Self-frontier and impact prediction
The construction of a coherent representation of our body and the mapping of the space immediately surrounding the body is really important to evolve and confront our environment as well as possible. In last decades, numerous studies were interested on the peripersonal space (PPS) corresponding to the space surrounding us in which we can interact with. A lot of different experiments and designs were performed to understand how this space is constructed, encoded and modulated. The majority of studies focused only on one part of the body: the hand, the face or the trunk. In the present review, we propose to sum up the last advances on this research which open news perspectives for futures investigations on this topic. We describe the recent methods used to estimate the PPS boundaries by the means of dynamic stimuli. We then highlight how impact prediction and approaching stimuli modulated this space by social, emotional and action components involving principally a parieto-frontal network. Last, we review evidence that there is not a unique representation of peripersonal space but at least three sub-sections (hand, face and trunk PPS) and how bodily self-consciousness (BSC) is link with this space. The parieto-frontal networks involved in these two processes are strongly connected but not exactly with the same areas suggesting that PPS areas underlie a multisensory-motor interface for body-objects interaction and BSC areas are involved in bodily awareness and self-consciousness. To conclude, this review show that our PPS representation is continuously change around us with sensory information, experiencing and feeling to adapt the best possible to our environment.
1 PERIPERSONAL SPACE
In our world, we are solicited by a multiple of things. The space around us is often filled with conspecifics, other animals and objects. The majority of time we interact with them but we not interact with the same way following the context and the nature of this objects. Therefore, it’s crucial to predict the probable consequences of contact with this objects, animals or people to avoid the object or prepare an appropriate response (to escape or to protect). This required the construction of a coherent representation of our body and the mapping of the space immediately surrounding the body. To do this, the brain has a specific system and mechanisms to specifically process information occurring in the space that direct surrounds us and in which we can interact, that is, to represent the so-called peripersonal space (PPS).
Research in non-human primates has shown that multisensory cues, in particular those involving the body, are processed and integrated by a specialized neural system mapping the peripersonal space. Specific populations of multisensory neurons integrate tactile information on the body (arm, face or trunk) with visual or auditory stimuli occurring in peripersonal space, i.e. close to the body. These multisensory neurons are described in a fronto-parietal network of the macaque brain involving the ventral premotor cortex (vPM; F4, G. Rizzolatti et al., 1981a, 1981b; or polysensory zone PZ, Graziano et al., 1994; M. S. A. Graziano et al., 1997; Graziano et al., 1999; Fogassi et al., 1996; Graziano and Cooke, 2006), the ventral intraparietal area on the fundus of the intraparietal sulcus (VIP, J. Hyvärinen and Poranen, 1974; Duhamel et al., 1997, 1998; Avillac et al., 2005; Schlack et al., 2005; Graziano and Cooke, 2006), in the parietal areas 7b and in the putamen (Graziano and Gross, 1993). The response properties of these neurons are independent from eye position but depend on the position of the different body part in space. This suggests that they encode a body-part centered multisensory of PPS (Duhamel et al., 1997; Avillac et al., 2005; Graziano and Cooke, 2006; Graziano et al., 2000).
Extinction is a phenomenon whereby patients fail to detect contralesional stimuli only under the condition of double (ipsilesional and contralesional) simultaneous stimulation (Bender, 1952; Mattingley et al., 1997; Làdavas and Serino, 2008). This phenomenon can emerge when concurrent stimuli are presented in the same (unimodal extinction) or different modality (cross-modal extinction). In right brain-damaged patients with tactile extinction, visual or auditory stimulations on the ipsilesional side exacerbates contralesional tactile extinction. If visual (or auditory) and tactile stimuli are on the same contralesional side, this can reduce the deficit (Làdavas et al., 1998a). Therefore, cross-modal extinction can be modulated as a function of the spatial arrangement of the stimuli with respect to the patient’s body (Farnè et al., 2005a, 2005b; for review, see Làdavas, 2002). Besides, this modulation is most consistently obvious when visuo-tactile interaction or auditory-tactile interaction occur in the space close to the patients’ body, compare to in the far space (di Pellegrino et al., 1997; Làdavas et al., 1998a, 1998b, 2000). This finding has shown, in humans, an evidence of the existence of a peripersonal space, with a integrated visuo-tactile system coding the space close to the body, in a similar way to that described in monkeys (Làdavas, 2002). Visuo-tactile information and auditory-tactile information are also integrated, similarly, in other regions of space surrounding different body parts, such as around the face (Farnè et al., 2005a; Farnè and Làdavas, 2002; Làdavas et al., 1998b).
This first evidence for the existence of a PPS system in the human brain was corroborated by behavioral studies in healthy participants (Spence et al., 2004; Macaluso and Maravita, 2010; Occelli et al., 2011). These studies showed that tactile perception is more strongly modulated by visual or auditory stimuli when these are presented close, as compared to far, from the body. Neuroimaging studies using EEG (Sambo and Forster, 2008), TMS (Serino et al., 2011) and fMRI (Bremmer et al., 2001; Makin et al., 2007; Gentile et al., 2011; Brozzoli et al., 2011, 2013) demonstrated that multisensory representation of PPS occurs in both in parietal and prefrontal areas where PPS neurons have been identified in the homologous macaque regions (for reviews, see Cléry et al., 2015b; di Pellegrino and Làdavas, 2015).
There is no physically separation between the PPS (near space) and the extrapersonal space (far space) in the real world, however the brain does represent a boundary between these two spaces. That is to say between what is close to our bodies, which can potentially impact, interact or attack us, and what is further away, at a distance in which we cannot acted upon. More importantly, this boundary is not fixed and can vary within individuals between contexts and situation, and also between individuals (Cléry et al., 2015b; de Vignemont and Iannetti, 2015; Farnè et al., 2005a, 2005b; Maravita and Iriki, 2004).
Objects approaching us or a predator may pose a threat, and signal the need to initiate defensive behavior. These potential impacts suggest an intrusion in our peripersonal space, which conduct to enhance the system to be more efficient and to face to the potential threat (Canzoneri et al., 2012; Cléry et al., 2015a; De Paepe et al., 2016; Kandula et al., 2015). Besides, the peripersonal space is the space closest at us, so it is the closest at self. Some studies and reviews show the link between peripersonal space a body self-consciousness, and in particular a recent paper of Grivaz et al. (2017) who made a meta-analysis on human studies to compare these two components.
The following sections will review the methods to measure PPS (sections 2), the role of impact prediction (section 3), modulations of peripersonal space (section 4), different representation of body-related PPS (section 5) and the link between peripersonal space and body self-consciousness (section 6).
2 MEASUREMENTS OF PERIPERSONAL SPACE
Interestingly, neural systems representing PPS both in humans and in monkeys show response preference for moving stimuli, over static stimuli. Indeed, neurophysiological studies in monkeys showed that bimodal and trimodal neurons are more effectively activated by presenting three dimensional objects approaching toward and receding from the animal’s body, compared to static stimuli, both in the ventral intraparietal area (Colby et al., 1993a; Duhamel et al., 1997) and in the premotor cortex (Fogassi et al., 1996; Graziano et al., 1994; M. S. A. Graziano et al., 1997; Graziano et al., 1999). Some of these neurons also show direction-selective and velocity dependent response patterns, as firing rates in certain cells increase as a function of the velocity of approaching stimuli (Fogassi et al., 1996). In humans, Bremmer and colleagues (2001) demonstrated an increased neural activity in the depth of the intraparietal sulcus and in the ventral premotor cortex evoked by approaching visual, auditory and tactile stimuli.
Based on these findings, Serino’s group has developed a method to estimate the boundary of the PPS using dynamic stimuli which have more ecological contexts because our environment is constantly moving, instead of static stimuli. Besides, this approach is more similar to the experimental conditions used in monkeys’ neurophysiology, thus allowing a more direct comparison across species (Canzoneri et al., 2012).
This paradigm consists to measure behavioral responses in humans reflecting the concept and the properties of receptive fields (RFs) in primate PPS neurons during a dynamic audio-tactile interaction task or visuo-tactile interaction task in order to assess the extension of PPS in a more functionally and ecologically valid condition. Participants are requested to respond as fast as possible to tactile stimulation administered on a part of their body, while task-irrelevant approaching or receding external cues (auditory or visual stimuli) from the stimulated body part are presented (Canzoneri et al., 2012, 2013a, 2013b, 2016; Galli et al., 2015; Noel et al., 2015a, 2015b; Teneggi et al., 2013). They measured reaction time (RTs) to the tactile stimulus at body part (the hand, the face or the trunk). On each trial, tactile stimulation was delivered at different temporal delays from the onset of the sound/visual, such that it occurred when the sound/visual source was perceived at varying distances from the participant’s body.
They show that RTs to tactile stimuli progressively decrease as a function of the sound/visual source’s perceived approach; and conversely, that they would increase as a function of the sound/visual source’s perceived recession. They used the function describing the relationship between tactile processing and the position of sounds or visual stimuli in space to estimate the critical distance at which an external stimulus affects tactile processing. This critical distance, along a spatial continuum between far and near space, can be considered as the boundary of PPS representation in humans.
