Peripersonal Space and Bodily Self-Consciousness: Implications for Psychological Trauma-Related Disorders

Peripersonal space (PPS) is defined as the space surrounding the body where we can reach or be reached by external entities, including objects or other individuals. PPS is an essential component of bodily self-consciousness that allows us to perform actions in the world (e.g., grasping and manipulating objects) and protect our body while interacting with the surrounding environment. Multisensory processing plays a critical role in PPS representation, facilitating not only to situate ourselves in space but also assisting in the localization of external entities at a close distance from our bodies. Such abilities appear especially crucial when an external entity (a sound, an object, or a person) is approaching us, thereby allowing the assessment of the salience of a potential incoming threat. Accordingly, PPS represents a key aspect of social cognitive processes operational when we interact with other people (for example, in a dynamic dyad). The underpinnings of PPS have been investigated largely in human models and in animals and include the operation of dedicated multimodal neurons (neurons that respond specifically to co-occurring stimuli from different perceptive modalities, e.g., auditory and tactile stimuli) within brain regions involved in sensorimotor processing (ventral intraparietal sulcus, ventral premotor cortex), interoception (insula), and visual recognition (lateral occipital cortex). Although the defensive role of the PPS has been observed in psychopathology (e.g., in phobias) the relation between PPS and altered states of bodily consciousness remains largely unexplored. Specifically, PPS representation in trauma-related disorders, where altered states of consciousness can involve dissociation from the body and its surroundings, have not been investigated. Accordingly, we review here: (1) the behavioral and neurobiological literature surrounding trauma-related disorders and its relevance to PPS; and (2) outline future research directions aimed at examining altered states of bodily self-consciousness in trauma related-disorders.

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Remapping Peripersonal Space by Using Foot-Sole Vibrations Without Any Body Movement

Psychological Science ◽

10.1177/0956797619869337 ◽

2019 ◽

Vol 30 (10) ◽

pp. 1522-1532 ◽

Cited By ~ 3

Author(s):

Tomohiro Amemiya ◽

Yasushi Ikei ◽

Michiteru Kitazaki

Keyword(s):

Spatial Cognition ◽

Multisensory Processing ◽

Body Movement ◽

Motor Program ◽

Peripersonal Space ◽

The Body ◽

Rhythmic Pattern ◽

Limited Space ◽

Tactile Stimuli ◽

Soles Of The Feet

The limited space immediately surrounding our body, known as peripersonal space (PPS), has been investigated by focusing on changes in the multisensory processing of audio-tactile stimuli occurring within or outside the PPS. Some studies have reported that the PPS representation is extended by body actions such as walking. However, it is unclear whether the PPS changes when a walking-like sensation is induced but the body neither moves nor is forced to move. Here, we show that a rhythmic pattern consisting of walking-sound vibrations applied to the soles of the feet, but not the forearms, boosted tactile processing when looming sounds were located near the body. The findings suggest that an extension of the PPS representation can be triggered by stimulating the soles in the absence of body action, which may automatically drive a motor program for walking, leading to a change in spatial cognition around the body.

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Increased Neural Strength and Reliability to Audiovisual Stimuli at the Boundary of Peripersonal Space

Journal of Cognitive Neuroscience ◽

10.1162/jocn_a_01334 ◽

2019 ◽

Vol 31 (8) ◽

pp. 1155-1172 ◽

Cited By ~ 8

Author(s):

Jean-Paul Noel ◽

Andrea Serino ◽

Mark T. Wallace

Keyword(s):

