Processing Speed Mediates Age Cohort and Prospective Memory Performance

Age has been shown to negatively impact prospective memory (PM), the ability to carry out intentions in the future. However, many age-related cognitive changes may reflect underlying declines in processing speed (Salthouse et al., 2004). The purpose of this study was to investigate whether processing speed mediates the relationship between age cohort and prospective memory performance. Older (n = 52) and younger adults (n = 40) completed WAIS-IV Coding and the Virtual Kitchen Protocol, which includes PM tasks with both time-based and event-based cues both in and out of virtual reality. Processing speed mediated the relationship between age cohort and PM performance both in and out of virtual reality. Partial mediation was observed in the analog-based PM, whereas full mediation was observed in the virtual reality-based PM. Processing speed may explain age-related changes in PM as measured by both analog and virtual reality tasks.