Task-Specific Neural Representations of Generalizable Metacognitive Control Signals in the Human Dorsal Anterior Cingulate Cortex.

The dorsal anterior cingulate cortex (dACC) plays a critical role in cognitive control over different domains of tasks. The dACC activities uniformly represent task-generic intensities of control signals across different tasks. However, it remains unclear whether the dACC activities could also encode task identities of control signals across different tasks. If so, how the two types of control information are coherently organized in the dACC? Decision uncertainty is an internally-generated control signal by retrospective monitoring, namely, metacognition, even with no external feedback. We here investigated neural representations of decision uncertainty accompanying three decision-making tasks in the domains of perception, rule-based inference, and memory using trial-by-trial univariate and multivariate analyses on functional magnetic resonance imaging (fMRI) data acquired on human male and female healthy subjects. Our results demonstrated that the dACC represented decision uncertainty commonly across the three decision-making tasks. Further, the multivariate fMRI analyses revealed a mosaic form of neural representations of decision uncertainty across tasks in the dACC. The identity and intensity information was separately represented in two dissociable components, the high-dimensional pattern and the scalar magnitude, of the dACC multivoxel fMRI activities. Lastly, a follow-up behavioral experiment confirmed that this mosaic form of neural representations of parallelly existing decision uncertainty across different tasks should lead to mutual interferences more on the intensity, but less on the identity of control signals. Thus, our findings suggest that the dACC with the mosaic form of neural representations could provide task-generic and task-specific metacognitive control signals to guide appropriate control on different decision-making tasks.SIGNIFICANCE STATEMENT Metacognition is a form of cognitive control using internally generated decision uncertainty to guide behavior adjustment with no needs of external feedback. Decision uncertainty as a generalizable control signal is commonly encoded in the human dorsal anterior cingulate cortex (dACC) accompanying different decision-making tasks. It remains unknown whether or not the task-specific control information is represented in the dACC. We here revealed that multivoxel functional magnetic resonance imaging (fMRI) activities associated with decision uncertainty in the dACC concurrently represented the identity and intensity information. The mixtures of neural representations of decision uncertainty across different tasks should cause specific interferences on each other. Hence, the neural representations of control signals in the human dACC should be task-generic and task-specific.