Specific cognitive training normalizes auditory sensory gating in schizophrenia : a randomized trial

Abstract

Background: The ratio of scalp-recorded brain responses occurring 50 msec after paired clicks (S2-evoked P50/S1-evoked P50) serves as a measure of sensory gating. An abnormally large ratio is commonly found in schizophrenia and is considered as a sign of reduced sensorygating or otherwise dysfunctional organization of the auditory/verbal system as a factor contributing to psychopathology and cognitivedysfunction in schizophrenia. This initial randomized clinical trial compared the efficacy of two 4-week, computer-based cognitive trainingmethods that emphasize either auditory discrimination and verbal memory or a broader range of cognitive functions in schizophrenia.Methods: Thirty-nine schizophrenia patients (ICD-F20.0 diagnosis) were assigned to Cognitive Exercises (CE) or Cognitive Package (Cogpack).The M50, the magnetoencephalographic analogue of electroencephalographic P50, and performance on verbal learning andmemory tests were used to evaluate training effects.Results: As expected, patients exhibited higher pretreatment gating ratios than 28 age-matched healthy comparison participants. Gatingratios decreased after CE but not after Cogpack. Cognitive test performance improved more after CE than after Cogpack.Conclusions: Appropriately specific psychological training changes the neural performance in schizophrenia, normalizing sensory and cognitive function.