scholarly journals Approaching threatening stimuli cause an expansion of defensive peripersonal space

2017 ◽  
Vol 118 (4) ◽  
pp. 1927-1930 ◽  
Author(s):  
R. J. Bufacchi
Keyword(s):  
Continuous Monitoring ◽  
Peripersonal Space ◽  
Blink Reflex ◽  
The Body ◽  
Environmental Threats ◽  
Environmental Stimuli ◽  
Defensive Responses ◽  
Threatening Stimulus ◽  
Threatening Stimuli

When sudden environmental stimuli signaling threat occur in the portion of space surrounding the body (defensive peripersonal space), defensive responses are enhanced. Recently Bisio et al. (Bisio A, Garbarini F, Biggio M, Fossataro C, Ruggeri P, Bove M. J Neurosci 37: 2415–2424, 2017) showed that a marker of defensive peripersonal space, the defensive hand-blink reflex, is modulated by the motion of the eliciting threatening stimulus. These results can be parsimoniously explained by the continuous monitoring of environmental threats, resulting in an expansion of defensive peripersonal space when threatening stimuli approach.

scholarly journals The Interrelation Between Peripersonal Action Space and Interpersonal Social Space: Psychophysiological Evidence and Clinical Implications

2021 ◽  
Vol 15 ◽  
Author(s):  
Yann Coello ◽  
Alice Cartaud
Keyword(s):  
Social Life ◽  
Social Space ◽  
Object Oriented ◽  
Peripersonal Space ◽  
Theoretical Framework ◽  
The Body ◽  
Action Space ◽  
Space Representation ◽  
Defensive Responses ◽  
Emotional Deficits

The peripersonal space is an adaptive and flexible interface between the body and the environment that fulfills a dual-motor function: preparing the body for voluntary object-oriented actions to interact with incentive stimuli and preparing the body for defensive responses when facing potentially harmful stimuli. In this position article, we provide arguments for the sensorimotor rooting of the peripersonal space representation and highlight the variables that contribute to its flexible and adaptive characteristics. We also demonstrate that peripersonal space represents a mediation zone between the body and the environment contributing to not only the control of goal-directed actions but also the organization of social life. The whole of the data presented and discussed led us to the proposal of a new theoretical framework linking the peripersonal action space and the interpersonal social space and we highlight how this theoretical framework can account for social behaviors in populations with socio-emotional deficits.

scholarly journals A geometric model of defensive peripersonal space

2016 ◽  
Vol 115 (1) ◽  
pp. 218-225 ◽  
Author(s):  
R. J. Bufacchi ◽  
M. Liang ◽  
L. D. Griffin ◽  
G. D. Iannetti
Keyword(s):  
Goodness Of Fit ◽  
Geometric Model ◽  
Peripersonal Space ◽  
Blink Reflex ◽  
The Body ◽  
Hand Position ◽  
Body Area ◽  
Empirical Observation ◽  
Spatial Features ◽  
The Face

Potentially harmful stimuli occurring within the defensive peripersonal space (DPPS), a protective area surrounding the body, elicit stronger defensive reactions. The spatial features of the DPPS are poorly defined and limited to descriptive estimates of its extent along a single dimension. Here we postulated a family of geometric models of the DPPS, to address two important questions with respect to its spatial features: What is its fine-grained topography? How does the nervous system represent the body area to be defended? As a measure of the DPPS, we used the strength of the defensive blink reflex elicited by electrical stimulation of the hand (hand-blink reflex, HBR), which is reliably modulated by the position of the stimulated hand in egocentric coordinates. We tested the goodness of fit of the postulated models to HBR data from six experiments in which we systematically explored the HBR modulation by hand position in both head-centered and body-centered coordinates. The best-fitting model indicated that 1) the nervous system's representation of the body area defended by the HBR can be approximated by a half-ellipsoid centered on the face and 2) the DPPS extending from this area has the shape of a bubble elongated along the vertical axis. Finally, the empirical observation that the HBR is modulated by hand position in head-centered coordinates indicates that the DPPS is anchored to the face. The modeling approach described in this article can be generalized to describe the spatial modulation of any defensive response.

