An Ideal Observer for Discrimination of the Global Direction of Dynamic Random Dot Stimuli
Document Type
Article
Publication Date
1-1-1993
Abstract
Random-dot cinematograms in which each dot’s successive movements are randomly drawn from a Gaussian distribution of directions can produce a percept of global coherent motion in a single direction. Discrimination of global direction was measured for various exposure durations, stimulus areas, and dot densities and bandwidths of the distribution of directions. Increasing the duration produced a greater improvement in performance than did increasing either the area or the density. Performance decreased as the distribution bandwidth increased. An ideal-observer model was developed, and the absolute efficiency for human direction discrimination was evaluated. Efficiencies were highest at large distribution bandwidths, with average efficiencies reaching 35%. A local–global noise model of direction discrimination, based on the ideal-observer model, containing a spatial and temporal integration limit as well as internal noise, was found to fit the human data well. The utility of ideal-observer analyses for psychophysical tasks and the interpretation of efficiencies is discussed.
Repository Citation
Watamaniuk, S. N.
(1993). An Ideal Observer for Discrimination of the Global Direction of Dynamic Random Dot Stimuli. Journal of the Optical Society of America, 10 (1), 16-28.
https://corescholar.libraries.wright.edu/psychology/629
DOI
10.1364/JOSAA.10.000016
