Visual perception: Where is the mind's eye?

Can you easily form mental pictures from the descriptions of scenery that are so frequently met with in novels and books of travel? More than 100 years ago Francis Galton [1] sent out a list of questions, including this one, to gather statistics on the character of mental imagery. Many people reported vivid mental imagery, but not the scientists on his list. “To my astonishment”, Galton reported, “I found that the great majority of the men of science to whom I first applied protested that mental imagery was unknown to them”. This response, which Galton attributed to a “mental deficiency”, might more kindly be attributed to excessive scrupulosity. Scientists like to be exact in their usage, and, judging by one of the responses Galton prints, these eminent fellows may have considered that examining a visual mental image was not the same as inspecting a painting: a mental image has a more sketchy character, and should be thought of more as a symbolic description.