Gut markers of bodily self-consciousness

Abstract

Bodily self-consciousness, the state of mind that allows humans to be aware of their own body, forms the backdrop for almost every human experience, yet its underpinnings remain elusive. Here we use an ingestible, minimally invasive capsule and surface electrogastrography to probe if gut physiology correlates with bodily self-consciousness during a virtual bodily illusion. We discover that specific patterns of stomach and large intestine activity (temperature, pressure, pH, and gastric peak frequency) covary with specific facets of bodily self-consciousness (feelings of body ownership, agency, location, and disembodiment). Furthermore, we show that the link between gastro-intestinal parameters and bodily self-consciousness depends also on individual levels of interoception. These results reveal a deep visceral pathway to the self-conscious perception of ourselves as embodied beings.

Weaker implicit interoception is associated with more negative body image: Evidence from gastric-alpha phase amplitude coupling and the heartbeat evoked potential

“…Regarding the association between gastric-alpha PAC and negative body image, emerging evidence indicates that the stomach and the brain influence each other via bidirectional (i.e., both ascending and descending) pathways (Mayeli et al, 2021;Monti et al, 2021;Rebollo et al, 2018;Richter et al, 2017). Specifically, in the initial identification of gastric-alpha PAC, transfer entropy analysis indicated that gastric-alpha coupling is attributable to an ascending influence from the stomach to the brain (Richter et al, 2017).…”

Gastrointestinal Interoception in Eating Disorders: Charting a New Path

“…Hydrogel capsules are a minimally invasive means capable of stimulating fullness sensations [74•]; the absence of caloric input associated with this approach allows for more naturalistic experiments separating the mechanosensory impact of gut distension from the caloric contents of a meal. Ingestible capsules for passive sensing of gut pressure, pH and temperature [75], and high-density electrogastrogram (EGG) arrays [76 •] have been developed, which could facilitate laboratory as well as ambulatory (i.e., real-world) assessments of gut physiology in eating disorders across different stages of illness recovery. The discovery of a cortical "gastric network" in the brain using simultaneous analysis of resting EGG and brain fMRI recordings [77•] lays the groundwork for experimental studies testing the state-specific role of this network as a homeostatic regulator of food intake and of motivationally relevant hunger and satiety cues [78].…”

Ingestible pills reveal gastric correlates of emotions

“… Mimee et al, 2018 ) and clinical research for non-invasive diagnostics of diseases affecting the GI system ( Mandsberg et al, 2020 ; Min et al, 2020 ; Rao et al, 2011 ), for local drug delivery ( Mandsberg et al, 2020 ), and for mapping heart rate, respiratory rate and apneic events, from within the human gastrointestinal tract ( Traverso et al, 2023 ). Interestingly, recent findings show that ingestible pills can be used to explore higher-order cognitive and emotional processes ( Mayeli et al, 2023 ; Mayeli et al, 2021 ; Monti et al, 2022 ). In particular, we used an ingestible capsule (SmartPill Motility Testing System, Medtronic plc) able to record pH, pressure and inner temperature throughout the entire GI tract ( Saad, 2016 ) when participants experienced the illusion of embodying a virtual breathing agent (referred to as the Embreathment, as described in Monti et al, 2020 ; Cantoni et al, 2024 ).…”