Why do reflexes and decision-based responses slow with age?

The slowing of reflexes and decision-based responses with age is primarily attributed to changes within the brain rather than the peripheral sense organs. While reflexes may become slightly more sluggish and nerve conduction speeds decrease, the most significant delays occur during tasks that require complex decision-making.1

This decline in response speed is linked to a gradual reduction in the rate of central nervous system processing. Research indicates that the aging brain may exist in a state of relative underarousal compared to younger adults, as evidenced by changes in electrical activity patterns, such as the slowing of alpha waves.23

While some neuron loss occurs, it is generally considered minor; functional changes in brain connectivity and the impact of factors like vascular health, oxygen supply, and lifestyle choices—such as aerobic exercise—play critical roles in cognitive performance. Importantly, aging does not inevitably lead to a decline in all intellectual functions, and the nervous system often compensates to maintain adequate function throughout the lifespan.453