Q49.4-3CC - Campbell Biology

Question

Suppose that a person with damage to the hippocampus is unable to acquire new long-term memories. Why might the acquisition of short-term memories also be impaired?

Step-by-Step Solution

Answer

The hippocampus is in charge of organizing new information. Without hippocampal function, the linkages required to obtain information from the cerebral cortex are absent, and no functional memory, short- or long-term, is generated.

Step 1: Short and long term memories

Storage is the more or less passive act of preserving information in the brain, whether in sensory memory, short-term memory, or longer-term memory. 

Each of these levels of human memory functions as a sort of filter, protecting one from the torrent of information that confronts one regularly, preventing information overload, and keeping one regular.

Step 2: Role of the hippocampus in memories

The hippocampus is an element of the limbic system. The limbic system is a region of the brain connected with memory, compassion, and desire. The limbic system is placed immediately above and below the cortex or just above the brain stem. Hence, the hippocampus is intimately linked to memories.

Step 3: Loss of hippocampus leads to impairment of short-term memory acquisition

Information is obtained in short-term memory through temporary linkages generated in the hippocampus. When long-term memories are formed, the interconnections in the hippocampus are displaced by connections inside the cerebral cortex.

The hippocampus assists in the formation of new long-term memories but not their maintenance. This hypothesis easily explains the symptoms of certain people who have hippocampal damage. 

They cannot generate new long-term and short-term memories, but they can recall experiences that occurred before their injury. In effect, their loss of normal hippocampus function keeps them trapped in the past.