Neural divergence and convergence for attention to and detection of interoceptive and somatosensory stimuli

Author: Aleksandra M Herman1, Clare Palmer2, Ruben T Azevedo3, Manos Tsakiris4
Affiliation: <sup>1</sup> Lab of Action and Body, Department of Psychology, Royal Holloway, University of London, UK. Electronic address: <sup>2</sup> ABCD Coordinating Center, Center for Human Development (CHD), University of California, San Diego, USA. <sup>3</sup> School of Psychology, University of Kent, Canterbury, UK. <sup>4</sup> Lab of Action and Body, Department of Psychology, Royal Holloway, University of London, UK; The Warburg Institute, School of Advanced Study, University of London, UK; Department of Behavioural and Cognitive Sciences, Faculty of Humanities, Education and Social Sciences, University of Luxembourg, Luxembourg.
Conference/Journal: Cortex
Date published: 2020 Dec 8
Other: Volume ID: 135 , Pages: 186-206 , Special Notes: doi: 10.1016/j.cortex.2020.11.019. , Word Count: 162

Body awareness is constructed by signals originating from within and outside the body. How do these apparently divergent signals converge? We developed a signal detection task to study the neural convergence and divergence of interoceptive and somatosensory signals. Participants focused on either cardiac or tactile events and reported their presence or absence. Beyond some evidence of divergence, we observed a robust overlap in the pattern of activation evoked across both conditions in frontal areas including the insular cortex, as well as parietal and occipital areas, and for both attention and detection of these signals. Psycho-physiological interaction analysis revealed that right insular cortex connectivity was modulated by the conscious detection of cardiac compared to somatosensory sensations, with greater connectivity to occipito-parietal regions when attending to cardiac signals. Our findings speak in favour of the inherent convergence of bodily-related signals and move beyond the apparent antagonism between exteroception and interoception.

Keywords: Attention; Exteroception; Interoception; MRI; Psychophysiological interactions; Signal detection; Somatosensation.

PMID: 33385747 DOI: 10.1016/j.cortex.2020.11.019