  Recent research has focused on assessing either event- or time-based
prospective memory (PM) using laboratory tasks. Yet, the findings pertaining to
PM performance on laboratory tasks are often inconsistent with the findings on
corresponding naturalistic experiments. Ecologically valid neuropsychological
tasks resemble the complexity and cognitive demands of everyday tasks, offer an
adequate level of experimental control, and allow a generalisation of the
findings to everyday performance. The Virtual Reality Everyday Assessment Lab
(VR-EAL), an immersive virtual reality neuropsychological battery with enhanced
ecological validity, was implemented to comprehensively assess everyday PM
(i.e., focal and non-focal event-based, and time-based). The effects of the
length of delay between encoding and initiating the PM intention and the type
of PM task on everyday PM performance were examined. The results revealed that
everyday PM performance was affected by the length of delay rather than the
type of PM task. The effect of the length of delay differentially affected
performance on the focal, non-focal, and time-based tasks and was proportional
to the PM cue focality (i.e., semantic relationship with the intended action).
This study also highlighted methodological considerations such as the
differentiation between functioning and ability, distinction of cue attributes,
and the necessity of ecological validity.
