Does Working Memory Actually Stop Working? By Madison Dziura

Ageism, which is a type of judgment, plays a huge role in how people perceive and treat older adults, especially in the United States of America where youth and beauty are valued (Cavanaugh & Blanchard-Fields, 2015).  One particular stereotype stemming from ageism that comes to mind when thinking about older adults is memory.  Many representations of older adults show them having difficulty remembering short-term information such as where they put their wallet or car keys.  Specifically, working memory faces a decline in older adulthood in both capacity and response time, which causes the older adult to have difficulty recalling information.

The first research study conducted by Padgaonkar, Zanto, Bollinger, and Gazzaley (2016) examines the declines in processing and working memory in older adults in the presence of irrelevant information.  The study was comprised of all men of good health: twenty young adults with a mean age of twenty-five and twenty older adults with a mean age of seventy-two.  All of the participants had electrodes that measured electrical activity during the experiment.  This study manipulated relevant and irrelevant facial and scenic images, and then tested the participants on previously seen images.  The results showed that the number of correct working memory answers were similar between the young and the older adults; however, older adults had a slower response time than the young adults, especially when the question involved irrelevant information or when less neural activity was present.  The research reveals that although response times in the presence of distracting visual information is slower among older adults, accuracy remains about the same despite age (Padgaonkar, Zanto, Bollinger, & Gazzaley, 2016).

This study refutes the stereotype that working memory declines over time.  Although the study shows the accuracy of working memory is about the same, it does show an increase in response time which means that working memory decreases in speed in older adulthood.  The significance of this research is that it contradicts the age based double standard, that older adult’s memory problems stem from a decrease in functioning and capacity, whereas younger adults memory problems come from stress (Cavanaugh & Blanchard-Fields, 2015).  Over time this finding should work to increase the awareness that working memory accuracy does not decrease later in life.

The second research study was conducted by O’Shea, Cohen, Porges, Nissim, and Woods (2016).  This study hypothesized that hippocampal volume decreases in size during aging, therefore decreasing working memory function.  The study was experimental and contained ninety-three older adults from Florida with a mean age of seventy-one who were recruited through advertisments.  Participants were tested on the Montreal Cognitive Assessment (MoCA) which measures cognitive deficiency, the NIH Toolbox Cognitive Battery (NIHTB-CB) which measures fluid functions such as working memory, and underwent a weighted brain scan to measure the volume of the hippocampus (O’Shea, Cohen, Porges, Nissim, & Woods, 2016).  There was no connection between crystallized functions and hippocampal volume; however, there was a connection between memory, including working, and volume.  The larger the hippocampus, the better the older adults performed on the memory tests.  This study identified the importance of the hippocampal size in functions such as working memory in older adults (O’Shea, Cohen, Porges, Nissim, & Woods, 2016).

This article confirms the stereotype that memory and other fluid tasks decrease over time; however, the study also found a protective factor of hippocampal volume in working memory.  Although older adults working memory showed declines when compared to the young adults, those with a greater hippocampal volume demonstrated better performance.  This enforces the idea that working memory can still function over time at a similar rate as in young adulthood.  This is significant finding, as it shows that working memory has biological components which may override age related declines.

The third research study was was completed by Ito, et al. (2013) and compared the function of visual working memory with the presence of an auditory distraction through experimention.  Three groups of fluent Japanese speakers were tested: twenty young adults in college with a mean age of twenty-two, twenty younger-old adults with a mean age of sixty-four, and twenty older-old adults with a mean age of seventy-three.  This study was experimental and manipulated auditory distraction, Japanese nouns played through headphones, while researchers measured the effects of visual recall of nouns in working memory by testing if they had remembered seeing a specific noun one or two tasks back.  The results of the study found that older-old adults had the worst performance and younger-old adults performed worse than young adults.  However, on the two back test, the older-old adults were the only group that showed a decline.  This shows that working memory declines with age due to difficulty in holding visual information in the prescence of a distraction.  Another result showed that the reaction time of both groups of older adults was slower than the young adults.  This illustrates that the distraction had more impact on older adults which increased with the number of tasks (Ito, et al., 2013).

As a result, this study confirms the stereotype that working memory decreases in older adulthood, both in reaction time and recall of previous visual information.  Similarly, this study also revealed that younger-old adults performed better on two back tasks than older-old adults which could mean that working memory is affected by aging processes.  Additionally, it is also significant in showing that working memory performance is almost equal to that of young adulthood until older-old adulthood.  However, this study does not take into account the cohort effect which may be causing the difference between the two age groups.

The final research study by Fernández-Cabello, et al. (2016) took place in Spain and examined the impacts of white matter hyperintensities and education on working memory.  The study involved ninety older adults, sampled from retirement homes, with a mean age of sixty-eight  and sixteen young adults. All participants were divided into high or low education level.  Each participant underwent a magnetic resonance imaging scan to look at white matter.  Then, participants were given a working memory task in which they had to recall which letter they had seen one, two, or three slides ago.  The results showed the more highly educated group of older adults answered more working memory tasks correctly.  Alternately, Those with lower education showed more difficulties with working memory capacity, especially if they had white matter.  The significance of this study is that despite the amount of white matter in the brain, higher education results in better working memory performance (Fernández-Cabello, et al., 2016).

Paradoxically, these research findings both confirm and contradict the working memory stereotype.  This study found that education was a protective factor from working memory declines even with the presence of white matter, revealing that there may be factors such as education that can override aging.  On the other hand, this study also confirms the working memory stereotype, because those with less education faced a decline in working memory, more so if the participant had white matter.

Although these research studies confirm and refute different areas of working memory, they show that there are both protective factors and key areas of decline or stability.  Over time as people come to realize the variations in working memory decline in older adulthood, stereotyping will decrease.  This would be beneficial in society as older adults would understand that aging processes are different in each individual and that memory problems are not always a sign of a greater mental disease.

References

Cavanaugh, J. C., & Blanchard-Fields, F. (2015). Adult Development and Aging. Stamford: Cengage Learning .

Fernández-Cabello, S., Valls-Pedret, C., Schurz , M., Vidal-Piñeiro, D., Sala-Llonch, R., Bargallo, N., . . . Bartrés-Faz, D. (2016). White matter hyperintensities and cognitive reserve during a working memory task: a functional magnetic resonance imaging study in cognitively normal older adults. Neurobiology of Aging, 48, 23-33.

Ito, K., Iwata, K., Kuratsubo, I., Kato, K., Nakamura, A., Yamagishi, M., & Kato, T. (2013). Age-Related Changes in Attentional Control Using an N-Back Working Memory Paradigm. Experimental Aging Research, 42(4), 390-402.

O’Shea, A., Cohen, R., Porges, E., Nissim, N., & Woods, A. (2016). Cognitive Aging and the Hippocampus in Older Adults. Frontiers in Aging Neuroscience, 8, 1-8.

Padgaonkar, N., Zanto, T., Bollinger, J., & Gazzaley, A. (2016). Predictive cues and age-related declines in working memory. Neurobiology of Aging, 49, 31-39.

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