Distinct signatures of reward value and variance on spiking activity and functional interactions in monkey fronto-parietal areas

The expected value (EV) and uncertainty of reward distributions have widespread effects on behavior and neural activity, but their effects on cognitive functions are poorly understood. Here we show that EV and uncertainty have dissociable effects on monkey frontal and parietal areas implicated in executive function. Uncertainty and EV were encoded by distinct populations of cells in each area, and they differentially modulated within- and across-area information transmission. EV enhanced the coherence between spikes and local field potential (SFC) within the frontal and the parietal lobe, suggesting that it enhanced within-area information transmission. In contrast, uncertainty enhanced parietal to frontal SFC but suppressed SFC in the top-down direction, suggesting that it selectively enhanced information transmission from the parietal to the frontal lobe. The results reveal cellular mechanisms through which reward and uncertainty can independently modulate executive function and support a primary role for the parietal cortex in processing information under uncertainty.