The limbic system is a complex set of structures that lies on both sides of the thalamus, just under the cerebrum. It includes the hypothalamus, the hippocampus, the amygdala, and several other nearby areas. Limbic system structures are involved in many of our emotions and motivations, particularly those that are related to survival. Such emotions include fear, anger, and emotions related to sexual behavior. The limbic system is also involved in feelings of pleasure that are related to our survival, such as those experienced from eating and sex. Certain structures of the limbic system are involved in memory as well. Two large limbic system structures, the amygdala and hippocampus play important roles in memory. The amygdala is responsible for determining what memories are stored and where the memories are stored in the brain. It is thought that this determination is based on how huge an emotional response an event invokes. The hippocampus sends memories out to the appropriate part of the cerebral hemisphere for long-term storage and retrieves them when necessary. We can see how this part of the brain would have been essential millions of years ago. Mammals did not have sophisticated weaponry or any means to defend themselves through the use of advanced equipment, their only necessities would have been the procuration of …show more content…
There is no such hierarchal system as this theory implies and the idea that our reptilian ancestor had something to do with the makeup of our brain doesn’t comply with modern understanding. However, we can accept a few general ideas—for example, that some structures in our brains are older than others, from an evolutionary standpoint, and that our emotions involve some relatively primitive brain circuits that have been preserved over the course of mammalian