Explain how biological factors may affect one cognitive process
Memory is essential to human beings. It’s not only the brain’s main function, but is also used everyday without us noticing: we acquire new information, store it, retain it and might retrieve it if needed. It’s thanks to memory and its three main stages: encoding, storage and retrieval, that humans can operate and recall events and information on a daily basis with no difficulty or effort whatsoever. In 1960, it was claimed that there was more than one memory system. Researchers Atkinson and Shiffrin (1968) suggested ‘the multistore model’, consisting of the three key types of memory stores: the sensory store, the short-term store (STS) and the long-term store (LTS). In order for memory to move from sensory to short-term, attention was needed, for short-term to long-term, rehearsal was needed, and to access long-term memory, retrieval was required. Furthermore, scientists have been able to map out the many different structures of long-term memory. LTM is firstly divided into two different systems: explicit memory- consisting of fact-based information, which can be recovered, and implicit memory- consisting of memories that we aren’t consciously aware of. Explicit memory is further divided into two ‘subsystems’: semantic memory- used for general knowledge, and episodic memory- memory of personal experiences and events. In contrast, implicit memory can be divided into numerous ‘subsystems’. These include procedural memories- consisting of how to do things, and emotional memories- consisting of memory of how emotional states. Scientifically speaking, the temporal lobe is where memory is stored. This is where the brain stores everything one remembers. The hippocampus is also responsible for a part of memory. This is where the process of new memories is introduced into long-term storage. If the hippocampus is damaged or absent, one would not remember what is happening in the present, but only remember what happened in the past. It’s in the frontal lobe that memory is recalled - this is where the brains explores and recalls important information. In this essay, I’m going to look at three cases, which study how memory is affected after a negative impact, such as an accident or a virus.
The first study I’m going to look at is HM’s case. HM was born in America in 1926. He fell off a bicycle at the age of 7, injuring his head. Three years later, he began suffering from minor epileptic seizures. By the age of 27, the frequency and severity of the attacks had prevented him from leading a normal life (it was taken into account that his family had a history of epilepsy). In the 1950s, HM was having approximately 10 seizures as well as blackouts a week. After many unsuccessful drugs recommended, he was suggested Dr. Scoville, who localized his seizures in the temporal lobe. Scoville then performed an experimental procedure called a bilateral medial temporal lobe resection. He therefore removed a large percentage of the temporal lobe from both left and right hemispheres, which resulted in extensive and severe damage. Tissue was taken out of the temporal lobes on the inner surface of the brain (extending 8cm), therefore the amygdala, two thirds of the hippocampus, the entorhinal and perirhinal cortices were removed. Although the surgery was successful in stopping the frequent epilepsies (he only had about two seizures a year), HM’s memory was diagnosed with profound anterograde amnesia and partial retrograde amnesia: he could no longer store new memories – most of his memories that dated from before the operation remained intact (partial retrograde amnesia); he couldn’t transfer new semantic and episodic memories into his long-term store; he was able to have a normal conversation, but forgot what it was about almost instantly. Thanks to this case, psychologists and scientists learnt about the relationship between the brain and memory. For example, HM was able to retain...
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