This new paradigm is first developed and used with dynamic audio-tactile interaction task with tactile stimulations delivered on the hand (Canzoneri et al., 2012, 2013a, 2013b). They used also this paradigm with dynamic audio-tactile interaction task with tactile stimulations delivered on the face to study the social effect on this boundary (Teneggi et al., 2013). Recently this group has developed also this paradigm using a dynamic visuo-tactile interaction task in full body illusion (Noel et al., 2015a, 2015b; Serino et al., 2015b).
This method developed by Serino’s group opens new perspectives to study the peripersonal and how it can be modulated following contexts, experiences and action.
3 LOOMING STIMULI AND IMPACT PREDICTION
The ecological significance between stable stimuli close to our body (e.g. a wall, a desk) and dynamic stimuli looming towards us (e.g. mosquito, a ball) are different. Looming stimuli are potentially more dangerous than other visual stimuli, including dynamic stimuli with no predicted impact to the body. A predator, a dominant conspecific, or a mere branch coming up at high speed are dangerous if one does not detect them fast enough to produce the appropriate escape motor repertoire. Indeed, such looming stimuli are known to trigger stereotyped defense responses (in monkeys: Schiff et al., 1962; in human infant: Ball and Tronick, 1971). Interestingly, threatening looming stimuli are perceived as having a shorter time-to-impact latency as compared to non-threatening objects moving at the same objective speed (Vagnoni et al., 2012).
In a visuo-auditory context, looming visual stimuli have shown to trigger pronounced orienting behavior toward simultaneous congruent auditory cues compared with receding stimuli, both in non-human primates (Maier et al., 2004) and in 5-month-old human infants (Walker-Andrews and Lennon 1985). Looming structured sounds can specifically benefit visual orientation sensitivity (Romei et al., 2009, Leo, et al 2011). In a recent study (Cléry et al., 2015a), we show that subjects have an enhanced tactile detection with looming visual stimuli rather with receding visual stimuli. Therefore, looming stimuli are more relevant than receding stimuli to the body. Indeed, while both size and depth cues most probably contribute to the modulation of tactile sensitivity on the face, we propose that the movement vector cue (away from or toward the subject) is actually the dominant cue affecting tactile detection. Slower looming stimuli result in a delayed predicted time of impact on the face, and hence a delayed time at which tactile sensitivity is maximally enhanced (Cléry et al., 2015a). So, the spatial, temporal, and dynamic predictive cues are fully accounted for by the trajectory and speed of the looming visual stimuli.
Other auditory or visuo-tactile integration studies (Canzoneri et al., 2012; Kandula et al., 2015) have shown the reaction time is shorter when the tactile is delivered at the impact time of the looming stimulus and suggest that looming stimuli predictively speeds up tactile processing. Besides, we found in our psychophysics study that also tactile sensitivity is enhanced at the predicted location and predicted time of impact of a looming visual stimulus to the face (Cléry et al., 2015a), reflecting the expected subjective consequence of the visual stimulus onto the tactile modality. Interestingly, the physiological and perceptual binding of two stimuli into the representation of a same and unique external source is subjected to some degree of temporal tolerance, which has driven of a multisensory temporal binding window description (for review, see Wallace and Stevenson, 2014).
On top of a baseline multisensory enhancement, tactile sensitivity is further enhanced by the predictive components of the heteromodal visual or auditory stimuli. To anticipate a potential impact onto the body and especially onto the face can be vital importance. This process involves cross-modal influences, and it was suggested that the cortical regions responsible for this multisensory impact prediction highly overlap with the multisensory convergence and integration functional network. Some studies are in accordance with this hypothesis. Firstly, the visual response occasionally observed in parietal tactile neurons (and more generally in bimodal visuo-tactile neurons) was initially interpreted as an “anticipatory activation”, predictive of touch in the corresponding skin (Juhani Hyvärinen and Poranen, 1974). Secondly, some neurons in the ventral intraparietal area (VIP) integrate vestibular proprioceptive self-motions and visual motion cues to encode relative self-motion with respect to the environment (Bremmer et al., 1997, 2000, 2002a, 2002b; Duhamel et al., 1997). These neurons have been shown to respond to both visual and tactile stimuli (Duhamel et al., 1997; Guipponi et al., 2013, 2015) and perform nonlinear sub-, super-, or additive multisensory integration operations (Avillac et al., 2004, 2007). Recently, a fMRI study on non-human primate confirms that this area VIP is implied in impact prediction to the face in a visuo-tactile context (Cléry et al., 2015b, Chapter 2). Thirdly, area F4 are also robustly activated, bilaterally by impact prediction. Most importantly, these activations are systematically significantly higher when the looming stimulus is predictive of the tactile stimulus than when these two stimuli are presented simultaneously (Cléry et al., 2015b, Chapter 2).
As seen in section 1, the area VIP and F4 play a key role in the definition of peripersonal space. A recent study in fMRI performed in monkeys to assess the neural bases encoding near and far space during naturalistic 3D moving objects, show the involvement both of VIP and F4 for peripersonal space encoding (Chapter 3). This confirms that it was found in electrophysiological studies in monkeys (Colby et al., 1993; Bremmer et al., 2002a, 2002b; Rizzolatti et al., 1981; Graziano et al., 1997) and notably the strong link between multisensory integration and peripersonal space representation.
In monkeys, the electrical microstimulation of the neurons of these two regions induces a behavioral defense and avoidance repertoire of whole body movements, suggesting their involvement in the coding of a defense peripersonal space (Cooke and Graziano, 2004; Graziano et al., 2002; Graziano and Cooke, 2006). Besides, a visual stimulus intruding into peripersonal space close to one’s cheek has a higher impact prediction effect on our cheek than a visual stimulus predicting an impact to the other cheek (Cléry et al., 2015b, Chapter 2). Therefore, we are alert to a potentially harmful impact to the face. Indeed, another study (Canzoneri et al., 2012) demonstrates that tactile processing on the hand is speeded by the presence of a looming sound, predicting an impact on the hand or within a well-defined distance from the hand. This suggests the existence of a security margin around the face and the body subserved by this parieto-frontal network (for reviews, see Cléry et al., 2015b; di Pellegrino and Làdavas, 2015).
Some studies performed in humans were interested not just in tactile stimuli but more precisely in nociceptive stimuli. In two studies (De Paepe et al., 2014, 2015), they use temporal order judgment tasks, to assess whether the spatial perception of nociceptive stimuli is coordinated with that of proximal visual stimuli into an integrated representation of peripersonal space. Participants judged which of two nociceptive stimuli, one presented to either hand, had been presented first. Each pair of nociceptive stimuli was preceded by lateralized visual cues presented either unilaterally or bilaterally, and either close to, or far from, the subject’s body. In the second study, during the task, participant’s hands were either uncrossed or crossed over the body midline. They found that the unilateral visual cue prioritized the perception of nociceptive stimuli delivered on the hand adjacent to the unilateral visual cue. This effect increased when the cue was presented close to the participant’s hand (De Paepe et al., 2014), irrespective of posture. This demonstrated that the temporal order of nociceptive stimuli was influenced by the position of the nociceptive stimuli on the body, but also mainly by the position itself of the stimulated hand in external space (De Paepe et al., 2015). In a third study (De Paepe et al., 2016), participants were asked to respond as fast as possible at which side they perceived a nociceptive stimulus on their hand while a visual stimulus with different temporal delays was either approaching or receding the participant’s left or right hand. Authors found that reaction times were fastest when the visual stimulus appeared near the stimulated hand and more pronounced for visual looming. These three studies suggest that the coding of nociceptive information in a peripersonal frame of reference may contribute to a safety margin representation around the body that is designed to protect it from potential physical threat.
A recent review (Van der Stoep et al., 2015) suggests that different combinations of sensory information might be more or less relevant depending on the distance from which this information happens to be presented. For example, touch and vision are dominant in peripersonal space, as they may imply an interaction between the body and the environment (e.g., for grasping or defense), whereas auditory and visual information may be more relevant in extrapersonal space as they provide useful information about farther objects, for spatial orienting, navigation and interaction with others (e.g. during conversation). As tactile stimuli can only be perceived when applied to the body, visuotactile and audiotactile interactions (like impacts onto the body) inherently occur near the body and the peripersonal space boundary can therefore be explained by spatial alignment of different stimulus modalities with the body. Another review (Nathan Van der Stoep, 2016) was interested on whether multisensory integration operates according to the same rules throughout the whole of 3-D space. They found not only that the space around us seems to be divided into distinct functional regions, but they also suggest that multisensory interactions are modulated by the region of space in which stimuli happen to be presented. Therefore, futures studies on peripersonal space and notably on impact prediction onto the body need to take account of the spatial constraints on multisensory integration (moving stimuli, 3D space, moving subject or isolated observers).
4 SOME MODULATIONS OF PERIPERSONAL SPACE
Peripersonal space seems to be really important in our representation of space. We have seen that in this space, some processes are enhanced (reaction times, sensitivity). In last years, a lot of studies were interest on the flexibility and plasticity of this peripersonal space (for review, see Cléry et al., 2015b; de Vignemont and Iannetti, 2015).
