In this case, the mapping between number and color is constant. For this person, the number 3 generally appears red, while the number 7 generally appears green. One way to test whether someone actually has this form of synesthesia is to have the person hunt for shapes hidden in an array of similar-looking numbers. For example, the following array contains 5s organized into a shape among 2s. What results would you expect when comparing participants with grapheme-color synesthesia against controls?
1. Individuals with grapheme-color synesthesia should be considerably faster and more accurate than controls at detecting the hidden shape.
2. Individuals with grapheme-color synesthesia should have more difficulty than controls at doing this task.
3. Control participants should be faster at completing this task but will show more errors than individuals with grapheme-color synesthesia.
4. Control participants should be unable to complete this task, while individuals with grapheme-color synesthesia will find it difficult but doable.