scholarly journals Audio-tactile and peripersonal space processing around the trunk in human parietal and temporal cortex: an intracranial EEG study

2018 ◽  
Author(s):  
Fosco Bernasconi ◽  
Jean-Paul Noel ◽  
Hyeong Dong Park ◽  
Nathan Faivre ◽  
Margitta Seeck ◽  
...  
Keyword(s):  
Multisensory Integration ◽  
Tactile Stimulation ◽  
Temporal Cortex ◽  
Insular Cortex ◽  
Peripersonal Space ◽  
Early Response ◽  
The Body ◽  
Spatial Modulation ◽  
Similar Time ◽  
Different Response

AbstractInteractions with the environment happen by the medium of the body within one’s peripersonal space (PPS) - the space surrounding the body. Studies in monkey and humans have highlighted a multisensory distributed cortical network representing the PPS. However, electrophysiological evidence for a multisensory encoding of PPS in humans is lacking. Here, we recorded for the first time intracranial electroencephalography (iEEG) in humans while administering tactile stimulation (T) on the trunk, approaching auditory stimuli (A), and the combination of the two (AT). To map PPS, in AT trials, tactile stimulation was delivered when the sound was far, at an intermediate location, or close to the body. We first identified electrodes showing AT multisensory integration (i.e., AT vs. A+T): 19% of the recording electrodes. Among those electrodes, we identified those showing a PPS effect (30% of the AT electrodes), i.e., a modulation of the evoked response to AT stimulation as a function of the distance between the sound and body. For most sites, AT multisensory integration and PPS effects had similar spatiotemporal characteristics, with an early response (~50ms) in the insular cortex, and later responses (~200ms) in pre‐ and post-central gyri. Superior temporal cortex showed a different response pattern with AT multisensory integration at ~100ms without PPS effect. These results, representing the first iEEG delineation of PPS processing in humans, show that PPS processing happens at neural sites where also multisensory integration occurs and at similar time periods, suggesting that PPS representation (around the trunk) is based on a spatial modulation of multisensory integration.

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

2016 ◽  
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.

scholarly journals Embodied precision: Intranasal oxytocin modulates multisensory integration

2018 ◽  
Author(s):  
Laura Crucianelli ◽  
Yannis Paloyelis ◽  
Lucia Ricciardi ◽  
Paul M Jenkinson ◽  
Aikaterini Fotopoulou
Keyword(s):  
Multisensory Integration ◽  
Tactile Stimulation ◽  
Estimation Error ◽  
The Body ◽  
Multisensory Perception ◽  
Subjective Feeling ◽  
Rubber Hand ◽  
Perceptual Inference ◽  
Double Blind ◽  
Multisensory Input

AbstractMultisensory integration processes are fundamental to our sense of self as embodied beings. Bodily illusions, such as the rubber hand illusion (RHI) and the size-weight illusion (SWI), allow us to investigate how the brain resolves conflicting multisensory evidence during perceptual inference in relation to different facets of body representation. In the RHI, synchronous tactile stimulation of a participant’s hidden hand and a visible rubber hand creates illusory bodily ownership; in the SWI, the perceived size of the body can modulate the estimated weight of external objects. According to Bayesian models, such illusions arise as an attempt to explain the causes of multisensory perception and may reflect the attenuation of somatosensory precision, which is required to resolve perceptual hypotheses about conflicting multisensory input. Recent hypotheses propose that the precision or salience of sensorimotor representations is determined by modulators of synaptic gain, like dopamine, acetylcholine and oxytocin. However, these neuromodulatory hypotheses have not been tested in the context of embodied multisensory integration. The present, double-blind, placebo-controlled, crossed-over study (N = 41 healthy volunteers) aimed to investigate the effect of intranasal oxytocin (IN-OT) on multisensory integration processes, tested by means of the RHI and the SWI. Results showed that IN-OT enhanced the subjective feeling of ownership in the RHI, only when synchronous tactile stimulation was involved. Furthermore, IN-OT increased the embodied version of the SWI (quantified as weight estimation error). These findings suggest that oxytocin might modulate processes of visuo-tactile multisensory integration by increasing the precision of top-down signals against bottom-up sensory input.

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

2019 ◽  
Vol 31 (8) ◽  
pp. 1155-1172 ◽  
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.

scholarly journals Embodied Precision: Intranasal Oxytocin Modulates Multisensory Integration

2019 ◽  
Vol 31 (4) ◽  
pp. 592-606 ◽  
Author(s):  
Laura Crucianelli ◽  
Yannis Paloyelis ◽  
Lucia Ricciardi ◽  
Paul M. Jenkinson ◽  
Aikaterini Fotopoulou
Keyword(s):  
Multisensory Integration ◽  
Tactile Stimulation ◽  
Estimation Error ◽  
The Body ◽  
Multisensory Perception ◽  
Subjective Feeling ◽  
Body Ownership ◽  
Rubber Hand ◽  
Perceptual Inference ◽  
Multisensory Input

