Until the 1960s it was commonly-assumed in neuropsychology that the adult human nervous system was hard-wired and had extremely limited capacity to change. Recently research has demonstrated that this earlier assumption was not accurate and that the adult human nervous system indeed is quite plastic and in a state of continuous change. Further, physical exercise has been demonstrated to promote positive effects on the adult human nervous system as a result of increased blood flow and modified neurotransmitters and neutrophins. These effects are hypothesized to improve the synaptic connectivity and promote neurogenesis, both of which are believed to play an important role in neural plasticity. The most commonly-used approaches to monitor neural plasticity have included the use of MRI images and measuring changes in levels of certain neurotransmitters in the brain. These approaches are expensive and not affordable to most physical activity researchers. The purpose of this study was to determine whether measures of simple and choice reaction time (SRT; CRT) could provide evidence of increased neural plasticity that has been documented to occur following moderate intensity aerobic exercise. I hypothesized that both SRT and CRT would decrease following moderate intensity aerobic exercise which might indicate improvement in neural plasticity compared to a control puzzle group. I assigned male and female volunteers (n=11), ages 18-30 years old, randomly to either an exercise group or a Sudoku puzzle-solving (control) group. I measured SRT using a computer software three times: pre-exercise/puzzle-solving (30 minutes), immediately post-exercise/puzzle-solving, and delayed (3 hours) post exercise/puzzle-solving. The between group independent variable was the intervention (either puzzle-solving or moderate aerobic exercise on a bicycle ergometer) and the within-subject (repeated measures) variable was the time of administration of pre-post-delayed-post reaction times (repeated measures) while the dependent measure was the simple reaction times (SRT) in milliseconds. The statistical analysis method used was a mixed factorial ANOVA. No significant differences in simple reaction time were discovered between the two groups or within the times of testing reaction time and no significant group by time interaction occurred. I concluded that one of four rationale could explain the lack of significant differences and have discussed the rationale in greater detail in the paper. I recommend the future replication of this study with a much larger sample size to increase the statistical power to detect differences as well as improving the consistency of the protocol and methods used in the study plus the addition of using choice reaction times or other valid measures of neural plasticity.
Stephen J. Langendorfer
Mostafa, Ahmed, "Reaction Time as a Measure of Neuroplasticity After Aerobic Exercise" (2017). Masters of Education in Human Movement, Sport, and Leisure Studies Graduate Projects. 52.