Using a tool to reach objects in the far space can extend the boundaries of PPS representation. In monkeys, Iriki et al. (1996) showed that, after a training period of using a rake, hand-centered visual RFs of neurons located in the intraparietal sulcus extended to retrieve pieces of food placed at a distance. In humans, neuropsychological (Farnè and Làdavas, 2000; Maravita et al., 2001) and psychophysical (Holmes et al., 2004; Maravita and Iriki, 2004; Serino et al., 2007; Galli et al., 2015) studies demonstrated that, after using a tool, crossmodal interactions between visual or auditory stimuli presented in the far space, more specifically at the location where the tool has been used, and tactile stimuli at the hand increase, suggesting extension of PPS representation. Taken together, these findings suggest that the extent of PPS representation is dynamically shaped depending on experience, extending the action possibilities of the body over its structural limits (Maravita and Iriki, 2004; Gallese and Sinigaglia, 2010; Costantini et al., 2011). At the beginning, some of these studies suggest that actively using the tool is necessary for extending PPS representation. Since, studies have shown that neither a physical, nor a functional interaction between near and far space is necessary to extend PPS representation (Bassolino et al., 2010; Goldenberg and Iriki, 2007; Serino et al., 2015a). This last study (Serino et al., 2015a) support to the unconventional hypothesis, generated by a neural network model, that plasticity in PPS representation after tool-use does not strictly depend on the function of the tool nor from the actions performed with the tool, but it is triggered by the sensory feedback of tool-use, i.e., synchronous tactile stimulation at the hand, due to holding the tool, and multisensory (auditory or visual) stimulation from the far space, where the tool is operated (for a review on tool-use, see Martel et al., 2016).
A lot of studies show that tool can remap the peripersonal space. This define the peripersonal space in a point of view of a “goal-directed action” in which we want to grasp and reach somethings (for review, see de Vignemont and Iannetti, 2015). However, some evidence show that other aspect can remap this space like fear, anxiety, social aspects and contribute rather to a “protective and defensive” peripersonal space.
Claustrophobia is a situational phobia featuring intense anxiety in relation to enclosed spaces and physically restrictive situations (American Psychiatric Association, 2000). Lourenco et al. (2011) investigated whether the size of near space relates to individual differences in claustrophobic fear, as measured by reported anxiety of enclosed spaces and physically restrictive situations and show that claustrophobic fear is associated with increased size of the near space immediately surrounding the body. Vagnoni et al. (2012) show the same results and extends these by showing that emotion not only alters the perception of space as a static entity, but it also affects the perception of dynamically moving objects, such as those on a collision course with the observer. Previous studies have described a facilitation of tactile processing when a physical threatening picture (for instance a snake or a knife) was presented nearby, leading to faster responses than when it was presented further away (for instance near a different body part) (Poliakoff et al., 2007; Van Damme et al., 2009). The distance from a visual stimulus has a stronger influence on tactile reaction times if it is perceived as threatening, which indicates that the distance to a threatening visual stimulus is more important for visuo-tactile interaction than to a non-threatening one (de Haan et al., 2016). Other studies found that noise sounds that elicited a negative emotion and negative ecological sounds (dogs barking, screaming woman, …), induced faster reactions times when threatened sounds appear close to the subject and are influencing earlier in the trial than sounds with a neutral or positive valence (Taffou and Viaud-Delmon, 2014; Ferri et al., 2015). Besides, whereas individuals low in claustrophobic fear demonstrated the expected expansion of peripersonal space using a stick during line bisection task, individuals high in claustrophobic fear showed less expansion, suggesting decreased flexibility (Hunley et al., 2017). Whatever the estimated level of objects’ danger, the extent of peripersonal space was reduced when the threatening part of dangerous objects was oriented towards participants, not when oriented away (Coello et al., 2012). This suggests that the characteristics of the here and now body-objects interaction are crucial in affecting the boundary of peripersonal space. These different studies show that the emotional aspects and characteristic of the danger itself in relation to the body can influence the defensive peripersonal space and so on the safety body margin but also can decrease peripersonal plasticity following the context.
Defensive reflex responses can be finely modulated by the position of the stimulus within the peripersonal space, particularly, in relation to the area of the body for which the reflex response provides protection (Sambo et al., 2012a, 2012b). Besides, the size of an individual’s peripersonal space is correlated with trait anxiety, with a larger peripersonal space in more anxious individuals (Sambo and Iannetti, 2013; for review, see de Vignemont and Iannetti, 2015). This is also observed with empathic subjects. Subcortical defensive responses like hand-blink reflex (HBR) is enhanced when the threat is brought close to the face by one’s own stimulated hand, by another person’s hand and when the hand of the participant enters in the PPS of another individual. The enhancement of this HBR is larger in participants with strong empathic tendency when the other individual is in a third person perspective suggesting that interpersonal interactions shape perception of threat and defensive responses (Fossataro et al., 2016).
Others evidence show that the presence and interaction with others shape the peripersonal space representation (Teneggi et al., 2013). Indeed, if we compare the peripersonal space measurements when subjects face another individual or face mannequin, placed in far space, peripersonal space boundaries shrink in condition in which subjects face another person, suggesting that one’s owns peripersonal space accommodates in the presence of others. Others experiments show that, peripersonal space boundaries between self and other merge after an economic game with another person, but only if the other behaved cooperatively. Peripersonal space is shaped by valuation of other people’s behaviour during the interaction, so there is a direct link between peripersonal representation a feelings generated by interaction with others. Therefore, the peripersonal space representation is sensitive to social modulation, showing a link between low-level sensorimotor processing and high-level social cognition. However, the expansion and contraction of our PPS representation may not be the only change induced by the presence of others. Some studies suggest that we remap observed sensory and motor experiences of others onto our own bodily representations. Indeed, a similar mirror system in the brain for both human and non-human primates exists, this system was activated both when we are touched ourselves, when we view another person being touched, and also when events occurring in the space near the other’s body (Blakemore et al., 2005; Keysers and Gazzola, 2009; Serino et al., 2008; Cardini et al., 2010). Ishida et al. (2009), using single cell recordings in non-human primates, show that bimodal parietal neurons which encode sensory events occurring in the space around the monkey’s own hand as well as the space around another monkey’s hand. Same results are observed in premotor cortex in humans (Brozzoli et al., 2013; Holt et al., 2014). However, Maister et al. (2015) show that increased multisensory integration near another person involved remapping of peripersonal space to the other person without including the space between the two people. A review by Ishida et al. (2015) based on monkey neurophysiology as well as human fMRI studies, reports shared self-other body representation coding in multiple brain areas including visuotactile neurons in parietal cortex (Ishida et al., 2009), secondary somatosensory cortex (Keysers et al., 2004, 2010; Blakemore et al., 2005; Ebisch et al., 2008; Keysers and Gazzola, 2009) and in insular cortex (Fitzgibbon et al., 2010, 2012; Lamm and Singer, 2010; Krahé et al., 2013) associated with affective touch and interoception.
Recent studies were interested in the link between the peripersonal space for acting and interpersonal space. It’s the space in which we maintain a distance around our bodies and in which any intrusion by others may cause discomfort. This space can be modified by emotional and socially relevant interactions. As we have seen previously PPS is also modulated by some social factors but also with more complex social information such as perceived morality of another person, age and gender (Iachini et al., 2015, 2016). Peripersonal space for acting and interpersonal space share a common motor nature and are sensitive, at different degrees, to social modulation. Therefore, social processing seems embodied and grounded in the body acting in space (Iachini et al., 2014). However, tool-use remapped the action-related PPS, measured by a reaching-distance toward a confederate, but did not affect the social-related interpersonal space measured by a comfort-distance task suggesting that these two space representation have no full functional overlap between them (Patané et al., 2016). But using another paradigm in which participants observed a point-light walker approaching them from different directions and passing near them at different distances from their right or left shoulder, Quesque et al.(2016) found that comfortable, interpersonal distance is linked to the representation of peripersonal space. As a consequence, increasing peripersonal space through tool use has the immediate consequence that comfortable interpersonal distance from another person also increases, suggesting that interpersonal-comfort space and peripersonal-reaching space share a common motor nature (Iachini et al., 2014, 2016; Coello and Fischer, 2015).
Peripersonal space is not a fixed space but a dynamic space with its own characteristics and which is continuously modulated by our environment (social, emotional, functional). The fact that this “boundary” vary suggests that the body tends to the more appropriate behaviour (protective, pro-active) using all the information around us and particularly multisensory integration cues (visual, tactile, auditory, proprioceptive…) (Cléry et al., 2015b; de Vignemont and Iannetti, 2015). Consequently, rules and effects of impact prediction to the body seen in section 3 are really dependant of numerous factors around us (type of stimulus, speed of stimulus, congruence of stimuli, the relevance of the stimulus impacting with the subject: static, moving, neutral, negative, social…). However, this is also depending of the body part stimulated or the is a unique body PPS representation?
