Humans have a natural and intuitive tendency to direct attention and to act upon objects of our environment that we value most. However, we often need to overcome this inclination to act in an appropriate manner. A compromised ability to exert such control lies at the root of major psychopathologies such as depression, addiction and obsessive-compulsive disorder. The overarching aim of our project is to establish well-defined human neurophysiological indices that open a direct window on the processes of attention, intention, and value, their dynamics and their dissociability. This will not only provid insight into inherently human aspects of decision making, but will also lead to clinical studies that can furnish a mechanistic account of disorders of value-based decision making. In preliminary work we examined the neural signatures of relative value encoding in a simple task where two eye movement (saccade) target alternatives are presented in the form of colored discs appearing on the left and right of a display, before a final action instruction is provided. e identified a robust, transient, electrophysiological index of the relative valuation of alternative action targets in space, observed in the visual evoked potential to the targets. Here, we propose a series of eight simple experiments to test the generality of this signal across motor and sensory parameters and more fully elucidate the nature of this process specifically in relation to the allocation of attention and the formation of an intentional motor plan. Experiment 1 will assess whether the signal encodes the magnitude of the relative value differential in a valence-independent manner by substituting losses for gains in the original task design. Experiment 2 and 3 will test the visual feature and motor output specificities of our signal by using different shapes instead of colors (exp 2) and button-presses instead of saccades (exp 3). In experiment 4 we will remove the speed pressure by lifting the movement execution deadline to determine the influence of this aspect of motor intention. Experiments 5 and 6 will determine whether the relative value representation is echoed on the presentation of target alternatives even when the identity and value of the target is known in advance (exp 5: color pre-cue, color-value), or alternatively, when the value is fixed to the target location (exp 6: color pre-cue, spatial-value) In experiments 7 and 8, we will address the scenario where the target location is known in advance and employ the same color (exp 7: spatial pre-cue, color-value) and spatial value associations (exp 8: spatial pre- cue, spatial-value). The completion of these experiments and the consequent clarification of value-associated target selection mechanisms will provide a well-grounded platform for conducting carefully designed studies of these processes in depression and addiction.
Humans have a natural tendency to direct attention and form intentions towards objects of our environment that we value most. However, these elements routinely require prying apart in the service of appropriate behavior. The overarching aim of our project is to establish well-defined, human neurophysiological indices that open a direct window on the processes underlying intention, attention and value, their dynamics and their dissociability. This will not only provide insight into inherently human aspects of decision making, but will also lead to clinical studies that can furnish a mechanistic account of disorders of value-based decision making such as addiction and depression.