Comparison of Global Field Power Measurement and Conventional Method in Multi-channel Auditory Event Related Potential P300 Determination

OBJECTIVE: The present study was designed to compare Global field Power Measurement and conventional method in P300 determination. METHOD: The subjects were composed of patients(N=20) with schizophrenia by DSM-IV and normal controls(N=20). The auditory event related potential P300 was measured by "oddball paradigm". P300 components were determined by Global Field Power Measurement and conventional method at 5 electrodes(Fz, Cz, Pz, T3, T4). RESULTS: P300 amplitudes of patients were smaller than those of controls across all electrodes and in both methods, but there was no differential power in P300 determination between two methods. Asymmetry of auditory event-related potential P300 was not shown between patients with schizophrenia and normal controls. CONCLUSION: It is implicated that it depends on clinical situations and research purposes what method of P300 determination will be more appropriate for patients with schizophernia.

Clinical Availability of Topographic Auditory Event Related Potential P300 as a Biological Marker in Patients with Schizophrenia / 신경정신의학

This study was designed to investigate the clinical availability of topographic auditory event related potential P300 as a biological marker in patients with schizophrenia. The subjects were composed of normal controls(N=30) and patients(N=30) with schizophrenia by DSM-IV. Topographic auditory event related potential P300 and N100 were measured by "oddball paradigm", which was known as a standard method. Schizophrenics were evaluated twice, initial and follow-up, by 4 week interval. P300 latency and N100 latency were deter-mined by Global Field Power. At this time point the maximum amplitude and its location, according to X-Y coordinates, were determined in brain topography. Clinical symptoms were evaluated by Positive and Negative Syndrome Scale(PANSS). P300 latencies of normal controls, initial group of schizophrenics, and follow-up group of schizophrenics were 315.8+/-24.2msec, 403.8+/-42.3msec, and 364.7+/-43.2msec, respectively. P300 amplitudes of normal controls, initial group of schizophrenics, and follow-up group of schizophrenics were 8.8+/-2.7microV, 4.4+/-1.9microV, and 4.4+/-2.5microV, respectively. They had significantly different P300 latencies one another by measuring ANCOVA, of which covariables were N100 latency, age, and CCP(correct counted percent)(p<0.01). X-Y coordinates was not significant. In P300, there were some different characters between normal controls and schizophrenics even though excluding N100, which was supposed to be exogeneous component by external stimuli. When clinical symptoms were improved, P300 latency was decreased. However, P300 amplitude was not changed. These results suggest that P300 woald be available clinically as a biological marker, P300 latency be a state marker, and P300 amplitude be a trait marker in schizophrenia.

How to Determine P300 Component in Auditory Event Related Potential Brain Topography / 신경정신의학

OBJECTS: This study was designed to make a comparison between methods to determine the components of topographic auditory event related potential P300. METHODS: The subjects were consisted of 44 normal controls and 44 patients with schizophrenia diagnosed by DSM-IV. The topographic auditory event related P300 was recorded in oddball paradigm. The components of P300, including latency, amplitude, and location of maximum amplitude in X-Y coordinates, were analized by computerized EP mapping system. The latency of P300 was determined by both global field power measurement and classic method. RESULTS: There was difference between two groups in latency(DF=1, F=35.28, P= 0.0001) and amplitude(DF=1, F=36.62, P=0.0001), but not in X coordinate(DF=1, F=0.37, P=0.55) and Y coordinate(DF=1, F=2.00, P=0.16). There was no difference between two mothods in latency(DF=1, F=0.04, P=0.85), in amplitude(DF=1, F=0.07, P=0.79), in X coordinate(DF=1, F=0.07, P=0.79), and in Y coordinate(DF=1, F=0.03, P=0.86). CONCLUSION: The results suggested that two methods to determine the components of topographic auditory event related potential P300 should be available for both research and clinical application to date.

Effects of Cigarette Smoking on Auditory Event-Related Potential P300 / 신경정신의학

OBJECTIVES: The authors studied the effects of cigarette smoking on the cognitive function with topographic mapping of auditory event-related potential P300. METHODS: The subjects, 24 smokers and 14 nonsmokers, were assessed in the latencies and amplitudes of topographic auditory event-related potential P300 determined by Global Field Power Measurement. RESULTS: 1) There were significant differences of P300 latencies between smokers and controls artier smoking(ANOVAL F=10.45, P=0.0026). 2) There were no significant differences of P300 amplitude but a trend was present between smokers and nonsmokers after smoking(ANOVAL F=3.77, P=0.06). 3) There were no significant differences of difference between amplitude in maximal point and amplitude in minimal point but a trend was present between smokers and nonsmokers artier smoking(ANOVAL F=3.68, P=0.063). 4) There were no significant differences of maximal point in X-axis and in Y-axis, minimal point in X-axis and in Y-axis of P300 between smokers and nonsmokers artier smoking. CONCLUSIONS: These results support that auditory event-related potential P300 change by cigarrete smoking is indicative of enhanced cognitive function.