Alva Noë
580 California St., Suite 400
San Francisco, CA, 94104
Real Presence
2005, Philosophical Topics
https://doi.org/10.5840/PHILTOPICS20053319visibility
…
link
1 file
Sign up for access to the world's latest research
checkGet notified about relevant papers
checkSave papers to use in your research
checkJoin the discussion with peers
checkTrack your impact
Abstract
When you approach an object, it looms in your visual field. When you move around it, its profile changes. In these and many other ways, how things look depends on what you do. Competent perceivers are not surprised by these changes in appearance as they move. Of course, objects don't usually appear to grow as we approach them; nor does it look as though they change their shape when we move. Perceptual constancy-size and shape constancy-coexists with perspectival nonconstancy. Two tomatoes, at different distances from us, may visibly differ in their apparent size even as we plainly see their sameness of size; a silver dollar may look elliptical-when we view it from an angle, or when it is tilted in respect of us-even though it also looks, plainly, circular.
Related papers
On Perceptual Presence
Phenomenology and the Cognitive Sciences, 2011
In his book Action in Perception, Alva Noë poses what he refers to as the “problem of perceptual presence” and develops his enactive view as solution to the problem. Noë describes the problem of perceptual presence as the problem of how to conceive of the presence of that which, “strictly speaking,” we do not perceive. I argue that the “problem of perceptual presence” is ambiguous between two problems that need to be addressed by invoking very different resources. On one hand, there is the problem of how to conceive of the presence of objects as wholes, front side and back, and their constant properties. On the other hand, there is the problem of how to account for the presence of unattended detail. I focus on the first problem, which Noë approaches by invoking Husserlian ideas. I argue that Noë’s enactive view encounters difficulties, which can be dealt with by complementing it with Edmund Husserl’s idea of fulfillment and generally restoring the view to its original Husserlian context. Contrary to Noë’s purport, this involves regarding the view not as a theory of perception and perceptual content but as part of a descriptive-clarificatory project of conceptual analysis. The Husserlian phenomenologist analyzes, e.g., the concept of shape or color by investigating the fulfillment conditions pertinent to shape or color. In general, my critique of Noë’s enactive view serves to caution philosophers against unprincipled uses of Husserlian ideas.
Accommodation and Size-Constancy of Virtual Objects
Annals of Biomedical Engineering, 2008
Accommodation has been suspected as a contributor to size illusions in virtual environments (VE) due to the lack of appropriate accommodative stimuli in a VE for the objects displayed. Previous experiments examining size-constancy in VE have shown that monocular cues to depth that accompany the object are a major contributor to correct size perception. When these accompanying cues are removed perceived size varied with the object's distance from the subject, i.e., visual angle. If accommodation were the dominant mechanism contributing to a visual angle response [due to its action to keep physical objects clear] in this condition, an open-loop accommodation viewing condition might restore size-constancy to this condition. Pinhole apertures were used to open-loop accommodation and examine if size-constancy might be restored when few accompanying monocular cues to depth were present. Visual angle performance when viewing a low cue environment was found with and without the use of the pinhole apertures. Thus, these results signify that accommodation does not play a dominate role in the loss of size-constancy in sparse visual environments often used in VE. These results suggest that size-constancy is driven by the inclusion of the remaining monocular cues to depth in VE as it is in the physical world.
Spatial-Perceptual Constancies
Discussion of spatial-perceptual constancies has loomed large in recent philosophy, due in part to and . To evaluate lessons drawn from constancy achievements it is important to understand what perceptual constancy is and how and when it is gained. I start by clarifying the subtle picture of perceptual constancy at work in perception science. As an illustrative example, I work through the empirical study of perceived object or surface shape. I then address the question of whether non-view-defined, 'objective' spatial (shape, size, slant, etc.) properties are represented in perceptual experience (the view of many perception scientists), or whether 'objective' shape, size, slant etc. are only represented post-perceptually--in (say) perceptual judgments derived from shifting shape (size, slant, etc.) 'appearances' (the view of many philosophers). I close by considering how accurate spatial-perceptual experience is-addressing methodological challenges faced in assessing spatial experience accuracy.
