Memory of Older Adults: By Gabrielle Mann

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In the United States, it is commonly believed that older adults are forgetful.  Regardless of the information, older adults are often portrayed as struggling to retain any memory.  This is commonly shown in the media and the ideological belief that older adults are forgetful has been fully integrated into various aspects of American society.  However, this is not necessarily always the truth.  In fact, I have personally experienced the exact opposite.  For as long as I can remember, my 82-year-old grandmother has had an excellent memory.  Throughout my childhood, I can recall her reciting full recipes from her cookbook and always memorizing her eight children and sixteen grandchildren phone numbers for a call on their birthday.  Research has also shown that my grandmother is not just an exception to the rule.  While changes in cognitive functioning do occur throughout the primary aging process, the common belief that older adults suffer from memory problems is not entirely accurate, and can even be lessened by just a few simple changes in behavior.

Memory processes make up are a very complex and intricate system.  This system can be broken into three steps: encoding, storage, and retrieval.  Research has shown that that the greatest age-related memory impairments occur during encoding and retrieval for older adults (Cavanaugh, 2015).  Encoding describes the process of inputting information into the memory system (Cavanaugh, 2015).  Proper encoding requires various regions of the brain, such as the hippocampus, prefrontal cortex, and parietal region, to coordinate activation and deactivation of these areas at specific times.  If one of these systems does not function effectively, then the encoding process will suffer (Miller et al., 2007).  Research conducted by Miller et al. (2007) has suggested that changes in the parietal region are the primary cause of age-related memory impairment.  To find this, 17 heath older adults, ranging from age 52 to 82, were compared to 17 healthy younger adults, age ranging from 20 to 29, on their ability to match a picture of a face to a fictional name.  All patients were shown pairs of correctly matches names and faces, and then were shown the faces with two different names.  Participants were responsible for deciding which of the two options was correct.  While doing so, all patients were monitored with an fMRI in order to closely monitor how the hippocampus and parietal region were functioning.  Results found that older adults did perform slightly worse at this task than the younger adults did.  Specifically, older adults could only correctly match 60.3% of the pairs while the younger adults could match 73.3% of the pairs (Miller et al., 2007).  With the help of fMRI data, the researcher found that proper encoding occurred when the hippocampus and prefrontal cortex were activated, and the parietal region was deactivated.  While almost no differences in the function of hippocampus existed, older adult brains struggled to deactivate the parietal region.  Data also suggested that older adult brains worked harder to over-activate the hippocampus and prefrontal cortex in order to compensate for the inability to deactivate the parietal region.  While this compensation was slightly effective, differences can still be found when comparing younger adult brains to older adult brains during the encoding phase of memory processes (Miller et al., 2007).  These differences are somewhat minor, but this research helps to explain how slight changes in cognitive functions can cause age-related memory impairments.

As previously mentioned, research has shown that the retrieval process, pulling information out of long-term memory for usage, is also affected by aging (Cavanaugh, 2015).  However, Giesen, Eberhard, and Rothermund (2015), found that this is not necessarily the case.  Their research found that older adult brains decline in inhibition, the ability to dismiss irrelevant information, but found that the retrieval process was not directly impacted by aging.  This was tested by comparing 43 older adults, ages ranging from 60 to 78, to 40 younger adults, ranged from ages 18 to 28.  Participants were shown a sequence of three letters, two of the letters flashing while the other was solid, but only had to recall the solid number.  This test aimed to see what kind of affect distraction would have on the different age groups’ retrieval process.  Results showed that older adult brains were less successful in identifying the correct letter, but were only affected due to their decrease of inhibition.  Younger adult brains only performed better due to their ability to eliminate the flashing letters, not because they could better recall the solid number (Giesen et al., 2015).  This research is an excellent example of the vast amount of intricate pieces that make up the memory process.  While research shows that encoding is slightly affected by aging, research does not consistently support that the two other process of memory, storage and retrieval, are impacted throughout the aging process.  

