The basic of them all are encoding, storage and retrieval. Your short-term memory (STM) has a limited time till the information is forgotten (10-30 seconds). Long-term memory (LTM) virtually has an unlimited storing capacity. Through process of consolidation and hints or cues you can retrieve past memory's and emotions. Our working memory has three areas: phonological loop, visuospatial sketchpad and central executive. These components basically store audio/visual information and "directs attention to various stimuli and assigns memory space" (Kalat, p. 352).
Many patients with Amnesia, Korsakoff's syndrome and Alzheimer's disease have various memory defects. Many patients with these complications and disease have trouble with putting their memory into words (declarative memory). While others have trouble remembering how do certain things, like physical movements (procedural memory). The patients with damage to the hippocampus region. Suffer from explicit and implicit memory functions. These patients do not that they are using memory or not. Memory is a very important contribution to life, "life with out memory is unlike life" (Kalat, p. 346).
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The biological reasons contributing to the memory process possibly lie within the hippocampus region. Biologically not a lot is known about what goes on in the brain, concerning memory and learning. What we mostly know is that the hippocampus when inflicted with injury, many memory difficulties arise. A result from the removal of the hippocampus is retrograde and anterograde amnesia. In a case with H.M. he finally memorized his way around the house after eight years. With the loss of one region of the limbic system you can acquire new skills, but many patients do not remember learning these skills. Another complication that comes with the removal is Explicit and implicit memory functions.
With us knowing many of the negative functions of the removal of the hippocampus.