Physiology

The brain has many parts. Most of which we are not really concerned withhere. The area we will be discussing, however, is within the forebrain. Infact most of the brain activity relating to classical conditioning occurs withinthe limbic system of the forebrain. In particular, the hypothalmus, whichcontrols some of our involuntary functions. Our eating, drinking, sleep/wakecycles, and body temperature are controlled from the hypothalmus. In addition,our emotional reactions to fear and stress come from the hypothalmus. Thelimbic system as a whole is a relatively new part of the brain, evolutionarily. Animals without this part carry out activities by simple instinctive behavior. Higher animals, such as mammals, inhibit some of their instinctiveness in favorof being more responsive to changes in its surroundings.