Motivational Influences on Attention

Attention is the selective processing of behaviorally relevant stimuli. But what selects certain stimuli as behaviorally relevant for attention? Motivational signals may, in part, determine the significance of stimuli for selection by attention. While distinct neural circuits are thought to process motivation and attention, deficits in attention observed in neurological disorders such as ADD/ADHD are associated with disruptions in motivational signaling, suggesting functional interaction between these neural systems. The influence of motivation on attention, both behaviorally and neurophysiologically, remains unknown. One possibility is that enhancing motivation sharpens attention. In the figure above, this would result in improved detection of stimuli at the highlighted location, but diminished detection of stimuli at unattended locations (upper right). A second possibility is that enhancing motivation improves overall performance without improving attentional focus (bottom right). To address this question, we are studying attention in human and monkey subjects while varying motivational context. In addition, we are studying the responses of neurons in parietal cortex in monkeys trained to attend to or ignore simple visual stimuli. Our preliminary data suggest that increasing motivation enhances selective attention, in both human and monkey subjects. Moreover, neurons in parietal cortex reporting the focus of attention become more selective with increases in motivation. These preliminary data suggest that motivation and arousal may make the brain more sensitive to behaviorally relevant stimuli, thus improving performance.