We can infer from the first paragraph that______ A. the word castanet has something to do with tuna B. the letter S can stimulate people to think of the color of red C. the phenomenon of synaesthesia was under study over a century ago D. synaesthesia involves the stimulation that evokes the sensation of another
And the revelations went further. Certain types of grapheme-color synaesthetes have more connectivity than others. As part of the study, researchers asked volunteers to fill out questionnaires about how they experience their color sensations. Some reported seeing color projected on to whatever word or number they were shown. Members of this group are known as "projectors". Others, known as "associators", reported color only in their mind’s eye. Although both groups of synaesthetes had much more connectivity than non-synaesthetes, projectors had noticeably more again than associators.
Researchers are not yet sure what form the stronger connections take. They could be the result of more filaments than normal connecting the areas in question. Or the filaments might be broader than normal. Or the fatty coatings of the filaments might be thicker, which would amplify the signal passing along them as well as keeping water molecules on the straight-andnarrow.
How synaesthesia starts is also unclear. There is evidence of a genetic component but learning must be involved as well. People are not born with the concept of the letter "A". And they certainly are not born with a bright red, cherry-colored "A"-however much it feels, as synaesthetes insist, as though they were.