The previous two studies focused on healthy adults that were experiencing primary aging.  However, a large portion of older adults are often affected by chronic disease.  Dementia is a disease that affects 47.5 million adults worldwide that causes a deterioration in memory and cognitive ability.  While this disease does affect a large amount of people, the belief that dementia is normal and happens to every aging adult is simply not true (World Health Organization, 2016).    Dementia’s cause of abnormal memory loss is not a natural process and this can be shown when looking at research aimed at finding the cause of dementia.  Schneider, Arvanitakis, Bang, and Bennett (2007) found that while the majority of aging adults do have some form of brain pathology, aging adults with dementia most often have multiple brain pathologies.  These results were found by testing a population of 141 of older adults that agreed to donate their brains to autopsy.  Eighty-six percent of brains did have at least one brain pathogen present but only 28% of these brains had dementia, and almost all of these brains had more than one brain pathogen (Schneider et al., 2007).  Clearly, the development of brain pathogens is a natural part of the aging process, however, developing dementia is not.  While the common portrayal of an older adult often has symptoms of dementia, the extreme memory loss caused by dementia does not occur in all aging adults.  

While slight changes in cognitive functions and chronic disease do occur, aging adults are not helpless to the effects of memory loss, as they are often portrayed.  In fact, there are copious amounts of research on different ways to minimize memory loss.  Erickson et al. (2015) found that aerobic exercise training can effectively help reduce some of the effects that aging has on the encoding process.  Exercise increased hippocampal volume by 2% in the 120 older adults, between ages 55 and 80 years, that were tested in a controlled setting.  This was tested by comparing a control group of older adults, ones that did not participate in exercise, to a group of older adults that had personalized workout programs.  While the control group experienced a decrease in their hippocampal volume, the group that participated in aerobic experienced a gain.  This gain in hippocampal volume aids in preserving cognitive functions and ensure a lower chance of memory loss in older adults (Erickson, 2015).  Simple changes in daily behaviors can assist aging adults avoid being anything like the stereotypical forgetful, aging adult.

Clearly, the stereotype that aging adults are forgetful is not necessarily true.  While this does stem from the truth, as declines to cognitive functions are caused by the aging process or chronic disease, not all aspects of memory are affected by the aging process and there are many ways to help combat the aspects that are affected.  The population of older adults is improving everyday, and they will not forget it.

 

References

 

Cavanaugh, J. C. (2015). Adult development and aging (7th ed.). Stamford, CT: Cengage Learning

Erickson, K. I., Voss, M. W., Basak, C., Szabo, A., Chaddock, L., Kim, J. S., Heo, S., Alves, H., White, S. M., Mailey, E., Vieira, V., Martin, S. A., Pence, B. D., and Woods, J. A. (2015). Exercise training increases size of hippocampus and improves memory. Proceeding of the National Academy of Sciences of the United States of America, 108, 3017-3022. doi:  10.1073/pnas.1015950108

 

Giesen, C., Eberhard, M., and Rothermund, K. (2015). Loss of attentional inhibition in older adults—Does it really exist? An experimental dissociation of inhibitory and memory retrieval processes. Psychology and Aging, 30, 220-231. doi: http://dx.doi.org.ezproxy2.library.colostate.edu:2048/10.1037/pag0000022

 

Miller, S. L., Celone, K., DePeau, K., Diamond, E., Dickerson, B. C., Rentz, D., Pihlajamaki, M., and Sperling, R. A. (2007).  Age-related memory impairment associated with loss of parietal deactivation but preserved hippocampal activation. Proceeding of the National Academy of Sciences of the United States of America, 6, 2181-2186. doi: 10.1073/pnas.0706818105

 

Schneider, J. A., Arvanitakis, Z., Bang, W., and Bennett, D. A. (2007). Mixed brain pathologies account for most dementia cases in community-dwelling older persons. Neurology, 69, 2197-2204. doi: http://dx.doi.org/10.1212/01.wnl.0000271090.28148.24

World Health Organization. (2016). Dementia. Retrieved from http://www.who.int/mediacentre/factsheets/fs362/en/

 

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