Eye movements and prospective memory: what the eyes can tell us about prospective memory

In this study we used eye tracking methodology in combination with multi-element displays to examine the processes underlying event-based prospective memory in a visual search paradigm. In the task individuals searched for a different target stimulus (i.e., a letter) on each trial that could be present or absent, and made prospective responses to the letters D or M. The response accuracy data revealed that target hits were more frequent than prospective hits, and that there was no difference in response time for target and prospective responses. The eye tracking data revealed that both first and total fixation durations increased from distractors (stimuli that were neither targets nor prospective cues) to targets to prospective cues when a target or prospective response was made. These measures also revealed that the presence of a target in the display served to disrupt prospective memory. In addition, prospective memory misses resulted from a combination of failures to fixate the prospective cues and failures to engage in strategic processing of the prospective cues. These data demonstrate the utility of eye tracking methods in examining the processes underlying event-based prospective memory.