Introducing the brain: synesthesia a strange mistake (Introduction)

by David Turell , Thursday, June 18, 2020, 15:40 (1400 days ago) @ David Turell
edited by David Turell, Thursday, June 18, 2020, 15:45

The four percent who have it don't mind it:

http://nautil.us/issue/86/energy/the-power-of-crossed-brain-wires?mc_cid=480c64000b&...

"When I was about 6, my mind did something wondrous, although it felt perfectly natural at the time. When I encountered the name of any day of the week, I automatically associated it with a color or a pattern, always the same one, as if the word embodied the shade. Sunday was dark maroon, Wednesday a sunshiny golden yellow, and Friday a deep green. Saturday was interestingly different. That day evoked in my mind’s eye a pattern of shifting and overlapping circular forms in shades of silver and gray, like bubbles in a glass of sparkling water.

"Without knowing it, I was living the unusual mental state called synesthesia, aptly described by synesthesia researcher Julia Simner as a “condition in which ordinary activities trigger extraordinary experiences.” More exactly, it is a neurological event where excitation of one of the five senses arouses a simultaneous reaction in another sense or senses.

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"In the 1980s new approaches made synesthesia amenable to more rigorous and objective study and research has blossomed, with about 1,000 new publications since 2000. One big step has been the acceptance of a consensus definition of synesthesia. Its key features are that a subject involuntarily experiences vivid responses to stimuli that combine two or more different sensory modalities, and that the responses are constant over time; for instance, a given word always induces the same color in a particular subject (the colors themselves are unique to each person). The psychologist Simon Baron-Cohen and colleagues introduced this last benchmark in 1987 as an objectively measurable standard of genuineness. True synesthetes give the same responses to the same stimuli when tested and retested over long time intervals. Childhood synesthesia generally continues into adulthood, though not always. I lost my automatic color associations by the time I was 12. Today I can only remember the colors.

"...new neuroimaging techniques have established synesthesia as a real neurological process. One widely used method is functional magnetic resonance imaging (fMRI) of the brain. Unlike regular MRI, which shows the anatomy of the brain (or other internal organs), fMRI identifies which parts of the brain are active, nearly in real time. Since 2002, some fMRI investigations of grapheme-color synesthesia—the most widely studied kind—have shown that graphemes stimulate the V4 region of the brain. This area deals specifically with color within the visual cortex, the part of the brain that processes what the eyes see (the auditory cortex and other specialized areas handle the remaining senses). This is consistent with a model where the regions of the brain that analyze graphemes and that deal with color are somehow hyper-connected to create a synesthetic event. But not all fMRI data show the same result, nor is it clear if it is the visual perception of a grapheme or its conceptual meaning that is the trigger.

"Remarkably, even with advanced methods, other basic questions have lingered since the 19th century. How prevalent is synesthesia in the general populace? Different studies had given values from over 20 percent to less than 1 percent, a disparity partly due to the use of self-reported data. To remedy this, in 2006 Simner, then at the University of Edinburgh, and her colleagues carried out a controlled approach. They interviewed nearly 1,700 subjects and tested them for consistency over time. The certified synesthetes constituted 4.4 percent of the group, 1 for every 23 people—rare, but not vanishingly so. The data also showed that the most common subvariant is the one I experienced: colored days of the week.

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"Research supports these accounts. Self-reported synesthetes appear at a relatively high rate among artistic types, and one study using objective testing found 7 percent synesthetes among 99 art students compared to 2 percent in a control group.

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"Mylopoulos and Ro considered how synesthesia can act as a test bed to choose among theories of consciousness, and examined prevalent candidates, none of which is as yet supported by much empirical evidence. “Higher order” theory assumes that conscious states are those that a person is aware of being in, which comes from another mental state operating at a higher level; but in “first-order” theory there is no need for a higher state because even a perceptual state such as viewing a flower is considered to be a conscious state. Significantly, these differences produce characteristic neural correlates operating in different parts of the brain for each theory. The authors conclude that the scope of synesthetic events spread over the brain and its functions can yield “initial clues as to the neural correlates of conscious perceptual experiences more generally,” and help guide researchers toward a valid theory of consciousness."

Comment: From the material side of the discussion we can only experience what the brain gives us as experience. This does not affect the ability to create immaterial concepts of ideation or glorious musical compositions. It is not really a mistake but a variation from the normal