Changes in event-based prospective memory across adulthood

Conflicting results in the literature raise the possibility of a nonmonotonic relationship between adult age and event-based prospective memory performance. In this study, young (n = 45, mean age = 20), middle aged (n = 56; mean age = 59), and elderly (rt = 59; mean age = 76) volunteers were shown slides of famous people. The background task was to name each face while the prospective memory task was to mark the trial number if the person was wearing glasses. Although the stimuli were selected to favor the older participants, the proportion of prospective memory responses to target events declined monotonically with increasing age (.77, .62, and .26, for the young, middle-aged, and elderly, respectively). Analysis of the prospective memory data in terms of hazard functions for the first failure and the first success also revealed some significant age deficits. The elderly group reported thinking less about the prospective memory component than the young and middle-aged groups. Also, the elderly group was less likely to blame the demands of the background task for their prospective memory failures than the young and middle-aged groups. However, age differences in prospective memory performance remained significant after controlling (in separate analyses) for past experience (hazard functions), memory for the task instructions, self-rated thoughts, and reasons for failure. The results are discussed in relation to work on goal neglect, and possible explanations for the conflicting results in the literature are presented.