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?

The result would be that the individuals with grapheme-color synesthesia should be considerably faster and more accurate than controls at detecting the hidden shape.

Explanation:

Given the fact that individuals with grapheme-color synesthesia naturally associate shapes of numbers and letters with colors, it would automatically be easy for them to recognize the distinction in shapes as a different shape would appear to them as a different color. Hence, when a person with grapheme-color synesthesia would be asked to find a particular shape alongside other controls having assigned the same task, the person with grapheme-color synesthesia would be the fastest to complete the task.

It is meant that like tapestry scientific theories often need to pull out since they are not relevant and often times the whole chain of theories may be pulled out.