Chess' Response to Memory Readings

This week’s readings focused on the purpose and process of memory and the specific structures associated with it. They sought to emphasis the vital role of memory in both humans and animals.

In McGaugh's "Memory and Emotion,” he agrees with other psychologists who state that rehearsal of information or skills creates stronger memories. Actually, others go so far as to suggest that emotionally intense experiences are remembered so vividly only because they are recalled often. McGaugh argues for the role of emotional arousal. In his preface, he mentions that in medieval times, before writing was used to keep historical records, other means had to be found in order to maintain record of important events. One such method was to select a child around seven years of age and instruct him to watch the proceedings very carefully. Afterwards, he was thrown into a river.
Just as victims of plane crashes and car accidents can testify, the child’s memory was almost always remarkably vivid and enduring. McGaugh asserts that emotional arousal activates stress hormones that regulate the consolidation of recently acquired information in separate brain regions. This makes sense when we consider our most vivid memories (referring here to explicit, declarative or conscious memories). People will not likely remember what they had for breakfast three Tuesdays prior, however a near death experience will stay with us forever. From an evolutionary perspective, this ability to remember emotionally charged events is highly advantageous. To use his example, it’s beneficial for the rabbit to remember where the fox lives and how s/he escaped from it.
However, McGaugh does note explicit memories’ selective nature. He agrees that this selectivity is critically important. However, he also recognizes that while emotional significance is great for creating enduring memories, they are not necessarily accurate ones.
Finally, McGaugh notes the differences in long and short-term memory. Interestingly, he believes that recent (short-term) and remote memories (long-term) are based on different process, rather than the same process differing only in durability. As his several case studies seem to prove, long-term memory does not require short-term memory. Lasting memories are not created instantly, but rather consolidate over time. Additionally, his research suggests that explicit (a.k.a. declarative or conscious) and implicit (a.k.a. nondeclarative, unconscious, or procedural) are also the result of separate processes.

Dolcos et al.’s experiment on the role of the amygdala and the medial temporal lobe memory system in retrieving emotional memories also yielded several interesting results. However I had so many problems with the methodology, I cannot accept the results too readily. Although I have several issues with this experiment, particularly their belief of a single year constituting as “long term,” my primary problem concerns their use of only nine (9!) females subjects, chosen because “ . . . compared with men, women are physiologically more reactive than to emotional stimuli and are more likely to report intense emotional experiences.” (Dolcos et al. 2627) This statement is grossly incorrect. Physiologically speaking, women generally respond more to disgusting or saddening imagery while men respond much, much more to threatening or aggressive images. (Barrett et al. 2006) (Verona & Curtin 2006) (Wagner & Ochsner 2004) (Wagner et al. 2005) etc. etc. As far as women being “more likely to report intense emotional experiences,” this only demonstrates the experimenter’s inherit bias and the subjects' compliance to current social norms regarding the description of emotional experiences, which vary greatly according to culture and individual differences. (Ellsworth & Yamaguchi 2006) (Wagner & Ochsner 2004)
That aside, the article did do a satisfactory job proving the memory-enhancing effecta of emotion. It also successfully explained the stages of the process of memory: (1) encoding: the creation of new memory traces, (2) consolidation and storage: the stabilization and persistence of these memories, and finally, (3) retrieval: the final access to these stored memories. (Dolcos et al. 2005 2) In the experiment, every one of the whopping nine subjects was shown both neutral and emotionally charged images one year earlier. Afterwards, they were again shown images in order to discover the effect of emotion on their memory recollection and familiarity in addition to the specific brain structures responsible. However, in order to fully understand the experiments results, it is important to first differentiate between the two forms of episodic memory retrieval: recollection (explicit memory) and familiarity (implicit memory). “Recollection refers to memory for an event that is accompanied by the retrieval of contextual information and other associated elements, whereas familiarity refers to the feeling that an event happened in the past, but no associated information can be retrieved.” (Dolcos et al. 2005 2) The emotional images were predictably remembered better, however this memory-enhancing effect only affected recollection, while familiarity remained uninfluenced. This successful retrieval of emotional images caused greater activity in the amygdala, entorhinal cortex, and hippocampus than the neutral ones. “Moreover, in the amygdala and hippocampus, the emotion effect was greater for recollection than for familiarity, whereas in the entorhinal cortex, it was similar in both forms of retrieval. (Dolcos et al. 2005 2)

Finally, there was LeDoux’s discussion of memory. Typical of his style, he cited the evolutionary reasons behind our current processes of memory and our learned responses to those memories, citing numerous examples from animal behavior. He played particular attention to fear responses and our ability (and apparently animal’s ability as well) to especially remember experiences that caused us fear. He also paid special attention to the amygdala and it various components in order to discover the various function(s) of each of the brain’s separate structure. I continually find it strange that although LeDoux repeatedly criticizes earlier psychologists for attempting to assign specific brain structures with specific roles, he too spends a large majority of his argument doing the same.