Abstract
The sensorimotor area, supplementary motor area, and cingulate cortex of the frontal medial wall are important regions for the generation and control of movement. Traditionally, investigations into the control of movement were performed using neuroimaging and electroencephalography recordings with subdural electrodes. Recent advances in electroencephalograph analysis with dipole-tracing analysis incorporating a realistic three-layer head model (scalp-skull-brain head model) provide a non-invasive method for the detection of dipoles in the millisecond range. These advances allow investigations into the underlying processing of cognitive function and movement execution. In the present study, we constructed a scalp-skull-brain head model from Montreal Neurological Institute standard brain images and detected dipole localizations in the millisecond range from the grand-averaged negative slope to motor potentials during a simple pinching movement. We used dipole analysis of the grand average for all subjects, incorporating the Montreal Neurological Institute standard brain images, and show the involvement of general locations related to the task. For left hand pinching, the electroencephalograph revealed the order as Bereitschafts potential, negative slope, motor potential. The dipoles were converged in the same order in the supplementary motor area proper, cingulate motor area, and in the sensorimotor area, area for hand motor area. A similar pattern was observed for right hand pinching movement. We show that the dipole converges in the contralateral side of the hippocampus and amygdala before the onset of the Bereitschafts potential. Since the hippocampus and amygdala are associated with the limbic cycles, our findings suggest that both the hippocampus and amygdala are required for the function of the cortico-basal ganglionic thalamocortical loop. Together, this study suggests that strong emotional factors must exist before intentional movement, and before activation of the higher cortical centers.