Multisensory Integration ◽

Multisensory Processing ◽

Peripersonal Space ◽

The Body ◽

Global Field ◽

Neural Dynamics ◽

Intraparietal Sulcus ◽

Global Field Power ◽

Sensory Stimuli ◽

Audiovisual Stimuli

The actionable space surrounding the body, referred to as peripersonal space (PPS), has been the subject of significant interest of late within the broader framework of embodied cognition. Neurophysiological and neuroimaging studies have shown the representation of PPS to be built from visuotactile and audiotactile neurons within a frontoparietal network and whose activity is modulated by the presence of stimuli in proximity to the body. In contrast to single-unit and fMRI studies, an area of inquiry that has received little attention is the EEG characterization associated with PPS processing. Furthermore, although PPS is encoded by multisensory neurons, to date there has been no EEG study systematically examining neural responses to unisensory and multisensory stimuli, as these are presented outside, near, and within the boundary of PPS. Similarly, it remains poorly understood whether multisensory integration is generally more likely at certain spatial locations (e.g., near the body) or whether the cross-modal tactile facilitation that occurs within PPS is simply due to a reduction in the distance between sensory stimuli when close to the body and in line with the spatial principle of multisensory integration. In the current study, to examine the neural dynamics of multisensory processing within and beyond the PPS boundary, we present auditory, visual, and audiovisual stimuli at various distances relative to participants' reaching limit—an approximation of PPS—while recording continuous high-density EEG. We question whether multisensory (vs. unisensory) processing varies as a function of stimulus–observer distance. Results demonstrate a significant increase of global field power (i.e., overall strength of response across the entire electrode montage) for stimuli presented at the PPS boundary—an increase that is largest under multisensory (i.e., audiovisual) conditions. Source localization of the major contributors to this global field power difference suggests neural generators in the intraparietal sulcus and insular cortex, hubs for visuotactile and audiotactile PPS processing. Furthermore, when neural dynamics are examined in more detail, changes in the reliability of evoked potentials in centroparietal electrodes are predictive on a subject-by-subject basis of the later changes in estimated current strength at the intraparietal sulcus linked to stimulus proximity to the PPS boundary. Together, these results provide a previously unrealized view into the neural dynamics and temporal code associated with the encoding of nontactile multisensory around the PPS boundary.

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Visual stimuli within peripersonal space prioritize pain

Seeing and Perceiving ◽

10.1163/187847612x647072 ◽

2012 ◽

Vol 25 (0) ◽

pp. 88

Author(s):

Annick De Paepe ◽

Valéry Legrain ◽

Geert Crombez

Keyword(s):

Visual Cues ◽

Peripersonal Space ◽

The Body ◽

Future Research ◽

Visual Localization ◽

Visual Cue ◽

Crossmodal Attention ◽

Point Of Subjective Simultaneity ◽

Extrapersonal Space ◽

Temporal Order Judgement

Localizing pain not only requires a simple somatotopic representation of the body, but also knowledge about the limb position (i.e., proprioception), and a visual localization of the pain source in external space. Therefore, nociceptive events are remapped into a multimodal representation of the body and the space nearby (i.e., a peripersonal schema of the body). We investigated the influence of visual cues presented either in peripersonal, or in extrapersonal space on the localization of nociceptive stimuli in a temporal order judgement (TOJ) task. 24 psychology students made TOJs concerning which of two nociceptive stimuli (one applied to each hand) had been presented first (or last). A spatially non-predictive visual cue (i.e., lighting of a LED) preceded (80 ms) the nociceptive stimuli. This cue was presented randomly either on the hand of the participant (in peripersonal space), or 70 cm in front of the hand (in extrapersonal space), and either on the left or on the right side of space. Biases in spatial attention are reflected by the point of subjective simultaneity (PSS). The results revealed that TOJs were more biased towards the visual cue in peripersonal space in comparison with the visual cue in extrapersonal space. This study provides evidence for the crossmodal integration of visual and nociceptive stimuli in a peripersonal schema of the body. Future research with this paradigm will explore crossmodal attention deficits in chronic pain populations.

