Cognitive Control, Cognitive Search, and Motivational Salience: A Systems Neuroscience Approach

An essential facet of adaptive and versatile behavior is the ability to prioritize actions in response to dynamically changing circumstances, in particular when circumstances require the coordination of a planned course of action vis-à-vis instantaneous urges and extraneously triggered reactions. This chapter focuses on one aspect of cognitive search: the exploration of internal and external milieu for motivationally salient events (stimuli that are novel, ambiguous, infrequent, deviant, or unexpected, or register as a risk for undesirable outcomes or a risk for the exhaustion of resources) which may require appropriate adaptive action. A neurocognitive framework is described for understanding how cognitive control and cognitive search are modulated by motivationally salient events. This framework emphasizes the integration of a salience network in the brain with other large-scale neural networks, neurotransmitter systems, and homeostatic (autonomic nervous system) functioning.

The anterior insula cortex and anterior cingulate cortex are core nodes of a salience network that monitors for motivationally salient stimuli. This framework helps to amalgamate findings from disparate literatures into a common conjecture and highlights the role of motivational salience in modulating cognitive search and cognitive control. The salience network transforms salience signals into an orienting response which serves to recruit the necessary physiological arousal and to engage task-relevant networks (involving attentional, working-memory, and adaptive action selection processes) while disengaging task-negative networks. Using representative examples as instructive points in case, it is argued that this integrative systems-neuroscience framework provides a parsimonious account of salience processing, and may provide novel insights into the neural basis of individual differences among healthy as well as pathological populations.