Multisensory integration processes are fundamental to our sense of self as embodied beings. Bodily illusions, such as the rubber hand illusion (RHI) and the size–weight illusion (SWI), allow us to investigate how the brain resolves conflicting multisensory evidence during perceptual inference in relation to different facets of body representation. In the RHI, synchronous tactile stimulation of a participant's hidden hand and a visible rubber hand creates illusory body ownership; in the SWI, the perceived size of the body can modulate the estimated weight of external objects. According to Bayesian models, such illusions arise as an attempt to explain the causes of multisensory perception and may reflect the attenuation of somatosensory precision, which is required to resolve perceptual hypotheses about conflicting multisensory input. Recent hypotheses propose that the precision of sensorimotor representations is determined by modulators of synaptic gain, like dopamine, acetylcholine, and oxytocin. However, these neuromodulatory hypotheses have not been tested in the context of embodied multisensory integration. The present, double-blind, placebo-controlled, crossover study ( n = 41 healthy volunteers) aimed to investigate the effect of intranasal oxytocin (IN-OT) on multisensory integration processes, tested by means of the RHI and the SWI. Results showed that IN-OT enhanced the subjective feeling of ownership in the RHI, only when synchronous tactile stimulation was involved. Furthermore, IN-OT increased an embodied version of the SWI (quantified as estimation error during a weight estimation task). These findings suggest that oxytocin might modulate processes of visuotactile multisensory integration by increasing the precision of top–down signals against bottom–up sensory input.

scholarly journals Spatial tuning of electrophysiological responses to multisensory stimuli reveals a primitive coding of the body boundaries in newborns

2021 ◽  
Vol 118 (12) ◽  
pp. e2024548118
Author(s):  
Irene Ronga ◽  
Mattia Galigani ◽  
Valentina Bruno ◽  
Jean-Paul Noel ◽  
Andrea Gazzin ◽  
...  
Keyword(s):  
Tactile Stimulation ◽  
Body Position ◽  
The Body ◽  
Spatial Modulation ◽  
Control Group ◽  
Sensory Environment ◽  
Adult Participants ◽  
Electrophysiological Responses ◽  
External Stimuli ◽  
Electrophysiological Mechanism

The ability to identify our own body and its boundaries is crucial for survival. Ideally, the sooner we learn to discriminate external stimuli occurring close to our body from those occurring far from it, the better (and safer) we may interact with the sensory environment. However, when this mechanism emerges within ontogeny is unknown. Is it something acquired throughout infancy, or is it already present soon after birth? The presence of a spatial modulation of multisensory integration (MSI) is considered a hallmark of a functioning representation of the body position in space. Here, we investigated whether MSI is present and spatially organized in 18- to 92-h-old newborns. We compared electrophysiological responses to tactile stimulation when concurrent auditory events were delivered close to, as opposed to far from, the body in healthy newborns and in a control group of adult participants. In accordance with previous studies, adult controls showed a clear spatial modulation of MSI, with greater superadditive responses for multisensory stimuli close to the body. In newborns, we demonstrated the presence of a genuine electrophysiological pattern of MSI, with older newborns showing a larger MSI effect. Importantly, as for adults, multisensory superadditive responses were modulated by the proximity to the body. This finding may represent the electrophysiological mechanism responsible for a primitive coding of bodily self boundaries, thus suggesting that even just a few hours after birth, human newborns identify their own body as a distinct entity from the environment.

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.

Pathway of Inflammation due to Asbestiform fiber "Fluoro-edenite" Exposure: an Update

2020 ◽  
Vol 16 ◽  
Author(s):  
Caterina Ledda ◽  
Claudia Lombardo ◽  
Elisabetta A. Tendi ◽  
Maria Hagnas ◽  
Gianluca Paravizzini ◽  
...  
Keyword(s):  
Immune System ◽  
Autoimmune Disease ◽  
Early Response ◽  
The Body ◽  
Volcanic Area ◽  
Asbestos Fibers ◽  
Inflammatory Processes

: Fluoro-edenite (FE) is an asbestos-like amphibole present in the bentonitic lavas extracted from a stone quarry in Biancavilla, a village sited in the Etnean Volcanic Area (Italy). : Thoracic pathologies are the results of excessive inflammatory processes that are the early response of the immune system to inhaled fibers. As demonstrated for asbestos, fibers may trigger immune system cells in an acute and/or chronic manner. This review aims to clarify the pathways of inflammation in workers exposed to FE fibers. : Based on the articles reviewed, it seems that a permanent stimulus created by repeatedly inhaling the FE fibers and their persistence in the body can act as trigger both in promoting inflammatory processes and in immunological induction of autoimmune disease.

scholarly journals Multisensory integration involved in the body perception of community-dwelling older adults