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The Interrelationships between Intestinal Permeability and Phlegm Syndrome and Therapeutic Potential of Some Medicinal Herbs

Biomolecules ◽

10.3390/biom11020284 ◽

2021 ◽

Vol 11 (2) ◽

pp. 284

Author(s):

Junghyun Park ◽

Tae Joon Choi ◽

Ki Sung Kang ◽

Seo-Hyung Choi

Keyword(s):

Public Health ◽

Therapeutic Potential ◽

Synergistic Effects ◽

Critical Role ◽

The Body ◽

Future Research ◽

Evidence Based ◽

Leaky Gut ◽

Gi Tract ◽

Phlegm Syndrome

The gastrointestinal (GI) tract has an intriguing and critical role beyond digestion in both modern and complementary and alternative medicine (CAM), as demonstrated by its link with the immune system. In this review, we attempted to explore the interrelationships between increased GI permeability and phlegm, an important pathological factor in CAM, syndrome, and therapeutic herbs for two disorders. The leaky gut and phlegm syndromes look considerably similar with respect to related symptoms, diseases, and suitable herbal treatment agents, including phytochemicals even though limitations to compare exist. Phlegm may be spread throughout the body along with other pathogens via the disruption of the GI barrier to cause several diseases sharing some parts of symptoms, diseases, and mechanisms with leaky gut syndrome. Both syndromes are related to inflammation and gut microbiota compositions. Well-designed future research should be conducted to verify the interrelationships for evidence based integrative medicine to contribute to the promotion of public health. In addition, systems biology approaches should be adopted to explore the complex synergistic effects of herbal medicine and phytochemicals on conditions associated with phlegm and leaky gut syndromes.

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Unconscious integration of multisensory bodily inputs in the peripersonal space shapes bodily self-consciousness

10.1101/048108 ◽

2016 ◽

Cited By ~ 1

Author(s):

Roy Salomon ◽

Jean-Paul Noel ◽

Marta Łukowska ◽

Nathan Faivre ◽

Thomas Metzinger ◽

...

Keyword(s):

Multisensory Integration ◽

Tactile Stimulation ◽

Visual Stimuli ◽

Peripersonal Space ◽

The Body ◽

Sensory Stimuli ◽

Tactile Stimuli ◽

Main Components ◽

Virtual Body

AbstractRecent studies have highlighted the role of multisensory integration as a key mechanism of self-consciousness. In particular, integration of bodily signals within the peripersonal space (PPS) underlies the experience of the self in a body we own (self-identification) and that is experienced as occupying a specific location in space (self-location), two main components of bodily self-consciousness (BSC). Experiments investigating the effects of multisensory integration on BSC have typically employed supra-threshold sensory stimuli, neglecting the role of unconscious sensory signals in BSC, as tested in other consciousness research. Here, we used psychophysical techniques to test whether multisensory integration of bodily stimuli underlying BSC may also occur for multisensory inputs presented below the threshold of conscious perception. Our results indicate that visual stimuli rendered invisible (through continuous flash suppression) boost processing of tactile stimuli on the body (Exp. 1), and enhance the perception of near-threshold tactile stimuli (Exp. 2), only once they entered peripersonal space. We then employed unconscious multisensory mechanisms to manipulate BSC. Participants were presented with tactile stimulation on their body and with visual stimuli on a virtual body, seen at a distance, which were either visible or rendered invisible. We report that if visuo-tactile stimulation was synchronized, participants self-identified with the virtual body (Exp. 3), and shifted their self-location toward the virtual body (Exp.4), even if visual stimuli were fully invisible. Our results indicate that multisensory inputs, even outside of awareness, are integrated and affect the phenomenological content of self-consciousness, grounding BSC firmly in the field of psychophysical consciousness studies.

