Action information processing

Human Information-Processing A view of the human operator as an information-processing system. Information-processing models are convention-aUy expressed in terms of diagrams which indicate the flow of information throu stages such as perception, decision-making, and action. 

Rule-Based Level of Control In the context of chemical industry tasks, the type of human information processing in which diagnoses are made and actions are formulated on the basis of rules (e.g., "if the symptoms are X then the problem is Y"). 

Skill-Based Level of Control A mode of information processing characterized by the smooth execution of highly practiced, largely physical actions requiring little conscious monitoring. 

Intelligence It has an internal information processing and decision-making capability by which it uses local information to select actions. 

Dopamine is a catecholamine (see Chapter 10 and Fig. 31.2) whose actions are mediated by dopamine receptors that are classified as Dj-like (Dj, D5) or D2-like (D2, D3, D4). Dopamine actions on Dj receptors exert an excitatory effect, whereas the actions of dopamine on D2 receptors inhibit neuronal activity. The loss of striatal dopamine produces an imbalance in information processing in the neostriatum that modifies transmission in other basal ganglia regions. Also important in neural transmission are the striatal interneurons that are found within the confines of the striatum, that use the excitatory neurotransmitter acetylcholine, and that modulate the activity of striatal output neurons. 

Information processing in the human brain via neuro-chemically defined neuronal systems is complex. Therefore, it remains a challenge to conceptualize psychiatric disorders and their treatment in a reductionistic framework of chemical neuroanatomy. We can nonetheless broadly state that the anatomic organization of neurotransmitter systems determines their behavioral affiliation, and that receptors modulate the electrical or biochemical properties of neurons, with direct relevance to the mechanism of action of psychotropic drugs. Future research will provide more detailed information on the subtypes of neurons and specific neurotransmitters systems that are abnormal in psychiatric disorders, and provide a more rational approach to the development of new treatment interventions. 

Information processing in the brain, therefore, includes electrochemical processes. Action potentials are electrical impulses, but the messages they carry are generally mediated by chemicals. These chemicals are known as neurotransmitters since they transmit messages between neurons as well as between neurons and muscles or glands. The following sidebar discusses neurotransmitters in more detail. 

---