Ajustement comportemental et mouvements de saccades oculaires dans la schizophrénie

Abstract

AimsEye movements have been used for diagnostic purposes in psychopathology since the 1980s. While this investigation has demonstrated some relevance, only smooth pursuit (regular pursuit or tracking) has been the subject of investigations, whether in this discipline, in cognitive psychology or in ergonomics. Yet there is a second category of movements implicated in charges in eye movement, that is to say saccades (shifting from one fixed point to another), which have not been scientifically investigated in psychopathology, or at least not in situations of interaction. MethodsIn order to measure the frequency of oculo-motor saccades in the dynamics of discourse and dialogue, we developed a system for simultaneous recording of visual-motor behaviour and verbal behaviour. This was tested in a clinical setting with the dyad “schizophrenic–psychologist”, in comparison with the dyad “typical subject–psychologist”. These involuntary movements in the control of attention are liable to provide precise information to confirm or anticipate diagnosis, and also information on the behavioural adaptation strategies of the different protagonists in the clinical interviews. ResultsOnce converted into attention indicators, our results show that the number of saccades per second enables a differentiation of the conversational interaction behaviour between subjects with schizophrenia and control subjects. Likewise, this indicator enables the assessment of behavioural variations adopted by the psychologist protagonist in the dyad, when interacting with subjects with schizophrenia or with controls. DiscussionNot only is measurement of ocular saccades perfectly suited to clinical situations, it also confirms the main results provided by measures of smooth, linear, eye pursuit, in particular in the area of diagnosis. However; this type of measure also enables analysis of the asymmetric behaviours of patient and interviewer. Finally, the indicators for variations in attention provided by saccades could be combined with analysis of shifts in points of fixation, and then related to analyses of discontinuities in discourse and other language features among patients seen in psychiatric care. ConclusionThis article thus aims to anticipate the development of a diagnostic strategy (confirmatory and then prodromic) and a considerably more heuristic clinical analysis than what we have available today. It could be based on a combination of a modelling of visual-motor behavioural attitudes and verbal skills and behaviours.