scholarly journals Auditory roughness elicits defense reactions

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
Marine Taffou ◽  
Clara Suied ◽  
Isabelle Viaud-Delmon
Keyword(s):  
Contextual Information ◽  
Reaction Times ◽  
Peripersonal Space ◽  
The Body ◽  
Healthy Human ◽  
Defensive Responses ◽  
Defensive Behaviors ◽  
Human Participants ◽  
Multisensory Information ◽  
Tactile Integration

AbstractAuditory roughness elicits aversion, and higher activation in cerebral areas involved in threat processing, but its link with defensive behavior is unknown. Defensive behaviors are triggered by intrusions into the space immediately surrounding the body, called peripersonal space (PPS). Integrating multisensory information in PPS is crucial to assure the protection of the body. Here, we assessed the behavioral effects of roughness on auditory-tactile integration, which reflects the monitoring of this multisensory region of space. Healthy human participants had to detect as fast as possible a tactile stimulation delivered on their hand while an irrelevant sound was approaching them from the rear hemifield. The sound was either a simple harmonic sound or a rough sound, processed through binaural rendering so that the virtual sound source was looming towards participants. The rough sound speeded tactile reaction times at a farther distance from the body than the non-rough sound. This indicates that PPS, as estimated here via auditory-tactile integration, is sensitive to auditory roughness. Auditory roughness modifies the behavioral relevance of simple auditory events in relation to the body. Even without emotional or social contextual information, auditory roughness constitutes an innate threat cue that elicits defensive responses.

scholarly journals Modulation of exteroceptive electromyographic responses in defensive peripersonal space

2019 ◽  
Vol 121 (4) ◽  
pp. 1111-1124 ◽  
Author(s):  
Viviana Versace ◽  
Stefania Campostrini ◽  
Luca Sebastianelli ◽  
Leopold Saltuari ◽  
Markus Kofler
Keyword(s):  
Silent Period ◽  
Peripersonal Space ◽  
Blink Reflex ◽  
The Body ◽  
Electromyographic Activity ◽  
Sensory Afferents ◽  
Eyes Closed ◽  
Cutaneous Silent Period ◽  
The Face ◽  
Long Loop Reflex

The cutaneous silent period (CSP) to noxious finger stimulation constitutes a robust spinal inhibitory reflex that protects the hand from injury. In certain conditions, spinal inhibition is interrupted by a brief burst-like electromyographic activity, dividing the CSP into two inhibitory phases (I1 and I2). This excitatory component is termed long-loop reflex (LLR) and is presumed to be transcortical in origin. Efficient defense from environmental threats requires sensorimotor integration between multimodal sensory afferents and planning of defensive movements. In the defensive peripersonal space (DPPS) immediately surrounding the body, we interact with objects and persons with increased alertness. We investigated whether CSP differs when the stimulated hand is in the DPPS of the face compared with a distant position. Furthermore, we investigated the possible role of vision in CSP modulation. Fifteen healthy volunteers underwent CSP testing with the handheld either within 5 cm from the nose (near) or away from the body (far). Recordings were obtained from first dorsal interosseous muscle following index (D2) or little finger (D5) stimulation with varying intensities. A subgroup of subjects underwent CSP recordings in near and far conditions, both with eyes open and with eyes closed. No inhibitory CSP parameter differed between stimulation in near and far conditions. LLRs occurring following D2 stimulation were significantly larger in near than far conditions at all stimulus intensities, irrespective of subjects seeing their hand. Similar to the hand-blink reflex, spinally organized protective reflexes may be modulated by corticospinal facilitatory input when the hand enters the DPPS of the face. NEW & NOTEWORTHY The present findings demonstrate for the first time that a spinally organized protective reflex, the cutaneous silent period (CSP), may be modulated by top-down corticospinal facilitatory input when the stimulated hand enters the defensive peripersonal space (DPPS) of the face. In particular, the cortically mediated excitatory long-loop reflex, which may interrupt the CSP, is facilitated when the stimulated hand is in the DPPS, irrespective of visual control over the hand. No spinal inhibitory CSP parameter differs significantly in or outside the DPPS.

