We have known for some time that sufferers from autistic spectrum disorders (ASDs) have mentalistic deficits--so-called mind-blindness. They tend to think in concrete, non-mental terms, and to be poor at detecting and interpreting social and emotional cues such as direction of gaze, facial expression, and body-language. And they are also poor at seeing things from another person's point of view. For example, if shown a tube of sweets which proves to contain a hidden pencil and then asked what the next child to be shown it would think it contains, many children under 3 or 4 tend to expect the next child to know what they already know, completely failing to appreciate the next child's inevitable ignorance. But much older children with ASD make the same mistake and fail this test of appreciating so-called false belief.
Thanks to specially-designed tests like this and others, researchers have been able to measure these deficits quantitatively. However, exactly the same tests have caused confusion as far as the imprinted brain theory and its distinctive, diametric model of mental illness is concerned because, when applied to those diagnosed with psychotic spectrum disorders (PSDs) such as schizophrenia, mentalistic deficits are also often found. The problem here is that the diametric model proposes that if ASD is symptomatically hypo-mentalistic--deficient in mentalism--then PSD is the opposite: hyper-mentalistic. Here are some examples (explained and illustrated at length with clinical examples in my book):
Other findings which fit the pattern here are the pathological single-mindedness of autistics v. the pathological ambivalence of psychotics, and the age of onset. This is early in ASD because mentalistic development is truncated but late in PSD because normal development has to be completed before mentalism can become pathologically over-developed.
Of course, you would expect to find mentalistic deficits in both under-mentalizing and over-mentalizing minds just as you would expect to find visual or hearing deficits in people with both over- and under-sensitive eyes or ears. What you have to do is to develop tests which can tell the difference, and now for the first time techniques are beginning to appear which do indeed do this where mentalism is concerned.
New research by Carla Sharp and others published in The Journal of the American Academy of Child & Adolescent Psychiatry (50, (6), 563-73, 6 June 2011) kindly brought to my attention by my colleague, Bernard Crespi, does exactly this, with results perfectly in line with our predictions.
The study used a naturalistic, video-based instrument for the assessment of mentalism called the Movie for the Assessment of Social Cognition (MASC). Subjects watch a depiction of an interactive social scenario and are periodically asked questions about it. This approach can distinguish between under-mentalizing, involving insufficient mentalistic reasoning resulting in incorrect, reduced mental-state attribution, and non-mentalizing involving a complete lack of mentalism in which a participant may fail to use any mentalistic term whatsoever in explaining behaviour. But crucially for the diametric model, the test can also assess hyper-mentalism, reflecting over-interpretation of mental states.
As the authors comment, this study is the first to use a mentalistic task that resembles the demands of social cognition in everyday-life to examine mentalizing difficulties in relation to borderline personality disorder (BPD) traits in adolescents. Although other studies have investigated aspects of emotional processing in young people diagnosed with BPD, this is the first to use a task specifically developed to assess mentalizing impairment in a psychiatric disorder by considering both insufficient mentalistic reasoning and a complete lack of mentalizing. The study found that neither under-mentalizing nor complete absence of mentalizing was linked to borderline traits. By contrast, hyper-mentalizing ("over-interpretive mental-state reasoning") was strongly associated with borderline features in adolescents.
According to the diametric model, BPD is a PSD and as the authors note, these adolescent BPD subjects showed the opposite tendency to ASD adolescents: where they hyper-mentalized and over-interpreted social cues, autistics symptomatically under-interpret social signs and fail to mentalize sufficiently.
In the words of the authors, "the current study adds to the growing body of evidence linking varying types of social-cognitive dysfunctions to particular psychiatric disorders and specifically linking hypermentalizing to borderline traits in adolescents. Taken together, these results confirm clinical, and theoretical evidence that, in patients with borderline personality disorder, the dysfunction of mentalization is more apparent in the emergence of unusual alternative strategies (hypermentalizing) than in the loss of the capacity per se (no mentalizing or undermentalizing)."
They add that "Hypermentalizing, which involves overinterpreting social cues in others, in turn, derails the emotion regulation system spinning the adolescent into a vicious cycle of overinterpreting what others are thinking and being unable to regulate the anxious rumination caused by this overinterpretation"--just as the diametric model predicts.
Let's hope that many other researchers begin to use tools like MASC to test the predictions of the diametric model and resolve once and for all the confusions surrounding the true meaning of mentalistic deficits in illnesses on both sides of the autism-psychosis spectrum.
(With thanks and acknowledgement to Bernard Crespi)