Bodily intolerance of uncertainty influences perceptual recalibration of abdominal boundaries
How sure are you, exactly, of where your abdomen begins? For most people that's an obvious question, but for some, uncertainty about their own body size feels uncomfortable, even distressing. Researchers Manja Engel (Utrecht University) and Valeria Peviani (Radboud University) investigated whether this so-called ‘bodily intolerance of uncertainty’ influences how people perceive and update their abdominal boundaries when what they see and what they feel don’t match.
For the study, published in Consciousness and Cognition, 34 female participants took part in a virtual reality task. Wearing a VR headset and holding a virtual stick, they estimated where they felt the boundary of their abdomen to be. They then received visuo-tactile feedback: they touched their abdomen with a physical stick, while seeing a virtual stick in VR. For one group, the length of the virtual and physical stick matched (congruent feedback); for the other group, the virtual stick was shorter than the physical stick, creating the impression of an expanding abdomen (incongruent feedback). After this feedback, participants again estimated where their abdominal boundary was.
Participants who scored higher on bodily intolerance of uncertainty beforehand showed a greater shift in their abdominal boundary estimates after incongruent feedback than participants with low intolerance of uncertainty. This relationship did not appear after congruent feedback: there, the level of bodily intolerance of uncertainty made no difference.
This pattern fits with the idea that the brain continuously updates its predictions about the body based on incoming sensory signals, and that people who struggle with uncertainty about their body are more inclined to reweight these signals once the information becomes conflicting. According to the researchers, this shows that not only the immediate sensory situation, but also stable personality traits such as bodily intolerance of uncertainty, play a role in how stable a person’s body image is.
The researchers stress that further research is needed, including with larger and more diverse groups of participants, to determine whether these findings also apply to men and non-binary individuals, and to explore whether these insights could contribute to interventions aimed at a more stable body image.