Online research in philosophy

While applauding the bulk of the account on offer, we question one apparent implication viz, that every difference in sensorimotor contingencies corresponds to a difference in conscious visual experience.

The target article proposes that visual experience arises when sensorimotor contingencies are exploited in perception. This novel analysis of visual experience fares no better than the other proposals that the article rightly dismisses, and for the same reasons. Extracting invariants may be needed for recognition, but it is neither necessary nor sufficient for having a visual experience. While the idea that vision involves the active extraction of sensorimotor invariants has merit, it does not replace the need for perceptual representations. Vision is not just for the immediate controlling of action; it is also for finding out about the world, from which inferences may be drawn and beliefs changed.

Machine generated contents note: -- 1. Introduction -- Consciousness and Sensorimotor Dynamics: Methodological Issues -- 2. Computational consciousness, D. Ballard -- 3. Explaining what people say about sensory qualia, J. Kevin O'Regan -- 4. Perception, action, and experience: unraveling the golden braid, A. Clark -- The Two-Visual Systems Hypothesis -- 5. Cortical visual systems for perception and action, A.D. Milner and M.A. Goodale -- 6. Hermann Lotze's Theory of 'Local Sign': evidence from pointing responses in an illusory figure, D.R. Melmoth -- Understanding Agency and Object Perception -- 7. Two visual systems and the feeling of presence, M. Matthen -- 8. Spatial coordinates and phenomenology in the two-visual systems model, P. Jacob and F. de Vignemont -- 9. Perceptual experience and the capacity to act, S. Schellenberg -- Perception and Action: Studies in Cognitive Neuroscience -- 10. Why does the perception-action functional dichotomy not match the ventral-dorsal streams in anatomical segregation: optic ataxia and the function of the dorsal stream, Y. Rossetti et al -- 11. Mapping the neglect syndrome onto neurofunctional streams, G. Vallar and F. Mancini -- 12. Motor representations and the perception of space: perceptual judgments of the boundary of action space, Y. Delevoye-Turrell -- The Role of Action and Sensorimotor Knowledge in Sensorimotor Theories of Perception -- 13. Vision without representation, A. Noe -- 14. Sensorimotor knowledge and the contents of experience, J. Kiverstein -- Boundaries of the Agent -- 15. Extended vision, R. A. Wilson.

This commentary focuses on shape constancy in vision and its relation to sensorimotor knowledge. I contrast “Protean” and “Constancian” views about how to describe perspectival changes in the appearance of an object’s shape. For the Protean, these amount to changes in apparent shape; for Constance, things are not merely judged, but literally appear constant in shape. I give reasons in favor of the latter view, and argue that Noë’s attempt to combine aspects of both views in a “dual aspect” account does not manage to avoid an unacceptable attribution of contradictory content to visual appearance. I argue also that my position here actually fits better with Noë’s critique of a “snapshot” conception of visual appearance than his own interpretation of visual constancy, and better supports his claim that experiential content is constituted by the exercise of sensorimotor understanding.

Many viewers presented with a round plate tilted to their line of sight will report that they see a round plate that looks elliptical from their perspective. Alva Noë thinks that we should take reports of this kind as adequate descriptions of the phenomenology of spatial experiences. He argues that his so-called enactive or sensorimotor account of spatial perceptual content explains why both the plate’s circularity and itselliptical appearance are phenomenal aspects of experience. In this paper, I critique the phenomenal adequacy of Noë’s sensorimotor account of spatial perceptual content. I begin by showing that some ofits central claims are in conflict with the phenomenology of perceptual experience. I then argue that shape appearances have no phenomenal reality, thus undermining this central motivation for his account.

Neuropsychological findings used to motivate the “two visual systems” hypothesis have been taken to endanger a pair of widely accepted claims about spatial representation in visual experience. The first is the claim that visual experience represents 3-D space around the perceiver using an egocentric frame of reference. The second is the claim that there is a constitutive link between the spatial contents of visual experience and the perceiver’s bodily actions. In this paper, I carefully assess three main sources of evidence for the two visual systems hypothesis and argue that the best interpretation of the evidence is in fact consistent with both claims. I conclude with some brief remarks on the relation between visual consciousness and rational agency.

