Wayfinding From Multiple Sources of Local Information in Retinal Flow

Although they concluded differently, N. G. Kim, R. Growney, and M. T. Turvey (1996) provided data that supports previous empirical ( J. E. Cutting, K. Springer, P. A. Braren, & S. H. Johnson, 1992 ) and metatheoretical ( J. E. Cutting, 1986 ) claims. Their data show that, in simulations of pursuit fixation during locomotion through a cluttered environment, multiple sources of local information in retinal flow-previously analyzed as differential parallactic displacements (DMP), inward motion (IM), and outward deceleration (OD)-appear to be used by observers to determine the direction of their heading. Four alternative versions of parallax information were considered. Three were global sources-differential motion, spatial pooling, size-weighted spatial pooling; the other was a local source-the displacement direction of the largest object (DDLO) in the field. Of these, DDLO was best predictor, outstripping DMP and the 3 global sources; but IM and OD remained important. Thus, it remains that several local sources of motion information best predict the wayfinding data.