Adult Article Corpus Callosum Depressive Disorder, Major Diffusion Tensor Imaging Gyrus Cinguli Humans Libet Nerve Net Prefrontal Cortex Ventral Striatum White Matter adult anatomy anatomy and histology anterior cingulate awareness of intent brain-machine interface cerebrospinal fluid cingulate gyrus cingulum (brain) controlled study corpus callosum corpus striatum decision depression diagnostic imaging diffusion tensor imaging functional connectivity human