Fig. 4
Grand average waveforms of Δ[oxy-Hb] (red), Δ[deoxy-Hb] (blue) and Δ[total-Hb] (green) during left hand grasping (a) and right hand grasping (b). Individual waveforms are displayed on schema of the probe configuration for near-infrared spectroscopy. For each channel, the x-axis denotes time from 0 to 160 s and the y-axis denotes activation between −0.5 and 0.5 mM∙mm. The hand grasping task period is marked by two vertical green lines at 10 and 100 s. The mean value of Δ[oxy-Hb] during the hand grasping task for each channel is color-coded in an ellipse according to the color scale at right. During the left hand grasping task, channels showing markedly elevated Δ[oxy-Hb] were located in the right hemisphere, while many channels showing decreased Δ[oxy-Hb] were distributed in the left hemisphere (a). During the right hand grasping task, channels showing moderate increases Δ[oxy-Hb] were distributed diffusely across the bilateral hemispheres (b). CH, channel