User:The.Filsouf/Action and Perception

There are a number of different approaches to studying Perception and Action, and also the relationship between the two.

Alva Noë
Philosopher from Berkeley came up with a new approach to the problem.

Noe takes an externalist approach which can be explored through the difference between causation and constitution.

Causation and Constitution (C&C) - Vehicle externalism
Noe argues for what is in one way a more radical form of externalism about experience. His externalism is vehicle externalism rather than content externalism.

Vehicles of contents are the physical items that have or express the content e.g. sentences.

In the same manner of Clark and Chalmers who claimed that memory and calculations constitutively include props such as a diary, Noe claims skilled active body partially constitutes the vehicle of experience.

Noe argues that atleast in some experiences the physical substrate of the experience may cross boundaries implicating neural, bodily and environmental features.

Enactive view & Embodied cognition
E.V is an activity of exploring the environment, drawing on knowledge of sensorimotor contingencies.

Reflecting on the importance of the whole agent (body) rather than just the brain, he declares "A neuroscience of perceptual consciousness must be an enactive neuroscience, that is, a neuroscience of embodied activity rather than a neuroscience of brain activity"

"Perceptual experience, according to the enactive approach, is an activity of exploring the environment drawing on knowledge of sensorimotor dependencies and thought"

According to the enactive perceptual experience is the practical bodily exercise of sensori-motor know-how. P.e. does not constitutively supervene on brain alone but only on the active boy that is renquired for the skilled exercise of the sensorimotor knowledge.

Sensorimotor knowledge
Perceptual experience can be identified with the skilled bodily exercise of Sensorimotor knowledge which includes visually guided action.

Ned Block argues that there are empirical results that suggest such knowledge does not reflect the phenomenology of conscious vision.

Sensorimotor knowledge, knowledge of sensorimotor contingencies, is knowledge of "the way sensory stimulation  varies as you move".

"Sensorimotor knowledge is knowledge of how objective appearances change as you move and as the things you see move. Sensorimotor knowledge is also a matter of knowing how rather than knowing that."

Vision
Vision is a process "that depends on interactions between the perceiver and the environment and involves contributions from sensory systems other than the eye"

Noe believes strongly that vision is not passive and uses the same analogy as touch to point this out: "Touch involved skillful probing and movement, and so does vision", such findings can be interpreted in other ways by mainstream vision scientists (e.g. Palmer)

Dreams
There is no dynamic exchange with environment when we dream (as far as we know so far) therefore neural states alone are sufficient or dreaming. This is unlike our perceptual experience which Noe basis around embodied cognition.

Block (2005) claims
- "Of course, there is often a process of perception that involves bodily activity (e.g. moving close for a better look) but that should not be conflated with the very different idea that perceiving is an activity or, worse, that perceptual experience is an activity. and even if perceptual experience depends casually or counter factually on movement or another form of activity, it does not follow that perceptual experience constitutively involves movement"

Block: Noe claims that not all perceptual experience can be produced (e.g. flashing visual lights) by using direct neural stimulation, however this is not about this. Of course the sensorimotor system is is important but it is the relevant brain state would lead to the experience anyway.

Block: Sensorimotor know-how and perceptual experience are casually related, but that is no reason to think that they are constitutively related.

Block attemps to provide evidence against the enactive view, using the visual system:

Humans and other primates have two distinct visual systems, a conscious visual ststem that starts in the back of the head, moving to the bottom and side (the "ventral" system) and a much less clearly conscious "dorsal" system that goes from back towards the top of the brain. - Science: Goodale and Milner "Visual brain in action" (1995), "Sight Unseen" (2003) - Philosophy: Clark, A "Visual experience and motor action: are the bonds too tight?" (2001)

The dorsal system (which feeds much more strongly than the ventral ststem to peripheral vision) is responsible for visually guided bodily movements that operate largely out of conscious (Schindler et al (2004) - automatic avoidance of obstacles is a dorsal stream function..) and it is this dorsal system that guides action from moment to moment, even though ventral system is mainly relevant to the perceptual experience.

Goodale & Murphy "Action and perception in the visual periphery" claim:

"The central perception pathway deals primarily with foveal vision (centra area of retine), a fact that is consistent with the crucial role this pathway plays in the perception and recognition of objects and scenes... in contrast, the dorsal "action" stream, which is known to play a critical role in the control of actions, such as goal-directed limb and eye movements, has a full representation of the visual field".

Block concludes: The upshot is that if the activity guided by sensorimotor knowledge with which the enactive approach identifies perceptual experience includes visually guided action, it simply does not reflect the phenomenology of conscious vision. That is sensorimotor knowledge (to the extent that it involves the visual guidance of action) is not true to perceptual experience.

Block also says that Noe should have focused his enactive account on spatial sense, a sense that is shared by many perceptual systems such as vision and proprioception and seems to be embodied in the dorsal system.

The applecart that he has been defending against Noes attack has two main tenents:

1- The minimal costitutive supervenience base for perceptual experience is the brain and does not include the res of the body.

2- Although motor outputs instructions affect perceptual experience (as has been shown since Helmohltz) much of perceptual experience can be understood in abstraction from such cause.

"I think there is a grain of truth in the enactive view: perceptual experience is indeed (casually) affected by sensorimotor continengencies, and our sense of 'presence in absence' may be a matter of spatio-motor imagery."

Noe's reply (2007)
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