Can fMRI solve the mind-body problem? Tim Crane, “How We Can Be”, TLS, 24/05/17

In the current TLS, an excellent article by Tim Crane on neuroimaging, consciousness, and the mind-body problem. Many of my previous posts here related to this have endorsed a kind of mild neuro-scepticism, Crane begins his article by describing an experiment which should the literally expansive nature of neuroscience:

In 2006, Science published a remarkable piece of research by neuroscientists from Addenbrooke’s Hospital in Cambridge. By scanning the brain of a patient in a vegetative state, Adrian Owen and his colleagues found evidence of conscious awareness. Unlike a coma, the vegetative state is usually defined as one in which patients are awake – they can open their eyes and exhibit sleep-wake cycles – but lack any consciousness or awareness. To discover consciousness in the vegetative state would challenge, therefore, the basic understanding of the phenomenon.

The Addenbrooke’s patient was a twenty-three-year-old woman who had suffered traumatic brain injury in a traffic accident. Owen and his team set her various mental imagery tasks while she was in an MRI scanner. They asked her to imagine playing a game of tennis, and to imagine moving through her house, starting from the front door. When she was given the first task, significant neural activity was observed in one of the motor areas of the brain. When she was given the second, there was significant activity in the parahippocampal gyrus (a brain area responsible for scene recognition), the posterior parietal cortex (which represents planned movements and spatial reasoning) and the lateral premotor cortex (another area responsible for bodily motion). Amazingly, these patterns of neural responses were indistinguishable from those observed in healthy volunteers asked to perform exactly the same tasks in the scanner. Owen considered this to be strong evidence that the patient was, in some way, conscious. More specifically, he concluded that the patient’s “decision to cooperate with the authors by imagining particular tasks when asked to do so represents a clear act of intention, which confirmed beyond any doubt that she was consciously aware of herself and her surroundings”.

Owen’s discovery has an emotional force that one rarely finds in scientific research. The patients in the vegetative state resemble those with locked-in syndrome, a result of total (or near-total) paralysis. But locked-in patients can sometimes demonstrate their consciousness by moving (say) their eyelids to communicate (as described in Jean-Dominique Bauby’s harrowing and lyrical memoir, The Diving Bell and the Butterfly, 1997). But the vegetative state was considered, by contrast, to be a condition of complete unconsciousness. So to discover that someone in such a terrible condition might actually be consciously aware of what is going on around them, thinking and imagining things, is staggering. I have been at academic conferences where these results were described and the audience was visibly moved. One can only imagine the effect of the discovery on the families and loved ones of the patient.

Crane’s article is very far from a piece of messianic neurohype, but he also acknowledges the sheer power of this technology to expand our awareness of what it means to be conscious and human, and the clinical benefit that is not something to be sniffed at. But, it doesn’t solve the mind-body problem – it actually accentuates it:

Does the knowledge given by fMRI help us to answer Julie Powell’s question [essentially a restatement of the mind-body problem by a food writer]? The answer is clearly no. There is a piece of your brain that lights up when you talk and a piece that lights up when you walk: that is something we already knew, in broad outline. Of course it is of great theoretical significance for cognitive neuroscience to find out which bits do what; and as Owen’s work illustrates, it is also of massive clinical importance. But it doesn’t tell us anything about “how we can be”. The fact that different parts of your brain are responsible for different mental functions is something that scientists have known for decades, using evidence from lesions and other forms of brain damage, and in any case the very idea should not be surprising. FMRI technology does not solve the mind–body problem; if anything, it only brings it more clearly into relief.

Read the whole thing, as they say. It is a highly stimulating read, and also one which, while it points out the limits of neuroimaging as a way of solving the difficult problems of philosophy, gives the technology and the discipline behind it its due.

Leandro Herrero – “The best contribution that Neurosciences can make to Management and Leadership is to leave the room”

A while back I reviewed I Know What You’re Thinking: Brain Imaging and Mental Privacy in the Irish Journal of Psychological Medicine, and discussed a couple of studies which illustrate the dangers of what could best be called neuro-fetishism:

In 2010, Dartmouth University neuroscientist Craig Bennett and his colleagues subjected an experimental subject to functional magnetic resonance imaging. The subject was shown ‘a series of photographs with human individuals in social situations with a specified emotional valence, either socially inclusive or socially exclusive’. The subject was asked to determine which emotion the individual in the photographs were experiencing. The subject was found to have engaged in perspective-taking at p<0.001 level of significance. This is perhaps surprising, as the subject was a dead salmon.

