcome, he persistently championed it as a measure of ‘intelligence’ – a fuzzy social idea that implies someone’s value.

Without any insight into the cultural specificity of these tests Eysenck argued for racial differences in IQ as likely based in genetics, and signed the notorious ‘Mainstream Science on Intelligence’ statement which reads like your drunk grandpa trying to justify why there are no black Nobel science winners.

Eysenck was apparently not racist himself, but believing that science was ‘value free’ he was also incredibly politically naive and took money from clearly racist organisations or published in their journals, thinking that the data would speak for itself.

He also doubted that smoking caused lung cancer and took money from tobacco giant Philip Morris to try and show that the link was mediated by personality, and at one point started espousing that there was some statistical basis behind astrology.

Some of his other main interests have not been rejected, but have just become less popular – not least the psychology of personality and personality tests.

This area is still important but has become a minority sport in contemporary psychology, whereas previously it was central to a field that was still battling fairytale Freudian theories as a way of understanding personal tendencies.

But perhaps his most important contributions to psychology are now so widely accepted that no-one really thinks about their origin.

When he was asked to create the UK’s first training course for clinical psychology he created a scientifically informed approach to understanding which treatments work but extended this philosophy to focus on a hypothesis-testing approach to work with individuals. This is now a core aspect of practice across the world.

His belief that psychologists should consistently look to make links between thoughts, experience, behaviour and biology is something that has been widely taken up by researchers, even if clinical psychologists remain a little neurophobic as a profession.

Because Eysenck loved an academic dust-up, he is most remembered for the IQ debate, on which he took a rigid position which history has, justifiably, not looked kindly on. But as someone who influenced the practice of psychology, his legacy remains important, if largely unappreciated.

A sticking plaster for a shattered world

The last paragraph of this article from the American Journal of Psychiatry on people displaced by the Syrian conflict essentially sums up the entire practice of conflict-related mental health.

Looking at this endless list of horrible stories from a psychiatrist’s perspective, I see only patients suffering from what my profession calls posttraumatic stress disorder. It is a disorder with well-described symptoms and therapeutic options. Looking at this same list from a human being’s perspective, I only see in the looks and attitudes of those patients—as I empathically explain to them their disorder, prescribe a few pills, and orient them to psychotherapy—something that is beyond what contemporary evidence-based medicine can describe scientifically.

In every one of these patients, I see intense, irreversible mistrust and a lack of belief in every principle or rule that is supposed to control our relationships with each other. I see question marks regarding the meaning of their whole existence as well as the meanings behind the most important concepts that seemed unquestionable to them in the past, such as religion, politics, work, family, and finally, last but not least, health. These patients manifest symptoms that justify the wide array of treatment modalities I offer to them, but I am left with a terrible feeling that this management is somehow wanting. All that has been shattered in these patients’ lives cannot be mended by the small treatment that we can offer.

It’s written by Lebanese psychiatrist Rami Bou Khalil, who mentions this little told but often learnt lesson about the effects of war.

Link to ‘Where All and Nothing Is About Mental Health’