MULTIPLICITY OF REPRESENTATION VERSUS PUNCTATE LOCALIZATION IN THE MOTOR CORTEX

Abstract

During the course of investigations of cortical motor function under the influence of pain impulses originating in the muscles (Gellhorn and Thompson¹) and of afferent impulses from the hypothalamus (Murphy and Gellhorn²) it was observed that stimulation of a discrete focus with condenser discharges at threshold and suprathreshold intensities led to the production of multiple movements instead of isolated muscular contractions restricted to a small bodily subdivision, which have been described repeatedly. On the basis of these observations, it was decided to reinvestigate the question of multiplicity of motor representation versus punctate localization.³ Experiments conducted in this study and their interpretation are the subject of the presentation which follows. A vast and detailed literature concerning motor cortical function has accumulated in the seventyfive years since Fritsch and Hitzig's⁴ epochmaking discovery of the electrical excitability of this part of the brain. The communications of Fritsch and Hitzig