Conférence ImpAct par Simon Nougaret (INT, Marseille)

Frontopolar cortex functions in the macaque monkey: from social monitoring to fast learning

The frontopolar cortex (FPC) appeared as a main innovation in the evolution of anthropoid primates and it has been placed at the top of the prefrontal hierarchy. Human imaging and neuropsychological studies suggest that this area contributes to a wide range of cognitive abilities, including integration of operations performed by other prefrontal areas, cognitive branching, mnemonic functions and exploratory decision making.The extreme anteriority of the FPC in monkeys led to a shortage of neurophysiological studies targeting this area. The only study that investigated the activity of FPC neurons in monkeys suggested that these cells were involved in the monitoring of self-generated actions. Additionally, from lesions studies in monkeys, FPC apears to be essential to perform one-trial learning and to consider the different altenatives during a decision process. I will present the results of two electrophysiological studies, each focusing on one of the above-mentionned process. First, we studied the social variant of a non match-to-goal behavior that required monitoring the actions of a human or computer agent and discovered that the role of FPC neurons extends beyond self-generated actions to include monitoring others’ actions. Second, we studied the neural bases of fast-learning process, and reported very specific pattern of activity by representing the learning stage, exploration versus explotation, and the goal of the action. However, our results do not support the hypothesis according to which the frontal pole compute an evaluation of different alternatives. Indeed, the position of the chosen target was strongly encoded at its acquisition but the position of the unchosen target was not. Our results highlighted important features of FPC neurons in retrospective monitoring and fast-learning processes but do not confirm its role in the disengagementof cognitive control from the current goals.