Investigating Prospective Memory Processes: ERP Evidence from Novel Semantic Judgment Tasks

Prospective memory (PM), the ability to plan and execute intentions in the future, plays a critical role in managing everyday tasks. A gap exists in our understanding of the neural mechanisms underlying PM retrieval based on semantic judgment, particularly when using picture-based stimuli. The current study tested 2 novel picture-based semantic-judgment PM tasks: Animal-cued Prospective Retrieval Task (Ac-PRT) and Object-cued Prospective Retrieval Task (Oc-PRT), designed to investigate PM processes involved in intention formation (Cue trials), intention retention (Ongoing trials), and intention retrieval (PM Retrieval trials). Twenty-three young adults, aged 18 to 30 years, completed the tasks while EEG data were recorded. Behavioral results showed that participants responded more slowly during Ongoing trials compared to Cue and PM Retrieval trials and were less accurate during PM Retrieval trials. Additionally, between the tasks, responses were faster and more accurate in Ac-PRT than in Oc-PRT during both Ongoing and PM Retrieval trials. ERP analyses revealed distinct neural signatures across trial types, particularly in P2, N2, N4, and Parietal Positivity (PP) components in both tasks. Additionally, task-specific differences were observed during the PM Retrieval trials in P2, N4, and PP amplitudes and in PP amplitude during the Ongoing trials. These findings demonstrate that the 2 tasks effectively dissociated core PM processes and showed category-specific differences in behavioral and neural mechanisms, offering a robust framework for future investigations of PM in aging and clinical populations.