title: Predeliberation activity in prefrontal cortex and striatum and the prediction of subsequent value judgment.
abstract: Rational, value-based decision-making mandates selecting the option with highest subjective expected value after appropriate deliberation. We examined activity in the dorsolateral prefrontal cortex (DLPFC) and striatum of monkeys deciding between smaller, immediate rewards and larger, delayed ones. We previously found neurons that modulated their activity in this task according to the animal's choice, while it deliberated (choice neurons). Here we found neurons whose spiking activities were predictive of the spatial location of the selected target (spatial-bias neurons) or the size of the chosen reward (reward-bias neurons) before the onset of the cue presenting the decision-alternatives, and thus before rational deliberation could begin. Their predictive power increased as the values the animals associated with the two decision alternatives became more similar. The ventral striatum (VS) preferentially contained spatial-bias neurons; the caudate nucleus (CD) preferentially contained choice neurons. In contrast, the DLPFC contained significant numbers of all three neuron types, but choice neurons were not preferentially also bias neurons of either kind there, nor were spatial-bias neurons preferentially also choice neurons, and vice versa. We suggest a simple winner-take-all (WTA) circuit model to account for the dissociation of choice and bias neurons. The model reproduced our results and made additional predictions that were borne out empirically. Our data are compatible with the hypothesis that the DLPFC and striatum harbor dissociated neural populations that represent choices and predeliberation biases that are combined after cue onset; the bias neurons have a weaker effect on the ultimate decision than the choice neurons, so their influence is progressively apparent for trials where the values associated with the decision alternatives are increasingly similar.
authors: Division of Biology, California Institute of Technology Pasadena, CA, USA.
authors: Uri
authors: U
authors: Maoz
authors: Ueli
authors: U
authors: Rutishauser
authors: Soyoun
authors: S
authors: Kim
authors: Xinying
authors: X
authors: Cai
authors: Daeyeol
authors: D
authors: Lee
authors: Christof
authors: C
authors: Koch
keywords: caudate nucleus; decision circuit-modeling; dorsolateral prefrontal cortex; free-choice decision making; monkey single-neuron recording; pre-deliberation decision bias; value-based decision-making; ventral striatum