The prefrontal cortex is found in the cortical regions of the frontal lobe of the brain and is thought to be involved in behaviors such as perception, memory, judgment, and reasoning, as well as the expression of social behavior and personality. The connection between the prefrontal cortex and memory arises as this part of the brain seems to play a key role in controlling working, or short-term, memory. The exact workings of the brain have yet to be uncovered but imaging technology has led to increased knowledge of the processes involved in memory. Research into short-term memory disorders such as schizophrenia has shed light on the connection between the prefrontal cortex and memory.
Neurologists work on the basis that there are two types of memory — long-term and short-term. Short-term, or working memory, is the information that is in use at any one time. Information is first gathered by the senses and this is held temporarily in the sensory memory. If the image that inspired the sensory memory is concentrated on for more than eight seconds, the stimulus is encoded into short-term memory. What happens to the memory after that depends on how the information is processed — it can either be rehearsed or repeated, stored in long-term memory or lost.
The connection between the prefrontal cortex and memory is one that is still being examined though a lot of progress has been made since the first use of advanced imaging techniques in 1997 showed what happens when the brain holds sensory stimuli in working memory and then the activity involved in the recall of that information. Because there are no actual physical changes in the synaptic connections involved in short-term memory, it is difficult to determine whether working memory is plastic in nature or dynamic. In the former theory, short-term memory would be formed by the temporary changes in the synaptic transmissions whereas in the latter theory, memories are held electrically within a loop and form a feedback circuit.
Its position at the front of the head behind the forehead makes this area of the brain very vulnerable. Because of the connection between the prefrontal cortex and memory, particularly working memory, any damage to the former will likely lead to an impairment of the latter. The functions of this part of the brain include planning, attention and decision making and the organization of the distributed information contained in the nervous system. Within the prefrontal cortex, high concentrations of nerve fibers containing dopamine, a neurotransmitter which conveys messages to the neurons via synapses, are integral to the processes determining working memory.