In 2007, Colorado State University’s McCabe and Castel published research indicating that undergraduates, presented with brief articles summarising fictional neuroscience research (and which made claims unsupported by the fictional evidence presented) rated articles that were illustrated by brain imaging as more scientifically credible than those illustrated by bar graphs, a topographical map of brain activation, or no image at all. Taken with the Bennett paper, this illustrates one of the perils of neuroimaging research, especially when it enters the wider media; the social credibility is high, despite the methodological challenges.

I am becoming quite addicted to Leandro Herrero’s Daily Thoughts and here is another. One could not accuse Herrero of pulling his punches here:

I have talked a lot in the past about the Neurobabble Fallacy. I know this makes many people uncomfortable. I have friends and family in the Neuro-something business. There is neuro-marketing, neuro-leadership and neuro-lots-of-things. Some of that stuff is legitimate. For example, understanding how cognitive systems react to signals and applying this to advertising. If you want to call that neuro-marketing, so be it. But beyond those prosaic aims, there is a whole industry of neuro-anything that aggressively attempts to legitimize itself by bringing in pop-neurosciences to dinner every day.

In case anyone doubts his credentials:

Do I have any qualifications to have an opinion on these bridges too far? In my previous professional life I was a clinical psychiatrist with special interest in psychopharmacology. I used to teach that stuff in the University. I then did a few years in R&D in pharmaceuticals. I then left those territories to run our Organizational Architecture company, The Chalfont Project. I have some ideas about brains, and some about leadership and organizations. I insist, let both sides have a good cup of tea together, but when the cup of tea is done, go back to work to your separate offices.

It is ironic that otherwise hard-headed sceptics tend to be transfixed by anything “neuro-” – and Leandro Herrero’s trenchant words are just what the world of neurobabble needs. In these days of occasionally blind celebration of trans-, multi- and poly- disciplinary approaches, the “separate offices” one is bracingly counter-cultural…

Review of I Know What You’re Thinking: Brain Imaging and Mental Privacy, Irish Journal of Psychological Medicine, February 2016

Original here

I Know What You’re Thinking: Brain Imaging and Mental Privacy, Edited by Richmond , Rees  and Edwards

 

In 2010, Dartmouth University neuroscientist Craig Bennett and his colleagues subjected an experimental subject to functional magnetic resonance imaging. The subject was shown ‘a series of photographs with human individuals in social situations with a specified emotional valence, either socially inclusive or socially exclusive’. The subject was asked to determine which emotion the individual in the photographs were experiencing. The subject was found to have engaged in perspective-taking at p<0.001 level of significance. This is perhaps surprising, as the subject was a dead salmon.

This may sound like a parody, or a debunking of neuroimaging, but in fact it was intended to point out the considerable challenge of neuroimaging research, and more specifically how the vast number of potential variables inherent in this research pushes ‘traditional’ statistical methodology to its limit.

In 2007, Colorado State University’s McCabe and Castel published research indicating that undergraduates, presented with brief articles summarising fictional neuroscience research (and which made claims unsupported by the fictional evidence presented) rated articles that were illustrated by brain imaging as more scientifically credible than those illustrated by bar graphs, a topographical map of brain activation, or no image at all. Taken with the Bennett paper, this illustrates one of the perils of neuroimaging research, especially when it enters the wider media; the social credibility is high, despite the methodological challenges.

The title of this book alone leads one to expect that it is an exploration of one widespread popular notion about neuroimaging; that it is a way of reading thoughts. Some of the essays do explore this theme; but most don’t, at least not that directly. Notwithstanding the inclusion of an essay by the former editor of this journal, the book is something like the proverbial curate’s egg, good in parts (without any partiality, Professor Kelly’s contribution is one of the good parts).

There are four sections to the book. First, an overview of the state of the art of neuroimaging and of the conceptual questions raised. Second, a focus on medical applications of mind reading through brain imaging. Third, a section on criminal justice, and finally one on mind reading and privacy.

Among the contributors, practitioners of neuroimaging-based research alternate with (relative) skeptics of the approach. It is interesting to observe the actual researchers, rather than being zealots, are tentative and provisional in their suggestions; the skeptics are more forthright. For instance, Colin Campbell and Nigel Eastman baldly evoke the ghost of phrenology – evidently a nearby shade for many contemplating this area – in the conclusion of their essay on neuroimaging on the law. Although this is a valid point – and undoubtedly some commercially promoted ‘mind reading’ technologies are pure hokum – it is rather jarring conclusion to their essay.

There is nevertheless much useful and stimulating material here. John-Dylan Haynes provides a useful overview of brain imaging technology itself and some of the possibilities and limits of the field. The second section, rather alarmingly titled ‘Medical applications of mind reading through brain imaging’, is generally comprised of thoughtful, nuanced discussions of the issues in non-responsive patients, pain, and mental health.

