Sense and Space
Tactile Object and Embodied Subject
Tony H. Y. Cheng
This talk starts with an empirical vindication of tactile field with the resources from various studies done by Patrick Haggard’s lab. The basic idea is that the tactile field supports computation of spatial relations between individual stimulus locations, and thus underlies tactile pattern perception. Perception of spatial patterns across the field is linked to a structural representation of one’s own body. Tactile pattern judgements depend on secondary factors over and above local tactile perceptual ability at the stimulated locations (section 1). While the nociceptive sense is neither exteroceptive nor object-directed, the thermal sense is exteroceptive but not object-directed, and the tactile sense is both exteroceptive and object-directed (Mancini et al. 2015, Marotta et al. 2015). The basic idea is that estimating distances between stimuli on the skin requires a metric representation of spatial relations, which underlies abilities of perceiving the size of external objects. Both the nociceptive sense and the thermal sense are poorly in estimating distances like this, but the tactile sense is much better in this regard thanks to the operation of tactile field (section 2). It will then be argued that contra O’Shaughnessy (1989) and Martin (1992), touch is intrinsically spatial thanks to the operation of tactile field. More specifically, exactly because tactile field brings us tactile objects as well as their spatial properties such as size, the spatiality of touch is intrinsic to the tactile sense itself (section 3). And finally, it will be discussed how we are aware of our bodies as physically as well as physiological objects. In this sense, tactile pattern perception presupposes a self that is an object embedded in the world, rather than simply a viewpoint on the world (Merleau-Ponty 1962, McDowell 1996).
Space and Phenomenal Presence
In visual perception things are experienced as really being there, present before the eyes. I’ll call this feature “phenomenal presence” (PP). (Other labels are feeling (or sense) of presence (Dokic 2012, Dokic/Martin 2012), feeling of reality (Farkas 2014), Leibhaftigkeit (Husserl 1907, Jaspers 1911).) Whereas imagery and pictorial seeing typically lack PP, many cases of hallucination do display it. So reflection on these different cases is arguably crucial for developing a comprehensive account of PP. Matthen (2005, 2010), who only focuses on seeing and pictorial seeing, has argued that PP depends on the kind of spatial cognition subserving (dorsal) motor-guiding vision. Though I also believe that certain spatial features of seen objects play an important role in explaining PP in the visual case, I think that Matthen’s proposal is untenable. The goal of this paper is to offer an alternative, attention-based explanatory account. (The account is “explanatory” because it remains neutral about the nature of PP, i.e. whether it is a phenomenal property of experience, some kind of doxastic attitude (Farkas 2014), a cognitive feeling (Dokic 2012, Dokic/Martin 2012), or some other thing). First, I shall present decisive empirical evidence (regarding, in particular, cases of dissociation between dorsal and ventral vision and a certain type of auditory hallucinations) against Matthen’s account. Second, I shall argue that PP is basically a matter of object-based attention by considering how perception and hallucination work both in the visual and in the auditory cases. Third, I shall argue that the case of pictorial seeing shows that, for the visual case, a purely attentional model needs to be complemented by reflection on spatial experience. Against Matthen, I shall defend the claim that the critical factor here is not motor-guiding spatial cognition, but rather whether visual objects are consciously experienced as voluminous.
Acquaintance, Spatial Properties and the Explanatory Gap
Of the many possible motivations for Naïve-Realism, one that has received relatively little discussion is the theory’s alleged ability to help solve the ‘Explanatory Gap’ – e.g. Fish (2008, 2009), Langsam (2011). I provide a reformulation of this general line of thought that makes clearer how and when a Relational theory of perceptual experience could help to explain the specific phenomenal nature of such experience. In particular, I show how and why this form of explanation will work best for the case of visual shape phenomenology rather than colour phenomenology. I also argue that the relational theory can give a natural explanation for why we should expect colour phenomenology to remain less readily intelligible than shape phenomenology.
Joint Experience, Demonstrative Reference, and Sense of Space
In this talk I consider the question of how to think about the kind of spatial experience that is necessary to make and understand demonstrative utterances in joint perceptual constellations. I take this ability to depend on the subjects’ common knowledge of which object they are demonstratively identifying. The problem is to spell out what this knowledge amounts to in joint cases. I argue that it presupposes the ability to draw what I call the ‘foundational distinction’ between subjects and objects, and suggest that this ability informs the capacity for perspective-taking. I consider some work in developmental psychology to shed light on the connection between the spatial sense of perspective and the social character of the environment in which a range of perspectives on a visually given object are available.
Do We Experience Cross-Modal Spatial Illusions?
Cross-modal illusions make up one of the main sources of evidence we have for perceptual processing being multisensory. These illusions are taken to show that, at the very least, processing in a sensory system associated with experience in one sense modality can influence what we experience in another sense modality. In this paper I query whether we have evidence that this takes place, focusing on a particular cross-modal illusion: the spatial ventriloquism effect. The ventriloquism effect is measured by measuring cross-modal biasing of localization. I suggest that we can explain the cross-modal biasing effect in terms of the recalibration of the mapping between sensory and motor reference frames. This explains the biasing effect in terms of how one is liable to respond to what one hears, and not in terms of changes to what one experiences in vision or audition.
