Binding the Self · how cortical oscillations bind sensory stimuli into a multisensory representation of the physical self

Binding the self: how cortical oscillations bind sensory stimuli into a multisensory representation of the physical self

Binding the Self tests the hypothesis that cortical oscillations serve as a temporal gateway for bodily perception, enabling the brain to bind self-related sensory signals into a coherent multisensory representation of the body. To achieve this aim, the project employs a multidisciplinary strategy that integrates innovative psychophysical paradigms with both correlational and causal neuroscientific approaches. Multisensory integration refers to the brain’s ability to combine sensory information from different modalities into coherent perceptions. A fundamental challenge is determining which sensory signals should be integrated and which should be segregated. Signals originating from the same external object or event ought to be integrated, whereas those from different sources should not. Spatiotemporal correlations help solve this multisensory integration problem: when signals occur with minimal temporal discrepancy, they are more likely to stem from the same event and should therefore be bound together. By contrast, larger temporal discrepancies suggest distinct events, and integration should not occur. Therefore, temporal resolution of this integrative mechanism determines which signals are bound together across time and modalities to generate the perception of meaningful objects and events. In this regard, the notion of temporal binding window (TBW) refers to the temporal interval, variable across individuals, within which sensory stimuli are more likely to be integrated into a unified percept. An influential theory proposes that alpha oscillations discretize sensory input into perceptual frames, thereby determining temporal resolution of perception and the individual width of the TBW. According to this view, multisensory perception occurs within temporal windows defined by the frequency of alpha oscillations, such that individual differences in oscillatory frequency predict variability in temporal resolution. In addition to combining or segregating sensory signals from external stimuli, the brain must determine whether to integrate or segregate signals originating from one’s own body. This is particularly important for the sense of body ownership—the perceptual experience of one’s limbs and body parts as one’s own. However, we still lack a mechanistic account of how the brain temporally integrates multisensory signals from the body itself. The aim of Binding the Self is to reveal the mechanism behind temporal integration of bodily signals, enhancing our knowledge of self-consciousness. Indeed, the role of brain oscillations in the fundamental sense of self and the distinction between self and non-self remains largely unexplored. Binding the self demonstrates that the frequency of cortical oscillations plays a crucial role in binding self-related sensory information into a coherent perceptual experience of one’s body and distinguishing this bodily self from external sensory events. This constitutes first evidence to link brain oscillations to such a foundational aspect of selfhood – the sense of bodily self. This overarching aim will be split into three objectives that will provide new scenarios to the mechanisms that allow us to bind the self: 1) The first objective is to demonstrate that temporal resolution of simultaneity perception correlates with temporal resolution of multisensory integration involved in body ownership, both when body ownership is induced by visuotactile information and when ownership is induced only by tactile and proprioceptive information alone in absence of vision. 2) The second objective is to demonstrate the role of parietal alpha oscillations in the temporal integration of somatosensory and bodily related visual signals, serving as the common electrophysiological mechanism underlying the temporal resolution of visuotactile processing in simultaneity and body ownership perception 3) The third objective is to investigate whether the temporal integration of bodily signals is supported by modality-specific oscillations, depending on the sensory modality through which the body is primarily perceived. Specifically, I hypothesize that beta oscillations mediate the temporal integration of bodily signals when body ownership is induced solely through proprioceptive and tactile cues in the absence of visual input. Binding the Self will uncover the oscillatory mechanisms underlying temporal integration of bodily signals, advancing our understanding of self-consciousness. Without clarifying the electrophysiological basis of this integration, our knowledge of self-related multisensory processing will remain incomplete. The project is expected to open new lines of research on cortical oscillations and their role in fundamental aspects of selfhood, such as the sense of agency and sensory attenuation. Clinically, the findings will inform rehabilitation strategies for conditions involving distorted body ownership probably due to distorted temporal integration, including schizophrenia, eating disorders, and body identity disorders. Technologically, they will support the development of prosthetics and brain–machine interfaces by providing tools to enhance embodiment and sensory feedback, reducing rejection rates and improving quality of life. Overall, the expected impact of the project will bridge basic neuroscience, clinical rehabilitation, and neurotechnology, creating tangible societal value.

Текст от CORDIS, на английски · Данни: CORDIS, © Европейски съюз