Perceiving motion while moving: how pairwise nominal invariants make optical flow cohere.
Computer-generated sequences simulated observer movement toward 10 randomly placed poles, 1 moving and 9 stationary. When observers judged their direction of movement, or heading, they used 3 related invariants: The (a) convergence and (b) decelerating divergence of any 2 poles specified that heading was to the outside of the nearer pole, and the (c) crossover of 2 poles specified that heading was to the outside of the farther pole. With all poles stationary, the field of 45 pairwise movements yielded a coherent specification of heading. With I pole moving with respect to the others, however, the field could yield an incoherent heading solution. Such incoherence was readily detectable; similar pole motion leading to coherent flow, however, was less readily detectable.
Cutting
James E
JE
Department of Psychology, Cornell University, Ithaca, New York 14853-7601, USA. jec7@cornell.edu
Readinger
Wilson O
WO
D000328:Adult; D004193:Discrimination Learning; D006801:Humans; D007699:Kinesthesis; D009039:Motion Perception; D009903:Optical Illusions; D009949:Orientation; D011597:Psychomotor Performance; D011601:Psychophysics; D015357:Vision Disparity