5 DIFFERENT REPRESENTATION OF BODY-RELATED PPS
Lot of studies on peripersonal space were interested on the face and more on the hand. We have seen that this “boundary” of peripersonal space representation was modulated both for action (for example after tool-use) and emotional/social context (fear, anxiety, cooperation). Besides, these modulations can vary within individuals between contexts and situation, and also between individuals. However, the representation of peripersonal space is it the same following the different part of the body?
Serino et al. (2015b) have applying the paradigm developed in section 2 (Canzoneri et al., 2012, 2013a, 2013b; Teneggi et al., 2013; Galli et al., 2015; Noel et al., 2015a, 2015b) to measure behavioural responses in humans with a tactile stimulus delivered at different part of the body and space. In first experiment, they test the effect of looming and receding auditory stimuli from the peri-trunk which is stimulated. They show that looming sounds modulated tactile processing as a function of the distance of the sound from the body and this effect was selective for looming sounds. The majority of experiments on peripersonal space are done only in the front space of the subject. Therefore, in second experiment, they test the effect of looming and receding auditory stimuli from the front or back of peri-trunk which is stimulated. This confirms that just the sounds looming from the trunk are mapped into the representation of the peri-trunk PPS. There found any effect of mapping space (Front vs. Back). In third experiment, they test the effect of looming and receding auditory stimuli from the peri-hand which is stimulated. They show that sounds modulated tactile processing as a function of the distance of the sound from the hand but in this case this effect was observed not only for the looming sounds but also for the receding sounds. Nonetheless, the effect is stronger for looming stimuli than for receding stimuli and the distance. Besides, the distance in which the sounds modulated tactile processing is shorter for the peri-hand than for peri-trunk. In experiment 4 and 5, they compare directly representation of the peri-hand PPS and peri-trunk PPS. For this, always using looming and receding sounds from the body part stimulated, the tactile stimulation is applied either in peri-trunk or in peri-hand placed close to the peri-trunk (experiment 4) or either in the peri-hand placed far to the peri-trunk (like in experiment 1) or close to the peri-trunk (experiment 5). They found that if the peri-hand is close to the peri-trunk, only the effect of looming sounds modulates tactile processing and the distance of boundary PPS was relatively the same between them whereas when the peri-hand is far to the trunk, they observed the same results as experiment 3, i.e, looming and receding sounds have an effect but for shorter distance. To summarize, there is two different PPS representations, one for peri-hand sensitive to looming and receding stimuli at close distance and another one for peri-trunk sensitive only for looming stimuli and for distance less closer than for peri-hand. Importantly, these two representations are not independents. In two last experiments, they test the effect of looming and receding stimuli (auditory or visual) from the peri-trunk or the peri-face while one or the other was stimulated. If tactile stimulus was applied in the peri-trunk they observed that only looming stimuli elicited a significant speeding effect on tactile processing, at the relatively same distance than the other experiments on the peri-trunk and with no difference either the looming stimuli was toward the face or the trunk. If tactile stimulus was applied in the peri-face, they observed that only looming stimuli towards the face elicited a significant speeding effect on tactile processing but at shorter distance than for peri-trunk.
To summarize this really complete study, authors show that the size of PPS representation varied according the stimulated body part, being progressively bigger for the hand, the face and largest for the trunk (Figure 1A). Tactile processing is modulated in a space-dependant manner by looming stimuli for these different body parts but also by receding stimuli for the hand, with a smaller effect. More importantly, the size of PPS representation around the trunk is relatively constant, the PPS representation around the hand or the face varied according to their relative distance positioning and stimuli congruency (Figure 1B). These findings are compatible with the function of the peripersonal space as a multisensory-motor interface for body-object interaction (Brozzoli et al., 2012b), as to plan an approaching.
Authors suggests that there is not a unique representation of body peripersonal space but at least three body-part specific PPS representation, with different extension and direction tuning, and referenced to the common reference frame of the trunk. For the future studies, research need to take these new characteristics of PPS representation into account for design experiments. This first extensive mapping in humans PPS representation opens a new sight on peripersonal space research: how these three body-part specific PPS representation interfered with the other PPS representation as know the “goal-directed action” and the “protective/defensive” space?
6 PERIPERSONAL SPACE AND BODILY SELF-CONSCIOUSNESS
The trunk PPS representation integrates both body-related signals but also information related to external stimuli potentially interacting with the body, in a global, egocentric reference frame. This representation may constitute a basic neural representation that is of relevance for the self and self-consciousness (Blanke and Metzinger, 2009; Blanke, 2012; Blanke et al., 2015; Tsakiris et al., 2007; Tsakiris, 2010; Serino et al., 2015b). What is the link between peripersonal space and body self-consciousness?
Bodily self-consciousness, that is the feeling that the physical body and its parts is one’s owns, (BSC), is argued to be one of the cardinal features of subjective experience (Gallagher, 2000; Blanke and Metzinger, 2009). In last years, multisensory bodily illusion paradigms have been developed to study BSC in the laboratory, describing the detailed behavioural mechanisms underlying the sensation of ownership for the hand using rubber hand illusion (Botvinick and Cohen, 1998), the face using enfacement illusion (Tsakiris, 2008; Sforza et al., 2010), the entire body using full-body illusion, out-of-body illusion or body-swap illusion (Ehrsson et al., 2007; Lenggenhager et al., 2007; Petkova and Ehrsson, 2008). These illusions are based on the application of visuo-tactile stimuli between the body (or part of body) of the participant and a virtual body (or fake part of body). By manipulating multisensory cues, it is possible to induce ownership over fake or virtual body parts or whole bodies. These studies, have led to a growing consensus that ownership over hands, faces, and bodies crucially relies on the integration of multiple bodily signals in the brain (Blanke, 2012; Blanke et al., 2015; Ehrsson et al., 2004; Ehrsson, 2012; Makin et al., 2008; Serino et al., 2013; Tsakiris, 2010).
Discussions on these studies suggest a direct link between the neural mechanism underlying multisensory PPS processing and BSC. However, nowadays, most of studies investigated separately the brain mechanism of either PPS or either BSC processing, using a lot of different paradigms. To compensate for this, a recent study (Grivaz et al., 2017), have conducted an extensive meta-analysis of functional neuroimaging studies to determine the key neural structures for PPS, for BSC and their potential common structures in humans.
To do this, authors performed a systematic quantitative coordinate-based meta-analysis on human functional neuroimagining studies (Eickhoff et al., 2009, 2012; Turkeltaub et al., 2002). They selected 35 PET or fMRI studies: 18 for the PPS category assessing brain regions involved in encoding of unisensory and multisensory stimuli within PPS (in peri-hand, peri-face and peri-trunk); 17 for the BSC category assessing brain regions involved of a body or a part of the body. They identified a bilateral PPS network including superior parietal, temporo-parietal and ventral premotor regions. These parioto-frontal networks are involved in many sensory-motor processes, mediating interactions between individual and the immediate environment, integrating sensory information and driving potential motor responses. (Graziano and Cooke, 2006; Làdavas and Serino, 2008; Cléry et al., 2015b; Grivaz et al., 2017). The BSC network include posterior parietal cortex (right intraparietal sulcus, IPS; and left IPS and superior parietal lobule, (SPL), right ventral premotor cortex, and the left anterior insula. These regions are involved in multisensory integration, attention and awareness. The insula plays a key role in integration of exteroceptive body-related cues and interoceptive signals that have been considered important for generating subjective experience (Craig, 2009; Damasio and Meyer, 2009; Park and Tallon-Baudry, 2014; Seth, 2013; Seth and Friston, 2016; Tsakiris, 2010). Although BSC and PPS representations was not associated with exactly the same functions, they have a largely overlapping fronto-parietal networks.
The conjunction analysis showed that PPS and BSC tasks anatomically overlapped only in two clusters located in the left parietal cortex (dorsally at the intersection between the SPL, the IPS and area 2 and ventrally between areas 2 and IPS). The activation of this dorsal SPL/IPS comforts the hypothesis that multisensory integration of bodily cues in the PPS is a crucial mechanism involved in BSC (Brozzoli et al., 2012a; Gentile et al., 2013; Grivaz et al., 2017).
The premotor and insular clusters involved in BSC were systematically co-activated with the parietal clusters involved in PPS processing during several cognitive tasks suggesting that these regions were functionally largely interconnected between each other. Fronto-parietal areas involved in PPS are located more proximal to the central sulcus and BSC areas appeared more distal. Therefore, this anatomical distinction can subserve the different functions of the two processes, whereby PPS areas underlie a multisensory-motor interface for body-objects interaction and BSC areas being involved in bodily awareness and self-consciousness.
Peripersonal space representation subserved principally by a parieto-frontal network, involved complex mechanisms and depend on a numerous factor. Our PPS representation is continuously change around us with sensory information, experiencing and feeling to adapt the best possible to our environment (Figure 1). Besides this PPS representation network have a strong connectivity with the BSC network and we may suggest that impairment in PPS representation can have consequences onto self-consciousness. This opens new research way for the future years.
