The Effects of Aerobic Exercise on Cognitive Flexibility

This experiment tested the hypothesis that that the Stroop test would show no improvement after normalization because of the intense cognitive function required to complete the task. We also predicted that one episode of exercise would not prompt a measurable difference in overall performance. Twenty five individuals between the ages of 20-23 were tested for resting blood pressure, heart rate and a Stroop test. Then, subjects ran up and down stairs to increase their heart rate to ~140 bpm. After exercise, each subject was then tested again for heart rate, blood pressure and the Stroop test. Heart rate and blood pressure were used to monitor the intensity of exercise. The Stroop test was used to monitor cognitive flexibility. Our results indicated that although no significant correlation between heart rate, blood pressure, and Stroop test score could be determined, there was an overall increase in Stroop scores after exercise. This project is physiologically significant in finding whether cognitive flexibility and performance can be altered with a healthy lifestyle. Introduction: Exercise has been implicated in many different tests of brain function. In a recent study moderate intensity aerobic exercise (defined by 70-80% of maximal heart rate) has been shown to improve working memory (Kavussanu 2013). The correlation between exercise and cognitive function has been investigated in many studies over the past thirty years and collectively they indicate an increase in cognitive function following exercise (Etnier 1997, Lambourne 2010). One recent area of interest is cognitive flexibility or the ability to construct and modify responses based upon information (Deak 2003). In the ever-evolving world in which we live, cognitive flexibility and the ability to quickly synthesize information seems more useful than routine memorization. One way to measure cognitive flexibility is the Stroop test. In performing this task, the name of a color is printed in a color not denoted by the name. The Stroop effect demonstrates the interference associated with reaction time and thus has been validated as a test of cognitive flexibility (MacLeod 1991). In older, sedentary adults who were put on a threemonth exercise program, cognitive flexibility, as measured by the Stroop test, was shown to increase (Bherer 2011). Despite the fact age has been proven not to be an indicator of Stroop test success, this effect has not been tested in younger adults leading relatively active lives (in comparison to older inactive adults previously tested) (De Meersman 1998). Recently, acute exercise has been shown to improve cognitive flexibility on the Stroop test in young, 19-24 years of age, Japanese adults by activating the dorsolateral, prefrontal cortex (Yanagiawa 2010). Our study seeks to demonstrate the effect of short-term aerobic exercise on cognitive flexibility in young adults. Specifically, will approximately five minutes of aerobic exercise on a staircase improve cognitive flexibility as measured by the Stroop task. Through literature review, aerobic exercise was found to improve cognitive function. By reviewing previous experiments, we noticed mainly memory was tested. We decided to expand this to include cognitive flexibility. Researching the Stroop task, it was determined to meet our criteria of testing cognitive flexibility. Exercise on a staircase was limited to approximately 5 minutes due to participant