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One of the questions currently vexing researchers is whether peripersonal space is better conceptualized as being extended or as being projected following tool use? It may turn out that the answer to this question depends on what exactly the tool user must do with their tool. An equally important, if putatively orthogonal, issue concerns whether the effects of tool use are best conceptualized in terms of an attentional modification (i.e., prioritization) of a certain region of space (where the tool is being, or has been, used to perform an action) versus a change in spatial representation. While there is now an extensive body of evidence documenting tool use in a variety of animals, including recently in invertebrates, the focus of this chapter is primarily on the evidence collected from studies of tool use in humans and other primates. In particular, it reviews those studies that have used the cross-modal congruency task in order to investigate how the perception of peripersonal space changes during tool use. It also briefly compares these results to those that have emerged from neuropsychological research with clinical patients suffering from crossmodal extinction (i.e., from an impaired ability to report a stimulus on the contralesional side when it is presented at the same time as an ipsilesional stimulus).

This chapter outlines evidence of the existence of a visual peripersonal space in humans that seems to be codified by an integrated visuotactile system. It describes the evidence of the existence of the peripersonal space centered on the hand and on the face. It also examines the functional properties of this space. It then considers the dynamic aspect of the peripersonal space, i.e., whether this space is fixed or whether it can be expanded or reduced depending on the action performed in space. The data shows the existence of an integrated system controlling both visual and tactile inputs within peripersonal space around the face and the hand and demonstrates how this system is functionally separated from that controlling visual information in the extrapersonal space. Moreover, evidence indicates that the visual experience of the body can somehow ‘boost’ the signal strength to neuronal circuits associated with the feel-touch experience. Furthermore, results illustrate that sight of the body part improves perception of visual stimuli presented in the peripersonal space.

This chapter introduces a model which connects representations of the space surrounding a virtual humanoid’s body with the space it shares with several interaction partners. This work intends to support virtual humans (or humanoid robots) in near space interaction and is inspired by studies from cognitive neurosciences on the one hand and social interaction studies on the other hand. We present our work on learning the body structure of an articulated virtual human by using data from virtual touch and proprioception sensors. The results are utilized for a representation of its reaching space, the so-called peripersonal space, a concept known from cognitive neuroscience. In interpersonal interaction involving several partners, their peripersonal spaces may overlap and establish a shared reaching space. We define it as their interaction space, where cooperation takes place and where actions to claim or release spatial areas have to be adapted, to avoid obstructions of the other’s movements. Our model of interaction space is developed as an extension of Kendon’s F-formation system, a foundational theory of how humans orient themselves in space when communicating. Thus, interaction space allows for measuring not only the spatial arrangement (i.e. body posture and orientation) between multiple interaction partners, but also the extent of space they share. Peripersonal and interaction space are modelled as potential fields to control the virtual human’s behaviour strategy. As an example we show how the virtual human can relocate object positions toward or away from locations reachable for all partners, thus facilitating cooperation in an interaction task.

Human perceptual and attentional systems operate to help us perform functional and adaptive actions in the world around us. In this review, we consider different regions of peripersonal space—peri-hand space, reachable space, and tool space when used in both peri- and extrapersonal space. Focusing on behavioural and electrophysiology/event-related potentials (EEG/ERP) studies using comparable target detection paradigms, we examine how visuospatial attention is facilitated or differentiated due to the current proximity and functional capabilities of our hands and the tools we hold in them. The functionality of the hand and tool is defined by the action goals of the user and the available functional affordances or parts available to achieve the goals. Finally, we report recent tool-use studies examining how the distribution of attention to tool space can change as a result of tool functionality and directional action crossing peripersonal and extrapersonal space boundaries. We propose that the functional capabilities of the hand and tools direct attention to action-relevant regions of peripersonal space. Although neural mechanisms such as bimodal neurons may enhance the processing of visual information presented in near-hand regions of peripersonal space, functional experience and the relevance of the space for upcoming actions more strongly direct attention within regions of peripersonal space. And, while some aspects of functionality can be extended into extrapersonal space, the multimodal nature of peripersonal space allows it to be more modifiable in the service of action.

To our introspection, space appears as a unitary, continuous, and uniform container for objects and events. In this chapter, we show that behind this impression are in fact multiple representations of space tied to multisensory and motor processes. Information about space is coded in profoundly different ways within visual, auditory, and somatosensory channels, yielding a multitude of spatial maps in the brain with completely different frames of reference. These maps need to be coordinated and brought into register within and across sensory channels to yield separate representations for personal, peripersonal, and distant space. The boundaries of these spatial representations are plastic, and can be modified by multisensory and sensorimotor processes and by the use of tools. Data from psychophysics, neurophysiology, and neurological patients are now beginning to identify the brain mechanisms behind these fascinating perceptual mechanisms at the subcortical and cortical levels.

