APA Dictionary of Psychology

any of the regions of the cerebral cortex that receive the main input from sensory receptors or send the main output to muscles. Examples are the primary motor cortex, primary visual cortex (see striate cortex), primary taste cortex, and primary somatosensory area. The primary motor cortex has a lower threshold for elicitation of motor responses than do adjacent motor cortical regions. Most neurons in primary sensory regions have more direct sensory input than do neurons in adjacent sensory cortical regions.