Emotional and Factual Recall:
The Effects of Damaging the Hippocampus and the Amygdala
In recent studies, psychological physiologists have been able to identify the effects of certain brain damage on both one’s emotional memory and sensory memory. Two areas of the brain that have been studied are the amygdala and hippocampus. Studies on animals have shown that damage onto the amygdala effects emotional conditioning, while damage to the hippocampus eliminates the ability to establish certain knowledge and learning abilities. The effects of damage on to the hippocampus and amygdala in humans had not been sufficiently study until Anotonie Bechara began an experiment testing the effects of these damages on humans in 1995. By using Skin Conductance Responses (SCR) and a type of memory test, Bechara administrated two types of experiments: auditory-auditory and visual-auditory, on participants that had damage to the hippocampus and/or the amygdala. The two experiments are similar, only changing the controlled stimuli. SCR measures electrical resistance as changes in emotional arousal take place by monitoring the activity of the autonomic nervous system. SCR is connected to patient’s skin and can continually measure the change in emotion in the participants. Though SCR can measure emotion, there is no way in defining what emotion one is feeling through SCR. Bechara chose three participants that had damage to the brain, while having four participants that had no brain damage but were similar in age and education as the controls. The areas that were damaged in the three participants were the hippocampus and amygdala, each one having different damages: participant 1 (SM046) was a 30 year old woman who had bilateral damage to her amygdala, participant 2 (WC1606) was a 47 year old man with bilateral damage to his hippocampus, and participant 3 (RH1951) suffered bilateral damage to both his hippocampus and his amygdala. All three of the brain damaged participants had normal speech, were right handed, and had at least 12 years of education. The purpose of having all three participants suffering from different brain damages is so the results can be compared against one another, identifying difference in the effects of each type of brain damage. The first experiment was a visual-auditory experiment, in which blue slides were the controlled stimuli (C.S. 1), while a loud boat horn is used as the uncontrolled stimuli (U.S.). This experiment contained three phases of conditioning protocol: habituation, conditioning, and extinction. The first phase, habituation, consisted of showing participants four different colored slides (red, green, yellow, and blue) in random order, repeatedly. While participates are shown the different colored slides, emotional levels are measured by using Skin Conductance Responses (SCR). The colored slides are constantly shown until participants SCR measures are near zero (< 0.05), meaning there is little emotional activity happening. In the conditioning phase participants are then shown twenty-six slides of the same four colors again in erratic order; however, this time six random blue slides (C.S.1) were shown with a loud boat horn (U.S). In addition, six blue slides are shown that have no boat horn, and the remaining fourteen slides (red, yellow, and green) are also shown with no boat horn. Throughout the process, participant’s SCR measures were taken; SCR magnitudes were usually shown as higher in participants when shown the blue slides (C.S 1) due to the noise associated with those slides. The extinction phase is followed immediately after. In the extinction phase participants are shown blue slides with no horn until SCR levels return to zero while looking at the blue slides. SCR results are taken and the second experiment is then administrated. The second experiment is an auditory-auditory experiment. This experiment has many of the same elements as the first experiment, except instead of four colored slides...
Please join StudyMode to read the full document