EXPLAIN HOW BIOLOGICAL FACTORS MAY AFFECT ONE COGNITIVE PROCESS By Yulia

Command Term Give a detailed account including reasons and causes Explain Biological factor – hippocampus Cognitive process - memory

Hippocampus Brain structure which lies under the medial temporal lobe, one on each side of the brain Critical for the formation of autobiographical and fact memories Functions as a memory “gateway” through which new memories pass before entering permanent storage Hippocampal damage can result in anterograde amnesia – loss of ability to form new memories, although older memories may remain Only affects declarative memory – procedural memory is unaffected and memories for new skills and abilities can be formed

Case study: Clive Wearing Musician in his 40’s Contracted herpes viral encephalitis in 1985, which caused extensive damage to his frontal lobes and the hippocampus Resulted in anterograde and retrograde amnesia – he has less than 30 s memory span and is unable to form new memories; he also cannot recall aspects of his past memories, frequently believing he has just awoken from a coma; unable to control emotions Clive could still remember things that were important to him in his life e.g. his wife and children Yet he cannot remember when he has last seen her, and every time she walks into the room he greets her as if they haven’t seen each other in years His abilities to play the piano and to conduct music are still intact Conclusion: damage to hippocampus, an area required to transfer memories from short-term to long-term memory, leads to inability to form lasting new memories

Milner and Scoville 1957 HM suffered from severe epileptic seizures since he fell off the bicycle as a boy Scoville performed surgery, which involved partial medial lobe resection – 8 cm of brain tissue from the anterior 2/3 of hippocampus was removed, as well as ancus and amygdala HM lost the ability to form new memories = anterograde amnesia; he had suffered some retrograde amnesia of events preceding the surgery, yet his childhood memories remained intact His anterograde procedural memory was totally unaffected e.g. HM was asked to trace a third star in the space between the outlines of two concentric stars, while he could only see the pencil and paper through a mirror; he improved over repeated trials, but had no memory of previous attempts Conclusion: the surgery to remove part of the hippocampus, the uncus, and amygdala resulted in total anterograde amnesia and partial retrograde amnesia

Evaluation of studies Case studies cannot be generalized to a larger population No data recorded before the incident e.g. the initial memory loss was reported by HM’s mother Both surgery and damage from viral injection affected various parts of the brain, not only hippocampus, so studies invalid

Conclusion After immediate sensory data is temporarily transcribed by neurons in the cortex, it travels to the hippocampus, where special proteins work to strengthen the cortical synaptic connections If the experience is strong enough or is recalled periodically, the hippocampus transfers the memory back to the cortex for permanent storage