Abstract
Visual detection thresholds were measured for one-dimensional static noise patterns centered at 2 c/deg on a logarithmic scale, for several widths and spatial frequency bandwidths in the presence and absence of a one-dimensional dynamic visual noise mask. Human performance was compared with the ideal observer's performance for the same task. The ideal's contrast thresholds increase with the fourth root of bandwidth. For thresholds measured in the presence and absence of noise, the fourth-root-law for bandwidth fitted the human observers data from 1 to 6 octaves for a space constant of 2° and from 2 to 6 octaves for a space constant of 0.25°. Detection efficiencies were quite high (30-60%) for patterns of 1- and 6-octave bandwidths. These results can be interpreted either in terms of a channel with an adjustable spatial frequency bandwidth or as very efficient combination of information between spatial frequency channels.
| Original language | English (US) |
|---|---|
| Pages (from-to) | 1029-1040 |
| Number of pages | 12 |
| Journal | Vision Research |
| Volume | 27 |
| Issue number | 6 |
| DOIs | |
| State | Published - 1987 |
Bibliographical note
Funding Information:Acknowledgementsw-1o uld like to thankD r G. E. Legge, Dr D. Pelli, Dr G. Rubin and G. Wakefieldf or manyh ours of usefuld iscussionI. also wish to thankD rs J. G. Robson, N. ViemeisterD, . Burkhardt,R . Purplea nd H. Gershenson for criticismsa nd suggestionsM. . Bergman,B . Witkofsky, M. Schleskea nd D. Koenen provided technicals upport. Joanne Kersten typed and Philip Kersten observed.T he experimentrse portedin thisp aperf ormedp artof a doctoral dissertations ubmittedto the Universityo f Minnesota( Ker-sten, 1983).T he researchw as supportedb y PHS grant EY02857 to Dr Legge and a University of Minnesota Doctoral DissertationG rant. This paperw as completeda t the PhysiologicalL aboratory, University of Cambridge, with the support of an NIH postdoctoral fellowship EYO5660.
Keywords
- Detection Efficiency Visual noise Spatial-frequency