• Journal of Biomedical Engineering Research
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• v.29 no.1
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• pp.73-81
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• 2008

The purpose of this study is to observe the brain activity patterns during visual oddball tasks with two difficulty levels by the analysis of high-density event-related potential (ERP). Along with conventional statistical analysis of averaged ERP waveforms, we applied independent component analysis (ICA) for the individual, single-trial analysis and verified its effectiveness. We could identify multiple ERP components such as early visual components (P1, N1), and two components which seem to be important task-related components and showed difficulty-dependent variability (P2, P300). The P2 was found around central region at $180{\sim}220ms$, and the P300 was found globally at $300{\sim}500ms$ poststimulus. As the task became difficult, the P2 amplitude increased, and the P300 amplitude decreased. After single-trial ERPs were decomposed into multiple independent components (ICs), several ICs resulting from P2 and P300 sources were identified. These ICs were projected onto scalp electrodes and the projected ICs were statistically compared according to two task difficulties. For most subjects, the results obtained from single-trial/individual analysis using ICA gave the tendencies of amplitude change that are similar to the averaged ERP analysis for most subjects. The temporal pattern and number of ICs corresponding to ${\mu}$ rhythm was not dependent on the task difficulty. It seems that the motor response was not affected by the task difficulty.

• Journal of Korea Multimedia Society
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• v.20 no.12
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• pp.1856-1864
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• 2017

The ultimate goal of multimedia in bio-signal research is to approach multimedia contents through bio-signal. Hence it is important to interpret user's emotions by analyzing his or her bio-signals. In this paper, we construct ERP task of oddball component to analyze EEG signal between normal stimuli and fear stimuli and measure EEG during ERP task. The results from extracted ERP component show that there is a difference in N200 in visual stimuli, P300 in auditory stimuli, and N100 and P300. Moreover, there are larger changes in audiovisual stimuli, indicating that users recognize greater fear of crime when visual and auditory stimuli are simultaneously presented.

• Science of Emotion and Sensibility
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• v.13 no.1
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• pp.179-186
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• 2010

The present study is a partial extension of the Duncan-Johnson and Donchin (1979) and Soskins, Rosenfeld, and Niendam (2001) studies that found some effects of high pass filter (HPF) setting on P300 waveform. EEGs were recorded while the subjects performed a visual three-stimulus oddball task, and the Fz and Pz EEG signals were passed through 0.01 Hz, 0.3 Hz, and 1.0 Hz HPFs. P300 amplitudes at Fz and Pz were reduced at 1.0 Hz HPF compared to 0.01 Hz and 0.3 Hz HPFs. The negative peaks post P300 at Fz and Pz were not observed at 0.01 Hz HPF, but observed at 0.3 Hz and 1.0 Hz HPFs. The combination of 0.3 Hz HPF and peak-to-peak P300 measures was more useful than that of 0.01 Hz, 0.3 Hz, or 1.0 Hz HPF and baseline-to-peak P300 measures to discriminate between non-target and standard stimuli. The peak-to-peak P300 measures were more useful than the baseline-topeak P300 measures at 1.0 Hz HPF setting.