Electrophysiological dissociation of human posterior cingulate cortex contributions to value- and memory-based decision-making

The human posterior cingulate cortex (PCC) has long been a subject of interest in cognitive neuroscience due to its involvement in various cognitive functions and its association with certain neurological disorders. Researchers have traditionally associated the PCC with episodic memory and the default mode network in human neuroimaging studies, while non-human primate electrophysiology research has focused on economic decision-making processes in this region.

A recent proposal suggests that the apparent discrepancy between these findings can be attributed to subregional organization within the PCC, with the dorsal PCC potentially serving as a convergence point for both value-based and memory-based decision-making processes.

In a recent study, researchers recorded local field potentials (LFPs) and single-unit neural activity from the human PCC while participants engaged in matched value- and memory-based decision-making tasks. The results indicated that LFPs exhibited sustained engagement in the dorsal PCC during both types of tasks, with the region demonstrating risk sensitivity only after the actual decision was made.

In contrast, single-unit activity from the PCC was more temporally circumscribed and could be categorized into distinct response profiles that were active either before or after the decision-making process. Importantly, the dorsal PCC was found to be engaged not only during value-based decision-making but also during memory encoding, recognition, and confidence judgments.

These findings provide compelling evidence for a functional dissociation between the dorsal PCC and ventral PCC, with the former acting as a domain-general interface between evaluative and mnemonic systems in the human brain. This conclusion effectively reconciles the seemingly contradictory accounts of PCC function found in both human neuroimaging studies and non-human primate electrophysiology research, and offers valuable insights for future targeted investigations into the role of the PCC in cognitive processes and neurological disorders.