Informal comments from Barbara Landau in response to the class question: Do blind people have visual representations?

a. If you mean "response from the area in the brain usually mapped to vision," a recent finding at least suggests that blind people might show responses from this region during certain tasks.

b. If you mean "a response that we know to be affected by visual representations in sighted people," the answer is yes: Rozin and Jonides showed that instructions to "imagine a relationship" between a pair of words enhanced performance in blind people to the same extent as in sighted people.

c. If you mean something more like "Do blind people dream in visual images?" the answer is that they certainly dream, but it is virtually impossible to determine whether these images have the same qualities as do those of sighted people.

d. If you mean "Do they have a structure for vision-based words, such as color terms?" the answer is yes: People have shown a reasonable (though not perfect) structure for color terms among the blind, when the blind are asked to make verbal similarity judgments across color terms (e.g. "Which two are more similar: Red, Orange, Blue). Further, Landau & Gleitman were able to show that blind adults possessed surprisingly rich representations of visual verbs usually thought to be based on visual experience, e.g. the differences among "gaze," "glance," "stare."

Here's a question for the students to ponder:

How would you KNOW if the blind had "visual" representations? And what would that mean?