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

Mirror neurons located in area F5 of the monkey encode specific goal-directed motor acts. Recent studies have shown that the discharge of many mirror neurons in this area is influenced by the location of the observed action, relative to the observer. Some neurons discharge selectively when the action is executed in the monkey’s peripersonal space, and others do so only if the action is performed in the monkey’s extrapersonal space. In this chapter the literature on the relation between the activity of mirror system in monkeys and humans and the location of the action in space is reviewed. It is concluded that, far from undermining the role of mirror neurons in cognition, this selectivity sheds new light on how deeply one’s own motor processes and representation are involved in understanding others’ actions.

Peripersonal space (PPS) is a dynamic representation of the space around the body subserving primarily the organization of goal-directed behaviours towards stimuli with the highest reward value. It must also be viewed as a space where potentially harmful stimuli receive specific attention in order to protect the body from the hazards ahead. In the present chapter, we will highlight the anticipatory motor nature of PPS representation and its dynamic properties. We will also show that stimuli in PPS receive particular attention that fosters perceptual and cognitive processes. Finally, we will propose that PPS serves as a mediation zone between the body and the environment, protecting the body from external threats and, as such, contributing to the organization of the social life.

Peripersonal space is defined as the space surrounding the body, which we can interact with and act upon. It has been hypothesized to play a key functional role in body representation and in the definition of a safety boundary around the body. More recently, growing evidence suggests that this space is dynamically resized both as a function of internal states such as anxiety or as a function of external contingencies such as social interactions or goal-directed actions. In the following review, we will review seminal and recent work in both human and non-human primates, describing the functional cortical networks involved in the coding of body margin (the skin), peripersonal space (around the body) and far space (away from the body), and we will describe how these networks are recruited during the prediction of an impact to the body (near the skin). We will propose a functional perspective to recent evidence for multiple behaviourally dissociable peripersonal spaces, and discuss the putative neuronal and network mechanisms that could account for the observed dynamic resizing of peripersonal space.

Research in neuroscience reveals that the brain constructs multiple representations of space. Here, we primarily focus on interpersonal representation—i.e. the region of space immediately surrounding our body, in which we interact with other people, in individuals with a deficit of social interaction, such as autism. We review results from several studies, revealing that autism affects the interpersonal space regulation, influencing both its size (permeability) and its changes depending on social interaction (plasticity). Indeed, individuals with autism prefer larger or shorter interpersonal space compared to healthy controls, thereby indicating a deficit of interpersonal space permeability. Furthermore, individuals with autism fail to modify their interpersonal space following a brief cooperative interaction with an unfamiliar adult, suggesting a deficit in interpersonal space plasticity. Interestingly, the deficit observed in interpersonal space plasticity depends on the person’s perspective and reflects the severity of social impairment. Finally, the link between social competence, action, and space is addressed, showing that autism affects social-interpersonal space, but not action-peripersonal space.

This chapter shows that multiple sensory information sources can generally be integrated in a similar fashion. However, seeing that different modalities are grounded in different frames of reference, integrations will focus on space or on identities. Body-relative spaces integrate information about the body and the surrounding space in body-relative frames of reference, integrating the available information across modalities in an approximately optimal manner. Simple topological neural population encodings are well-suited to generate estimates about stimulus locations and to map several frames of reference onto each other. Self-organizing neural networks are introduced as the basic computation mechanism that enables the learning of such mappings. Multisensory object recognition, on the other hand, is realized most effectively in an object-specific frame of reference – essentially abstracting away from body-relative frames of reference. Cognitive maps, that is, maps of the environment are learned by connecting locations over space and time. The hippocampus strongly supports the learning of cognitive maps, as it supports the generation of new episodic memories, suggesting a strong relation between these two computational tasks. In conclusion, multisensory integration yields internal predictive structures about spaces and object identities, which are well-suited to plan, decide on, and control environmental interactions.

The neuroscientific approach to peripersonal space (PPS) stems directly from electrophysiological studies assessing the response properties of multisensory neurons in behaving non-human primates. This multisensory context fostered frameworks which i) stress the PPS role in actions (including defensive reactions) and affordances, which are optimally performed through multiple sensory convergence; and ii) largely make use of tasks that are multisensory in nature. Concurrently, however, studies on spatial attention reported proximity-related advantages in purely unisensory tasks. These advantages appear to share some key PPS features. Activations in brain areas reported to be multisensory, indeed, can also be found using unimodal (visual) paradigms. Overall, these findings point to the possibility that closer objects may benefit from being processed as events occurring in PPS. The dominant multisensory view of PPS should therefore be expanded accordingly, as perceptual advantages in PPS may be broader than previously thought.

