Measuring Time Windows in Patients With Schizophrenia and Healthy Controls

Relating the 'Experienced Present' With the Mechanisms of Neuronal Function: A Comparative Study in Patients With Schizophrenia and Healthy Controls Using Psychophysical and Neurophysiological Methods

Abnormalities in the ability to distinguish events in time may have a great impact on everyday life. The main objective of the study is to evaluate the magnitude of the temporal windows in schizophrenia, i.e. the time interval during which two events are perceived as synchronous. The investigators test the hypothesis that these temporal windows are enlarged, and check the relationship between this impairment and disorganization symptoms, in order to explore the link between this cognitive impairment and clinical symptoms. They explore also the neurobiological bases of the impairment by means of electroencephalogram (EEG) recordings. Event-related potentials (N50) will reveal whether or not the coding of the stimuli has the same temporal characteristics in patients and controls. The distribution and amplitude of oscillatory activities will be analyzed as a function of the synchronous or asynchronous response of the subject, thus allowing to explore the links between synchrony perception and neuronal synchronization phenomena.

Inclusion Criteria:

• Patients with schizophrenia (DSM-IV criteria)
• Healthy controls matched with patients on age, sex and education level
• Age between 18 and 50
• Informed consent signed
• No severe somatic illness
• No invalidating sensory disease
• No drug abuse, as defined by DSM-IV criteria
• No general anesthesia in the past 3 months
• No intake of drug affecting the CNS, except for patients