The event-based prospective memory of adults with developmental dyslexia under naturalistic conditions

Prospective memory (PM) is memory for delayed intentions. Broadly speaking, PM tasks require responses either to events in the environment (event-based PM; EBPM) or at a specific point in time (time-based PM; TBPM). Dyslexia-related deficits in TBPM have been reported under laboratory conditions but group differences in EBPM have yet to be found. However, self-reports suggest that people with dyslexia do experience day-to-day EBPM difficulties. To determine whether EBPM was affected by dyslexia when task demands were more closely related to the demands of everyday life, a task was presented to groups of adults with and without dyslexia, matched for age and short-form IQ. The participants were required to make a response outside the laboratory setting one week after the task had been set. The group with dyslexia were worse at remembering to perform the EBPM task one week later, despite reporting equivalent levels of motivation to perform it successfully. Fewer adults with dyslexia reported remembering the PM instruction at the time it was required. However, they did not differ from adults without dyslexia in the self-reported frequency with which they thought of the PM task over the intervening period. The results suggest that EBPM deficits can be found in dyslexia over longer delay intervals. Dyslexia-related problems with EBPM may relate to the reliable access to verbal information at the point at which it is required. These results are considered in the light of the current understanding of PM impairments in dyslexia.