Individual Differences in the Flexibility of Peripersonal Space

2017 ◽  
Vol 64 (1) ◽  
pp. 49-55 ◽  
Author(s):  
Samuel B. Hunley ◽  
Arwen M. Marker ◽  
Stella F. Lourenco
Keyword(s):  
Individual Differences ◽  
Peripersonal Space ◽  
The Body ◽  
Laser Pointer ◽  
Baseline Measure ◽  
Bisection Task ◽  
Defensive Function ◽  
Representational Space ◽  
Laser Condition ◽  
Line Bisection Task

Abstract. The current study investigated individual differences in the flexibility of peripersonal space (i.e., representational space near the body), specifically in relation to trait claustrophobic fear (i.e., fear of suffocating or being physically restricted). Participants completed a line bisection task with either a laser pointer (Laser condition), allowing for a baseline measure of the size of one’s peripersonal space, or a stick (Stick condition), which produces expansion of one’s peripersonal space. Our results revealed that individuals high in claustrophobic fear had larger peripersonal spaces than those lower in claustrophobic fear, replicating previous research. We also found that, whereas individuals low in claustrophobic fear demonstrated the expected expansion of peripersonal space in the Stick condition, individuals high in claustrophobic fear showed less expansion, suggesting decreased flexibility. We discuss these findings in relation to the defensive function of peripersonal space and reduced attentional flexibility associated with trait anxieties.

scholarly journals Capturing the dynamics of peripersonal space by integrating sound propagation properties and expectancy effects

2019 ◽  
Author(s):  
Lise Hobeika ◽  
Marine Taffou ◽  
Thibaut Carpentier ◽  
Olivier Warusfel ◽  
Isabelle Viaud-Delmon
Keyword(s):  
Sound Propagation ◽  
Current Method ◽  
Peripersonal Space ◽  
The Body ◽  
Logarithmic Scale ◽  
List Type ◽  
Expectancy Effects ◽  
Near Space ◽  
Propagation Properties ◽  
Tactile Integration

AbstractHighlightsLogarithmically distributed auditory distances provides an apt granularity of PPSMeasuring expectation helps to interpret behavioral impact of audiotactile integrationTactile RTs follows a logarithmic decrease due to audiotactile integrationPeripersonal space is better characterized and quantified with this refinementBackgroundHumans perceive near space and far space differently. Peripersonal space, i.e. the space directly surrounding the body, is often studied using paradigms based on auditory-tactile integration. In these paradigms, reaction time to a tactile stimulus is measured in the presence of a concurrent auditory looming stimulus.New MethodWe propose here to refine the experimental procedure considering sound propagation properties in order to improve granularity and relevance of auditory-tactile integration measures. We used a logarithmic distribution of distances for this purpose. We also want to disentangle behavioral contributions of the targeted audiotactile integration mechanisms from expectancy effects. To this aim, we added to the protocol a baseline with a fixed sound distance.ResultsExpectation contributed significantly to overall behavioral responses. Subtracting it isolated the audiotactile effect due to the stimulus proximity. This revealed that audiotactile integration effects have to be tested on a logarithmic scale of distances, and that they follow a linear variation on this scale.Comparison with Existing Method(s)The granularity of the current method is more relevant, providing higher spatial resolution in the vicinity of the body. Furthermore, most of the existing methods propose a sigmoid fitting, which rests on the intuitive framework that PPS is an in-or-out zone. Our results suggest that behavioral effects follow a logarithmic decrease, thus a response graduated in space.ConclusionsThe proposed protocol design and method of analysis contribute to refine the experimental investigation of the factors influencing and modifying multisensory integration phenomena in the space surrounding the body.

scholarly journals Experimentally induced pain does not influence updating of peripersonal space and body representations following tool-use

2018 ◽  
Author(s):  
Axel Davies Vittersø ◽  
Monika Halicka ◽  
Gavin Buckingham ◽  
Michael J Proulx ◽  
Mark Wilson ◽  
...  
Keyword(s):  
Chronic Pain ◽  
Tool Use ◽  
Experimental Pain ◽  
Peripersonal Space ◽  
The Body ◽  
Body Representations ◽  
Tactile Target ◽  
The Difference ◽  
Chronic Pain Conditions ◽  
Crossmodal Congruency