Presence in response to dynamic visual realism: A preliminary report of an experiment study
2006
This paper describes an experiment that examines the influence of visual realism on reported presence. 33 participants experienced two different renderings of a virtual environment that depicts a pit in the centre of a room, in a head-tracked head-mounted display. The environment was rendered using parallel ray tracing at 15fps, but in one condition ray casting (RC) was used achieving a result equivalent to OpenGL based per-pixel local illumination, and in the second full recursive ray tracing (RT). The participants were randomly allocated to two groups -one that experienced RC first followed by RT, and the second group in the opposite order. Reported presence was obtained by questionnaires following each session. The results indicate that reported presence, in terms of the 'sense of being there' was significantly higher for the RT than for the RC condition.
Related topics
Cited by
The structure of sensorimotor explanation
Synthese, 2017
distinguish two groups of theories of visual perception: orthodox and heterodox theories. The orthodoxy states that visual perception is a process whereby the brain builds up detailed representations of the environment on the basis of the sensory inputs delivered by receptors (2005, p. 2). The most obvious example of orthodoxy is computational approach, which characterizes visual perception as information processing at three distinct stages of representations, from the primal sketch to 3D representations (cfr. also Frisby & Stone 2007). In contrast with the orthodoxy, heterodox approaches usually reject or downplay the role of representations in visual perception. Paradigmatic examples of such theories are Gibson's (1979) ecological optics, Ballard's (1991) animate vision, and O'Regan & Noë (2001ab) sensorimotor theory (SMT). Defenders of the sensorimotor theory maintain that visual perception is constituted by the active exercise of our sensorimotor skills that obey a set of specific sensorimotor laws (cfr.
The unity of consciousness, within subjects and between subjects
Philosophical Studies, 2016
The unity of consciousness has so far been studied only as a relation holding among the many experiences of a single subject. I investigate whether this relation could hold between the experiences of distinct subjects, considering three major arguments against the possibility of such 'between-subjects unity'. The first argument, based on the popular idea that unity implies subsumption by a composite experience, can be deflected by allowing for limited forms of 'experience-sharing', in which the same token experience belongs to more than one subject. The second argument, based on the phenomenological claim that unified experiences have interdependent phenomenal characters, I show to rest on an equivocation. Finally, the third argument accuses between-subjects unity of being unimaginable, or more broadly a formal possibility corresponding to nothing we can make sense of. I argue that the familiar experience of perceptual co-presentation gives us an adequate phenomenological grasp on what between-subjects unity might be like. Keywords Unity of consciousness Á Consciousness Á Philosophy of mind Á Phenomenology Á Metaphysics Á Experiences Á Perception Á Mereology 1 Introducing between-subjects unity Much recent discussion of consciousness has focused on its unity, the way that our many experiences are somehow had together, forming a single integrated conscious field. When I see the screen in front of me, hear the sound of traffic, and reflect on & Luke Roelofs
Seeing the Invisible: How to Perceive, Imagine, and Infer the Minds of Others
Erkenntnis, 2017
The psychology and phenomenology of our knowledge of other minds is not well captured either by describing it simply as perception, nor by describing it simply as inference. A better description, I argue, is that our knowledge of other minds involves both through 'perceptual co-presentation', in which we experience objects as having aspects that are not revealed. This allows us to say that we perceive other minds, but perceive them as private, i.e. imperceptible, just as we routinely perceive aspects of physical objects as unperceived. I discuss existing versions of this idea, particularly Joel Smith's, on which it is taken to imply that our knowledge of other minds is, in these cases, perceptual and not inferential. Against this, I argue that perceptual co-presentation in general, and mind-perception in particular, yields knowledge that is simultaneously both perceptual and inferential.
Enactivism and the Perception of Others’ Emotions
Midwest Studies In Philosophy, 2017
2. The latter proposals are roughly those offered by so-called "theory-theorists" and "simulation theorists," respectively. For contemporary phenomenologists pressing the argument just outlined, see (e.g.) Gallagher (2008), Krueger (2012), Ratcliffe (2007), Zahavi (2011). Krueger (forthcoming) provides a lucid summary of the debates surrounding DSP.
