Biological Bases Of Human Memory

Case studies of patients with brain damage/abnormalities and animal models of human memory have informed our understanding of biological bases of human memory. The case study of patient H.M. the hippocampus and the medial temporal lobe were removed. Memory prior to surgery was intact that lead us to believe that long term memory storage is elsewhere. H.M. had perfectly good short-term memory therefore short-term memory storage is elsewhere. However, short-term memories cannot be converted to long-term memory therefore hippocampus and medial temporal lobe are essential to convert short-term to long-term. H.M. could learn motor tasks so hippocampus and medial are not involved with implicit memories but with rather explicit memories (Brain Regions

in Memory, slide 7).
Another patient that helped inform us about human memory was patient K.C.

He had semantic memory but no episodic memory therefore those two types of memory rely on different brain regions. The parahippocampus was intact that is why he had semantic memory. Another finding was that the parahippocampus can slowly absorb new facts if it has to since he was able to learn the Dewey decimal system (Kean, 2014).

A different case study was “Beth” who was born without a heartbeat. She had no memory for any autobiographical events. Albeit, her performance in school was normal. She didn’t have episodic memory but the semantic memory was intact. Beth had a small hippocampus; in spite of this she had an intact entorhinal cortex (EC) and perihinal cortex (PC). Since she had part of her hippocampus this helped inform us about an intact hippocampus is important to have episodic memory. Individuals without a hippocampus have very little to none semantic memory acquisition (Brain Regions in Memory, slides 15-16).

One more case study that helped inform us about human memory was patient E.P. who was diagnosed with viral encephalitis. Consequently he had a bilateral hippocampus destruction. He was unable to form new memories and lacked semantic knowledge. This study shows how damage to the hippocampus disrupts the formation of new explicit memories (Brain Regions in Memory, slide

16).
Animal models have been useful to understand memory. In this specific animal model a rat was trained to locate cheese until it became a long term memory for the location of cheese.
The rat would forget the location for the cheese if all of the cortex was removed. This study has informed us that long term memories are stored diffusely throughout the cortex (Brain Regions in Memory, video in slide 18).

There are 8 factors discussed in class that affect the efficiency of encoding or storing new information.

One factor is how much value something is worth (Toppino, et al., 2010). A second factor is making information personally relevant for instance in a class activity we made personal relevant cues to help us store the words from the list. A third factor is using spaced practice for storing difficult information (Toppino, et al., 2010). In the class activity where a paragraph was read to us not a lot of information was grasped but when we knew it was about laundry the paragraph made perfect sense therefore a fourth factor is recognizing or identify context before learning occurs aids to store that new information. A fifth factor is using mnemonic techniques to help store new information, we had a class example where a long algebra expression was given to us and we could apply the order of operations and we all know the order because of PEMDAS. Another factor is overlearning (mass practice) studying material even when it has been thoroughly learned helps us with retention that information (Toppino., et al., 2010). The primary and recency effect, which helps store information that are at the beginning or end (textbook, page 9). Another factor is presentation time. If something is presented for a longer period of time it helps us store that information versus if something is presented briefly (Toppino., et al.,

2010).