An eye-tracking investigation of intentional motion perception in patients with schizophrenia

Background: schizophrenia has been characterized by an impaired attribution of intentions in social interactions. however,it remains unclear to what extent poor performance may be due to low-level processes or to later,higher-level stages or to what extent the deficit reflects an over- (hypermentalization) or underattribution of intentions (hypomentalization). methods: we evaluated intentional motion perception using a chasing detection paradigm in individuals with schizophrenia or schizoaffective disorder and in healthy controls while eye movements were recorded. smooth pursuit was measured as a control task. eye-tracking was used to dissociate ocular from cognitive stages of processing. results: we included 27 patients with schizophrenia,2 with schizoaffective disorder and 29 controls in our analysis. as a group,patients had lower sensitivity to the detection of chasing than controls,but showed no bias toward the chasing present response. patients showed a slightly different visual exploration strategy,which affected their ocular sensitivity to chasing. they also showed a decreased cognitive sensitivity to chasing that was not explained by differences in smooth pursuit ability,in visual exploration strategy or in general cognitive abilities. limitations: it is not clear whether the deficit in intentional motion detection demonstrated in this study might be explained by a general deficit in motion perception in individuals with schizophrenia or whether it is specific to the social domain. conclusion: participants with schizophrenia showed a hypomentalization deficit: they adopted suboptimal visual exploration strategies and had difficulties deciding whether a chase was present or not,even when their eye movement revealed that chasing information had been seen correctly. © 2015 8872147 canada inc.