Unveiling the neural correlates of prospective memory: An ecological EEG study

The ability to remember intentions for future actions is a fundamental aspect of human functioning in everyday life. This process is typically studied in laboratory settings with tasks designed to isolate it, but these often lack ecological validity because they may not fully capture the complexity and variability of prospective memory (PM) in real-world contexts. The present exploratory study was designed to overcome these limitations. Firstly, participants watched a movie simulating to be home on their sofa. They then continued to watch the movie on their "smart TV", while simultaneously maintaining and executing intentions related to everyday activities, such as "virtual cooking". Neurophysiological activity was recorded during these tasks using an hd-EEG system to investigate the role of brain oscillations in strategic monitoring processes involved in PM. Power spectral density was analyzed across the theta, alpha, and high beta frequency bands. Administration of time-based and event-based instructions in an ecological context revealed two distinct patterns of brain activity. Time-based PM was characterized by widespread and sustained fronto-temporal activation, along with pronounced engagement of high beta frequencies in prefrontal areas. Event-based PM was associated with theta and alpha power localized to focal areas of the occipito-parietal lobes. According to the PM literature, modulations of theta and alpha oscillations are associated with attentional mechanisms for rehearsing different PM intentions in memory. The involvement of high beta frequencies in the time-based PM condition, already associated with temporal abilities, highlights their role in determining optimal timing for retrieval of future intentions.