Psychobiology Background Neuroscience Issues

In order to understand how trauma affects psychobiological activity, it is useful to briefly revisit some basic tenets of neurobiology. Paul McLean (1990) defined the brain as a detecting, amplifying, and analyzing device for the maintenance of the internal and external environment. These functions range from the visceral regulation of oxygen intake and temperature balance to the categorization of incoming information necessary for making complex, long-term decisions affecting both individual and social systems. He proposed that, in the course of evolution, the human brain has developed roughly three interdependent subanalyzers, each with different anatomical and neurochemical substrates: (1) the brainstem and hypothalamus, which are primarily associated with the regulation of internal homeostasis, (2) the limbic system, which maintains the balance between the internal world and external reality, and (3) the neocortex, which is responsible for analyzing and interacting with the external world (McLean, 1990).

The circuitry of the brainstem and hypothalamus is most innate and stable, while the limbic system contains both innate circuitry and circuitry modifiable by experience, while the neocortex is most affected by environmental input (Damasio, 1995). It therefore would be expected that trauma would most profoundly affect neocorti-cal functions, and have least effect on structures related to basic regulatory functions. However, while this seems to be true for the ordinary stress response, trauma (stress that overwhelms the organism) seems to affect core self-regulatory functions.

Anxiety and Depression 101

Anxiety and Depression 101

Everything you ever wanted to know about. We have been discussing depression and anxiety and how different information that is out on the market only seems to target one particular cure for these two common conditions that seem to walk hand in hand.

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