However, the essays are overall quite mixed in tone and content. Some bear the hallmarks of generic essays on particular topics with relatively little directly on the topic of the book (for instance, Annabelle Lever’s chapter on ‘Neuroscience versus privacy’ which is rather an extended discussion of privacy with some mentions of neuroscience). Contributors often rehash discussions that are covered at greater length, sometimes rather tediously so, in other essays.

The Hastings Centre Report ‘Interpreting neuroimages: an introduction to the technology and its limits’ – available at http://www.thehastingscenter.org/Publications/SpecialReports/Detail.aspx?id=6841 – covers much of the same ground as this book but more concisely and more accessibly, particularly Martha J. Farah’s essay in the ‘Brain images, babies, and bathwater: critiquing critiques of functional neuroimaging’. With the Hastings Centre Report freely accessible in the public domain it is hard to advise readers to part with their money for this volume.

“Godterms”

Yesterday I came across the following tweet:

I had never come across the coinage “Godterm” before – and the meaning I ascribed to it was simply this: something that is, as the saying goes, like motherhood and apple pie; no-one wants to be seen to be arguing against it. This usually reflects that it is indeed a Good Thing, maybe even a Very Good Thing, maybe an Extremely Good Thing. However the term becomes something of a rhetorical blunderbuss – this is Patient-Centered, and YOU AREN’T AGAINST PATIENT-CENTEREDNESS, ARE YOU?

I tweeted Lorelei Lingard expressing that “godterm” was a useful find and she replied:

There are indeed godterms lurking everywhere – “innovation” is another. Note that pointing out that X is a godterm does not mean one is criticising X, but rather the use of X as a shield to deflect scrutiny.

Thanks again to Lorelei Lingard for introducing me to this term! I look forward to happy godterm excavation.

 

“Nitrazepam made dreams everydayish” – searching for “dreams” in the BJPsych

Following on from  my recent posts about dreams and psychiatry (and the changes in how psychiatrists engage in questions of the meaning of symptoms reported to them) I have just searched the British Journal of Psychiatry site using the word “dreams”. As the BJPsych is the journal of the Royal College of Psychiatrists and the third most cited psychiatry journal in the world, it is fair to regard it as reflecting contemporary psychiatry.

 

Using the “Best match” search criteria,  the top 10 results  for “dreams” are all from other decades – with the most recent being from 1974 – a paper which dealt with the impact on dreaming of then-commonly-used sleeping tablets. Haven’t read the full paper yet, but here is the abstract (and I haven’t come across the word “everydayish” before!) :

It was predicted that amylobarbitone and nitrazepam would make dreams less active, and withdrawal would make them especially intense. Dream reports were collected from subjects before, during and after chronic administration of either of the two drugs or placebo. Dreams were rated as conceptual or perceptual, and as visually active or passive. They were also rated for hostility, anxiety, sexuality, psychotic thinking, bizarreness and degree of reality. A variety of other measures of content were made, such as the number of characters, activities, social interactions and emotions in each dream report. An experienced, `blind’ judge tried to assign reports according to whether they came from baseline, drug or withdrawal conditions. Subjective estimates of dreaming were also collected.

Contrary to prediction, dreams were virtually indistinguishable under the three conditions. Two effects were that nitrazepam made dreams everydayish and its withdrawal made them bizarre, and withdrawal of amylobarbitone produced exceptionally vivid dreaming and nightmares at home but not in the laboratory. Consideration of the results suggests that these hypnotics affect the quality of thought processes in sleep, and that in clinical use their withdrawal would be expected to produce unpleasant, anxiety-filled dreams and nightmares.

 

The number 1 result is from 1962. Again I hope to read the actual paper but here is the abstract, again rather “of its time”:

Spoken personal names which were randomly presented during the rapid eye movement periods of dreaming were incorporated into the dream events, as manifested by the ability of the experimental subjects and an independent judge subsequently to match correctly the names presented with the associated dreams more often than would be expected by guessing correctly by chance alone. Incorporation of emotional and neutral names into the dream events occurred equally often. The manner in which the names appeared to have been incorporated into the dream events fell into four categories of decreasing frequency: (a) Assonance, (b) Direct, (c) Association, and (d) Representation. Perceptual responses to the stimulus names, as manifested by subsequent dream recall, occurred without any accompanied observable differential electroen-cephalographic or galvanic skin responses compared with those occasions on which no such perceptual responses were evident. The frequency of recall of colour in dreams was higher than has been previously reported.

The results are discussed in relation to the function of dreams and perception during dreaming.

