The Effect Of Cold Water Immersion On Prefrontal Cortex Oxygenation, Salivary Cortisol Levels, And Executive Functioning

ASU Author/Contributor (non-ASU co-authors, if there are any, appear on document)
Brandon Ellis (Creator)
Institution
Appalachian State University (ASU )
Web Site: https://library.appstate.edu/
Advisor
Jared Skinner

Abstract: PURPOSE: Cold water immersion (CWI) is a popular form of voluntary cold exposure. In an environment such as a cold-water immersion, survival becomes paramount, and the ability to engage in top-down processing and take control of our actions through Executive function (EF) becomes imperative. The difficulty associated with the imposition of EF during stress like CWI is due to an increase in circulating cortisol levels, which have been associated with considerable impairments in working memory, a component of EF. This investigation aims to examine the feasibility and the effects of CWI on brain activation in the prefrontal cortex and executive function (EF) in young, healthy adults. METHODS: In this study, thirty-four healthy young adults (19 M and 15 F;22.74±2.39 yrs) participated. All participants arrived fasted without any consumption of caffeine or alcohol or heavy exercise within the last 24 hours. Participants completed the Mental Fatigue Scale and an assessment of basic anthropometrics. The collection of O2Hb levels using near-infrared spectroscopy (fNIRS) in the prefrontal cortex, scores on EF-specific tests from the NIH-EXAMINER, and scores on a verbal categorization task (VCT) were assessed pre and post-CWI. After collecting baseline data, participants were immersed in a tank containing 50–60 degrees Fahrenheit water up to the base of the neck, with both hands out of the water, for 5-10 minutes. During immersion, a verbal cold discomfort scale was administered. fNIRS data, verbal categorization task data, and NIH-EXAMINER EF tests were analyzed using repeated measures ANOVA, and post hoc t-tests were performed to examine specific differences. RESULTS: Examination of the fNIRS data indicated a significant decrease in prefrontal recruitment from a pre immersion resting state to post immersion resting state (Pre: 35.21±10.36 vs. Post: 27.81±7.83,p=0.004), as well as from pre immersion executive function testing to post immersion executive function testing (Pre: 38.69±11.60 vs. Post: 28.58±8.69, p=<0.001). There were no significant differences between NIH Examiner and VCT scores pre and post-CWI. CONCLUSIONS: This study provides evidence that acute CWI does affect O2Hb levels without negatively affecting EF.

Additional Information

Publication
Thesis
Ellis, B. (2023). The Effect Of Cold Water Immersion On Prefrontal Cortex Oxygenation, Salivary Cortisol Levels, And Executive Functioning. Unpublished Master’s Thesis. Appalachian State University, Boone, NC.
Language: English
Date: 2023
Keywords
Cold water immersion, Executive function, Cerebral blood flow, Functional Near-infrared Spectroscopy, Cortisol

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