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Visuo-tactile predictive mechanisms of peripersonal space

The World at Our Fingertips ◽

10.1093/oso/9780198851738.003.0005 ◽

2021 ◽

pp. 81-100

Author(s):

H.C. Dijkerman ◽

W.P. Medendorp

Keyword(s):

Motor Control ◽

Contextual Information ◽

Peripersonal Space ◽

Higher Order ◽

The Body ◽

Physical Contact ◽

Auditory Stimuli ◽

Tactile Stimuli ◽

Bodily Contact ◽

Predictive Mechanisms

Our daily living includes bodily contacts with objects and people. While this physical contact occurs naturally, it could also pose a risk of bodily harm—for example, when objects are sharp, or people have bad intentions. It is therefore imperative to have a mechanism that predicts the consequences of bodily contact before it occurs, to guide our interactions appropriately. Evidence from a range of studies suggests a neurofunctional coupling between external visual or auditory stimuli near the body and tactile stimuli on the body. While these multisensory peripersonal representations have been linked to spatial attention, motor control, and social behaviour, a discussion on whether these functions involve a similar mechanism has been missing. Here we suggest that prediction is central to this multimodal coding: visual or auditory stimuli near the body predict tactile consequences of bodily contact. This predictive mechanism is based on learned visuo-tactile associations and modulated by higher-order visual contextual information.

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Seeing Your Own Touched Hands in a Mirror Modulates Cross-Modal Interactions

Psychological Science ◽

10.1111/j.0956-7976.2002.00463.x ◽

2002 ◽

Vol 13 (4) ◽

pp. 350-355 ◽

Cited By ~ 61

Author(s):

Angelo Maravita ◽

Charles Spence ◽

Claire Sergent ◽

Jon Driver

Keyword(s):

Neural Networks ◽

Retinal Image ◽

Visual Stimuli ◽

Peripersonal Space ◽

The Body ◽

Modal Interactions ◽

Tactile Stimuli ◽

True Source ◽

Visual Distractors

In mirror reflections, visual stimuli in near peripersonal space (e.g., an object in the hand) can project the retinal image of far, extrapersonal stimuli “beyond” the mirror. We studied the interaction of such visual reflections with tactile stimuli in a cross-modal congruency task. We found that visual distractors produce stronger interference on tactile judgments when placed close to the stimulated hand, but observed indirectly as distant mirror reflections, than when directly observed in equivalently distant far space, even when in contact with a dummy hand or someone else's hand in the far location. The stronger visual-tactile interference for the mirror condition implies that near stimuli seen as distant reflections in a mirror view of one's own hands can activate neural networks coding peripersonal space, because these visual stimuli are coded as having a true source near to the body.

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The ontogeny of multisensory peripersonal space in human infancy: From visual-tactile links to conscious expectations

10.1101/2020.09.07.279984 ◽

2020 ◽

Author(s):

Giulia Orioli ◽

Irene Parisi ◽

José L. van Velzen ◽

Andrew J. Bremner

Keyword(s):

Visual Motion ◽

Peripersonal Space ◽

Early Ontogeny ◽

Object Motion ◽

The Body ◽

Visual Object ◽

Self Awareness ◽

Human Infants ◽

Tactile Stimuli ◽

First Year Of Life

AbstractThe influence of visual object motion on the processing of bodily events offers a marker for the development of human infants’ perception of themselves in peripersonal space. We presented 4- (n = 20) and 8-month-old (n = 20) infants with an unattended visual object moving towards or away from their body followed by a vibrotactile stimulus on their hands. The 4-month-olds’ somatosensory evoked potentials (SEPs) were modulated by approaching visual motion, demonstrating the early ontogeny of the cortical multisensory foundations of peripersonal space representations. We also observed rapid changes in these markers within the 8-month-old age group: as infants approach 9 months, salient SEP components were increasingly enhanced by (unexpected) tactile stimuli following receding visual motion. These findings provide important clues to the ontogeny of human self-awareness in the first year of life, and suggest important postnatal developments in infants’ expectations about interactions between the body and the external world.

