The Comparison Of The Stroop Color-word Interference Effects And Visual P3 Between Schizophrenia Patients And Normoal People Based On ERP

Objective:To study stroop interference effects and visual P3 in patients with schizoprenia by ERP.Methods:The electrophysiological correlations between the P3 wave in event-relatend potential (ERP) and Stroop color-word interference effects were studied in eighteen patients with schizophrenia and sixteen healthy controls with a 32-leads cap. Four tasks were presented, meaningly the color discrimination, the long-presentation Stroop, the short-presnetation Stroop and the visual oddball paradigm. All of the four tasks'response modes were button pressing. The aims of this study were comparing the reaction time(RT), accuracy rate and ERP extracted from EEG between the patients and healthy controls.Results:(1)Behavioral results The patients' RTs were significantly prolonged (P<0.05) than controls in all the four tasks. The accuracy rate was significantly lower(P<0.05) in patients than that in controls in long-presentation Stroop and visual oddball paradigm. The accuracy rate was lower in patients than that in controls in color discrimination and short-presentation Stroop paradigm, but the differences were not significant(P>0.1). (2) ERP results In color discrimination task, the average amplitude between 350-450ms (N450) of the ERP in controls was larger than that in patients, but the difference was not significant. In both stroop tasks, N450 amplitude and Positive Slow Wave(PSW) between 600 and 800ms were significantly different(P<0.05). N450 amplitude in the patients was larger than that in the controls, and the PSW in the patients was much unsteady. In visual oddball task, the P3 amplitude in patients was significantly reduced(P<0.05), but there was no significant difference in latency.Conclusions:(1) N450 was abnormal in patients with schizophrenia, and abnormalities of the anterior cingulate cortex(ACC) may cause these changes. (2) P3 was abnormal in the patients with schizophrenia, the P3 amplitude was lower, but latency may not be delayed. (3) At lease in simple tasks, the patients with schizophrenia may be not slowed at perceiving and categorizing the stimulus but slowed at selecting, preparing, or executing the appropriate response.