Using Pupillometry to Observe Covert Mental Activity during Prospective Memory Tasks

2019-05-14T19:27:54Z (GMT) by Edward A Christopher
Remembering to complete some future intention (i.e., prospective remembering) is a frequent requirement of everyday activities. Prospective memory failures (e.g., forgetting to take one’s medication) can have devastating consequences. Cognitive psychologists have sought to understand how individuals can successfully fulfill their prospective memory intentions. Unfortunately, it has been difficult to find evidence for specific cognitive mechanisms that could feasibly account for prospective memory behaviors. In part, this is because many theories of prospective memory stipulate that prospective remembering is accomplished through discrete/covert mental processes. In the current set of experiments, eye-tracking technology was used to test these various mechanistic explanations. Using an eye-tracking computer to measure pupillary responses to prospective memory task characteristics allowed for the observation of changes in discrete mental activity during the course of a prospective memory task scenario. Across two experiments, I observed elevated pupil dilation when participants were given additional prospective memory demands. Furthermore, when participants correctly recognized the presentation of a prospective memory target, it appeared that their pupil dilation increased dramatically, and elevated dilation persisted for several trials. This pattern of pupil dilation is consistent with an account of prospective remembering that suggests individuals sometimes engage in actively monitoring for an opportunity to
complete their prospective memory intention, and that at other times, individuals will reduce or discontinue monitoring activity until some cue brings the prospective memory intention back into mind. Consistent with such an account, individual differences in working memory were positively associated with pupil size only when the prospective memory task afforded monitoring. This was in line with recent research implicating the working memory system in facilitating active monitoring during certain prospective memory contexts. Finally, the current set of experiments demonstrated the utility of pupillometric methods for measuring active monitoring in a prospective memory scenario.