Work in both animals and humans has demonstrated that the brain specifically tracks the space near the body—the so-called ‘peripersonal space’ (PPS). These representations appear to be multimodal and expressed in body-centred coordinates. They also play an important role in defence of the body from threat, manual action within PPS, and the use of tools—the latter, notably, ‘extending’ PPS to encompass the tool itself. Yet different authors disagree about important aspects of these representations, including how many there are. I suggest that the questions about the nature and number of PPS representations cannot be separated from the question of the mathematical basis of the corresponding representational spaces. I distinguish cartographic from functional bases for representation, suggesting that the latter provides both a plausible account and support a single-representation view. I conclude with reflections on functional bases and what they show about representation in cognitive science.

The brain evolved to give special representation to the space immediately around the body. One of the most obvious adaptive uses of that peripersonal space is self-protection. It is a safety buffer zone, and intrusions can trigger a suite of protective behaviours. Perhaps less obvious is the possible relationship between that complex protective mechanism and social signalling. Standing tall, cringing, power poses and handshakes, even coquettish tilts of the head that expose the neck, may all relate in some manner to that safety buffer, signalling to others that one’s protective mechanisms are heightened (when anxious) or reduced (when confident). Here I propose that some of our most fundamental human emotional expressions such as smiling, laughing, and crying may also have a specific evolutionary relationship to the buffer zone around the body, deriving ultimately from the reflexive actions that protect us.

In his personal essay On Peripersonal Space, Brian Blanchfield uses the concept of peripersonal space-the entire volume of space within a person's reach, or within a single conceivable momentary extension of his person-as a metaphor to explore the complicated relationship with his mother both throughout childhood and after coming out as gay in adulthood.

How are the sense of ownership and the sense of agency related? Does one need to be able to control one’s body to experience it as one’s own? One may suggest that the sense of bodily ownership is grounded in action-orientated representations of the body. However, this agentive hypothesis cannot explain how one can experience as one’s own a rubber hand that is not under control, while not experiencing as one’s own tools that are under control. The chapter then argues that one needs to distinguish between two kinds of hot body maps: the working body map involved in instrumental actions, and the protective body map involved in self-defence. It is proposed that one experiences as one’s own the body represented in the protective body map, which represents the body that has a special significance for the evolutionary needs of the organism.

Touch gives us tactile sensations that inform us of events that happen in and on our bodies (T), and haptic perception of things with which we are in direct or indirect contact (i.e. through intervening objects) (H). In the first part of this paper, I argue that these are distinct mental states (i.e. that T≠H). My strategy is to establish a double dissociation between T and H. Thus, it is possible to have similar sequences of tactile sensations T1 and T2, such that one yields a haptic perception and the other does not. And it is also possible to have the same haptic perception through different sequences of tactile sensations. This contradicts the idea that the switch from touch-awareness of one’s own body and touch-awareness of external objects is merely attentional: that being aware of something that you are touching is merely a matter of attending to your own body, but in a different way. In the second part of the chapter, I argue that tactile sensation does not represent space, but rather represents the relationships among parts of the body. This argument involves a reinterpretation of experimental results regarding touch-awareness by Patrick Haggard and co-workers.

How do bodily experiences get a rich spatial content on the basis of the limited information carried by bodily senses? This chapter argues that one needs a map of the body, which represents its enduring properties (i.e. configuration and dimensions). This representation can be decoupled from the biological body leading the subject to experience sensations not only in phantom limbs but also in tools that bear little visual resemblance with the body. Does it entail that there is almost no limit to the malleability of the body map? Or that bodily sensations can be felt even beyond the apparent boundaries of the body, in peripersonal space, and possibly even farther? This chapter examines a series of cases that may cast doubt on the role of the body map for the localization of bodily sensations.

This chapter presents the authors’ view of the future, discussing new digital technologies and mediations and their impact on film and its reception. The subheadings are: “New positioning,” a discussion of the future of film and cinema in the light of new and emerging technologies and the few empirical studies addressing these issues; “Digital presences,” an overview of how the authors’ model can help in formulating new theoretical and empirical approaches; “Death by chat,” an analysis of the film Unfriended with a discussion of how new mediations of filmic content reshape the spectator’s relation to film; “A new film grammar,” which introduces action cams and their impact on film viewing; and “Goodbye to the screen?” which envisions how the new filmic mediation may generate a new form of film reception.