Insights on memory
Drs. Christine N. Smith and Larry R. Squire, both with the VA San Diego Healthcare System and the University of California, San Diego, found that declarative memory–recalling facts and events–depends on conscious knowledge of what has been learned. The finding helps explain how the hippocampus controls the process of memory. They also showed that conscious knowledge is compromised in patients with damage to the hippocampus.
Smith sums up the findings by saying, “Our study shows that awareness is a key feature of declarative memory.”
The results appeared in the Nov. 20, 2018, issue of the Proceedings of the National Academy of Sciences.
Past research has shown that damage to the medial temporal lobe (MTL), the brain region that contains the hippocampus, can cause problems with declarative memory. This type of memory, the ability to remember information about past facts and events, has been linked to the hippocampus. It is expressed through direct recollection. Another type of memory–nondeclarative–refers to skill and habit learning, as well as and other types of learning, that are based on performance rather than recollection. Nondeclarative memory does not seem to be affected by MTL damage. For example, a person with MTL damage may still remember how to ride a bike, but might not remember what he or she did yesterday.