Differences in spatio-temporal distribution of the visual P3b event-related potential between young men and women

Here, we evaluated the P3b potential evoked in a visual two-stimulus oddball paradigm. The experiment was conducted in 20 healthy students (23.1±1.1 years, 10 women), using a 32 channel electroencephalography (EEG) montage system. The paradigm included geometric figures; a black square on a white background as a target and a white circle on a black background as a standard stimulus. We examined the maximal amplitude and latency of the P3b component at 18 electrode sites, as well as, temporal changes of scalp voltage distribution. We observed a non-equal spatial distribution of the visual ERP (event related potentials) waveforms on the scalp surface, with the highest P3b waveform observed over midline parietal areas and the lowest over frontal regions. Moreover, the spatial distribution of ERP signal on the scalp surface was more lateralized towards the right side in men and more centralized in women. Gender-related differences in P3b amplitude and latency were observed only in left hemisphere. Differences in P3b between men and women observed in our study arose not only from different P3b amplitudes and latencies, but also from the speed and character of P3b waveform fall, resulting in spatio-temporal amplitude changes. Moreover, the spatial distribution of the P200 potential also changed on the scalp differently in men and women. These results suggest that gender-related differences evoked in visual two-stimulus oddball paradigm, which engage attention processes, are complex and include spatio-temporal changes in P3b waveform generation, distribution, and suppression across the scalp.