Representations of the body and peripersonal space can be distorted for people with some chronic pain conditions. Experimental pain induction can give rise to similar, but transient distortions in healthy individuals. However, spatial and bodily representations are dynamic, and constantly update as we interact with objects in our environment. It is unclear whether induced pain disrupts the mechanisms involved in updating these representations. In the present study, we sought to investigate the effect of induced pain on the updating of peripersonal space and body representations during and following tool-use. We compared performance under three conditions (pain, active placebo, neutral) on a visuotactile crossmodal congruency task and a tactile distance judgement task to measure updating of peripersonal space and body representations, respectively. We induced pain by applying 1% capsaicin cream to the arm, and for placebo we used a gel that induced non-painful warming. Consistent with previous findings, the difference in crossmodal interference from visual distractors in the same compared to opposite visual field to the tactile target was less when tools were crossed than uncrossed. This suggests an extension of peripersonal space to incorporate the tips of the tools. Also consistent with previous findings, estimates of the felt distance between two points (tactile distance judgements) decreased after active tool-use. In contrast to our predictions, however, we found no evidence that pain interfered with performance on either task when compared to the control conditions. This suggests that the updating of peripersonal space and body representations is not disrupted by induced pain. Therefore, acute pain does not account for the distorted representations of the body and peripersonal space that can endure in people with chronic pain conditions.

What do ‘peripersonal space measures’ really reflect? The action field perspective

2021 ◽  
pp. 155-180
Author(s):  
R.J. Bufacchi ◽  
G.D. Iannetti
Keyword(s):  
Peripersonal Space ◽  
The Body ◽  
Spatial Distance ◽  
Impact Prediction ◽  
Environmental Objects ◽  
Action Value ◽  
Continuous Fields ◽  
Field Perspective ◽  
The Relationship ◽  
Interactive Behaviour

The magnitude of a large number of behavioural and neurophysiological measures depends on the proximity between an individual and environmental objects. This relationship has led to the concept of peripersonal space (PPS). Here we argue that the proximity-dependence of such PPS measures could arise as a result of calculating the relevance of actions that aim to create or avoid contact with objects in the world. This perspective, supported by the interactive behaviour framework of systems-level brain function, allows us to describe PPS as a set of continuous fields reflecting contact-related action relevance. The action relevance perspective gets rid of incorrect notions about PPS, such as it being a single in-or-out zone that mainly reflects the spatial distance between objects and the body. This reconceptualization incorporates PPS into mainstream theories of action selection and behaviour. Furthermore, the formal comparison of this framework to others shows that contact-action value allows for a more complete description of PPS measures than proximity coding, impact prediction, and multisensory integration do, while simultaneously explaining the relationship between those concepts and PPS measures.

Intelligent Bed Sheet Detects Respiratory Patterns

2018 ◽  
Vol 62 (1) ◽  
pp. 1177-1181 ◽  
Author(s):  
Laura Nicholson ◽  
Olivia Lin ◽  
Edward Shim
Keyword(s):  
Continuous Monitoring ◽  
Resource Constraints ◽  
New Technology ◽  
Vital Signs ◽  
The Body ◽  
Second Phase ◽  
Age In Place ◽  
Sensor Validation ◽  
Health Canada ◽  
Respiratory Conditions

A new technology using an intelligent bed sheet made of fabric sensors is described as a novel advancement that supports wireless and continuous monitoring of vital signs without requiring wire attachments to the body. The intelligent bed sheet developed by Studio 1 Labs Inc. (Studio 1 Labs), can be used to support three distinct groups: i) healthcare institutions with human resource constraints, ii) caregivers who provide care for seniors, infants and children at home, and iii) independent seniors who prefer to age in place. This article describes two complementary research phases using the intelligent bed sheet to detect heart rate, respiratory rate, and respiratory effort. The first phase explores sensor validation from the intelligent bed sheet with preset respiratory conditions from high technology mannequins. The second phase involves a use case with healthy young adults comparing between physiological signals from the bed sheet with standard nursing protocols of manual counts and a pulse oximeter approved by Health Canada.

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

2020 ◽  
Vol 14 ◽  
Author(s):  
Daniela Rabellino ◽  
Paul A. Frewen ◽  
Margaret C. McKinnon ◽  
Ruth A. Lanius
Keyword(s):  
Multisensory Processing ◽  
Premotor Cortex ◽  
Critical Role ◽  
Psychological Trauma ◽  
Peripersonal Space ◽  
The Body ◽  
Future Research ◽  
Altered States ◽  
Tactile Stimuli ◽  
Defensive Role

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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