Inside the Self: from interoception to self- and other-awareness

Project Information

INtheSELF

Grant agreement ID: 724537

DOI

10.3030/724537

Project closed

EC signature date 27 June 2017

Start date 1 September 2017

End date 31 August 2024

Funded under

• EXCELLENT SCIENCE - European Research Council (ERC)

Total cost

€ 1 998 393,75

EU contribution

€ 1 998 393,75

Coordinated by

ROYAL HOLLOWAY AND BEDFORD NEW COLLEGE
United Kingdom

Periodic Reporting for period 5 - INtheSELF (Inside the Self: from interoception to self- and other-awareness)

Reporting period: 2023-09-01 to 2024-08-31

Summary of the context and overall objectives of the project

Modern psychology has long focused on the importance of the body as the basis of the self. However, this focus concerned the exteroceptive body, that is, the body as perceived from the outside, as when we recognize ourselves in the mirror. This influential approach has neglected another important dimension of the body, namely the interoceptive body, that is, the body as perceived from within, as for example when one feels her racing heart. INtheSELF, however, goes beyond this approach, aiming instead to show how interoception and interoceptive awareness serve the unity and stability of the self, analogous to the role of interoception in maintaining physiological homeostasis. INtheSELF developed novel, pioneering methods for the study of causal relationships between interoceptive and exteroceptive awareness, allowing us to test how these two sources of information about the self interact to reflect the balance between stability and adaptation; how their inter-relation is built in parallel to the development of self-awareness in early childhood and adolescence; and the role that their interaction has for social relatedness. INtheSELF elucidates how humans navigate the challenging balance between inside and out, in terms of both the individual’s natural (interoception vs. exteroception) and social (self vs. others) embodiment in the world. The questions we are asking are timely, and the answers that INtheSELF gives can be impactful within and beyond academia. In a society which constantly exposes us to external, idealised images of the body and the self, my project stands to offer a unique window of insight into how our self can be built from the inside out.

Work performed from the beginning of the project to the end of the period covered by the report and main results achieved so far

INtheSELF aimed to show how interoception and interoceptive awareness serve the unity and stability of the self, analogous to the role of interoception in maintaining physiological homeostasis. INtheSELF developed novel, pioneering methods for the study of causal relationships between interoceptive and exteroceptive awareness (WP1), allowing us to test how these two sources of information about the self interact to reflect the balance between stability and adaptation (WP2); how their inter-relation is built in parallel to the development of self-awareness in early childhood and adolescence (WP3); and the role that their interaction has for social relatedness (WP4). The following results have been achieved (broken down by WP):
WP1: we made substantial progress as we developed and validated new ways of non-invasive manipulations of interoception, new tasks of measuring interoceptive accuracy and new neural evidence. Our approach was multimodal, combining behavioural, subjective, physiological and neuroimaging data. The COVID-lockdowns also gave us the opportunity to develop, test and share with the scientific community tools for online recording of cardiac interoceptive data leading to the development of a new task that can be implemented online.
WP2: we showed how interoceptive signals can change the ability to recognize one’s own face, how embodiment driven by exteroceptive signals is constrained by the presence and quality of interoception, as well as how interoceptive signals can inform our sense of agency, that is, the feeling of control over one’s own actions. We made substantial advances in understanding how interoceptive signals modulate time-perception, another fundamental feature of self-awareness beyond body-ownership and agency.
WP3: we traced the origins and the effects of interoceptive awareness in two critical periods, in early infancy and early adolescence. Our longitudinal study in early infancy tested and confirmed our hypothesis about the inverse correlation between interceptive and exteroceptive awareness. Our cross-sectional study in early adolescence tested and confirmed our hypothesis about an inverse correlation between interoception and body-image satisfaction. The longitudinal and to a lesser extent the cross-sectional designs of these studies provide findings that can speak for the causal role that interoception plays in self-awareness.
WP4: we showed how interoceptive signals and awareness thereof may shape people’s empathic responses towards others, our social perception as well as the influence that others have on our social processing. The findings support the model we put forward of social relatedness based on the role of interoception for the stability of the self.
Overall, INtheSELF met its primary objectives of developing four WPs to test theoretically-driven hypotheses about the functional role of the relation between interoception and exteroception.

Progress beyond the state of the art and expected potential impact (including the socio-economic impact and the wider societal implications of the project so far)

We produced empirical findings and theoretical insights that go beyond the state of the art. Below we present some of these highlights.
In terms of methods, we used a non-invasive pattern of vagus stimulation through its auricular branch and showed improvements in people’s interoceptive accuracy. We also adapted a method that we had developed for studying interoceptive sensitivity in infants to the study of interoceptive sensitivity in non-human primates and we showed for the first time that macaque monkeys show evidence of interoceptive sensitivity in a pattern similar to the one found in human infants, paving the way for cross-species studies of interoceptive awareness.
In terms of ontogenetic development, our longitudinal study in early infancy showed, for the first time and in line with our hypothesis, that higher levels of interceptive greater interoceptive sensitivity at 13 months led to delays in mirror self-recognition at 21 months. Thus, the ability to recognise oneself in the mirror in early toddlerhood partly depends on levels of interoceptive representations in infancy, extending the finding in adults. The findings have important implications for understanding the developmental pathways to explicit self-awareness. Moreover, our cross-section study in pre- and post-puberty girls showed, for the first time, that lower levels of interoceptive awareness at late, but not early puberty, increase the probability body dissatisfaction. Taken together these two studies conducted at critical developmental stages provide new insights on how body-awareness develops with implications about our understanding of mental health vulnerabilities.
In terms of self-awareness, our studies demonstrate how interoception interacts with exteroceptive signals to create a coherent representations of one’s self and applied this insight in a range of domains : from body-ownership to the sense of agency and from information sampling to time-perception.
In terms of social cognition, we show how interoception is not simply important for awareness of our one’s states, but it also shapes how we relate to other people’s emotions: interoceptive signals were shown to modulate impressions of trustworthiness, to influence our egocentric biases when we interact with others and how much our social perceptions are influenced by other people.
Taken together, INtheSELF met most of its objective and in several instances led to empirical findings that go well beyond the state of the art, using a range of methods and techniques in a range of populations and addressing important methodological and theoretical debates of the field.

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