Neural evidence accumulation persists after choice to inform metacognitive judgments
The ability to revise one's certainty or confidence in a preceding choice is a critical feature of adaptive decision-making but the neural mechanisms underpinning this metacognitive process have yet to be characterized. In the present study, we demonstrate that the same build-to- threshold decision variable signal that triggers an initial choice continues to evolve after commitment, and determines the timing and accuracy of self-initiated error detection reports by selectively representing accumulated evidence that the preceding choice was incorrect. We also show that a peri-choice signal generated in medial frontal cortex provides a source of input to this post-decision accumulation process, indicating that metacognitive judgments are not solely based on the accumulation of feedforward sensory evidence. These findings impart novel insights into the generative mechanisms of metacognition.
1 Summary For Case Western Reserve University’s debut participation in TREC, we chose to participate in the Enterprise Track expert search task. Our motivation for participation stems from our work developing expert search capability for our prototype vertical digital library, MEMS World Online 1 . Our work incorporates two unique aspects. First, our relevance ranking mechanism relies on term position within each document rather than the number of term occurrences. This mechanism takes into account both term document rank and term co-occurrence proximity. Second, the expert score of closely related colleagues has a small eect on the score of each related expert. This follows the intuition that experts on a particular topic within a single organization tend to closely collaborate with one another. We also make some use of WordNet synonyms. We submitted a total of three runs to this years expert search task.