American Psychiatric Association, 2000. Diagnostic and statistical manual of mental disorders. (4th ed., text rev.). Washington DC.
Avillac, M., Denève, S., Olivier, E., Pouget, A., Duhamel, J.-R., 2005. Reference frames for representing visual and tactile locations in parietal cortex. Nat Neurosci 8, 941–949. doi:10.1038/nn1480
Avillac, M., Hamed, S.B., Duhamel, J.-R., 2007. Multisensory Integration in the Ventral Intraparietal Area of the Macaque Monkey. J. Neurosci. 27, 1922–1932. doi:10.1523/JNEUROSCI.2646-06.2007
Avillac, M., Olivier, E., Denève, S., Ben Hamed, S., Duhamel, J.-R., 2004. Multisensory integration in multiple reference frames in the posterior parietal cortex. Cognitive Processing 5, 159–166. doi:10.1007/s10339-004-0021-3
Ball, W., Tronick, E., 1971. Infant responses to impending collision: optical and real. Science 171, 818–820.
Bassolino, M., Serino, A., Ubaldi, S., Làdavas, E., 2010. Everyday use of the computer mouse extends peripersonal space representation. Neuropsychologia 48, 803–811. doi:10.1016/j.neuropsychologia.2009.11.009
Bender, M.., 1952. Disorders of perception. Springfield, IL: Charles C. Thomas.
Blakemore, S.-J., Bristow, D., Bird, G., Frith, C., Ward, J., 2005. Somatosensory activations during the observation of touch and a case of vision–touch synaesthesia. Brain 128, 1571–1583. doi:10.1093/brain/awh500
Blanke, O., 2012. Multisensory brain mechanisms of bodily self-consciousness. Nat Rev Neurosci 13, 556–571. doi:10.1038/nrn3292
Blanke, O., Metzinger, T., 2009. Full-body illusions and minimal phenomenal selfhood. Trends Cogn. Sci. (Regul. Ed.) 13, 7–13. doi:10.1016/j.tics.2008.10.003
Blanke, O., Slater, M., Serino, A., 2015. Behavioral, Neural, and Computational Principles of Bodily Self-Consciousness. Neuron 88, 145–166. doi:10.1016/j.neuron.2015.09.029
Botvinick, M., Cohen, J., 1998. Rubber hands “feel” touch that eyes see. Nature 391, 756–756. doi:10.1038/35784
Bremmer, F., Duhamel, J.-R., Ben Hamed, S., Graf, W., 2002a. Heading encoding in the macaque ventral intraparietal area (VIP). European Journal of Neuroscience 16, 1554–1568. doi:10.1046/j.1460-9568.2002.02207.x
Bremmer, F., Duhamel, J.R., Ben Hamed, S., Graf, W., 2000. Stages of self-motion processing in primate posterior parietal cortex. Int. Rev. Neurobiol. 44, 173–198.
Bremmer, F., Duhamel, J.-R., Ben Hamed, S., Graf, W., 1997. The representation of movement in near extra-personal space in the macaque ventral intraparietal area (VIP)., in: Thier, P., Karnath, H.-O. (Eds.), Parietal Lobe Contributions to Orientation in 3D Space, Experimental Brain Research Series, Vol 25. Springer, pp. 619–630.
Bremmer, F., Klam, F., Duhamel, J.-R., Ben Hamed, S., Graf, W., 2002b. Visual–vestibular interactive responses in the macaque ventral intraparietal area (VIP). European Journal of Neuroscience 16, 1569–1586. doi:10.1046/j.1460-9568.2002.02206.x
Bremmer, F., Schlack, A., Kaminiarz, A., Hoffmann, K.-P., 2013. Encoding of movement in near extrapersonal space in primate area VIP. Front Behav Neurosci 7, 8. doi:10.3389/fnbeh.2013.00008
Bremmer, F., Schlack, A., Shah, N.J., Zafiris, O., Kubischik, M., Hoffmann, K., Zilles, K., Fink, G.R., 2001. Polymodal motion processing in posterior parietal and premotor cortex: a human fMRI study strongly implies equivalencies between humans and monkeys. Neuron 29, 287–296.
Brozzoli, C., Gentile, G., Bergouignan, L., Ehrsson, H.H., 2013. A Shared Representation of the Space Near Oneself and Others in the Human Premotor Cortex. Current Biology 23, 1764–1768. doi:10.1016/j.cub.2013.07.004
Brozzoli, C., Gentile, G., Ehrsson, H.H., 2012a. That’s near my hand! Parietal and premotor coding of hand-centered space contributes to localization and self-attribution of the hand. J. Neurosci. 32, 14573–14582. doi:10.1523/JNEUROSCI.2660-12.2012
Brozzoli, C., Gentile, G., Petkova, V.I., Ehrsson, H.H., 2011. fMRI Adaptation Reveals a Cortical Mechanism for the Coding of Space Near the Hand. J. Neurosci. 31, 9023–9031. doi:10.1523/JNEUROSCI.1172-11.2011
Brozzoli, C., Makin, T.R., Cardinali, L., Holmes, N.P., Farnè, A., 2012b. Peripersonal Space: A Multisensory Interface for Body–Object Interactions, in: Murray, M.M., Wallace, M.T. (Eds.), The Neural Bases of Multisensory Processes, Frontiers in Neuroscience. CRC Press/Taylor & Francis, Boca Raton (FL).
Canzoneri, E., di Pellegrino, G., Herbelin, B., Blanke, O., Serino, A., 2016. Conceptual processing is referenced to the experienced location of the self, not to the location of the physical body. Cognition 154, 182–192. doi:10.1016/j.cognition.2016.05.016
Canzoneri, E., Magosso, E., Serino, A., 2012. Dynamic Sounds Capture the Boundaries of Peripersonal Space Representation in Humans. PLoS ONE 7, e44306. doi:10.1371/journal.pone.0044306
Canzoneri, E., Marzolla, M., Amoresano, A., Verni, G., Serino, A., 2013a. Amputation and prosthesis implantation shape body and peripersonal space representations. Scientific Reports 3, 2844. doi:10.1038/srep02844
Canzoneri, E., Ubaldi, S., Rastelli, V., Finisguerra, A., Bassolino, M., Serino, A., 2013b. Tool-use reshapes the boundaries of body and peripersonal space representations. Exp Brain Res 228, 25–42. doi:10.1007/s00221-013-3532-2
Cardini, F., Costantini, M., Galati, G., Romani, G.L., Làdavas, E., Serino, A., 2010. Viewing One’s Own Face Being Touched Modulates Tactile Perception: An fMRI Study. Journal of Cognitive Neuroscience 23, 503–513. doi:10.1162/jocn.2010.21484
Cléry, J., Guipponi, O., Odouard, S., Wardak, C., Ben Hamed, S., 2015a. Impact prediction by looming visual stimuli enhances tactile detection. J. Neurosci. 35, 4179–4189. doi:10.1523/JNEUROSCI.3031-14.2015
Cléry, J., Guipponi, O., Wardak, C., Ben Hamed, S., 2015b. Neuronal bases of peripersonal and extrapersonal spaces, their plasticity and their dynamics: Knowns and unknowns. Neuropsychologia 70, 313–326. doi:10.1016/j.neuropsychologia.2014.10.022
Coello, Y., Bourgeois, J., Iachini, T., 2012. Embodied perception of reachable space: how do we manage threatening objects? Cogn Process 13, 131–135. doi:10.1007/s10339-012-0470-z
Coello, Y., Fischer, M.H., 2015. Perceptual and Emotional Embodiment: Foundations of Embodied Cognition. Routledge.
Colby, C.L., Duhamel, J.R., Goldberg, M.E., 1993a. Ventral intraparietal area of the macaque: anatomic location and visual response properties. Journal of Neurophysiology 69, 902–914.
Colby, C.L., Duhamel, J.R., Goldberg, M.E., 1993b. Ventral intraparietal area of the macaque: anatomic location and visual response properties. Journal of Neurophysiology 69, 902–914.