Spatial perception: The perspectival aspect of perception
Philosophy Compass, 2017
When we perceive an object, we perceive the object from a perspective. As a consequence of the perspectival nature of perception, when we perceive, say, a circular coin from different angles, there is a respect in which the coin looks circular throughout, but also a respect in which the coin's appearance changes. More generally, perception of shape and size properties has both a constant aspect-an aspect that remains stable across changes in perspective-and a perspectival aspect-an aspect that changes depending on one's perspective on the object. How should we account for the perspectival aspect of spatial perception? We present a framework within which to discuss the perspectival aspect of perception and put forward three desiderata that any account of the perspectival aspect of perception should satisfy. We discuss views on which the perspectival aspect of perception is analyzed in terms of constitutively mind-dependent appearance properties as well as views on which the perspectival aspect of perception is analyzed in terms of representations of mind-independent perspectival properties. 1 | INTRODUCTION When we perceive objects, we perceive them as having a multitude of spatial properties, including size, shape, and location. While the study of spatial perception has a distinguished history in philosophy, the topic has received relatively little recent attention compared with, say, the perception of color. This entry should help rectify this state of affairs. We will focus on a specific question about spatial perception, namely, the question of how to account for the perspectival aspect of perception. When we perceive an object, we perceive the object from a perspective. As a consequence, when we perceive a circular coin from different angles, there is a respect in which the coin looks circular throughout, but also a respect in which the coin's appearance changes. Likewise, when we perceive two trees of the same size located at different distances from us, there is a respect in which they look the same size, but also a respect in which they appear different
Magic Realism and the Limits of Intelligibility: What Makes Us Conscious*
Philosophical Perspectives, 2007
Perceptual experiences are widely believed to supervene narrowly on neural states and processes. Some philosophers and scientists find it natural to think that for every experience there is some specific neural state or process whose occurrence suffices for that state. Let's call this the Narrow Substrate thesis or Narrow Substrate, for short. One philosopher who endorses Narrow Substrate is Ned Block. He writes (Block 2005) that "nothing outside the brain" is "a metaphysically necessary part of a metaphysically sufficient condition of perceptual experience" (Block's italics). In making this claim, what is at stake, for Block, "is the issue of what is-and is not-part of the minimal metaphysically sufficient condition for perceptual experience (i.e. the minimal supervenience base)." 1 John Searle is also committed to Narrow Substrate. He writes: "Consciousness and other sorts of mental phenomena are caused by neurobiological processes in the brain, and they are realized in the structure of the brain. In a word, the conscious mind is caused by brain processes and is itself a higher level feature of the brain" (2000: 566). Some neuroscientists endorse Narrow Substrate. Christof Koch (2004), for example, discusses "the" NCC and defines this as "the minimal set of neuronal events and mechanisms jointly sufficient for a specific conscious percept" (16). He writes: "If there is one thing that scientists are reasonably sure of, it is that brain activity is both necessary and sufficient for biological sentience.. ." (section 1.4). 2 In this essay I present evidence that Narrow Substrate is false. Experiences are neural processes, to be sure; but they are not only neural processes. Perceptual experience depends constitutively on factors that are not neural. The substrates of perceptual consciousness are (in this sense) extended. Let's call this claim, which I believe to be true, the Extended Substrate thesis or Extended Substrate, for short. 458 / Alva Noë Kinds of Externalism Extended Substrate is a variety of philosophical externalism about the mind. I would like to say a word about this proposal in relation to other styles of externalism. According to content externalism, of the sort espoused by Hilary Putnam (1975) and Tyler Burge (1979), psychology does not supervene on internal constitution. That is, facts about a person's physical, neurophysiological, or phenomenological make-up do not fix the content of his or her thoughts. That you are now thinking about water, for example, depends on the character of your embedding in and causal history in relation to your environment; in particular, it depends on the fact that your current state bears some relation, however distal, to actual water. Content internalism does not deny that your thoughts about water are in the head. It denies that what is in your head alone suffices to make it the case that your thought is a water-thought. Content internalism can be thought of as a theory of how we individuate mental states. Compare thinking about water to sunburn (to give what is now a classic example). 3 Tissue damage of a specific physical kind doesn't suffice to make something a sunburn; for it to be a sunburn, it must have come about in the right, sun-involving way. Sunburn does not supervene on the intrinsic physical character of tissue damage alone, even though, as Wilson (1997) has stressed, the sunburn is literally on your skin. And so with mental states, according to content externalism. They are literally in your head, even though they wouldn't be what they are if not for the world-involving manner in which they have been produced in you. Vehicle externalists, in contrast with content externalists, challenge whether the physical substrates of mental states-their underlying realizations or mechanisms-are, as a matter of fact, literally in the head. 4 Clark and Chalmers (1998), for example, have urged that it is prejudice to think that the limits of the cognitive system must be those of the organism. Environmentally situated artifacts, symbols or tools-e.g. maps, landmarks, systems of writing, the abacus-may be no less inextricably linked with cognitive operations than what is internal. For example, the ability to perform long division may constitutively depend on the deployment of pencil and paper just as it requires the normal action of the brain. Or consider memory-based belief, a case Clark and Chalmers (1998) discuss at length. This kind of cognitive accomplishment consists, Clark and Chalmers suppose, in having an attitude of endorsement to a proposition encoded in memory to which one has quick and reliable access and which one acquired thanks to some normal belief-like process. Crucially, there is nothing in such a functional specification of "belief embedded in memory" that requires that the memory store itself be internal (in the brain, say) rather than external (in a notebook, say). Whether the performance specifications of memory could be taken over by an external information repository is an empirical question.
