Aging and preparatory effect: Synthesis on the foreperiod effect and new insights

Reacting quickly is a crucial ability for survival in many situations. Results in research on forperiod effects show that this ability could be reduced in older people. In these experiments, participants must react as quickly as possible to a presented stimulus. The foreperiod is defined as the delay between a warning signal and the reaction stimulus. This warning signal facilitates preparation and makes responding faster, but this facilitation effect is modulated by numerous variables. In neuropsychology, it is known that preparation is controlled essentially by the frontal lobes, which are also known to be altered in normal aging. The present review summarizes results on preparatory effects in normal aging. The results generally demonstrate that healthy elderly, in addition of presenting a general slowing in responding, present specific difficulties in preparing to uncertain events.