Cooke, D.F., Graziano, M.S.A., 2004. Sensorimotor Integration in the Precentral Gyrus: Polysensory Neurons and Defensive Movements. Journal of Neurophysiology 91, 1648–1660. doi:10.1152/jn.00955.2003
Costantini, M., Ambrosini, E., Sinigaglia, C., Gallese, V., 2011. Tool-use observation makes far objects ready-to-hand. Neuropsychologia 49, 2658–2663. doi:10.1016/j.neuropsychologia.2011.05.013
Craig, A.D., 2009. How do you feel — now? The anterior insula and human awareness. Nat Rev Neurosci 10, 59–70. doi:10.1038/nrn2555
Damasio, A., Meyer, K., 2009. CHAPTER 1 – Consciousness: An Overview of the Phenomenon and of Its Possible Neural Basis1, in: The Neurology of Consciousness. Academic Press, San Diego, pp. 3–14. doi:10.1016/B978-0-12-374168-4.00001-0
de Haan, A.M., Smit, M., Stigchel, S.V. der, Dijkerman, H.C., 2016. Approaching threat modulates visuotactile interactions in peripersonal space. Exp Brain Res 234, 1875–1884. doi:10.1007/s00221-016-4571-2
De Paepe, A.L., Crombez, G., Legrain, V., 2016. What’s Coming Near? The Influence of Dynamical Visual Stimuli on Nociceptive Processing. PLOS ONE 11, e0155864. doi:10.1371/journal.pone.0155864
De Paepe, A.L., Crombez, G., Legrain, V., 2015. From a Somatotopic to a Spatiotopic Frame of Reference for the Localization of Nociceptive Stimuli. PLoS ONE 10, e0137120. doi:10.1371/journal.pone.0137120
De Paepe, A.L., Crombez, G., Spence, C., Legrain, V., 2014. Mapping nociceptive stimuli in a peripersonal frame of reference: evidence from a temporal order judgment task. Neuropsychologia 56, 219–228. doi:10.1016/j.neuropsychologia.2014.01.016
de Vignemont, F., Iannetti, G.D., 2015. How many peripersonal spaces? Neuropsychologia 70, 327–334. doi:10.1016/j.neuropsychologia.2014.11.018
di Pellegrino, G., Làdavas, E., 2015. Peripersonal space in the brain. Neuropsychologia 66, 126–133. doi:10.1016/j.neuropsychologia.2014.11.011
di Pellegrino, G., Làdavas, E., Farné, A., 1997. Seeing where your hands are. Nature 388, 730–730. doi:10.1038/41921
Duhamel, J.-R., Bremmer, F., BenHamed, S., Graf, W., 1997. Spatial invariance of visual receptive fields in parietal cortex neurons. Nature 389, 845–848. doi:10.1038/39865
Duhamel, J.-R., Colby, C.L., Goldberg, M.E., 1998. Ventral Intraparietal Area of the Macaque: Congruent Visual and Somatic Response Properties. Journal of Neurophysiology 79, 126–136.
Ebisch, S.J.H., Perrucci, M.G., Ferretti, A., Del Gratta, C., Romani, G.L., Gallese, V., 2008. The Sense of Touch: Embodied Simulation in a Visuotactile Mirroring Mechanism for Observed Animate or Inanimate Touch. Journal of Cognitive Neuroscience 20, 1611–1623. doi:10.1162/jocn.2008.20111
Ehrsson, H.H., 2012. The concept of body ownership and its relation to multisensory integration. Stein—The New Handbook of Multisensory Processes. MIT Press.
Ehrsson, H.H., Spence, C., Passingham, R.E., 2004. That’s my hand! Activity in premotor cortex reflects feeling of ownership of a limb. Science 305, 875–877. doi:10.1126/science.1097011
Ehrsson, H.H., Wiech, K., Weiskopf, N., Dolan, R.J., Passingham, R.E., 2007. Threatening a rubber hand that you feel is yours elicits a cortical anxiety response. PNAS 104, 9828–9833. doi:10.1073/pnas.0610011104
Eickhoff, S.B., Bzdok, D., Laird, A.R., Kurth, F., Fox, P.T., 2012. Activation likelihood estimation meta-analysis revisited. NeuroImage 59, 2349–2361. doi:10.1016/j.neuroimage.2011.09.017
Eickhoff, S.B., Laird, A.R., Grefkes, C., Wang, L.E., Zilles, K., Fox, P.T., 2009. Coordinate-based activation likelihood estimation meta-analysis of neuroimaging data: A random-effects approach based on empirical estimates of spatial uncertainty. Hum. Brain Mapp. 30, 2907–2926. doi:10.1002/hbm.20718
Farnè, A., Demattè, M.L., Làdavas, E., 2005a. Neuropsychological evidence of modular organization of the near peripersonal space. Neurology 65, 1754–1758. doi:10.1212/01.wnl.0000187121.30480.09
Farnè, A., Iriki, A., Làdavas, E., 2005b. Shaping multisensory action–space with tools: evidence from patients with cross-modal extinction. Neuropsychologia, Movement, Action and Consciousness: Toward a Physiology of Intentionality A Special Issue in Honour of Marc Jeannerod 43, 238–248. doi:10.1016/j.neuropsychologia.2004.11.010
Farnè, A., Làdavas, E., 2002. Auditory peripersonal space in humans. J Cogn Neurosci 14, 1030–1043. doi:10.1162/089892902320474481
Farnè, A., Làdavas, E., 2000. Dynamic size-change of hand peripersonal space following tool use. Neuroreport 11, 1645–1649.
Ferri, F., Tajadura-Jiménez, A., Väljamäe, A., Vastano, R., Costantini, M., 2015. Emotion-inducing approaching sounds shape the boundaries of multisensory peripersonal space. Neuropsychologia 70, 468–475. doi:10.1016/j.neuropsychologia.2015.03.001
Fitzgibbon, B.M., Enticott, P.G., Rich, A.N., Giummarra, M.J., Georgiou-Karistianis, N., Bradshaw, J.L., 2012. Mirror-sensory synaesthesia: Exploring “shared” sensory experiences as synaesthesia. Neuroscience & Biobehavioral Reviews 36, 645–657. doi:10.1016/j.neubiorev.2011.09.006
Fitzgibbon, B.M., Giummarra, M.J., Georgiou-Karistianis, N., Enticott, P.G., Bradshaw, J.L., 2010. Shared pain: From empathy to synaesthesia. Neuroscience & Biobehavioral Reviews 34, 500–512. doi:10.1016/j.neubiorev.2009.10.007
Fogassi, L., Gallese, V., Fadiga, L., Luppino, G., Matelli, M., Rizzolatti, G., 1996. Coding of peripersonal space in inferior premotor cortex (area F4). J. Neurophysiol. 76, 141–157.
Fossataro, C., Sambo, C.F., Garbarini, F., Iannetti, G.D., 2016. Interpersonal interactions and empathy modulate perception of threat and defensive responses. Scientific Reports 6, 19353. doi:10.1038/srep19353
Gallagher, S., 2000. Philosophical conceptions of the self: implications for cognitive science. Trends in Cognitive Sciences 4, 14–21. doi:10.1016/S1364-6613(99)01417-5
Gallese, V., Sinigaglia, C., 2010. The bodily self as power for action. Neuropsychologia, The Sense of Body 48, 746–755. doi:10.1016/j.neuropsychologia.2009.09.038
Galli, G., Noel, J.P., Canzoneri, E., Blanke, O., Serino, A., 2015. The wheelchair as a full-body tool extending the peripersonal space. Front. Psychol. 6. doi:10.3389/fpsyg.2015.00639
Gentile, G., Guterstam, A., Brozzoli, C., Ehrsson, H.H., 2013. Disintegration of multisensory signals from the real hand reduces default limb self-attribution: an fMRI study. J. Neurosci. 33, 13350–13366. doi:10.1523/JNEUROSCI.1363-13.2013
Gentile, G., Petkova, V.I., Ehrsson, H.H., 2011. Integration of Visual and Tactile Signals From the Hand in the Human Brain: An fMRI Study. Journal of Neurophysiology 105, 910–922. doi:10.1152/jn.00840.2010
Goldenberg, G., Iriki, A., 2007. From sticks to coffee-maker: mastery of tools and technology by human and non-human primates. Cortex 43, 285–288.
Graziano, M.S., Gross, C.G., 1993. A bimodal map of space: somatosensory receptive fields in the macaque putamen with corresponding visual receptive fields. Exp Brain Res 97, 96–109.
Graziano, M.S., Hu, X.T., Gross, C.G., 1997. Visuospatial properties of ventral premotor cortex. J. Neurophysiol. 77, 2268–2292.
Graziano, M.S., Yap, G.S., Gross, C.G., 1994. Coding of visual space by premotor neurons. Science 266, 1054–1057.
Graziano, M.S.A., Cooke, D.F., 2006. Parieto-frontal interactions, personal space, and defensive behavior. Neuropsychologia 44, 845–859. doi:10.1016/j.neuropsychologia.2005.09.009
Graziano, M.S.A., Cooke, D.F., Taylor, C.S.R., 2000. Coding the Location of the Arm by Sight. Science 290, 1782–1786. doi:10.1126/science.290.5497.1782
Graziano, M.S.A., Hu, X.T., Gross, C.G., 1997. Visuospatial Properties of Ventral Premotor Cortex. Journal of Neurophysiology 77, 2268–2292.
