Representations of motion and direction

In 6 experiments, incidental memory was tested for direction of motion in an old-new recognition paradigm. Ability to recognize previously shown directions depended greatly on motion type. Memory for translation and expansion-contraction direction was highly veridical, whereas memory for rotation direction was conspicuously absent. Similar results were obtained in conditions in which motions were illustrated with pictures. Results suggest that explicit representations of direction in long-term memory are not so much related to motion per se as to the consequences of motion, the displacements of objects. Memory for all motions following circular pathways was found to be corrupted by a generic bias to regard the clockwise direction as familiar. Assessment of memory in these cases required disentangling familiarity bias for the clockwise direction from explicit recognition of direction.