Motor Preparatory Activity in Posterior Parietal Cortex is Modulated by Subjective Absolute Value

Abstract

Author SummaryThe expected outcome of voluntary actions profoundly shapes human decision making. For instance, expected monetary reward and punishment are powerful modulators of human behavior. Yet how these factors influence brain activity responsible for the preparation of such behavior is not fully understood. This is especially true for demanding tasks, in which the outcome—e.g. reward versus punishment—critically depends on the accuracy of actions. In our human fMRI study we investigated brain activity in specific cortical areas that are related to the planning of voluntary behavior. We show that planning activity in these areas is strongly influenced by the expected monetary gain or loss that subjects associated with their performance in a demanding motor task. Planning activity was highest for large expected gains in subjects who believed that they performed well; conversely, activity was highest for large expected losses in subjects who thought that they performed poorly. This pattern of planning activity was best described by a model which we refer to as the “subjective absolute value model.” We suggest that absolute value signals in motor planning areas can be used to mobilize motor resources in behaviorally relevant situations—both to maximize gains and to avoid losses.