Memory Physiology 

Brain areas involved in the neuroanatomy of memory such as the hippocampus, the amygdala, the striatum, or the mammillary bodies are thought to be involved in specific types of memory. For example, the hippocampus is believed to be involved in spatial learning & declarative learning, while the amygdala is thought to be involved in emotional memory. Damage to certain areas in patients & animal models & subsequent memory deficits is a primary source of information. However, rather than implicating a specific area, it could be that damage to adjacent areas, or to a pathway traveling through the area is actually responsible for the observed deficit. Further, it is not sufficient to describe memory, & its counterpart, learning, as solely dependent on specific brain regions. Learning & memory are attributed to changes in neuronal synapses, thought to be mediated by long-term potentiation & long-term depression.

Hebb distinguished between short-term & long-term memory. He postulated that any memory that stayed in short-term storage for a long enough time would be consolidated into a long-term memory. Later research showed this to be false. Research has shown that direct injections of cortisol or epinephrine help the storage of recent experiences. This is also true for stimulation of the amygdala. This proves that excitement enhances memory by the stimulation of hormones that affect the amygdala. Excessive or prolonged stress might hurt memory storage. Patients with amygdalar damage are no more likely to remember emotionally charged words than nonemotionally charged ones. The hippocampus is important for explicit memory. The hippocampus is also important for memory consolidation. The hippocampus receives input from different parts of the cortex & sends its output out to different parts of the brain also. The input comes from secondary & tertiary sensory areas that have processed the information a lot already. Hippocampal damage might also cause memory loss & problems with memory storage.