Graziano, M.S.A., Reiss, L.A.J., Gross, C.G., 1999. A neuronal representation of the location of nearby sounds. Nature 397, 428–430. doi:10.1038/17115
Graziano, M.S.A., Taylor, C.S.R., Moore, T., 2002. Complex Movements Evoked by Microstimulation of Precentral Cortex. Neuron 34, 841–851. doi:10.1016/S0896-6273(02)00698-0
Grivaz, P., Blanke, O., Serino, A., 2017. Common and distinct brain regions processing multisensory bodily signals for peripersonal space and body ownership. NeuroImage 147, 602–618. doi:10.1016/j.neuroimage.2016.12.052
Guipponi, O., Cléry, J., Odouard, S., Wardak, C., Ben Hamed, S., 2015. Whole brain mapping of visual and tactile convergence in the macaque monkey. NeuroImage 117, 93–102. doi:10.1016/j.neuroimage.2015.05.022
Guipponi, O., Wardak, C., Ibarrola, D., Comte, J.-C., Sappey-Marinier, D., Pinède, S., Hamed, S.B., 2013. Multimodal Convergence within the Intraparietal Sulcus of the Macaque Monkey. J. Neurosci. 33, 4128–4139. doi:10.1523/JNEUROSCI.1421-12.2013
Holmes, N.P., Calvert, G.A., Spence, C., 2004. Extending or projecting peripersonal space with tools? Multisensory interactions highlight only the distal and proximal ends of tools. Neuroscience Letters 372, 62–67. doi:10.1016/j.neulet.2004.09.024
Holt, D.J., Cassidy, B.S., Yue, X., Rauch, S.L., Boeke, E.A., Nasr, S., Tootell, R.B.H., Coombs, G., 2014. Neural Correlates of Personal Space Intrusion. J. Neurosci. 34, 4123–4134. doi:10.1523/JNEUROSCI.0686-13.2014
Hunley, S.B., Marker, A.M., Lourenco, S.F., 2017. Individual Differences in the Flexibility of Peripersonal Space. Experimental Psychology 64, 49–55. doi:10.1027/1618-3169/a000350
Hyvärinen, J., Poranen, A., 1974. Function of the parietal associative area 7 as revealed from cellular discharges in alert monkeys. Brain 97, 673–692.
Hyvärinen, J., Poranen, A., 1974. Function of the Parietal Associative Area 7 as Revealed from Cellular Discharges in Alert Monkeys. Brain 97, 673–692. doi:10.1093/brain/97.1.673
Iachini, T., Coello, Y., Frassinetti, F., Ruggiero, G., 2014. Body Space in Social Interactions: A Comparison of Reaching and Comfort Distance in Immersive Virtual Reality. PLoS ONE 9. doi:10.1371/journal.pone.0111511
Iachini, T., Coello, Y., Frassinetti, F., Senese, V.P., Galante, F., Ruggiero, G., 2016. Peripersonal and interpersonal space in virtual and real environments: Effects of gender and age. Journal of Environmental Psychology 45, 154–164. doi:10.1016/j.jenvp.2016.01.004
Iachini, T., Pagliaro, S., Ruggiero, G., 2015. Near or far? It depends on my impression: moral information and spatial behavior in virtual interactions. Acta Psychol (Amst) 161, 131–136. doi:10.1016/j.actpsy.2015.09.003
Iriki, A., Tanaka, M., Iwamura, Y., 1996. Coding of modified body schema during tool use by macaque postcentral neurones. Neuroreport 7, 2325–2330.
Ishida, H., Nakajima, K., Inase, M., Murata, A., 2009. Shared Mapping of Own and Others’ Bodies in Visuotactile Bimodal Area of Monkey Parietal Cortex. Journal of Cognitive Neuroscience 22, 83–96. doi:10.1162/jocn.2009.21185
Ishida, H., Suzuki, K., Grandi, L.C., 2015. Predictive coding accounts of shared representations in parieto-insular networks. Neuropsychologia 70, 442–454. doi:10.1016/j.neuropsychologia.2014.10.020
Kandula, M., Hofman, D., Dijkerman, H.C., 2015. Visuo-tactile interactions are dependent on the predictive value of the visual stimulus. Neuropsychologia 70, 358–366. doi:10.1016/j.neuropsychologia.2014.12.008
Keysers, C., Gazzola, V., 2009. Expanding the mirror: vicarious activity for actions, emotions, and sensations. Current Opinion in Neurobiology, Motor systems • Neurology of behaviour 19, 666–671. doi:10.1016/j.conb.2009.10.006
Keysers, C., Kaas, J.H., Gazzola, V., 2010. Somatosensation in social perception. Nat Rev Neurosci 11, 417–428. doi:10.1038/nrn2833
Keysers, C., Wicker, B., Gazzola, V., Anton, J.-L., Fogassi, L., Gallese, V., 2004. A Touching Sight: SII/PV Activation during the Observation and Experience of Touch. Neuron 42, 335–346. doi:10.1016/S0896-6273(04)00156-4
Krahé, C., Springer, A., Weinman, J.A., Fotopoulou, A. (Katerina), 2013. The Social Modulation of Pain: Others as Predictive Signals of Salience – a Systematic Review. Front. Hum. Neurosci. 7. doi:10.3389/fnhum.2013.00386
Làdavas, E., 2002. Functional and dynamic properties of visual peripersonal space. Trends in Cognitive Sciences 6, 17–22. doi:10.1016/S1364-6613(00)01814-3
Làdavas, E., di Pellegrino, G., Farnè, A., Zeloni, G., 1998a. Neuropsychological evidence of an integrated visuotactile representation of peripersonal space in humans. J Cogn Neurosci 10, 581–589.
Làdavas, E., Farnè, A., Zeloni, G., Pellegrino, G. di, 2000. Seeing or not seeing where your hands are. Exp Brain Res 131, 458–467. doi:10.1007/s002219900264
Làdavas, E., Serino, A., 2008. Action-dependent plasticity in peripersonal space representations. Cogn Neuropsychol 25, 1099–1113.
Làdavas, E., Zeloni, G., Farnè, A., 1998b. Visual peripersonal space centred on the face in humans. Brain 121 ( Pt 12), 2317–2326.
Lamm, C., Singer, T., 2010. The role of anterior insular cortex in social emotions. Brain Struct Funct 214, 579–591. doi:10.1007/s00429-010-0251-3
Lenggenhager, B., Tadi, T., Metzinger, T., Blanke, O., 2007. Video ergo sum: manipulating bodily self-consciousness. Science 317, 1096–1099. doi:10.1126/science.1143439
Lourenco, S.F., Longo, M.R., Pathman, T., 2011. Near space and its relation to claustrophobic fear. Cognition 119, 448–453. doi:10.1016/j.cognition.2011.02.009
Macaluso, E., Maravita, A., 2010. The representation of space near the body through touch and vision. Neuropsychologia, The Sense of Body 48, 782–795. doi:10.1016/j.neuropsychologia.2009.10.010
Maister, L., Cardini, F., Zamariola, G., Serino, A., Tsakiris, M., 2015. Your place or mine: Shared sensory experiences elicit a remapping of peripersonal space. Neuropsychologia 70, 455–461. doi:10.1016/j.neuropsychologia.2014.10.027
Makin, T.R., Holmes, N.P., Ehrsson, H.H., 2008. On the other hand: Dummy hands and peripersonal space. Behavioural Brain Research 191, 1–10. doi:10.1016/j.bbr.2008.02.041
Makin, T.R., Holmes, N.P., Zohary, E., 2007. Is That Near My Hand? Multisensory Representation of Peripersonal Space in Human Intraparietal Sulcus. J. Neurosci. 27, 731–740. doi:10.1523/JNEUROSCI.3653-06.2007
Maravita, A., Husain, M., Clarke, K., Driver, J., 2001. Reaching with a tool extends visual–tactile interactions into far space: evidence from cross-modal extinction. Neuropsychologia 39, 580–585. doi:10.1016/S0028-3932(00)00150-0
Maravita, A., Iriki, A., 2004. Tools for the body (schema). Trends in Cognitive Sciences 8, 79–86. doi:10.1016/j.tics.2003.12.008
Martel, M., Cardinali, L., Roy, A.C., Farnè, A., 2016. Tool-use: An open window into body representation and its plasticity. Cognitive Neuropsychology 33, 82–101. doi:10.1080/02643294.2016.1167678
Mattingley, J.B., Driver, J., Beschin, N., Robertson, I.H., 1997. Attentional competition between modalities: extinction between touch and vision after right hemisphere damage. Neuropsychologia 35, 867–880. doi:10.1016/S0028-3932(97)00008-0
Nathan Van der Stoep, A.S., 2016. Depth: the Forgotten Dimension in Multisensory Research. Multisensory research. doi:10.1163/22134808-00002525
Noel, J.-P., Grivaz, P., Marmaroli, P., Lissek, H., Blanke, O., Serino, A., 2015a. Full body action remapping of peripersonal space: The case of walking. Neuropsychologia 70, 375–384. doi:10.1016/j.neuropsychologia.2014.08.030
Noel, J.-P., Pfeiffer, C., Blanke, O., Serino, A., 2015b. Peripersonal space as the space of the bodily self. Cognition 144, 49–57. doi:10.1016/j.cognition.2015.07.012
Occelli, V., Spence, C., Zampini, M., 2011. Audiotactile interactions in front and rear space. Neuroscience & Biobehavioral Reviews 35, 589–598. doi:10.1016/j.neubiorev.2010.07.004
Park, H.-D., Tallon-Baudry, C., 2014. The neural subjective frame: from bodily signals to perceptual consciousness. Philos. Trans. R. Soc. Lond., B, Biol. Sci. 369, 20130208. doi:10.1098/rstb.2013.0208
Patané, I., Iachini, T., Farnè, A., Frassinetti, F., 2016. Disentangling Action from Social Space: Tool-Use Differently Shapes the Space around Us. PLoS ONE 11. doi:10.1371/journal.pone.0154247
Petkova, V.I., Ehrsson, H.H., 2008. If I Were You: Perceptual Illusion of Body Swapping. PLOS ONE 3, e3832. doi:10.1371/journal.pone.0003832
Poliakoff, E., Miles, E., Li, X., Blanchette, I., 2007. The effect of visual threat on spatial attention to touch. Cognition 102, 405–414. doi:10.1016/j.cognition.2006.01.006
Quesque, F., Ruggiero, G., Mouta, S., Santos, J., Iachini, T., Coello, Y., 2016. Keeping you at arm’s length: modifying peripersonal space influences interpersonal distance. Psychological Research 1–12. doi:10.1007/s00426-016-0782-1
Rizzolatti, G., Scandolara, C., Matelli, M., Gentilucci, M., 1981a. Afferent properties of periarcuate neurons in macaque monkeys. I. Somatosensory responses. Behav. Brain Res. 2, 125–146.
