Second-order mappings in grapheme-color synesthesia.
Typically, the search for order in grapheme-color synesthesia has been conducted by looking at the frequency of certain letter-color associations. Here, we report stronger associations when second-order similarity mappings are examined--specifically, mappings between the synesthetic colors of letters and letter shape, frequency, and position in the alphabet. The analyses demonstrate that these relations are independent of one other. More strikingly, our analyses show that each of the letter-color mappings is restricted to one dimension of color, with letter shape and ordinality linked to hue, and letter frequency linked to luminance. These results imply that synesthetic associations are acquired as the alphabet is learned, with associations involving letter shape, ordinality, and frequency being made independently and idiosyncratically. Because these mappings of similarity structure between domains (letters and colors) are similar to those found in numerous other cognitive and perceptual domains, they imply that synesthetic associations operate on principles common to many aspects of human cognition.
Department of Psychology, University of British Columbia, 2136 West Mall, Vancouver, British Columbia V6T 1Z4, Canada. marcusw@psych.ubc.ca
Marcus R
MR
Watson
Kathleen A
KA
Akins
James T
JT
Enns
D003116:Color; D003118:Color Perception; D006801:Humans; D010364:Pattern Recognition, Visual; D010468:Perceptual Disorders / Q000523:psychology; D010775:Photic Stimulation; D011930:Reaction Time