The brain is regarded as the central site of memory. However, it is a highly specialized and differentiated organ with many different regions such as the brain stem, the basal brain area, the midbrain and the brain cortex. There is a close link between information perception, processing, storage and retrieval. Only information storage and retrieval are regarded as memory. The major prerequisite for memory is cognition.
Cognition is the process of receiving signals from outside of the organism via our five senses.
Stimuli from outside trigger biochemical reactions in the cells of the central nervous system and certain molecules transduce information from one form to another. These neurotransmitters are responsible for vegetative as well as cognitive performance. The best-known neurotransmitters are adrenaline, its precursor, noradrenaline, and dopamine. If the production of these neurotransmitters can be increased, cognitive performance will improve. The rate limiting enzyme for dopamine and adrenaline biosynthesis is tyrosine hydroxylase.