Grand average waveforms of changes in [oxy-Hb] (red), [deoxy-Hb] (blue) and [total-Hb] (green) during the Shiritori task. For each channel, the x-axis denotes time from 0 to 160 s and the y-axis denotes activation between −0.8 and 0.8 mM∙mm. The Shiritori task period is marked by two vertical dashed lines at 10 and 100 s. CH, channel. (PDF 830 kb)