Spatial frequency and orientation specificities in metacontrast

Spatial frequency and orientation specific effects were found in metacontrast. A circular target stimulus (TS) patch and an annular masking stimulus (MS) patch were used, both with square wave gratings, the frequency of which were either 6.6 or 13.2 cpd. Orientation of TS was always vertical and that of MS was either vertical or horizontal. There was a spatial gap (d), 0′, 6′ or 12′ in visual angle between TS and MS. The masking effect was measured in terms of the apparent shrinkage in size (or completeness) of TS by the magnitude estimation method under four conditions of SOA (15, 55, 95 and 135 ms). The greatest masking occurred when TS and MS were matched in frequency and orientation and d was 0′. As frequency and orientation discrepancies between TS and MS increased, the masking effect diminished considerably

Cognitive psychology · Geometry · Masking (illustration) · Optics · Orientation (vector space) · Physics · Spatial frequency · Stimulus (psychology) · Advanced Optical Imaging Technologies · Infrared Target Detection Methodologies · Mathematics · Psychology · Visual perception and processing mechanisms