Conjoint activity of anterior insular and anterior cingulate cortex: awareness and response

Abstract

There is now a wealth of evidence that anterior insular and anterior cingulate cortices have a close functional relationship, such that they may be considered together as input and output regions of a functional system. This system is typically engaged across cognitive, affective, and behavioural contexts, suggesting that it is of fundamental importance for mental life. Here, we review the literature and reinforce the case that these brain regions are crucial, firstly, for the production of subjective feelings and, secondly, for co-ordinating appropriate responses to internal and external events. This model seeks to integrate higher-order cortical functions with sensory representation and autonomic control: it is argued that feeling states emerge from the raw data of sensory (including interoceptive) inputs and are integrated through representations in conscious awareness. Correspondingly, autonomic nervous system reactivity is particularly important amongst the responses that accompany conscious experiences. Potential clinical implications are also discussed.

Fig. 1

Subdivisions of cingulate cortex according to the four-subregion model proposed by Vogt (see text). aMCC anterior midcingulate cortex, cas callosal sulcus, cgs cingulate sulcus, dPCC dorsal posterior cingulate cortex, irs inferior rostral sulcus, mr maginal ramus of cgs, pACC pregenual anterior cingulate cortex, pcgs paracingulate sulcus, pMCC posterior midcingulate cortex, RSC retrosplenial cortex, sACC subgenual anterior cingulate cortex, spls splenial sulci, vPCC ventral posterior cingulate cortex. (reproduced with permission from Vogt 2005)

Fig. 2

Anterior cingulate–insula relationships in behaviourally integrated autonomic control. This figure plots locations of dissociated and conjoint activations of anterior/mid/subgenual cingulate and insular cortical activity across experimental studies involving the Critchley laboratory exploring central correlates of peripheral autonomic activity during different task conditions, representation/perturbation of afferent visceral feedback or both (biofeedback, baroreceptor or autonomic patient vs. control studies). The figure does not explore lateralization of insular response with the observation that across studies activity was generally bilateral or right lateralized. The figure highlights a paucity of cingulate or insula-only engagement and notes the contexts in which these are observed. While not a comprehensive view of coupling between these regions, the figure focuses directly on the control of internal bodily state. EDA electrodermal activity, PAF pure autonomic failure, BP blood pressure, LF-HRV low frequency (sympathetic) power in heart rate variability, HR heart rate. Panel I 1 Critchley et al. , 2 Critchley et al. , 3 Critchley et al. , 4 Kavia et al. , 5 McKay et al. , 6 Harrison et al. , 7 Nicotra et al. . Panel II 1 Critchley et al. , 2 Critchley et al. , 3 Critchley et al. , 4 Gray et al. . Panel III A Critchley et al. , B Critchley et al. , C Critchley et al. , D Nagai et al. , E Critchley et al. , F Critchley et al. , G Critchley et al. , H Gianaros et al. , I Harrison et al.