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Auditory Peripersonal Space in Humans

Journal of Cognitive Neuroscience ◽

10.1162/089892902320474481 ◽

2002 ◽

Vol 14 (7) ◽

pp. 1030-1043 ◽

Cited By ~ 77

Author(s):

Alessandro Farnè ◽

Elisabetta Làdavas

Keyword(s):

Spatial Representation ◽

Tactile Stimulus ◽

Specific Effect ◽

Noise Burst ◽

Spatial Arrangement ◽

Peripersonal Space ◽

The Body ◽

Space Representation ◽

Tactile Stimuli ◽

Neuropsychological Evidence

In the present study we report neuropsychological evidence of the existence of an auditory peripersonal space representation around the head in humans and its characteristics. In a group of right brain-damaged patients with tactile extinction, we found that a sound delivered near the ipsilesional side of the head (20 cm) strongly extinguished a tactile stimulus delivered to the contralesional side of the head (cross-modal auditory-tactile extinction). By contrast, when an auditory stimulus was presented far from the head (70 cm), cross-modal extinction was dramatically reduced. This spatially specific cross-modal extinction was most consistently found (i.e., both in the front and back spaces) when a complex sound was presented, like a white noise burst. Pure tones produced spatially specific cross-modal extinction when presented in the back space, but not in the front space. In addition, the most severe cross-modal extinction emerged when sounds came from behind the head, thus showing that the back space is more sensitive than the front space to the sensory interaction of auditory-tactile inputs. Finally, when cross-modal effects were investigated by reversing the spatial arrangement of cross-modal stimuli (i.e., touch on the right and sound on the left), we found that an ipsilesional tactile stimulus, although inducing a small amount of cross-modal tactile-auditory extinction, did not produce any spatial-specific effect. Therefore, the selective aspects of cross-modal interaction found near the head cannot be explained by a competition between a damaged left spatial representation and an intact right spatial representation. Thus, consistent with neurophysiological evidence from monkeys, our findings strongly support the existence, in humans, of an integrated cross-modal system coding auditory and tactile stimuli near the body, that is, in the peripersonal space.

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Attachment Organization in Suicide Prevention Research

Crisis ◽

10.1027/0227-5910/a000231 ◽

2014 ◽

Vol 35 (1) ◽

pp. 60-66 ◽

Cited By ~ 10

Author(s):

Amanda Venta ◽

Carla Sharp

Keyword(s):

Risk Factors ◽

Suicidal Ideation ◽

Suicide Attempt ◽

Interpersonal Relationships ◽

Suicide Ideation ◽

Suicide Attempts ◽

Critical Role ◽

Self Report ◽

Future Research ◽

Self Harm

Background: Identifying risk factors for suicide-related thoughts and behaviors (SRTB) is essential among adolescents in whom SRTB remain a leading cause of death. Although many risk factors have already been identified, influential theories now suggest that the domain of interpersonal relationships may play a critical role in the emergence of SRTB. Because attachment has long been seen as the foundation of interpersonal functioning, we suggest that attachment insecurity warrants attention as a risk factor for SRTB. Aims: This study sought to explore relations between attachment organization and suicidal ideation, suicide attempts, and self-harm in an inpatient adolescent sample, controlling for demographic and psychopathological covariates. Method: We recruited 194 adolescents from an inpatient unit and assigned them to one of four attachment groups (secure, preoccupied, dismissing, or disorganized attachment). Interview and self-report measures were used to create four variables reflecting the presence or absence of suicidal ideation in the last year, single lifetime suicide attempt, multiple lifetime suicide attempts, and lifetime self-harm. Results: Chi-square and regression analyses did not reveal significant relations between attachment organization and SRTB, although findings did confirm previously established relations between psychopathology and SRTB, such that internalizing disorder was associated with increased self-harm, suicide ideation, and suicide attempt and externalizing disorder was associated with increased self-harm. Conclusion: The severity of this sample and methodological differences from previous studies may explain the nonsignificant findings. Nonsignificant findings may indicate that the relation between attachment organization and SRTB is moderated by other factors that should be explored in future research.

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