Related papers
Phenomenological Properties of Perceptual Presence: A Constructivist Grounded Theory Approach
Constructivist Foundations , 2021
Context • Perceptual presence is the experience wherein veridical objects are experienced as belonging to an observer-independent world. > Problem • Experimental investigations of perceptual presence are rare. It may be that the standard conceptualizations of perceptual presence are not suitable for experimental operationalization. > Method • Using the framework of constructivist grounded theory, three observational perspectives (engaged, nearecological, and receptive) are employed to discern method-invariant phenomenological properties of perceptual presence. Inductive coding is used as a main analytical instrument. > Results • Four phenomenological properties of perceptual presence are constructed: perceptually present objects (a) appear inexhaustible in the amount of modal detail they contain; (b) are experienced as a particular arrangement of lived space; (c) allow for some and preclude other bodily interactions; and (d) are marked by a specific feeling of coupling. > Implications • Descriptions of lived experience of perceptual presence, in particular the structure of lived space, may further allow for the design of experiments that more precisely target individual properties of this phenomenon. > Constructivist content • Perceptual presence is conceived of as one of the main properties of consciousness: it is the experience of objects as belonging to an observer-independent world. Phenomenological properties contributing to how this sense of veridicality is constructed are presented.
Authors' Response: The Boundaries and Frontiers of Perceptual Presence
Constructivist Foundations , 2021
In our response, we demonstrate how theoretical constructs of philosophical phenomenology do not correspond to findings from lived experience. We provide additional subjective reports illustrating the active nature of perceptual presence, and how this phenomenon can be considered a socially reinforced mastery of veridicality. Finally, we outline future directions for computational modelling.
The core of presence: Presence as perceptual illusion
Presence Connect, 2003
Progress in understanding presence is inhibited by the fact that we are unable to agree what it is we are talking about. What one researcher means by presence is not the same as what another means, and from this stems confusion about how to evaluate models of presence, how to measure it, and how it relates to other psychological phenomena such as mental imagery, attention and emotional engagement. If presence is a phenomenon worthy of investigation, it has at least to be characterised in a way that differentiates it from other phenomena already under long-term investigation (such as those listed above). And this characterisation should lead to ways of measurement that can, in the best case, cleanly discriminate between changes in presence and changes in other phenomena. Over the two decades of increasingly active presence research, several definitions of what characterises presence have been put forward. We suggest that, of these, there is one that meets the needs of future progress in the field: electronically mediated presence is the perceptual illusion of being in an external environment. The key word here is perceptual, not least because of the implications it carries for measurement. We know how to measure the effectiveness of perceptual illusions objectively, and we can expect to be able to distinguish presence defined in this way from other psychological phenomena.
An investigation of presence response across variations in visual realism
2004
Abstract This paper describes reports on the results of an experiment designed to study the impact of realism on the reported presence in an immersive virtual environment. An experiment was carried out with 40 participants who were asked to walk through a virtual street, which had virtual characters walking through it. Two factors were varied–texture quality (2 levels) and virtual character realism (2 levels). 10 participants were assigned to each cell, which was also balanced for gender.
This document is currently being converted. Please check back in a few minutes.