Rizzolatti, G., Scandolara, C., Matelli, M., Gentilucci, M., 1981b. Afferent properties of periarcuate neurons in macaque monkeys. II. Visual responses. Behav. Brain Res. 2, 147–163.
Rizzolatti, G., Scandolara, C., Matelli, M., Gentilucci, M., 1981. Afferent properties of periarcuate neurons in macaque monkeys. II. Visual responses. Behav. Brain Res. 2, 147–163.
Sambo, C.F., Forster, B., 2008. An ERP Investigation on Visuotactile Interactions in Peripersonal and Extrapersonal Space: Evidence for the Spatial Rule. Journal of Cognitive Neuroscience 21, 1550–1559. doi:10.1162/jocn.2009.21109
Sambo, C.F., Forster, B., Williams, S.C., Iannetti, G.D., 2012a. To blink or not to blink: fine cognitive tuning of the defensive peripersonal space. J. Neurosci. 32, 12921–12927. doi:10.1523/JNEUROSCI.0607-12.2012
Sambo, C.F., Iannetti, G.D., 2013. Better Safe Than Sorry? The Safety Margin Surrounding the Body Is Increased by Anxiety. J. Neurosci. 33, 14225–14230. doi:10.1523/JNEUROSCI.0706-13.2013
Sambo, C.F., Liang, M., Cruccu, G., Iannetti, G.D., 2012b. Defensive peripersonal space: the blink reflex evoked by hand stimulation is increased when the hand is near the face. J. Neurophysiol. 107, 880–889. doi:10.1152/jn.00731.2011
Schiff, W., Caviness, J.A., Gibson, J.J., 1962. Persistent fear responses in rhesus monkeys to the optical stimulus of “looming.” Science 136, 982–983.
Schlack, A., Sterbing-D’Angelo, S.J., Hartung, K., Hoffmann, K.-P., Bremmer, F., 2005. Multisensory space representations in the macaque ventral intraparietal area. J. Neurosci. 25, 4616–4625. doi:10.1523/JNEUROSCI.0455-05.2005
Serino, A., Alsmith, A., Costantini, M., Mandrigin, A., Tajadura-Jimenez, A., Lopez, C., 2013. Bodily ownership and self-location: Components of bodily self-consciousness. Consciousness and Cognition 22, 1239–1252. doi:10.1016/j.concog.2013.08.013
Serino, A., Bassolino, M., Farnè, A., Làdavas, E., 2007. Extended Multisensory Space in Blind Cane Users. Psychological Science 18, 642–648. doi:10.1111/j.1467-9280.2007.01952.x
Serino, A., Canzoneri, E., Avenanti, A., 2011. Fronto-parietal Areas Necessary for a Multisensory Representation of Peripersonal Space in Humans: An rTMS Study. Journal of Cognitive Neuroscience 23, 2956–2967. doi:10.1162/jocn_a_00006
Serino, A., Canzoneri, E., Marzolla, M., di Pellegrino, G., Magosso, E., 2015a. Extending peripersonal space representation without tool-use: evidence from a combined behavioral-computational approach. Front. Behav. Neurosci. 9. doi:10.3389/fnbeh.2015.00004
Serino, A., Noel, J.-P., Galli, G., Canzoneri, E., Marmaroli, P., Lissek, H., Blanke, O., 2015b. Body part-centered and full body-centered peripersonal space representations. Scientific Reports 5. doi:10.1038/srep18603
Serino, A., Pizzoferrato, F., Làdavas, E., 2008. Viewing a Face (Especially One’s Own Face) Being Touched Enhances Tactile Perception on the Face. Psychological Science 19, 434–438. doi:10.1111/j.1467-9280.2008.02105.x
Seth, A.K., 2013. Interoceptive inference, emotion, and the embodied self. Trends in Cognitive Sciences 17, 565–573. doi:10.1016/j.tics.2013.09.007
Seth, A.K., Friston, K.J., 2016. Active interoceptive inference and the emotional brain. Phil. Trans. R. Soc. B 371, 20160007. doi:10.1098/rstb.2016.0007
Sforza, A., Bufalari, I., Haggard, P., Aglioti, S.M., 2010. My face in yours: Visuo-tactile facial stimulation influences sense of identity. Soc Neurosci 5, 148–162. doi:10.1080/17470910903205503
Spence, C., Pavani, F., Maravita, A., Holmes, N., 2004. Multisensory contributions to the 3-D representation of visuotactile peripersonal space in humans: evidence from the crossmodal congruency task. Journal of Physiology-Paris, Representation of 3-D Space Using Different Senses In Different Species 98, 171–189. doi:10.1016/j.jphysparis.2004.03.008
Taffou, M., Viaud-Delmon, I., 2014. Cynophobic Fear Adaptively Extends Peri-Personal Space. Front. Psychiatry 5. doi:10.3389/fpsyt.2014.00122
Teneggi, C., Canzoneri, E., di Pellegrino, G., Serino, A., 2013. Social modulation of peripersonal space boundaries. Curr. Biol. 23, 406–411. doi:10.1016/j.cub.2013.01.043
Tsakiris, M., 2010. My body in the brain: A neurocognitive model of body-ownership. Neuropsychologia, The Sense of Body 48, 703–712. doi:10.1016/j.neuropsychologia.2009.09.034
Tsakiris, M., 2008. Looking for myself: current multisensory input alters self-face recognition. PLoS ONE 3, e4040. doi:10.1371/journal.pone.0004040
Tsakiris, M., Schütz-Bosbach, S., Gallagher, S., 2007. On agency and body-ownership: Phenomenological and neurocognitive reflections. Consciousness and Cognition, Subjectivity and the Body 16, 645–660. doi:10.1016/j.concog.2007.05.012
Turkeltaub, P.E., Eden, G.F., Jones, K.M., Zeffiro, T.A., 2002. Meta-Analysis of the Functional Neuroanatomy of Single-Word Reading: Method and Validation. NeuroImage 16, 765–780. doi:10.1006/nimg.2002.1131
Vagnoni, E., Lourenco, S.F., Longo, M.R., 2012. Threat modulates perception of looming visual stimuli. Current Biology 22, R826–R827. doi:10.1016/j.cub.2012.07.053
Van Damme, S., Gallace, A., Spence, C., Crombez, G., Moseley, G.L., 2009. Does the sight of physical threat induce a tactile processing bias?: Modality-specific attentional facilitation induced by viewing threatening pictures. Brain Research 1253, 100–106. doi:10.1016/j.brainres.2008.11.072
Van der Stoep, N., Nijboer, T.C.W., Van der Stigchel, S., Spence, C., 2015. Multisensory interactions in the depth plane in front and rear space: A review. Neuropsychologia 70, 335–349. doi:10.1016/j.neuropsychologia.2014.12.007
Wallace, M.T., Stevenson, R.A., 2014. The construct of the multisensory temporal binding window and its dysregulation in developmental disabilities. Neuropsychologia 64C, 105–123. doi:10.1016/j.neuropsychologia.2014.08.005
Cite This Work
To export a reference to this article please select a referencing stye below:
Related ServicesView all
Related ContentAll Tags
Content relating to: "Neurology"
Neurology is the specialist branch of medicine that deals with the treatment of disorders of the nervous system. This means that neurologists concern themselves with issues affecting the brain, the nerves, and the spinal cord.
Effects of TRPM2 Inhibition in Neuroprotection following Neonatal Hypoxic-Ischemic Brain Injury
Effects of TRPM2 Inhibition in Neuroprotection following Neonatal Hypoxic-Ischemic Brain Injury Abstract Neonatal hypoxic-ischemic (HI) brain injury is a major cause of acute mortality and chronic ...
Endoplasmic Reticulum Stress Response and Alzheimer’s Disease
Endoplasmic Reticulum Stress Response and Alzheimer’s Disease Abstract The endoplasmic reticulum is a vital organelle found in eukaryotic cells. It performs many functions from protein synthesis and...
DMCA / Removal Request
If you are the original writer of this dissertation and no longer wish to have your work published on the UKDiss.com website then please: