The aging process affects reaction time due to a breakdown in the neural processes that occur in the brain. However, the effects brought on by aging generally vary from individual to individual and can be reversed by regularly engaging in physical exercise, states the University of Rochester Medical Center.
Reaction time pertains to the time interval between the start of a perceivable stimulus and the ensuing observable reaction to the impulse, according to the University of Colorado. As a person ages, reaction times normally decrease. This decline has been linked directly to excessive "cross-talk," which is prevalent in the elderly, notes Psych Central.
Cross-talk is controlled by a structure in the brain called the corpus callosum, which blocks signals from one hemisphere during one-sided motor responses. However, this function diminishes with age and the ability of the brain to regulate cross-talk results in reduced reaction times.