Oral referral is central to multisensory flavour perception. The phenomenon, first described a little over a century ago, is characterized by the mislocalization of food-related olfactory stimuli to the oral cavity. Many researchers believe that it contributes to the widespread confusion concerning which sense really provides the information that is bound together in flavour percepts. In this review, evidence supporting the role of a number of factors that have been suggested to modulate oral referral, including tactile capture of olfaction, the relative timing of olfactory and gustatory stimuli, and gustatory capture (possibly involving prior entry) is critically evaluated. The latest findings now support the view that the oral referral of orthonasal aroma (what some have chosen to call orthonasal location binding) is modulated by taste intensity, while for retronasal odours, it is the congruency between the ordour-taste(s) pairing that is key. Specifically, the more congruent a particular combination of olfactory and gustatory stimuli, the more likely the component unisensory stimuli will be bound together as a flavour object (or Gestalt) and, as a result, localized together to the oral cavity. The possible roles of attention, attentional capture, and the nutritional significance of the taste in the phenomenon of oral referral are also reviewed. Ultimately, the suggestion is made that oral referral may reflect a qualitatively different kind of multisensory interaction.
Gombrich and the Dual Content Theory of Pictorial Experience
A number of philosophers have maintained that everyday visual experience comprises two distinct ‘layers’ or ‘folds’ of representational content. The content of the first layer represents viewpoint-dependent appearances or ‘looks’, where these are typically taken to be phenomenally 2D in character. The second layer of content, in contrast, is supposed to represent intrinsic, viewpoint-independent properties as well as distance in depth. Pictorial perception is arguably the best case for this dual content theory of visual experience, since a picture really is a flat patchwork of colors that, when present to sight, elicits the experience of depth and 3D structure. One of E.H. Gombrich’s main aims in Art and Illusion is to demonstrate that the theory fails even as an account of pictorial experience. In defending this assessment, I show that two of the better known attempts to eliminate the appearance of paradox at the heart of the dual content theory of pictorial experience are unsuccessful. The two putative layers of representational content in pictorial experience, I conclude, aren’t merely different. As Gombrich insists, they are also incompatible.
Space and Spatial Direction in Olfactory Experience
Accommodating the fact that the location of the nose puts a restriction on olfactory experiences need not involve succumbing to the idea that we in olfaction only can be aware of the location where the nose is. I argue that in those of our olfactory experiences where the concentration of the odours is significantly lower than usual, an awareness of a larger space is integral to our experience. Moreover, I suggest that if olfactory experiences include experiences over time, as well as experiences at a time, there can be olfactory awareness of spatial direction.
Spatial Awareness and the Chemical Senses
It’s widely assumed that the chemical senses are proximal or contact senses, telling us about ourselves, not about the spatial world around us. That’s because experiences, like those of taste and smell, are conceived as mere sensations rather than perceptions of anything external to us. This is a mistaken view of the chemical senses, which also leaves out the role of spatial awareness in our experiences of taste, smell and flavour. I shall argue for the spatial dimension of these sensory experiences by reference to, among other things, key spatial illusions they can give rise to.
Spatial Representations of Vision and Touch in Early Life
Jannath Begum Ali
When we feel a touch, we do not simply locate that sensation on the body surface, but also in external space. The “crossed-hands effect”, a deficit in the localisation of tactile stimuli to the hands when they are placed in the crossed-hands posture, has been used as a marker of the influence of an external frame of reference for localising touch; it is considered to arise out of conflict (when the hands are crossed) between the anatomical and external (non-anatomical) frames of reference within which touches can be perceived. Because early visual experience is implicated in the development of an external frame of reference I will also report on a study in which the development of an ability to perceive visual and tactile stimuli in a common spatial location was examined.
Unseen Colour Constancy and the Relationship between Sensation and Perception of the External World
What are ‘sensation’ and ‘perception’? A pervasive view, held by most since the Ancient Greeks, is (with some variation in the details) that sensations are conscious experiences of the effects that stimuli from the outside world have on our sense organs and that, from these sensations, we arrive a model of the objects in the outside world that are likely to have elicited those sensations – our percepts of the external world. Critically, perception depends upon sensation. Recent experiments on colour perception suggest that this is not the case. My colleagues and I showed that percepts of colour as a property of objects in the world influence behaviour despite being unseen. They do so in a consistent manner even under changes in lighting suggesting that it is an unconscious representation of the colour of an object, rather than the effect of the object on sense organs (which will change with changes of lighting), that is driving behaviour. As subjects have no conscious experience of the object they must have constructed a perceptual representation of it that is not derived from sensation.
