Is our vision of reality correct? color perception (Introduction)

by David Turell @, Thursday, January 11, 2018, 18:56 (102 days ago) @ David Turell

In this article the point is made that color is really not a property of an object so much as it is how the brain perceives it:

"My response is to say that colors are not properties of objects (like the U.N. flag) or atmospheres (like the sky) but of perceptual processes—interactions which involve psychological subjects and physical objects. In my view, colors are not properties of things, they are ways that objects appear to us, and at the same time, ways that we perceive certain kinds of objects. This account of color opens up a perspective on the nature of consciousness itself.


"Modern science, as inherited from the 17th century, gives us a perspective on material objects that is radically different from our ordinary sensory one. Galileo tells us that the world contains “bodies” which have properties like size, shape, and movement, regardless of anyone perceiving them. By measuring and describing things in terms of those “primary” properties, science promises to give us knowledge of the objective world, the world as it is independently of the distortions of human perception. Science can explain how it is that the molecules released into the air by a sage plant could stimulate my nose, or how its petals could reflect light and appear blue-violet to my eye. But the scent and the color itself—the conscious, sensory experience of them—make no showing in that explanation.

"The problem of color as we know it today is an ontological issue, a question about what there is in the universe. With the scientific worldview it becomes commonplace to say that the only properties of objects that are unquestionably real are the ones described in physical science. For Galileo they were sizes, shapes, quantities, and motions; for physicists today there are more intangible properties like electric charge. This excludes from fundamental ontology any qualitative properties, such as color, that are known to us only through our perceptual faculties. But once colors are excluded, how do we account for their manifest appearance as properties belonging to everyday objects? Either we say that our senses trick us into believing that external objects are colored, when colors do not in fact exist, or we try to find some account of colors that is compatible with a scientific ontology, locating them among material objects.


"Hardin’s case was that the most adequate account of color must be a neural one. In other words, colored objects are not part of extra-mental physical reality, but a construction or projection of the brain.


"Vision scientists Rainer Mausfeld, Reinhard Niederée, and K. Dieter Heyer write that, “the concept of human color vision involves both a subjective component, as it refers to a perceptual phenomenon and an objective one ... We take this subtle tension to be the essential ingredient of research on color perception.”


"In an influential textbook, perceptual psychologist Stephen E. Palmer writes that color is not reducible to visual experience or properties of objects or lights; rather, Palmer writes, “Color is more accurately understood as the result of complex interactions between physical light in the environment and our visual nervous systems.”


"It is common for physicists to explain the blue appearance of the sky as due to “Rayleigh scattering,” the fact that short wavelengths of visible light are scattered more by the Earth’s atmosphere than longer ones, so that diffuse blue light comes to us from all regions of the sky when the sun is high and cloudless. But we should not be tempted to say the blue of the sky is simply a property of the scattered light. There is no blueness unless the light interacts with perceivers like us, who have photoreceptors that respond differently to short versus long wavelengths of light.

"So, precisely speaking, the sky is not blue. We see it in a blue way.


"We’re used to thinking of conscious experience as something like a series of sounds and images rolling past on an inner movie screen. This is the conception of our mental life that the philosopher Alva Noë wants to break away from. In his 2009 book Out of Our Heads, Noe claims that consciousness is not confined to the brain but is somehow “in between” the mind and our ordinary physical surroundings, and that consciousness must be understood in terms of activities.5 By themselves these ideas are quite perplexing. But taking the example of visual experience, color adverbialism is a way to make sense of consciousness being “out of our heads.” According to adverbialism, color experience comes about because of our interaction with the world, and would not exist without this exposure to our surroundings. Our inner mental lives are dependent on this outer context."

Comment: We cannot get around the point that what we perceive from our brains is secondhand.

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