An investigation of the neurological basis of movement was carried out by studying the responses of single cells in the striate cortex of the unanesthetized cat. Three aspects of movement perception were studied: velocity, direction of movement, and apparent-movement. It was found that the relation between velocity of movement and rate of cell discharge was a power function, that the idea that cells respond to one direction of movement is true only in a statistical sense, and that the cortical mechanisms for real movement probably differ from those for apparent-movement. Several developments in methodology are also described. / Thesis / Doctor of Philosophy (PhD)