Diametric Differences in Seeing the Other’s Point of View

Opposite cognitive perspectives underlie normal cognition.

Posted May 13, 2015

The diametric model of the mind is distinctive in proposing that mentalizing varies along a continuum stretching from extreme autistic deficit on one side to equally extreme psychotic excess on the other. An obvious implication is that tests of mentalizing should reveal pathology at both extremes by comparison to normal. But the problem for the diametric model, as a recent paper recognizes, is that you need to be able to distinguish between not simply pathological and normal mentalizing, but between the excessive hyper-mentalizing that the model predicts you will find in psychotic spectrum disorders and the deficient, hypo-mentalizing symptomatic of autistic spectrum ones.

This study used the Movie for the Assessment of Social Cognition (MASC) described in a previous post and found that hyper-mentalizing (“overmentalizing”) was associated with positive symptoms of schizophrenia and that mentalistic deficits (“under-mentalizing”) were unrelated to symptoms—just as the diametric model predicts. This suggests to the authors that “schizophrenia is characterized by accuracy problems rather than a fundamental lack of mental state concept,” and they conclude that their findings call for the use of more sensitive measures than the “right/wrong”-dichotomy when investigating mentalizing in schizophrenia. Indeed, they go on to cite Abu-Akel and Bailey's (2000)* “hyper-theory of mind,” which anticipated the diametric model and its key concept of hyper-mentalism.

Now Ahmad Abu-Akel, writing with Stephen Wood, Peter Hansen and Ian Apperly, has reported the first study to use just such a more sophisticated measure of mentalizing to show that “co-occurring autistic and psychotic traits can exert opposing influences on performance, producing a normalizing effect possibly by way of their diametrical effects on socio-cognitive abilities.” As these authors also note, this advances, not just measures of mentalizing, but “the notion that some individuals may, to some extent, be buffered against developing either illness or present fewer symptoms due to a balanced expression of autistic and psychosis liability.” They continue:

On the assumption that both autistic tendencies and psychotic proneness exist on a continuum, ranging from typicality to disorder, one approach to evaluating the impact of co-occurring traits on social cognition is by examining the association of autistic tendencies and psychosis proneness among non-clinical populations. This approach allows us to study both schizophrenia- and autism-like socio-cognitive characteristics without the confounding effects of medication or active symptomatology.

To do this, the authors used a test of perspective taking where participants were presented with a computer-generated scenario like that illustrated in A) below. Participants were required to follow the instructions of a male director who stood behind a grid and of a female director who stood in front of it, sharing the participant’s view (C) below). Because the male—but not the female—director’s view of five of the locations on the grid was obscured (B) below), participants had to take the director’s differing points of view into account when interpreting that director’s instructions to move objects on the grid by means of clicking and dragging the object with a mouse.

Image courtesy Ahmad Abu-Akel
Source: Image courtesy Ahmad Abu-Akel

Additionally, there were critical objects varying in size or shape (e.g., different sizes of block: X, Y above in C) which participants had to take into account when following instruction (e.g., to “Move the large block…”). Some trials involved two critical objects described by the same word (e.g., a computer mouse and its animal equivalent) of which only one was visible to the director. In both cases, correct responses required participants to ignore a potential object that was not visible from the director’s view, and select one that was (D) above). As the authors point out, “this task captures a critical social component of interpersonal communication that relies on efficient use of perspective-taking abilities”—in other words, seeing things from another person’s point of view.

Two hundred and one healthy adults participated whose proneness to psychosis was assessed using the positive scale of the Community Assessment of Psychic Experiences (CAPEp) Questionnaire, and tendencies to autism were assessed using the Autism Spectrum Quotient (AQ) Questionnaire. The figure below provides a 3-D representation of the relationship revealed between autism tendencies, psychosis proneness, and the probability of making perspective-taking errors. The negative scores represent low tendencies and the positive scores represent high tendencies.

Image courtesy Ahmad Abu-Akel
Source: Image courtesy Ahmad Abu-Akel

Referring to the figure above, these authors comment that

the performance of participants presenting with high tendencies to both disorders is similar to participants presenting with low tendencies to both disorders. Thus the association of the interaction between autistic tendencies and psychosis proneness with a decrease in mentalizing difficulties can be seen as support for the diametrical model () which posits that autism and schizophrenia have opposing effects on behavior and cognition.

But how is this to be explained? The authors speculate that overly narrow information selection in tests such as this can lead to under-mentalizing, whereas overly broad selection can lead to over-mentalizing. Information capture tends to be slow in autism due to increased focus of attention, and fast in individuals with positive schizotypy/ schizophrenia. In this way, these different mentalizing styles characteristic of autism and schizophrenia could compensate for one another.

Indeed, the attenuating effect observed in individuals presenting with high expressions in both autism and psychosis traits graphically revealed in the figure above predicts the presence of a brain mechanism that can accommodate the co-existence of these contrasting cognitive styles. The authors note that “The anti-correlational nature of the default mode network (associated with mentalistic thinking) with the task positive network (associated with mechanistic thinking) (...) is a promising neural framework to investigating these contrasting mentalizing styles in autism and schizophrenia” as I also pointed out in a previous post.

Abu-Akel, Wood, Hansen, and Apperly conclude as follows:

Our study is the first to observe that co-occurring autistic and psychotic traits can exert opposing influences on socio-cognitive performance. Reminiscent of the ‘normality effect’ that is observed in certain co-occurring diametrical pathologies such as Parkinson’s disease and hemiballismus (…), our findings thus raise the possibility that autism-schizophrenia comorbidity can have an attenuating effect on socio-cognitive difficulties. More broadly, this suggests that some individuals may, to some extent, be buffered against developing either illnesses or present fewer symptoms due to a balanced expression of autistic and psychosis liability, and will only be diagnosed at the extreme state of either illness. In this regard, our analytical approach of indexing these factors in terms of bias and additive effects is potentially a useful framework to understanding the effect of common risk factors.

* Abu-Akel A, Bailey AL. The possibility of different forms of theory of mind impairment in psychiatric and developmental disorders. Psychological medicine. 2000; 30 (3):735-8.

(With thanks to Ahmad Abu-Akel, Amar Annus, and Bernard Crespi for their help.)