Persistence of Illusion

In my Neuroscience of Consciousness course yesterday, my instructor presented Jackson’s (1982) Mary’s Room thought experiment, also known as the knowledge problem.

This is the thought experiment:

Mary is a brilliant scientist who is, for whatever reason, forced to investigate the world from a black and white room via a black and white television monitor. She specializes in the neurophysiology of vision and acquires, let us suppose, all the physical information there is to obtain about what goes on when we see ripe tomatoes, or the sky, and use terms like ‘red’, ‘blue’, and so on. She discovers, for example, just which wavelength combinations from the sky stimulate the retina, and exactly how this produces via the central nervous system the contraction of the vocal cords and expulsion of air from the lungs that results in the uttering of the sentence ‘The sky is blue’. […] What will happen when Mary is released from her black and white room or is given a color television monitor? Will she learn anything or not?

What gets me about this thought experiment is the question as to whether or not Mary will learn anything or not. To me, the question should be whether Mary has a new type of experience, or whether the knowledge that she has in the black and white room somehow accounts for the experience of color. The setup is such that it isolates the distinction between knowing about something and actually experiencing something, which I do value.If the knowledge in the black in white room could account for the experience of color, then Mary would somehow be able to imagine color even in its absence and therefore the release into a colored world would not have that much of a significant intervening role for her learning. So I do think there is something in experience that knowledge alone cannot produce.

I was the only one in my class bedsides my teacher who took the view that Mary would not learn anything new. This is how I defended my view:

I think that Mary could learn something new or have a new type of experience, but I don’t think this learning or this experience would be immediate when Mary is released to the world or given a color television.Mary will be exposed to sensory information (color) that her sensorimotor system has no means to interpret. Mary’s nervous system has to adapt to a new pattern of sensorimotor contingencies within a dynamical feedback system that now includes color. Thus, Mary has to learn a new pattern of associations with color wavelength stimuli upon the retina in order to make sense of this new information, probably by relating it back to the shade and hue variants she had experienced in the black and white room. Even so, this implies something closer to a sensory substitution, a translation of one mode of experiencing something into another, which is not entirely the same as the experience of seeing color as gradient, light, hue, and wavelength frequency all at once for the full experience of color. The conceptual understanding of color cannot produce the experience of color even when color is presented to a sensory system fit to perceive it if that sensory system has not been habituated to perceive color.

Patients with brain-damage induced achromatopsia have all of their memories and mental imagery turned to black and white. That is, they can no longer even conjure or recall color even though they had once experienced it. Neil Harbisson has an antenna that allows him to hear color, but this is not the same as true synaesthesia since for a color-sound synesthete the experiences necessarily occur together: one sees the color and hears the sound, whereas Neil hears the color just as a sound and re-interprets the missing sensory information as color. Moreover, Neil can perceive color through this sensory substitution to much more attuned distinctions than the human eye. However, what he is perceiving is not color directly but the color as encoded and transduced into a different sensory modality, in the same way that a scientist measuring radioactivity is not perceiving radioactive light directly but is instead interpreting the reality through what is available by means of various tools.

What this reminds me of the most though is cases of recovery from blindness (which is, ironically, what the first poem I ever wrote is about). There are examples throughout history of individuals with congenital blindness who recovered sight (from cataracts, for instance, or other forms of cortical blindness). These individuals were not able to visual perceive objects in their immediacy, but still go about navigating objects through touch and other modes of sensory exploration. The restoration of a sense does not immediately give one the experience of that sense reality.

This leads to the Molyneux problem:

Suppose a man born blind, and now adult, and taught by his touch to distinguish between a cube and a sphere of the same metal, and nearly of the same bigness, so as to tell, when he felt one and the other, which is the cube, which is the sphere. Suppose then the cube and the sphere placed on a table, and the blind man made to see: query, Whether by his sight, before he touched them, he could now distinguish and tell which is the globe, which the cube? To which the acute and judicious proposer answers: ‘Not. For though he has obtained the experience of how a globe, and how a cube, affects his touch; yet he has not yet attained the experience, that what affects his touch so or so, must affect his sight so or so…’

Oliver Sacks writes of a man called Virgil in An Anthropologist on Mars, who with severe cataracts could see very little until the cataracts were surgically removed. Sacks writes that Virgil was very often confused, unable to decipher what he saw, behaving like a “mentally blind” person who despite being able to see could not understand what he saw. Virgil’s confusion led to depression.

One of the earliest cases of recovery from blindness is 13-year old Willian Cheselden in 1798 when the cataract from his lens (rendering his vision opaque) was removed. In Space and Sight: The Perception of space and Shape in the Congenitally Blind Before and After Operation, Marius von Senden (1930) writes describes Cheselden’s regained vision as follows:

When he first saw, he was so far from making any judgment of distances, that he thought all object whatever touched his eyes (as he expressed it) as what he felt did his skin, and thought no object so agreeable as those which were smooth and regular, though he could form no judgment of their shape, or guess what it was in any object that was pleasing to him: he knew not the shape of anything, nor any one thing from another, however different in shape or magnitude; but upon being told what things were, whose form he knew before from feeling, he would carefully observe, that he might know them again.

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