Discusses the origin of the cerebral cortex and its significance. The child's first experience are with completed physiological circuits which are rapidly modified by experience. No sensory impulses reach the cortex but only nervous impulses arising from lower correlation centers are possible. The thalamus of lower vertebrates is the organ of the highest associations. In higher mammals, the higher neural resistance of the cortical pathways has been overcome by summation of stimuli and the cortex is excited to function. The connections between the cortical centers, are not hereditary and the differences between the cortex and the lower centers of the brain are relative and not absolute. The functions of the higher association centers of the cerebral cortex consist of the coordination and integration of highly elaborated subcortical organic circuits which are the reflex and the instinctive life of the species. (PsycINFO Database Record (c) 2006 APA, all rights reserved)