Looking before Seeing: Directing Visual Attention by the Primary Visual Cortex
Visual attention limits the amount of visual inputs for detailed processing since
the brain has limited resources. We mainly direct our attention by directing our gaze to attended spatial locations. Traditional wisdom presumes that brain areas at or near the front of the brain are in charge of directing visual attention.
I show that for exogenous attentional guidance, i.e., attention guided by external visual inputs rather than internal goal, the primary visual cortex is responsible. Hence, attention can be directed to locations before objects at those locations are seen or recognized. I will show some data as well as a demo.
The Two-Visual-Systems Hypothesis and the Perspectival Intuition
In a recent article, Berit Brogaard (2012) argues that the two-visual-systems hypothesis (TVSH) (Goodale & Milner, 1992) is incompatible with the perspectival claim. This raises a problem for psychofunctionalists, who hold that the best answer to the question of what it is to instantiate a particular mental state will be provided by our best cognitive psychological theories. Given that the perspectival claim seems to capture a fundamental feature of our visual experience, Brogaard concludes that we should reject a central claim of the TVSH that is incompatible with the perspectival claim.In this article, I argue that there is no conflict between the TVSH and the perspectival claim. As such, the psychofunctionalist can maintain both the TVSH and the perspectival claim without fear of inconsistency. In what follows, I first outline Brogaard’s argument. I then argue that the apparent tension between the dissociation hypothesis and the perspectival claim results from an ambiguity in the use of the terms ‘allocentric’ and ‘egocentric’. Finally, I argue that dorsal stream processing is not the right kind of processing to explain egocentric features of conscious visual experience.
A Sense of Body Ownership
Hong Yu Wong
Our bodies and our sense of embodiment are critical to our sense of ourselves as material beings (Cassam 1997, Longuenesse 2006). One prominent strand of research on embodiment concerns the sense of ownership that we have over our bodies. The key questions are how to understand this sense of ownership, and what its function is. I begin by characterising the sense of body ownership and its relation to basic forms of bodily awareness, such as proprioception (Martin 1995, de Vignemont 2007, Peacocke 2014). A major issue is the shape of a constitutive account and its status with respect to pathologies where it is compromised, such as somatoparaphrenia and alien limb syndrome (Vallar and Ronchi 2009, de Vignemont 2007 and 2011). In this talk, I will sketch an account of body ownership that diverges from the three major accounts.
Ebbinghaus Illusion Seems to Deceive Literates but not Non-literates
Theory of Mind development is dependent on the maturation of several brain systems and is shaped by parenting, social relations, schooling, and education. The emerging field of social neuroscience has also begun to address this debate, by imaging humans while performing tasks demanding the understanding of an intention, belief or other mental state. Studies about the effects of context on size perception have given rise to extensive debates concerning the conditions under which illusion effects occur and how they are to be interpreted, under the Theory of Mind scope. In this essay I will assess the effect of an illusory symbolic system, the Ebbinghaus illusion, in children and in non-human primates. My aim is to understand whether the deceiving induced by Ebbinghaus illusion could be correlated with literacy. I will start by reviewing the literature on the physiological and functional impact of literacy in the brain, and then I will assess object recognition in Ebbinghaus illusion in non-human primates and in non-literate children. These two groups are chosen due to its mental age and non-literacy. The hypothesis is that this illusion deceives literate but non-literate. I expect this to be possible in virtue of Dahaene’s Neuronal Recycling Hypothesis. Moreover, this process could be similar to the mirror invariance process.
ROBO-GUIDE: Autonomous Navigation of Dynamic Spatial and Social Environments
David Cameron, Jonathan M. Aitken, Luke Boorman, Adriel Chua, Emily C. Collins, Samuel Fernando, Uriel Martinez-Hernandez, Owen McAree, & James Law.
Assistive robots will need to seamlessly integrate into environments that have been expressly designed with human-use in mind. For mobile robots, this not only comprises accurate perception and reliable navigation of the spatial environment but also effective social communication in shared-space social environments. ROBO-GUIDE (ROBOtic GUidance and Interaction DEvelopment) is an interdisciplinary project, bringing together psychology, natural language, computational neuroscience, control systems, and formal verification to address how mobile robots can successfully perceive and operate in human-focused spatial and social environments.
Two-Sided Map: A Critical Study of Geography 2.0
Traditionally, cartography was a mean to create maps for orientation. Right now, in a map is included statistical, demographic and economic information. In the near future, maps will be generated in a highly personalized way, highlighting places frequented by our social network friends, places that we have talked about in the emails or places we have looked for in the search engines. This up-to-date scenery could be interpreted in two different was. On the one hand, Google’s representation of space is deeply conservative and backward-looking. Places that we have never searched online – or for which we have never shown interest – would be rather more difficult to be visualized. On the other hand, an online map shows us that space is not a passive «out there» condition, a sort of substance that exists only outside. space is a human creation, a kind of internal-external relationship. The aim is to explore these different approaches.