Spontaneous imagery scanning in mental extrapolation.

We report an experiment that suggests a functional application of mental-image scanning. After subjects inspected a simple dot pattern, the pattern was removed, and they were then shown an arrow at an unexpected location. Their task was to judge as quickly as possible whether the arrow pointed at any of the dots in the previously observed pattern. Although the subjects were never instructed to form or scan mental images, most of them reported having done so in order to make their judgments, and their reaction times were directly proportional to the distances separating the dots and the arrows, as typically found in image-scanning experiments. Imagery scanning may therefore serve a useful function when one must judge spatial relations between the positions of remembered objects and newly specified locations.