title: Changes in interoceptive processes following brain stimulation.
abstract: The processing and perception of individual internal bodily signals (interoception) has been differentiated to comprise different levels and processes involved. The so-called heartbeat-evoked potential (HEP) offers an additional possibility to examine automatic processing of cardiac signals. Knowledge on neural structures potentially supporting different facets of interoception is still sparse. One way to get insights into neuroanatomical function is to manipulate the activity of different brain structures. In this study, we used repetitive transcranial magnetic stimulation (rTMS) and a continuous theta-burst protocol to inhibit specific central locations of the interoceptive network including the right anterior insula and the right somatosensory cortices and assessed effects on interoceptive facets and the HEP in 18 male participants. Main results were that inhibiting anterior insula resulted in a significant decline in cardiac and respiratory interoceptive accuracy (IAc) and in a consistent decrease in perception confidence. Continuous theta-burst stimulation (cTBS) over somatosensory cortices reduced only cardiac IAc and affected perception confidence. Inhibiting right anterior insula and right somatosensory cortices increased interoceptive sensibility and reduced the HEP amplitude over frontocentral locations. Our findings strongly suggest that cTBS is an effective tool to investigate the neural network supporting interoceptive processes.This article is part of the themed issue 'Interoception beyond homeostasis: affect, cognition and mental health'.
authors.affiliation: Clinical and Health Psychology, Institute of Psychology and Education, Ulm University, Albert Einstein Allee 41, Ulm, Germany olga.pollatos@uni-ulm.de.
authors.forename: Olga
authors.identifier: 0000-0002-0512-565X
authors.initials: O
authors.lastname: Pollatos
authors.affiliation: Clinical Psychology and Psychotherapy, Department of Psychology, Eberhard Karls University of Tübingen, 72076 Tübingen, Germany.
authors.forename: Beate M
authors.identifier: 0000-0002-3284-4529
authors.initials: BM
authors.lastname: Herbert
authors.affiliation: Clinical and Health Psychology, Institute of Psychology and Education, Ulm University, Albert Einstein Allee 41, Ulm, Germany.
authors.forename: Sandra
authors.initials: S
authors.lastname: Mai
authors.affiliation: Section for Neurostimulation, Department of Psychiatry, Ulm University, 89075 Ulm, Germany.
authors.forename: Thomas
authors.identifier: 0000-0002-2769-5645
authors.initials: T
authors.lastname: Kammer
mesh_terms: D000328:Adult; D002540:Cerebral Cortex / Q000502:physiology*; D005858:Germany; D006339:Heart Rate; D006801:Humans; D065812:Interoception; D008297:Male; D056152:Respiratory Rate; D050781:Transcranial Magnetic Stimulation; D055815:Young Adult
keywords: HEP; TMS; insula; interoception; interoceptive accuracy; somatosensory cortex