Fig. 3

Grand average waveforms of changes in [oxy-Hb] during the Shiritori task for all channels. 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 task period is shown by two vertical dashed lines at 10 and 100 s. Frames are color coded by channel, as shown in the dendrogram. In the dendrogram each channel is divided into four clusters of different colors by hierarchical cluster analysis (Ward’s method). Numbers indicate the channel numbers. Four waveforms shown in the right panel are representative of Clusters I to IV, made by averaging waveforms in the each cluster. The clusters are ranked from I to IV in descending order of mean changes in [oxy-Hb] of the representative waveform. The colors of the representative waveforms match those of the clusters. CH, channel; *, channel with significant activation