Study on sharp power spectrum change on alpha frequency band after Direction-Cue

Abstract

The purpose of our study is to obtain knowledge of decision-making related to movements.

We especially focus on the EEG signals when the Direction-Cue is presented to a subject. The Direction-Cue indicates the direction to press a button. In this paper, we investigate the variation of power spectrum in alpha frequency band (8-12Hz) by the time-frequency analysis.

We perform an experiment on pressing a button over 11 subjects. In this experiment, two cues are shown to subjects. First cue is called the Direction-Cue, and the other cue is called the Go-Cue. The Go-Cue indicates a starting time to press a button by beep sound.

As the results from the short-term Fourier transformation, we obtained two features of power spectrum change. 1) The sharp change of the ERS occurred after 200～500[ms] in presenting the Direction-Cue. 2) The sharp change of ERD occurred after 800～1000[ms]in presenting the Direction-Cue.