Sleight of mind in fMRI

I’ve written a piece for the BPS Research Digest about a fascinating study that caused people to feel their thoughts were being controlled by outside forces.

It’s a psychologically intriguing study because it used the psychology lab to conduct the study but it also used the psychology lab as a form of misdirection, so participants wouldn’t realise that the effect of having their ‘thoughts read’ and ‘thoughts inserted into their mind’ was in fact a common trick used in stage mentalism.

The interesting bit came where the researchers recorded whether participants reacted differently when they thought their thoughts were being read (they did) and asked about their experience of it happening (when it never actually did).

They reported a range of anomalous effects when they thought numbers were being “inserted” into their minds: A number “popped in” my head, reported one participant. Others described “a voice … dragging me from the number that already exists in my mind”, feeling “some kind of force”, feeling “drawn” to a number, or the sensation of their brain getting “stuck” on one number. All a striking testament to the power of suggestion.

A really wonderfully conceived study that may provide a useful tool for temporarily inducing the feeling of not controlling your own thoughts – something that occurs in a range of psychological difficulties and disorders.

Link to piece on BPS Research Digest.

A temporary blindness during a wrongful conviction

I’m just reading Clinical Psychology in Britain: Historical Perspectives which is a wonderful book if you are a clinical psychologist but probably about as exciting to non-clinical psychologists as you might expect. However, it does contain a few gems of wider interest.

This is a remarkable story from the chapter on the history of forensic clinical psychology which concerns the case of Barry George during the original trial that wrongfully convicted him for the murder of television journalist Jill Dando.

On 26 April 1999, Jill Dando, the presenter of BBC programme Crimewatch, was shot dead outside her home in Fulham, London. On 2 July 2001 Barry George, who lived nearby, was convicted of her murder. Prior to the trial, three defence experts, Gisli Gudjonsson, Susan Young and Michael Kopelman, had reported that Mr George’s fitness to stand trial was contingent on his receiving clinical psychological support in court throughout the trial, which lasted from 23 April to 2 July 2001.

Mr George had a complex presentation, including a long history of primary generalised epilepsy (first identified at age two or three), severely abnormal EEG, intellectual deterioration, significant cognitive and executive deficits, rigid and obsessive personality structure, hypochondriacal preoccupations, and an extreme reaction to stress in the form of anxiety and panic attacks, which increased the frequency of absence epileptic seizures. The court appointed Susan Young, a forensic clinical psychologist, who initially sat in the dock with Mr George and provided him with the required assistance. On 26 April 2001, on the fourth day of the legal arguments and prior to swearing in the jury, Mr George turned to Susan Young and declared, ‘I can’t see’. Prior to this Mr George had been observed having difficulties concentrating on the legal arguments and he claimed to be experiencing petit mal epileptic seizures in the dock.

The trial before the jury was due to commence on 2 May, but the court determined that the trial could only proceed if Mr George’s eyesight could be restored. On the morning of 1 May, all three defence experts were asked to meet Mr George and try to restore his eyesight by 2pm (when the court commenced that day). Michael Kopelman conducted a medical examination and informed Mr George that there was no physical explanation for his blindness. All attempts to persuade Mr George that it was in his interest to to regain his eyesight proved fruitless; he simply kept saying ‘I can’t see’.

At 12.30pm Gisli Gudjonnson, who was trained in hypnosis techniques, suggested that hypnosis might prove successful in bringing back his sight. Mr George agreed to this approach. After an initial induction to the process, Mr George was asked to imagine that he was being taken through a tunnel, accompanied by suggestions that his eyesight would gradually return during the journey and improve further during the lunchbreak (i.e. posthypnotic suggestion). After being brought out of the hypnosis, Mr George said he could see but his eyesight was blurred. He was reassured that it would continue to improve and by 2.00pm his eyesight had fully recovered and after the final legal arguments that afternoon, the trial commenced before a jury.

The defence experts construed Mr George’s blindness as being psychogenic in origin caused by the inability to cope with the stress generated by the legal arguments (i.e. putting a physical barrier between himself and the court), which was unlocked by the process of hypnosis. This was not the first time Mr George had presented with psychogenic symptoms as he had presented with a functional aphonia (i.e. nonorganic loss of speech) following a stressful environmental event in 1994. Psychogenic blindness and psychogenic aphonia are both a form of ‘conversion disorder’ and are often caused by stress that manifests itself as physical symptoms.

