Study on Temporal and Spatial Patterns of Brain in Emotional State Based on Steady State Visual Evoked Potentials

Abstract

The high signal-to-noise ratio steady state visually evoked potential (SSVEP) signal has been used in many brain computer interface (BCI) experiments and cognition task. In this paper, we used steady-state probe topography (SSPT) to analyze the brain patterns in processing different emotional pictures. We used pleasant, unpleasant and neutral pictures from the International Affective Picture System (IAPS) that were either presented in intact or phase-scrambled form. Pictures were flickering at 10Hz and enabled us to record steady-state visual evoked potentials. Global Power of the electroencephalogram (EEG) signals were computed to yield four time windows, P2, P3, late P3, and slow wave (SW), respectively. SSVEP amplitudes for different emotional pictures were extracted in these windows and submitted to paired-t test. Significantly differences were found between emotional and neutral pictures mainly at both late P3 and SW intervals, as well as at frontal, left parietal, occipital regions as reflected in a significant drop in SSVEP amplitudes. These results revealed the key time windows and brain regions in emotional cognition task.