An interaction between cognition and physiology can be demonstrated through the localization of function of the hippocampus (physiological factor) pertaining to memory (cognitive factor). Localization of function (LOF) is the theory that different parts of the brain correspond to different functions. In cognitive psychology, memory can be defined as the process through which humans encode, store and retrieve information. Removal of the hippocampus has been linked to the onset of amnesia, memory deficit due to brain damage. This suggests the hippocampus plays a role in the consolidation of memories from short term to long term. LOF is valuable to neuropsychology and neurology as it informs our understanding of neurophysiology and allows us to identify biological abnormalities and their effect on behavior such as within dementia. In this case, an interaction between cognition and physiology is assumed, where the hippocampus enables cognitive encoding of information.
             HM was a man who underwent brain surgery where his hippocampus and adjoining areas were removed by Dr. William Scoville, due to severe epilepsy. Milner's 1957 case study of HM established that HM developed severe anterograde amnesia after the operation. Anterograde amnesia refers to memory impairment following brain damage that affects post-operative memories. HM showed an inability to form new long-term explicit memories. Long-term memory refers to a permanent store of information retrievable for later use, split into two types: explicit (facts and events) and implicit (skills). Encompassed in explicit long-term memory is semantic and episodic memory. Semantic memories are those considered to be general knowledge. HM's inability to form new semantic memories manifested partly through prosopagnosia pertaining only to those he met after surgery. Prosopagnosia is the inability to recognize faces, where the structure of a familiar face constitutes general knowledge (accord...