Combining the inner self with the map of the body: evidence for white matter contribution to the relation between interoceptive sensibility and nonaction-oriented body representation

Author: Maddalena Boccia1, Simona Raimo2, Antonella Di Vita3, Alice Teghil4, Liana Palermo2
Affiliation:
1 Department of Psychology, Sapienza University of Rome, Rome, Italy; Cognitive and Motor Rehabilitation and Neuroimaging Unit, IRCCS Fondazione Santa Lucia, Rome, Italy. Electronic address: maddalena.boccia@uniroma1.it.
2 Department of Medical and Surgical Sciences, Magna Graecia University, Catanzaro, Italy.
3 Department of Human Neuroscience, Sapienza University of Rome, Rome, Italy.
4 Department of Psychology, Sapienza University of Rome, Rome, Italy; Cognitive and Motor Rehabilitation and Neuroimaging Unit, IRCCS Fondazione Santa Lucia, Rome, Italy.
Conference/Journal: Neuroscience
Date published: 2023 May 2
Other: Special Notes: doi: 10.1016/j.neuroscience.2023.04.021. , Word Count: 262


Very recent studies on healthy individuals suggest that changes in the sensibility toward internal bodily sensations across the lifespan affect the ability to mentally represent one's body, in terms of action-oriented and nonaction-oriented body representation (BR). Little is known about the neural correlates of this relation. Here we fill this gap using the neuropsychological model provided by focal brain damage. Sixty-five patients with unilateral stroke (20 with left and 45 with right brain damage, LBD and RBD, respectively) participated in this study. Both action-oriented BR and nonaction-oriented BR were tested; interoceptive sensibility was assessed as well. First, we tested whether interoceptive sensibility predicted action-oriented BR and nonaction-oriented BR, in RBD and LBD separately. Then, a track-wise hodological lesion-deficit analysis was performed in a subsample of twenty-four patients to test the brain network supporting this relation. We found that interoceptive sensibility predicted the performances in the task tapping nonaction-oriented BR. The higher interoceptive sensibility was, the worse patients performed. This relation was associated with the disconnection probability of the corticospinal tract, the fronto-insular tract, and the pons. We expand over the previous findings on healthy individuals, supporting the idea that high levels of interoceptive sensibility negatively affect BR. Specific frontal projections and frontal u-shaped tracts may play a pivotal role in such an effect, likely affecting the development of a first-order representation of the self within the brainstem autoregulatory centers and posterior insula and of a second-order representation of the self within the anterior insula and higher-order prefrontal areas.

Keywords: body schema; diffusion tractography; interoception; topological body map; visuo-spatial body map.

PMID: 37142183 DOI: 10.1016/j.neuroscience.2023.04.021

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