2021 ◽  
Vol 11 (1) ◽  
Author(s):  
M. Hide ◽  
Y. Ito ◽  
N. Kuroda ◽  
M. Kanda ◽  
W. Teramoto
Keyword(s):  
Older Adults ◽  
Multisensory Integration ◽  
Fall Risk ◽  
Community Dwelling ◽  
The Body ◽  
Risk Of Falling ◽  
Body Perception ◽  
Rubber Hand ◽  
Timed Up And Go ◽  
Community Dwelling Older Adults

AbstractThis study investigates how the multisensory integration in body perception changes with increasing age, and whether it is associated with older adults’ risk of falling. For this, the rubber hand illusion (RHI) and rubber foot illusion (RFI) were used. Twenty-eight community-dwelling older adults and 25 university students were recruited. They viewed a rubber hand or foot that was stimulated in synchrony or asynchrony with their own hidden hand or foot. The illusion was assessed by using a questionnaire, and measuring the proprioceptive drift and latency. The Timed Up and Go Test was used to classify the older adults into lower and higher fall-risk groups. No difference was observed in the RHI between the younger and older adults. However, several differences were observed in the RFI. Specifically, the older adults with a lower fall-risk hardly experienced the illusion, whereas those with a higher fall-risk experienced it with a shorter latency and no weaker than the younger adults. These results suggest that in older adults, the mechanism of multisensory integration for constructing body perception can change depending on the stimulated body parts, and that the risk of falling is associated with multisensory integration.

The locust jump. I. The motor programme

1977 ◽  
Vol 66 (1) ◽  
pp. 203-219
Author(s):  
W. J. Heitler ◽  
M. Burrows
Keyword(s):  
High Frequency ◽  
Tactile Stimulation ◽  
The Body ◽  
Flexor Muscle ◽  
Tactile Stimuli ◽  
Extensor Muscles ◽  
Trigger Activity ◽  
Three Stages ◽  
Motor Programme ◽  
Made In

A motor programme is described for defensive kicking in the locust which is also probably the programme for jumping. The method of analysis has been to make intracellular recordings from the somata of identified motornuerones which control the metathoracic tibiae while defensive kicks are made in response to tactile stimuli. Three stages are recognized in the programme. (1) Initial flexion of the tibiae results from the low spike threshold of tibial flexor motorneurones to tactile stimulation of the body. (2) Co-contraction of flexor and extensor muscles followa in which flexor and extensor excitor motoneurones spike at high frequency for 300-600 ms. the tibia flexed while the extensor muscle develops tension isometrically to the level required for a kick or jump. (3) Trigger activity terminates the co-contraction by inhibiting the flexor excitor motorneurones and simultaneously exciting the flexor inhibitors. This causes relaxation of the flexor muscle and allows the tibiae to extend. If the trigger activity does not occur, the jump or kick is aborted, and the tibiae remain flexed.

scholarly journals Responses of Anterior Superior Temporal Polysensory (STPa) Neurons to “Biological Motion” Stimuli

1994 ◽  
Vol 6 (2) ◽  
pp. 99-116 ◽  
Author(s):  
M. W. Oram ◽  
D. I. Perrett
Keyword(s):  
Biological Motion ◽  
Temporal Cortex ◽  
The Body ◽  
Body Motion ◽  
Whole Body ◽  
Global Pattern ◽  
Lighting Conditions ◽  
Specific Direction ◽  
Direction Of Movement ◽  
Light Stimuli

Cells have been found in the superior temporal polysensory area (STPa) of the macaque temporal cortex that are selectively responsive to the sight of particular whole body movements (e.g., walking) under normal lighting. These cells typically discriminate the direction of walking and the view of the body (e.g., left profile walking left). We investigated the extent to which these cells are responsive under “biological motion” conditions where the form of the body is defined only by the movement of light patches attached to the points of limb articulation. One-third of the cells (25/72) selective for the form and motion of walking bodies showed sensitivity to the moving light displays. Seven of these cells showed only partial sensitivity to form from motion, in so far as the cells responded more to moving light displays than to moving controls but failed to discriminate body view. These seven cells exhibited directional selectivity. Eighteen cells showed statistical discrimination for both direction of movement and body view under biological motion conditions. Most of these cells showed reduced responses to the impoverished moving light stimuli compared to full light conditions. The 18 cells were thus sensitive to detailed form information (body view) from the pattern of articulating motion. Cellular processing of the global pattern of articulation was indicated by the observations that none of these cells were found sensitive to movement of individual limbs and that jumbling the pattern of moving limbs reduced response magnitude. A further 10 cells were tested for sensitivity to moving light displays of whole body actions other than walking. Of these cells 5/10 showed selectivity for form displayed by biological motion stimuli that paralleled the selectivity under normal lighting conditions. The cell responses thus provide direct evidence for neural mechanisms computing form from nonrigid motion. The selectivity of the cells was for body view, specific direction, and specific type of body motion presented by moving light displays and is not predicted by many current computational approaches to the extraction of form from motion.

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