Computer-implemented method for improving cognition and memory in an aging adult, utilizing a computing device to present stimuli to the adult, and to record responses from the adult. A psychophysical threshold for an aging adult with respect to stimuli in a cognitive development exercise is determined using a maximum likelihood procedure, such as QUEST (quick estimation by sequential testing) or ZEST (zippy estimation by sequential testing). The threshold is a stimulus intensity value associated with a specified performance level of the adult. A plurality of trials in the exercise are then performed with stimuli at or near the determined threshold to improve the adult's cognition and memory skills. This threshold determination and exercise performance may be repeated in an iterative manner to further improve the adult's cognition and memory skills.