The Effects of Psychological Stress on Reaction Time

1. The Effects of Psychological Stress on Reaction Time Jade Vega University of Maryland University College, Adelphi MD abstract Psychological stress impacts, and has the potential to impact, many aspects of individuals’ lives, including physiological and emotional states. Research correlating anxiety, sleep deprivation, and other factors which can be closely aligned with psychological stress, indicate that perhaps psychological stress can lead to an increase in individual reaction time. This study recruited 100 adult participants who do not have any diagnosed mental disorders which could be the cause of their stress. Half of the participants were assessed and placed in a “significantly psychologically stressed” group, and half were considered non-significantly stressed. Participants then completed a simple, computer-based reaction time task. Results of the trials, which are inconclusive but suggest future research is warranted, are presented here. Introduction Psychological stress produces a number of emotional and physiological symptoms, although it affects each person differently and occurs in varying degrees of severity. Research has shown that significant stress can also cause increases in heart rate, blood pressure, and respiration rates. These- and other symptoms associated with significant psychological stress- can be distracting to a person, and thus diminish their ability to react as quickly as unstressed individuals. While several studies have involved researching the effects of stress on reaction time, few have made the distinction between psychological and physical stress. In addition, most studies have studied multiple factors and their effects on reaction time. For example, studies have shown that- stress increases processing time for language skills (Rai, Loschky, Harris, Peck, & Cook, 2011) psychological stress "resulted in a significant decline in the reaction time" to a specific color in male participants (Venkates, Ramachandra, Baboo & Rajan, 2002, p. 560). stress in premenstrual phases results in decreased reaction times (Das, Gandhi, & Mondal, 1997) anxiety tends to result in an increased reaction time (Swann, 2011). Existing research makes it difficult to draw conclusions about the effects of psychological stress alone. There is reason to believe that psychological stress may have a significant impact, however. The hypothesis of this study is that stress increases reaction time. methods Participants: 100 participants in this study who were placed into two equal groups. Group A was comprised of significantly psychologically stressed persons; Group B consisted of non-psychologically stressed persons. No individuals with mental disorder diagnoses were included Materials: Two self-assessments- the PSM-9 measure of psychological stress, and a Perceived Stress Scale A blood pressure cuff, sphygmomanometer, and stethoscope to measure blood pressure A cardiovascular belt to measure heart and respiratory rates Computers to complete the reaction time tasks Procedure: Need for research realized Review Board Form submitted and experiment approved Participants volunteered via online system; given appointments Individuals were given several assessments to determine which group they belonged to. First, a psychiatrist conducted short diagnostic interviews to rule out any individuals who may meet the criteria for a DSM-V psychological disorder diagnosis. Remaining participants were administered self-assessments. One of the self-assessments was the PSM-9, a 49-item measure of psychological stress and their perceptions of recent stressful events. A perceived stress scale consisting of ten questions, also related to participant perceptions, was also administered. Following self-assessments, physiological data (heart rate, blood pressure, and respiratory rate) were collected, since significant psychological stress may impact any or all of these (Costin, Rotariu & Păsărică, 2013). Overall, participants were placed into the psychologically stressed group if they: were not experiencing stress as a byproduct or symptom of a psychological disorder, indicated on self-report measures that they feel overwhelmed with stress, and had some sort of abnormal physiological rate. Participants completed a computer-based simple reaction time task. Each trial displayed a visual stimulus, and participants were told to react as quickly as possible to the stimulus (a different color flashing onto the screen) by pressing any key. Each trial was repeated 20 times. A two-sample unpaired t test was performed to calculate the t and p values for the data. An alpha level of .05 was employed to determine the significance of the difference. results conclusions This study attempted to discover whether or not non-experimentally induced psychological stress has an impact on reaction time. While there was a difference, it is not conventionally considered to be quite statistically significant. Future research could incorporate: more reaction time tests, larger sample sizes and perhaps more varied methods of testing them. More rigorous assessment methods, such as longer diagnostic interviews More stress and life event-related self assessments Figure 1.1 Mean of psychologically stressed and non-psychologically stressed reaction times T test calculations were performed with 98 degrees of freedom. The t value for this data was 0.0516. The two-tailed p value of this data was calculated to be 0.0516. This is not quite statistically significant. However, it is important to note that this is close to statistical significance; future studies may yield results that indicate a stronger statistical relationship. Figure 1.2 Statistical Results References Costin, H., Rotariu, C., & Păsărică, A. (2013). Identification of psychological stress by analyzing electrocardiographic signal. Environmental Engineering & Management Journal , 12(6), 1255-1263. Das, S., Gandhi, A., & Mondal, S. (1997). Effect of premenstrual stress on audiovisual reaction time and audiogram. Indian Journal of Physiology and Pharmacology, 41(1). Rai, M., Loschky, L., Harris, R., Peck, N., & Cook, L. (2011). Effects of stress and working memory capacity on foreign language readers' inferential processing during comprehension. Language Learning, 187-218. Swann, J. (2011). Understanding the common triggers and effects of stress. British Journal of Healthcare Assistants, 5(10). Venkatesh, D., Ramachandra, D., Baboo, N., & Rajan, B. (2002). Impact of psychological stress, gender and colour on visual response latency. Indian Journal of Physiology and Pharmacology, 46(3).