Final answer:
The neurocognitive model of color-graphemic synesthesia explains how some individuals uniquely associate colors with letters or numbers due to possible hyperconnectivity in the brain. It is concerned with the integration of color and grapheme processing, not treatment options for synesthesia.
Step-by-step explanation:
The neurocognitive model of color-graphemic synesthesia is not a model outlining treatment options for synesthesia, but rather a framework explaining how some individuals experience a unique sensory overlap between colors and letters or numbers. In this phenomenon, certain graphemes (letters or numbers) consistently evoke the perception of specific colors. The model suggests that in people with color-graphemic synesthesia, there may be hyperconnectivity or atypical cross-wiring between the areas of the brain involved in color perception and those that process graphemes. This might be due to genetic factors, structural differences in the brain, and the developmental trajectory of sensory processing. The model addresses how the brain integrates and processes multisensory information differently in synesthetes compared to non-synesthetes.
Color perception itself involves the trichromatic theory of color vision on a retinal level, with cones responsive to red, blue, and green wavelengths. At subsequent neural processing stages, the opponent-process theory comes into play, with brain cells responding to color in an antagonistic manner. For individuals with color-graphemic synesthesia, these theories of color vision intersect uniquely with how graphemes are processed.