How dyou know a person has synesthesia?

Question

How dyou know a person has synesthesia?

Answer 1

http://www.bu.edu/neuropsychology/synvc....

Answer 2

There are several methods:

1.) Test-retest. On a test with a large range of choices, tested over even years synesthesetes have a large consistancy (90% compared to 30-40% from over a month)

This is the simplest and most convincing test.

2.) for grapheme/colour synesthesia (or similar) there is a modified stroop task (the stroop task is when words like "red" and "blue" are printed in colour ink (other than the colour the word represents) and you have to either name the colour or the word. Tests include the colour of the word of the synesthesia acts as the colour of the stroop task, or impairment is greater when "their" colour contrasts with the colour of a word, etc - basically they show a greater impairment)

3.) for grapheme/colour synesthesia again, they show improvement in noticing "embedded figures" (i.e. a pattern of 2's in a field of five - synethesetes are more likely to notice them making a diamond or square, because to them the 2s stand out more)