Can Movement Identify Neuropsychiatric Disorder?

[Posted on 10 September, 2019 by Jonathan Delafield-Butt]

It struck me many years ago the power of movement to give an accurate picture of a person, especially in the diagnosis of psychopathology.  Roger Sperry, the Caltech neurologist and Nobel Prize winner made it clear that “the sole product of brain function is motor coordination” (Sperry, 1952).   It stands to reason all psychological concerns are by nature brain-mediated, and by Sperry’s logic they will necessarily be expressed in bodily movement.

I first came to understand this can be a very subtle, but very significant expression by way of Acute Psychiatry.  I was working in the acute wards at the Royal Edinburgh Hospital and came to be discussing schizophrenia with a colleague.  She told me anecdotally she could ‘diagnose’ schizophrenia within the first seconds of a person entering her consulting room.  The tell-tale information was in that person’s movement, the manner of their opening the door, entering through the doorway, moving their body and hands, and exchanging their posture to make their way to the doctor’s chair. 

Those simple acts of entering, walking, and sitting were rich in detail of the psychophysiology of the individual.  The manual manipulation of the door handle, effortful push of the door, expectant stride to gain pace, eye gaze shift from door to doctor to chair were made in anticipation as gait increased proximity to the doctor.  A sense of threat or care was constantly evaluated, impacting on thoughts and feelings, and giving colour to facial expressivity, gesture, and cadence of stride.  All of these movements were controlled second-by-second, made in anticipation of the discussion to come and evident in what child psychiatrist Daniel Stern called their ‘forms of vitality’ (Stern, 2010).  They bring the patient to sit next to the doctor, whose rich social response is being anticipated, and prepared for. 

I trusted this doctor’s intuition that there is a truth the ‘diagnosis’ can be done in those seconds before her patient sits down.  But she was also right not do that in her professional capacity, and to put that felt impression to the side to focus on the logic of a diagnostic rationale as she proceeded with a structured assessment of the individual, on the basis of established medical knowledge and fact. 

But as a research scientist, her story remained with me, because it called to attention a fundamental truth about body movement as “the sole product of brain activity”, and its potential power to be useful medically.  Recent improvements in the neuroscience of perception show that our eyes and ears are attending to very subtle, micro-second shifts in body movement and posture when we observe others.  We read each other’s social intentions, interests, and plans through what philosophers call ‘direct experience’ (Gallagher, 2008).  These are implicit assessments of the other’s mind made by rapid, direct neural computations or ‘neural resonance’ (Gallese, 2014), rather than through thinking about their state of mind with slower, higher-order mentalisations. 

The neuropsychology of implicit, direct social ‘mind reading’ has improved significantly in the past decade (Schilbach et al., 2013).  We now understand that while the mirror neuron system enables reading others’ intentions in body movement (Rizzolatti & Sinigaglia, 2008), we also share autonomic regulations of arousal and interest within a highly evolved ‘social engagement system’ so that one person modulates the other directly (Delafield-Butt, 2018).  This gives grounding to the idea that we may implicitly understand or ‘feel’ the other persons’ state of mind read in the subtlety of their subsecond adjustment of fingers, hands, head, and eyes.  Compare this idea to the old notion of the counter-transference and you are getting close to understanding how direct experience feels the other person’s mind.

What is particularly exciting for me is that we are now at a cross-road where this implicit knowledge of other minds can be made explicit by a growing neuroscience of social communication in body movement.  And taken together with technological advances in wearable movement sensors such as those in your iWatch or Fitbit supported by new, powerful artificial intelligence methods of data analysis, we are now in a position to extract with computational detail the movement patterns my clinical colleague perceived many years ago, but could not make use of in the formal logic of medical practice.  In my work, and those of my lab (https://www.strath.ac.uk/research/innovationinautism/), we are working to make significant gains in understanding the motor aetiology of neuropsychopathology, especially in the case of childhood autism where diagnosis can be a long and uncertain processes.  These computational motor measurements deliver precise statistical analyses that can be used to aid diagnosis (Anzulewicz, Sobota, & Delafield-Butt, 2016) – an intuition now turned to hard, objective science. 

[This is a blog. The purpose of the blog is to provide information and raise awareness concerning important issues. All views and opinions expressed are those of the writer and not necessarily shared by the GNC.]