Using the “Newest first” search criteria does throw up more recent results, but in most of the top 10, the word “dreams” is not referring to a subject of clinical or research interest. The number one result is an article in which a psychiatrist discusses ten books that influenced him. The next result uses “dream” in the sense of “hope” or “aspiration”:

 

The National Institute of Mental Health (NIMH), under the leadership of Thomas Insel, powerfully steered national and international researchers, policy makers and research commissioners to buy into a hopeful dream that one day the basic sciences will afford opportunities to prevent and treat mental illness at its root cause

Of the rest of the “Most recent” top ten, we have three poems, one film review, another “Ten Books” feature, one paper whose mention of dreams is in passing as an adverse drug effect, and just two papers which, from my brief reading, dreams seem to feature as a topic of clinical interest. Both are papers in child psychiatry and both deal with dreams in the context of psychotic phenomena:

 

It has been suggested that there may be shared patterns of neuroanatomical, neurochemical and neurophysiological pathways occurring in nightmares and the positive symptoms of psychosis, for example, the finding that cortical dopamine levels are raised during nightmares41 and the functional significance of sleep spindles in psychosis42 that are consistently reduced in schizophrenia.43 Some studies have also reported a continuity between dreams and psychotic experiences; with overlapping content44 and indistinct barriers between these experiences.45 This is related to the increased interest in dreams46 or REM sleep47 as a neurobiological model for schizophrenia or psychotic phenomena.

Here to, we see that interest in dreams is confined to their possible utility as a model for psychosis – an interesting topic, but one from which issues of “meaning” are excluded.One of this paper’s references is worth reviewing – and I find it  interesting that a projective test (the TAT) was used in this study:

Many previous observers have reported some qualitative similarities between the normal mental state of dreaming and the abnormal mental state of psychosis. Recent psychological, tomographic, electrophysiological, and neurochemical data appear to confirm the functional similarities between these 2 states. In this study, the hypothesis of the dreaming brain as a neurobiological model for psychosis was tested by focusing on cognitive bizarreness, a distinctive property of the dreaming mental state defined by discontinuities and incongruities in the dream plot, thoughts, and feelings. Cognitive bizarreness was measured in written reports of dreams and in verbal reports of waking fantasies in 30 schizophrenics and 30 normal controls. Seven pictures of the Thematic Apperception Test (TAT) were administered as a stimulus to elicit waking fantasies, and all participating subjects were asked to record their dreams upon awakening. A total of 420 waking fantasies plus 244 dream reports were collected to quantify the bizarreness features in the dream and waking state of both subject groups.

Two-way analysis of covariance for repeated measures showed that cognitive bizarreness was significantly lower in the TAT stories of normal subjects than in those of schizophrenics and in the dream reports of both groups.

The differences between the 2 groups indicated that, under experimental conditions, the waking cognition of schizophrenic subjects shares a common degree of formal cognitive bizarreness with the dream reports of both normal controls and schizophrenics. Though very preliminary, these results support the hypothesis that the dreaming brain could be a useful experimental model for psychosis.

 

Sexual Dimorphism in Temporal Discrimination.

While EMBASE screening, one comes across abstracts of interest. I was a little struck by the following abstract. I am sure all sorts of hilarious one-liners suggest themselves relating to this study, but right now I can’t think of any:

The temporal discrimination threshold (TDT) is the shortest time interval at which two sensory stimuli presented sequentially are detected as asynchronous by the observer. TDTs are known to increase with age. Having previously observed shorter thresholds in young women than in men, in this work we sought to systematically examine the effect of sex and age on temporal discrimination. The aims of this study were to examine, in a large group of men and women aged 20-65 years, the distribution of TDTs with an analysis of the individual participant’s responses, assessing the “point of subjective equality” and the “just noticeable difference” (JND). These respectively assess sensitivity and accuracy of an individual’s response. In 175 participants (88 women) aged 20-65 years, temporal discrimination was faster in women than in men under the age of 40 years by a mean of approximately 13 ms. However, age-related decline in temporal discrimination was three times faster in women so that, in the age group of 40-65 years, the female superiority was reversed. The point of subjective equality showed a similar advantage in younger women and more marked age-related decline in women than men, as the TDT. JND values declined equally in both sexes, showing no sexual dimorphism. This observed sexual dimorphism in temporal discrimination is important for both (a) future clinical research assessing disordered mid-brain covert attention in basal-ganglia disorders, and (b) understanding the biology of this sexual dimorphism which may be genetic or hormonal.

Via the magic of Google ripping off the veil of anonymity which the abstracts are presented with on Embase is simplicity itself, and imagine my surprise when it turns out this paper came from a centre very familiar to me indeed. Go SVUH!