Effects of Stress On Working Memory
(This project was presented as my MA Thesis in May, 2021.)
We often separate different emotional experiences to make them seem like stand-along scenarios that only occur one at a time. It is important for us to remember that many of these emotional experiences may constantly accompany each other — “I’m happy and excited”, “I’m angry and stressed”. While past literature often provide insights to how negative emotions such as sadness, anger, grief, could cause impairments in one's working memory, it is important to see that the experience of stress often accompanies these feelings, which indicates that stress itself may also have a direct link to the damaging of working memory.
In this study, we hope to learn whether one’s
working memory functions would show
significant impairments under stressful scenarios.
Why This Topic
Stress is present as a cause of many different severe mental disorders that involve impairments to one’s memory. It is common for us to look at the disorder and the symptoms together while we often overlook the relationship between the cause factors and the symptoms.
Emotions can effect task performance (Galindo-Aldana et al., 2020). In many cases, when we feel stressed, we also tend to have worse performance on specific tasks, such as taking a test. By finding out the link between stress and working memory, we may be able to help with the negative consequences that accompany.
How to find out
In order to see what stress and only stress can do to one’s working memory, we can compare and contrast the responses to working memory tasks between two groups of people, where one group is under stress while the other is not.
Hypothesis
The stressed group (experimental group) will show lower accuracy in responses for the tasks than that of the not stressed group (control group).
The difference between the two groups will be more obvious as the difficulty of the tasks increase.
The Process (expected)
Who
The participants in this experiment are expected to consist of 176 mentally healthy adults (d = 0.5), randomly selected through online research participation systems, with no past psychological or neurological related history. The sample size of 176 individuals was calculated through power analysis, with the power of 95%, error probability as well as effect size data (d = .5) provided in the research study by Shields et al. (2020), in which the procedures of this research is meant to replicate.
Participants would consist of individuals without extreme/life-endangering conditions, with vision or corrected vision of around 20/15 to 20/20. All individuals are expected to have either a bachelor’s degree or above on educational history with similar levels of mathematical education and similar letter grades in order to rule out the probability that some may consider math to be less stressful than others. The sampled participants are expected to consist of both sexes (preferably with the ratio of around 50/50, assigned at birth), with ages ranging from 25 to 35 (Mage = 28.88 years, SDage = 3.16).
The racial and ethnical identity of participants would be expected to be random and diverse, with similar percentage as the percentage of each different racial groups present in the United States, referencing the most recent US Census report. Participants would be expected to be recruited at will with $20 provided as compensation. Participants would be randomly divided, equally, into either the control group, with no emotional manipulation; or the experimental group with stress-inducing scenarios as manipulations.
Materials
30-minute math tests with ticking clock and time announcements
According to Pizzie, Raman and Kraemer (2020), math-related anxiety is closely linked with the presence of feeling stressed, and the impairment of working memory due to the increased work load as a result of stress.
Computers and monitors from the same producers
To rule out other difference factors.
Program capable of recording answers as well as producing feedback (of only correct and incorrect responses)
Instant feedback on personal performance
Procedure
Both groups would begin at the same time.
Control group would be given a simple exam (elementary-school-leveled) with no ticking clock and a less constant time announcement.
Experimental group would be under stress-manipulation with difficult math exam, along with a ticking clock and more constant time announcements.
After manipulation - The experiment
A visual recognition task would be presented as the working memory task.
Participants would be shown color blocks in specific positions on a black background for 5 seconds, followed by a blank screen for another 5 seconds. Then the position of the blocks would be shown in grey again, followed by another blank screen. Participants would then be shown a single color block and would be asked to identify whether this block was shown in the original stimuli (same color and position).
Three levels to the study — 2 blocks, 5 blocks, 8 blocks.
Simple demonstration of the visual task stimuli.
Challenges
Lack of participants due to COVID-19
Possible fatigue
Solutions
Projected data from smaller sample
Breaks between each levels
Outcome
A 2x3 mixed ANOVA was performed. The results suggested significant main effects in both between and within subject. There was no significant interaction. Also, in each level of the study, significance was present between the two groups as well. The results of the post-hoc Tukey’s HSD that was performed also supported the hypothesis.
This indicates that there is a very high likelihood that stress can cause direct impairment to one’s cognitive abilities, in this case, one’s visual working memory.
Also, the results suggested that having different difficulty levels was meaningful. As the task becomes more difficult, a more obvious difference between the two groups can be detected, suggesting higher levels of impairment for the stressed group.
The Future and more…
The intention of this research project was to learn more about the links between stress and cognitive impairments, which could help us further understand how to avoid detrimental mistakes that may be caused by stress.
In the future, if possible, it would be interesting and meaningful to dig deeper into the neurological mechanisms that may underly the process cognition impairment by emotion.
References
Galindo-Aldana, G., Ledesma-Amaya, L., García-Gomar, L., Negrete-Cortes, A., Galarza-Del-Ángel, J., & Padilla-López, A. (2020). Risk behavior and emotionally interfered working memory in adolescents from rural areas: Normative data and correlations. Psychology & Neuroscience, 13(1), 61–75.
Pizzie, R. G., Raman, N., & Kraemer, D. J. M. (2020). Math anxiety and executive function: Neural influences of task switching on arithmetic processing. Cognitive, Affective & Behavioral Neuroscience, 20(2), 309–325.
Shields, G. S., Spahr, C. M., & Yonelinas, A. P. (2020). Feel free to write this down: Writing about a stressful experience does not impair change detection task performance. Emotion, 20(2), 317–322.