Visualizing human motor activity by using non-invasive optical topography.

To visualize the spatial and temporal hemodynamic changes in the cortex associated with human cortical activity, a 12-channel non-invasive optical topography (NOT) measurement system has been developed. This NOT system, which is based on near-infrared light spectroscopy, can visualize changes in the oxygenation states of human tissue. The hemodynamic changes caused by human motor activity were measured and analyzed using NOT. Five subjects randomly performed unilateral finger opposition during 30 s for motor activation. When the subjects performed contralateral (right) finger movement, significant increases in oxygenated and total hemoglobin were observed around the motor cortex in the left fronto-central region. Significant differences in the hemodynamic changes were observed in four of the five subjects between for contralateral (right) and ipsilateral (left) finger movement around the motor cortex.