Title: Neural underpinnings of metamemory
Description: Functional MRI was used to characterize the neural underpinnings of metamemory monitoring, that is monitoring retrieval contents for accuracy and relevance to the current task. The approach taken was to: (1) isolate the neural correlates of metamemory processes from memory processes; (2) characterize and compare patterns of activity associated with the metamemory task and the subjective level of metamemory rating given; (3) determine the consistency of metamemory related activation; and (4) compare the neural basis of metamemory in younger and older adults. To address these goals: Paper 1 compares the neural correlates of retrospective confidence judgments to recognition; Paper 2 examines confidence-related neural activity in younger and older adults; and Paper 3 compares the neural mechanisms for retrospective confidence judgments feeling-of-knowing judgments. Metamemory tasks, namely feeling-of-knowing and retrospective confidence judgments, were consistently associated with greater activity in medial parietal and lateral parietal regions compared to non-metamemory tasks, and it is proposed that these regions play a role in multiple forms of metamemory monitoring. In contrast, activity related to the subjective metamemory rating given varied between tasks. Higher compared to lower retrospective confidence ratings were associated with greater activity in MTL, medial prefrontal, medial parietal, and lateral parietal regions, and less activity in a frontal-parietal network. In contrast, higher compared to lower feeling-of-knowing judgments were associated with greater lateral prefrontal activity. The different patterns of neural activity for specific metamemory ratings suggest that neural activity associated with the subjective level of confidence or feeling-of-knowing expressed are related to the basis of the judgment.

Further evidence that neural activity associated with the subjective metamemory rating depends on the basis of the judgment comes from comparisons in aging. Younger and older adults differed in regions that showed greater activity for high confidence compared to low confidence responses, yet both younger and older adults both exhibited greater activity in frontal-parietal network for low compared to high confidence responses. Taken together, these findings indicate that there are both shared and distinct neural underpinnings of metamemory, which furthers our understanding of metamemory processes and also of previously characterized functional brain networks.