ABSTRACT
The somatic nervous system comprises the sensory and motor nerves of the peripheral nervous system, together with their associated parts in the central nervous system, all needed to control conscious actions and mental activities. Regarding mental processing, in cognitive psychology the common concept is that information must pass through three stages of mental processing: sensory input, short-term memory, and long-term memory. The simplest model of mental work has two distinct phases: first, the evaluation of occurring events and, then bringing about changes, the execution. In the 1920s, E. H. Berger attached metal electrodes to the skin of the head and recorded brain waves, electrical neural activity of the brain, the encephalon, via electroencephalograms. The body can perform some motions without the involvement of the brain proper; yet most muscular activities need fine regulation. The cerebrum consists of dense, convoluted masses of tissue divided into two halves, the left and right cerebral hemispheres, connected by nerve fibers.
