APA Dictionary of Psychology

n. (pl. thalami) a mass of gray matter, forming part of the diencephalon of the brain, whose two lobes form the walls of the third ventricle. It consists of a collection of sensory, motor, autonomic, and associational nuclei, serving as a relay for nerve impulses traveling between the spinal cord and brainstem and the cerebral cortex. Specific areas of the body surface and cerebral cortex are related to specific parts of the thalamus. Many structural and functional regions of the thalamus have been identified, including the dorsomedial nucleus, the lateroventral nucleus, and the ventroposterior nucleus. See also epithalamus; subthalamus. —thalamic adj.