Cognition, emotion, and the central autonomic network.

The demands of both mental and physical activity are integrated with the dynamic control of internal bodily states. The set of neural interactions that supports autonomic regulation extends beyond afferent-efferent homeostatic reflexes (interoceptive feedback, autonomic action) to encompass allostatic policies reflecting more abstract and predictive mental representations, often accessed as conscious thoughts and feelings. Historically and heuristically, reason is contrasted with passion, cognition with emotion, and 'cold' with 'hot' cognition. These categories are themselves arbitrary and blurred. Investigations of psychological processes have been generally pursued during states of musculoskeletal quiescence and are thus relatively insensitive to autonomic interaction with attentional, perceptual, mnemonic and decision-making processes. Autonomic psychophysiology has nevertheless highlighted the bidirectional coupling of distinct cognitive domains to the internal states of bodily arousal. More powerfully perhaps, in the context of emotion, autonomically mediated changes in inner bodily physiological states are viewed as intrinsic constituents of the expression of emotions, while their feedback representation is proposed to underpin emotional and motivational feelings. Here, we review the brain systems, encapsulated by the notion of central autonomic network, that provide the interface between cognitive, emotional and autonomic state. These systems span the neuraxis, overlap with the more general governance of behaviour, and represent district levels of proximity to survival-related imperatives. We touch upon the conceptual relevance of prediction and surprise to understanding the integration of cognition and emotion with autonomic control.