Alva Noë is a modern-day empiricist. His book Action in Perception is chockablock with contemporary cognitive science; its preface and notes (not to mention general erudition) point to on-going collaboration with Evan Thompson, Kevin O’Regan, and Susan Hurley. Their research investigates the sensorimotor bases of consciousness, and Action in Perception is offered as its philosophical backdrop. As such, the book presents a series of ideas and interpretations that constitute what Noë calls the “enactive approach” to perception, many of which are explicitly phenomenological in orientation. So those on the lookout for imaginative philosophy of mind will find Noë's work particularly compelling. (Noë would prefer "already feeling about for imaginative philosophy of mind," because on his account paradigmatic perceptual activity is tactile rather than visual.) In this review I will not address the empirical details concerning Noë and his compatriots, but will instead focus on the way Noë’s enactive approach should be situated vis-à-vis traditional phenomenology. Action in Perception is part of the grand project of a robustly scientific knowledge of human perceptual experience, but it is clearly also a philosophical theory, so I will address it philosophically. I address it as I take it to be: one of the best works in the philosophy of perception to appear in a very long time.

This paper contrasts two enactive theories of visual experience: the sensorimotor theory (O’Regan and Noë, Behav Brain Sci 24(5):939–1031, 2001; Noë and O’Regan, Vision and mind, 2002; Noë, Action in perception, 2004) and Susan Hurley’s (Consciousness in action, 1998, Synthese 129:3–40, 2001) theory of active perception. We criticise the sensorimotor theory for its commitment to a distinction between mere sensorimotor behaviour and cognition. This is a distinction that is firmly rejected by Hurley. Hurley argues that personal level cognitive abilities emerge out of a complex dynamic feedback system at the subpersonal level. Moreover reflection on the role of eye movements in visual perception establishes a further sense in which a distinction between sensorimotor behaviour and cognition cannot be sustained. The sensorimotor theory has recently come under critical fire (see e.g. Block, J Philos CII(5):259–272, 2005; Prinz, Psyche, 12(1):1–19, 2006; Aizawa, J Philos CIV(1), 2007) for mistaking a merely causal contribution of action to perception for a constitutive contribution. We further argue that the sensorimotor theory is particularly vulnerable to this objection in a way that Hurley’s active perception theory is not. This presents an additional reason for preferring Hurley’s theory as providing a conceptual framework for the enactive programme.

Much recent work on cognition is characterized by an augmentation of the role of action coupled with an attenuation of the role of representation. This coupling is no accident. The appeal to action is seen either as a way of explaining representation or explaining it away. This paper argues that the appeal to action as a way of explaining, supplementing, or even supplanting, representation can lead to a serious dilemma. On the one hand, the concept of action to which we appeal cannot, on pain of circularity, be a representational concept. Such an appeal would presuppose representation and therefore can neither explain it nor explain it away. On the other hand, I shall argue, if the concept of action to which we appeal is not a representational one, there is every reason for supposing that it will not be the sort of thing that can explain, or supplement, let alone supplant, representation. The resulting dilemma, I shall argue, is not fatal. But avoiding it requires us to embrace a certain thesis about the nature of action, a thesis whose broad outline this paper delineates. Anyone who wishes to employ action as a way of explaining or explaining away representation should, I shall argue, take this conception of action very seriously indeed. I am going to discuss these issues with respect to a influential recent contribution to this debate: the sensorimotor or enactive model of perception developed by Kevin O’Regan and Alva Noë.

Alva Noë’s _Action in Perception _offers a provocative and vigorous defense of the thesis that vision is enactive: visual experience depends on dispositional motor responses. On this view, vision and action are inextricably bound. In this review, I argue against enactive perception. I raise objections to seven lines of evidence that appear in Noë’s book, and I indicate some reasons for thinking that vision can operate independently of motor responses. I conclude that the relationship between vision and action is causal, not constitutive. I then address three other contentious hypotheses in the book. Noë argues that visual states are not pictorial; he argues that all perception is conceptual; and he argues that the external world makes a constitutive contribution to experience. I am unpersuaded by these arguments, and I offer reasons to resist Noë’s conclusions.