2867 – Behavioral and Brain Measures of Semantic Priming in Patients with Schizophrenia: Test-Retest Effect in a Longitudinal Study

Objective:The purpose of the present study was to investigate whether deficits of behavioral or/and N400 semantic priming (SP) effect observed in patients with schizophrenia is a stable cognitive feature of the disorder or whether it may be influenced by the severity of the actual symptomatology that may fluctuate over time.Methods:A Test-Retest one year study was conducted on fifteen patients with schizophrenia and 10 healthy participants who performed a SP task. Both behavioral measures and Event-related potentials (ERPs) of SP were recorded twice (Test and Retest sessions).Results:At Test, patients exhibited a deficit of SP as revealed by both the behavioral and the ERP measures (the amplitude of the N400 component). At Retest, behavioral SP remained impaired in contrast to the N400 SP which was significantly improved in relation probably to the patients' clinical improvement.Conclusion:The results conveyed evidence that the N400 SP impairments in schizophrenia may not be considered as stable cognitive markers of the disorders. Significance: The behavioral and the N400 measures of SP had different level of sensitivity to subtle cognitive and brain processes which were subjected to change over the clinical course of schizophrenic disorder.