Abstract
Our sensory environment is replete with visual stimuli associated with positive or negative outcomes. However, such value-associated stimuli are often irrelevant for ongoing tasks. Although previous behavioral studies show that these stimuli may inappropriately capture attention, we know little about the underlying brain processes mediating these effects. To investigate this issue, we recorded event-related potentials (ERP) from healthy human adults who had first learned to associate three different colored squares with three different monetary outcomes (gain, no outcome, or loss). These stimuli were then viewed in a simple, speeded choice task. Four squares were arranged in a cross pattern around central fixation. Participants were asked to attend to the two squares on the vertical meridian and to ignore squares on the horizontal meridian. On target-present trials (20%), both vertically-located squares were colored and both horizontally-located squares were gray; the task was to maximize reward by choosing a color. Immediate feedback was given. On target-absent trials (80%) both vertically-located squares were gray, requiring participants to press a different key to indicate target-absence. On these critical trials, one horizontally-located square was gray and the other (distractor) was colored. Response time (RT) was expected to vary with the value association of the irrelevant distractor. Indeed, RT was significantly slower when the distractor color was associated with gain versus no outcome or loss. ERPs measured on these trials showed that gain-associated distractors induced greater cognitive conflict (as indexed by the anterior N2 component) and greater attentional deployment (as indexed by the N2pc component). A second study that made target absent trials more distinct from target present trials replicated RT and anterior N2 results but instead found attentional suppression (as indexed by the Pd) of gain-associated distractors. These findings suggest that cognitive processing of value-associated distractors involves both conflict monitoring and attentional control systems.
Meeting abstract presented at VSS 2013