REACTION TIME AND IMPLICIT LEARNING IN PATIENTS WITH MULTIPLE-EPISODE SCHIZOPHRENIA

Cognitive impairment in schizophrenia involves multiple cognitive functions, especially memory, attention, motor skills, executive functions and intelligence. Our study set out to outline and assess impairments of executive functions in multiple episode schizophrenia patients, particularly reaction time, response selection and implicit learning. The study involved a number of 39 patients diagnosed with schizophrenia according to DSM-IV-TR criteria, with at least one prior psychotic episode, and 30 controls with no family or personal history of psychiatric disorders. Both groups were assessed through the Set Shifting Test and the Go-No-Go Test on a Cogtest Console (Cogtest, Inc.). The results of the Set Shifting Test revealed that implicit learning, expressed in the decrease of reaction times in response to stimuli sequences, occurs to a similar extent in multiple episode schizophrenia patients and in controls. However, implicit learning leads to a significantly higher number of erroneous responses in schizophrenia patients. The Go-No-Go Test revealed an augmentation of reaction times in the case of patients, when the task involved selection between the execution and non-execution of a response. Moreover, patients with schizophrenia recorded a significantly higher rate of errors whenever non-execution of response was the correct response for the task.