Friday, 1 April 2016

What It IS Like To See: A Sensorimotor Theory Of Perceptual Experience

     
             This is a review of an article by J. K. O'Regan and A. Noe 'What It Is Like To See: A Sensorimotor Theory Of Perceptual Experience'. It proposes a way of bridging the gap between physical processes happening in the brain and the 'felt' aspect of sensory experience happening when coming into direct contact with the world around us. It has a new idea that the process of experience does not happen in the brain only but it is constituted in a way the brain processes enable a form of 'give and take' between the perceiving person and the environment. J.K. O'Regan also approaches issues of visual awareness and consciousness, as well as change blindness.
J.K. O'Regan talks about sensory experience as a way of doing things in life. He uses an example of special feeling a person has when driving a Porsche as compared to other cars. The particular experience of driving a Porsche does not come directly from the brain as the person feels the luxury of the car with the body and the feeling is processed in the brain, therefore it can be applied to 'give and take' process between the person and the environment, namely the Porsche in this case.
He then introduces a missile guidance system and explains how it exercises mastery of apparatus related sensorimotor contingencies of airplane tracking. It depends on the nature of three-dimensional space and how it senses things in that space, which is in fact, visually tracking the airplane.
J.K. O'Regan then talks about the sensation of red, what it is like to see red, to feel it and to experience it. He claims that the sensation of red colour is a way of doing things, it is not something that emerges from neural excitation. The visual sensation is constituted by the knowledge and even if a person blinks the sensation does not disappear even though the visual field is shielded by the blink for a moment. It appears this happens because the occurrence of sensation is a system based phenomenon. The sensation, however, is apparatus and space related. The eyeball has a spherical shape and there are certain distortions that occur in the image when it shifts. Another sensorimotor contingency is that of a 3D space, that is when a person moves forward or backwards his visual field expands or narrows down, which means it adjusts to the space. Both contingencies, however, are independent of the nature of the objects which are being seen.
According to J.K. O'Regan, perception is the exercise of mastery of object related sensorimotor contingency. He gives example of feeling something with your hand. The sensitivity of different parts of it is quite different (fingertips, palm, nails, etc), the fingers themselves are of different length yet that has no impact on the ability to recognize the object. The same kind of analysis he applies to visual perception. In the case of vision, the local sensitivities of different parts of the retina are quite different, therefore we have the impression of seeing a whole object and not part of it.  Whereas if you feel an object with your fingers without being able to see it, you can only feel the part of it, sense whether it is soft, smooth, hard, soft, triangular, circle, etc.
J.K.O'Regan also talks about the blind spot, which is a region in the visual field of each eye corresponding to the place where the optic nerve passes out of the ocular globe. He claims that having the visual blind spot does not affect the vision itself as vision occurs through movement, and not despite movement. He also presents the binding issue, that is how different attributes like red and triangle can be bound together in the brain so that we can perceive a red triangle as a whole. He gives the answer by saying that it is something that is constituted by a way of behaving.
The author also talks of being aware or not so of the system and its use of perceptual information. For example, a driver might be aware of the red traffic signal and stop in front of it or he might be busy talking to his friend while driving and not actively notice the red traffic signal yet still stop in front of it because of being visually aware of it.
J.K. O'Regan also compares different experiences of 'feels'. What is the difference say between feeling rich and feeling of the red colour? The feeling of richness consists of knowledge of the things he can do with money yet he can not visualise the feeling rich as such while a person can certainly visualize something that is red. The visual world is immediately accessible to our exploration in which case it can be said that the world functions as an external memory store. If we need to visualize suppose what is the colour of someone's pet cat, we can visualize it and see its colour in our memory.
More things on memory and what it is like to see as well as the full article by J.K.O'Regan and A.Noe can be found here .

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