the layer of gray matter that covers the outside of the cerebral hemispheres in the brain and is associated with higher cognitive functions, such as language, learning, perception, and planning. It consists mostly of neocortex, which has six main layers of cells (see cortical layers); regions of cerebral cortex that do not have six layers are known as allocortex. Differences in the cytoarchitecture of the layers led to the recognition of distinct areas, called Brodmann’s areas, many of which are known to serve different functions.
n. a graphic tracing of some aspect of heart activity, usually electrical activity (see electrocardiogram). The tracing is produced by the stylet of a recording instrument called a cardiograph, and the procedure itself is called cardiography.