The interactive effect of autism tendencies and psychosis proneness on saliency and theory of mind in the typical population

Difficulties with the ability to appreciate the perspective of others (mentalizing) and saliency-based selection are central to both autism and psychosis spectrum disorders. Both disorders can co-occur in the same individual at both the diagnostic and trait levels. It has been hypothesized that their co-occurrence would lead to greater impairment than would be observed in each of the disorders alone. An alternative theory suggests that these disorders are etiologically and phenotypically diametrical, and thus predicts that these disorders would have opposing effects on these abilities. The current thesis examined these contrasting hypotheses using behavioral, eye-tracking and neuroimaging paradigms, in neurotypical adults in whom both autism tendencies and psychosis proneness were assessed in tandem. The thesis provides converging evidence that autism and psychosis tendencies interactively improve mentalizing abilities as well as target selection in the presence of irrelevant salient distractors. This interactive effect is also discerned at the neuronal level where autism and psychosis tendencies diametrically modulate activity within the attentional and mentalizing subdivisions of the right temporo-parietal junction (rTPJ). These findings suggest that co-occurring autistic and psychotic traits can exert opposing influences on performance, resulting in improvement possibly by way of their diametrical effects on attentional and socio-cognitive abilities