Editorial: The bodily self in the multisensory world

Summary & key facts

This editorial introduces a Research Topic about how the brain combines different senses to make a sense of the body. The collected studies look at touch, space, body image, and rehab methods and show the brain is flexible in how it uses sensory signals. The editors also say we still do not have a clear map of the brain networks behind bodily self-awareness and list many open questions for future work.

Key facts:

• The Research Topic page lists 8 articles by 41 authors and reports 31,424 total views for the topic.
• The editorial says the work explores somatosensation, spatial perception, bodily-self representation, and rehabilitation techniques and highlights the brain's flexibility in multisensory processing.
• One included study (Matteo Girondini et al.) reported preliminary evidence from virtual reality that spatial tactile localization depends on sensorimotor binding (4,576 views; 5 citations).
• Another included study reported that intermittent theta burst stimulation (iTBS) of the left dorsolateral prefrontal cortex was associated with reductions in drive for thinness and body dissatisfaction in people with self-reported dysregula
• The topic summary stresses that changing or depriving one sensory modality can lead to perceptual adjustments at both single-sense and multisensory levels, and that dysfunctional multisensory integration may prevent a coherent bodily self-r
• The editors list open questions that remain unanswered, such as when bodily self-awareness arises, which cortical areas build it, how it develops over the lifespan, which senses matter most, and whether/when impaired bodily self-representat

Abstract

The present research topic investigates the relationship between sensory perception, multisensory integration, and bodily self-representation. Here, the collected seven novel publications explore the fields of somatosensation, space, bodily-self representation, and rehabilitation techniques, unveiling the remarkable flexibility and adaptability of the human brain in navigating the multisensory landscape. Below is a brief overview of the original research contributions that focus on the bodily self, from virtual reality experiments to clinical case studies, by offering profound insights into how our brains construct and integrate sensory experiences, ultimately reshaping our understanding of perception and consciousness.From a clinical perspective, multisensory processing has been extensively studied. For example in neurological patients (Fossataro et al., 2020;Fossataro et al., 2018;Leo et al., 2008;Noel et al., 2019) it is established that multisensory integration fosters bodily delf representation and perceptual processing, whereas alterations have been reported in psychiatric and neurodevelopmental (Galigani et al., 2022;Noel et al., 2021) conditions (Brizzi et al., 2023;Gröhn et al., 2022;Hornix et al., 2019). Here, Have and colleagues investigated the profound implications of brain damage on somatosensory processing. A single case sheds light on the complex interplay between vision and somatosensation, revealing a pathological imbalance in somato-representation following left parietal brain damage. Despite a preserved ability to localize tactile stimuli via motor responses, the patient exhibits deficits in discriminating stimuli applied to distal hand regions. The authors show a fascinating interplay between somatosensation and somato-representation, highlighting the pivotal role of visual information in shaping our perception of bodily sensations. In parallel, Schlienger and colleagues highlight the power of visuo-proprioceptive integration as a promising rehabilitation tool to alleviate phantom limb pain, and facilitate motor recovery. Exploiting the mirror paradigm (Ramachandran & Rodgers-Ramachandran, 1996) in healthy participants, they demonstrate the efficacy of combining congruent visual and proprioceptive feedback to enhance movement perception of lower limbs. These findings open new avenues for therapeutic interventions, offering promising prospects for individuals grappling with motor impairments. Finally, Barone and coworkers provide insights into the multifaceted nature of the bodily self in the context of dysregulated eating behaviors. Exploring the effect of intermittent theta burst stimulation on individuals with self-reported dysregulated eating behaviors showed that body dissatisfaction and drive for thinness rely on an interplay between brain laterality, cognitive processes, and emotional responses to body image. These findings could help establish asymmetric cortical excitability in the dorsolateral prefrontal cortex as a potential neurophysiological marker of dysregulated eating, and as an index in the continuum between neurotypical and neurodivergent eating behaviors.From a developmental perspective, pivotal studies demonstrate that multisensory interactions with the external world shape the development of a coherent sense of self since birth (Begum Ali et al., 2021;De Klerk et al., 2021;Orioli et al., 2018;Ronga et al., 2021). Here, Cook and coworkers investigate the malleability of self-face representation through multisensory stimulation, unveiling interesting links between bodily perception and social cognition in children. By blurring the boundaries between self and other with the enfacement illusion (Tsakiris, 2008), the authors found that multisensory stimulation can significantly impact children's self-face representation and body image attitudes. Specifically, the bodily illusion leads to changes in how children perceive their own faces and bodies, as well as how they view the bodies of others, with a preference for larger body size and reduced social comparisons between self and others, suggesting an increased positive body size attitude. Interestingly, Ntoumanis and colleagues investigate attentional engagement in human motion perception with a developmental perspective, from children to young adults. By employing naturalistic videos containing human goaldirected movement, the authors show that scenes featuring limb movements, especially simultaneous arm and leg movements, elicit higher attentional engagement than scenes without limb movement. Interestingly, the power of naturalistic limb movements in enhancing attentional engagement changes across the life span and is more pronounced in older participants, and thus can be exploited to increase the viewers' attentional focus.Finally, by adopting different perspectives, two studies focused on how sensory information is processed and integrated in the brain. Xu and colleagues explore neural differences between airplane pilots and non-pilots, assuming that pilots' flight expertise leads to changes in their brain function and structure. They find that pilots' spontaneous activity in brain areas related to visual information processing and coordinated movement of the body are significantly enhanced, suggesting that extensive training modifies bodily-related capabilities by improving monitoring, body balance, eye movement, concentration, and brain function, aiding in perception and coordination. Girondini and coworkers investigate how the brain processes somatosensory stimuli concerning anatomical and spatial frames of reference. Utilizing virtual reality tasks, the authors explore the impact of congruent and incongruent sensory-motor interactions on spatial perception by inducing a misalignment between the visual-motor-proprioceptive cues from body movement and the somatosensory feedback received. They spatially shift the somatosensory feedback resulting from right-hand interactions toward the opposite hand and find that participants show a bias in left-right tactile localization, and that the perceived body-midline shifts accordantly with the location of somatosensory feedback. These findings highlight the potential for understanding spatial biases induced by sensory-motor interactions in virtual environments, contributing to advancements in bodily perception mechanisms in normal and pathological contexts.These studies offer a kaleidoscopic view of bodily perception, from clinical manifestations to neuroscientific insights and social cognition processes. By embracing interdisciplinary approaches and cutting-edge methodologies, researchers continue to unravel the mysteries of the multisensory world, paving the way for transformative advancements in neuroscience and beyond.

Topics

Multisensory perception and integration Virtual Reality Applications and Impacts

Categories

Experimental and Cognitive Psychology Psychology Social Sciences

Tags

Cognitive psychology Cognitive science Neuroscience Psychology