Calabro, Finnegan J.Rana, Kunjan D.Vaina, Lucia M.2020-05-122020-05-122011-01-01Finnegan J Calabro, Kunjan D Rana, Lucia M Vaina. 2011. "Two mechanisms for optic flow and scale change processing of looming." JOURNAL OF VISION, Volume 11, Issue 3, 9 pp. https://doi.org/10.1167/11.3.51534-7362https://hdl.handle.net/2144/40799Published in final edited form as: J Vis. ; 11(3): . doi:10.1167/11.3.5.The detection of looming, the motion of objects in depth, underlies many behavioral tasks, including the perception of self-motion and time-to-collision. A number of studies have demonstrated that one of the most important cues for looming detection is optic flow, the pattern of motion across the retina. Schrater et al. have suggested that changes in spatial frequency over time, or scale changes, may also support looming detection in the absence of optic flow (P. R. Schrater, D. C. Knill, & E. P. Simoncelli, 2001). Here we used an adaptation paradigm to determine whether the perception of looming from optic flow and scale changes is mediated by single or separate mechanisms. We show first that when the adaptation and test stimuli were the same (both optic flow or both scale change), observer performance was significantly impaired compared to a dynamic (non-motion, non-scale change) null adaptation control. Second, we found no evidence of cross-cue adaptation, either from optic flow to scale change, or vice versa. Taken together, our data suggest that optic flow and scale changes are processed by separate mechanisms, providing multiple pathways for the detection of looming.9 pagesen-USScience & technologyLife sciences & biomedicineOphthalmologyMotion-3DVisual cortexHuman visual system2nd-order motionArea MTFrequency-selectivityTemporal frequency1st-order motionBrain damageHuman visionFirst orderAdaptation, physiologicalCuesDepth perceptionHumansOptic flowSize perceptionSpace perceptionVisual pathwaysMedical and health sciencesPsychology and cognitive sciencesExperimental psychologyArticle10.1167/11.3.50000-0002-5636-8352 (Vaina, Lucia M)68305