Gisli Gudjonnson was originally a policeman in his native Iceland but became interested in the psychological aspects of the crimes he was investigating, moved to the UK to study psychology, and has been massively influential in the development of forensic psychology.

He has been involved in some of the most high profile cases in the country and, TV producers, is the likely subject of your next Nordic detective drama.

Link to details of Clinical Psychology in Britain: Historical Perspectives.

A Million Core Silicon Brain

For those of you who like to get your geek on (and rumour has it, they can be found reading this blog) the Computerphile channel just had a video interview with Steve Furber of the Human Brain Project who talks about the custom hardware that’s going to run their neural net simulations.

Furber is better known as one of the designers of the BBC Micro and the ARM microprocessor but has more recently been involved in the SpiNNaker project which is the basis of the Neuromorphic Computing Platform for the Human Brain Project.

Fascinating interview with a man who clearly likes the word toroid.

In the mind of a drone

CC Licensed Image from Wikimedia Commons. Click for source.Longreads has an excellent article on the psychology of drone warfare that looks at this particularly modern form of air-to-ground combat from many, thought-provoking angles.

These include the effect of humanless warfare, how suicide bombers are being dronified, how reducing the risk to soldiers might make civilians a more inviting target, whether remote-drone-pilot PTSD is convenient myth, and most interesting, the reliance of ‘Pattern-of-Life Analysis’ on which to base strikes.

Apart from these “personal strikes,” there are also “signature strikes,” here meaning strikes authorized on the basis of traces, indications, or defining characteristics. Such strikes target individuals whose identity remains unknown but whose behavior suggests, signals, or signs membership in a “terrorist organization.”

In such cases, the strike is made “without knowing the precise identity of the individuals targeted.” It depends solely on their behavior, which, seen from the sky, appears to “correspond to a ‘signature’ of pre-identified behavior that the United States links to militant activity.” Today, strikes of this type, against unknown suspects, appear to constitute the majority of cases…

An analysis of the pattern of a person’s life may be defined more precisely as “the fusion of link analysis and a geospatial analysis.” For some idea of what is involved here, imagine a superimposition, on a single map, of Facebook, Google Maps, and an Outlook calendar. This would be a fusion of social, spatial, and temporal particulars, a mixed mapping of the socius, locus, and tempus spheres—in other words, a combination of the three dimensions that, not only in their regularities but also in their discordances, constitute a human life.

This anonymous death by heuristics is also the type of problem that yields well to statistical approaches and, with enough data, machine learning algorithms such as deep learning.

It’s the sort of problem that cloud-based on-tap-AI systems like IBM’s Watson are designed to help with and you can bet your bottom dollar that there’s research going on to use machine learning to identify terrorists from their Pattern-of-Life. The Skynet of fiction will probably become the Skyapp of reality.

The article is remarkably wide-ranging and genuinely thought-provoking for a subject where much has already been written. Recommended.

Link to ‘Theorizing the Drone’.

More on the enigma of blindness and psychosis

A long-standing enigma in psychiatry has been why no-one has been able to find someone who has both congenital blindness and a diagnosis of schizophrenia. The newest and most comprehensive archive study to date has just been published on exactly this issue although it raises more questions than it answers.

Evelina Leivada and Cedric Boeckx from the University of Barcelona in Spain conducted an extensive medical literature search and did come up with some cases of congenital blindness and schizophrenia – 13 in total, although only two case studies (outlining a total of four cases) were found which were convincing enough to be unaffected by other serious problems, like severe genetic disorders.

And these remaining four were hardly straightforward and as one report was from 1943 and the other from 1967 where standards of both vision and psychiatric assessment were significantly short of modern standards.

Notably, all cases of co-occurrence were from blindness due to eye problems or where blindness happened relatively late (after 6 years of age). No cases were found were people had a diagnosis of schizophrenia and were congenitally cortically blind – where blindness was caused by problems with the brain’s visual system.

What this new study provides is weak evidence for the possibility of certain sorts of blindness coexisting with a diagnosis of schizophrenia and more comprehensive support for the curious finding that blindness seems to reduce the risk of developing psychosis.

It’s worth noting that what is really needed is a prospective epidemiological study of psychosis in blind people. However, researchers have been searching for congenitally blind people with psychosis since the issue of non-co-occurrence was first seriously raised in the 1980s and none have been found. Based on the rates of occurrence for each condition, the combination should be fairly common. This suggests that hypothesis of protective effects of congenital blindness needs to taken seriously.

