Comparing Time Onsets: Does it Require to Mentally Group Items? A Question Derived From Results in Patients with Schizophernia

  • Anne Giersch
  • Laurence Lalanne
  • Mitsouko van Assche


Disturbed temporal event-coding has been repeatedly described in schizophrenia and mayrepresent a core impairment in this invalidating pathology. Impairments have been observedespecially when the task involves simultaneity/asynchrony discrimination. In these tasks, twobars are presented left and right from the centre of the screen and subjects decide if barsappear simultaneously or asynchronously. Patients have a difficulty to consciously detect anasynchrony between stimuli, which can be dissociated from a bias effect. Despite this, ourown results and the literature suggest that patients are very sensitive to very-short durationstimuli. This suggests difficult comparison of time-onsets of separate stimuli, rather than anenlarged time window in which all events would be fused in time. This leads to the question ofthe relationship between spatial and temporal event-coding. We will especially discuss thepossibility that comparing time-onsets requires mental grouping of the compared stimuli.
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