The Leivada and Boeckx paper goes on to speculate about neuropsychological reasons why congenital blindness might protect against schizophrenia (essentially, changes in the interaction between key visual system components and the language system) and, somewhat less convincingly, genetic reasons – as just extrapolating likely genes from case studies is very speculative and both the eye and brain develop from the same cells during embryo development so it’s not clear shared genes won’t just reflect generally impaired neurodevelopment.

I have to say, I find the concept of schizophrenia to be a fairly useless, but if the increasingly plausible hypothesis that congenital blindness protects against psychosis is confirmed, it has interesting implications for those that argue that psychosis is nothing but the result of marginalisation, stigma or difficult life circumstances where biological explanations are irrelevant.

Blindness, clearly would increase your chances of all of these, and so on this theory, we would expect an increased rate of psychosis, but this doesn’t seem to be the case.

It’s not that marginalisation, stigma or difficult life circumstances aren’t causal factors in developing psychosis, they clearly are, but ignoring neuro-level explanations outside these effects is equally as narrow as suggesting that they are the only relevant influences.

Link to ‘Schizophrenia and cortical blindness’ in Frontiers.

Trifles make the sum of life

I’ve just found a curious scientific paper that looks at whether computational models of neural function are of relevance to clinical psychiatry. Oddly, it is written as a debate between two Charles Dickens characters.

The paper was published in the journal Neural Networks and is entitled “Are computational models of any use to psychiatry?”.

It starts entirely normally and then suddenly introduces two characters from the novel David Copperfield who begin to discuss the cognitive science of computational psychiatry.

Wise old Dr. Strong (Dickens, 1850) will now put the case against CMs [computational models] from the point of view of a psychiatrist. Our optimistic – or maybe unrealistic – friend Mr. Micawber will try to enthuse him about their cause. He is also a fan of reinforcement learning models.

It’s worth noting that in the original version of David Copperfield, Mr. Micawber barely mentions his admiration of computational reinforcement learning models (reading between the lines, he always seemed more of learning mechanism agnostic autoassociative memory man to me – but hey, I’m no English literature scholar).

Dr. Strong: First and foremost, CMs have failed to influence clinical practice.

Mr. Micawber: I would agree, Dr. Strong, that CMs have not influenced clinical practice to date; but neither have most advances in neurosciences. In fact, we believe that CMs will be instrumental in helping to bridge the gap between neurobiology and psychiatry because CMs are able to link levels of descriptions and make well-founded predictions at one level based on information at another level.

Dr. Strong: I disagree. The question is: are they clinically relevant, not will they be at some point in the future. All the models omit the very centre of psychiatry: subjective experiences. No one I have met believes that computers feel duty, personal bonds, or sexual titillation.

Weirdly, this is not the first cognitive science paper to be presented as a debate between two rather unexpected people.

Jerry Fodor’s paper “Fodor’s Guide to Mental Representation: The Intelligent Auntie’s Vade-Mecum” involves a discussion between him and his aunty about the finer points of mental representation.

Sadly, the paper is behind a pay-wall because Elsevier know that the cognitive science / Dickens combination can be deadly in the wrong hands.

Link to locked article “Are computational models of any use to psychiatry?”

Taste illusions

I’ve just found a 2008 review article on the multisensory perception of flavour that is full of fascinating examples of taste illusions and demonstrates the surprisingly complexity of the gustatory system.

The following is one of my favourites. The article first makes the interesting observation that the majority of odour names refer to objects and most non-object odour names like ‘acrid’ and ‘pungent’ actually refer not to smell but to felt sensation.

Another manifestation of the object-based nature of olfactory perception is the constant error made, when eating, of attributing to taste what really belongs to the sense of smell. The error of localizing the odors coming from food as originating in the mouth has been termed the olfactory illusion. It has been compared to the ventriloquism effect, that is, the influence of visual cues on the identification of the location of a sound source. Green (2001) has provided a similar explanation for the fact that although flavor is perceived by receptors on the tongue, in the nose, and even in the eyes, the brain interprets the overall sensation as originating from within the mouth. According to Green, all of the sensory information is localized in the mouth in order that we associate this information with the food being consumed, in the same way that we typically use both touch and vision to localize a point on our bodies.

The paper is by psychologists by Malika Auvray and Charles Spence and it’s sadly locked – but someone has handily a put a pdf online.

Link to journal hosted locked article (via @velascop)
pdf of full text.