2004/09/01 by Fred W. Mast, Charles M. Oman · 1 citation
Neuroscience · Computer Science · #Visual perception and processing mechanisms #Virtual Reality Applications and Impacts #Tactile and Sensory Interactions
paper · doi:10.1024/1421-0185.63.3.143
openalex publication_date 2004/09/01 · openalex created_date 2025/10/10 · openalex updated_date 2026/06/26
The role of top-down processing on the horizontal-vertical line length illusion was examined by means of an ambiguous room with dual visual verticals. In one of the test conditions, the subjects were cued to one of the two verticals and were instructed to cognitively reassign the apparent vertical to the cued orientation. When they have mentally adjusted their perception, two lines in a plus sign configuration appeared and the subjects had to evaluate which line was longer. The results showed that the line length appeared longer when it was aligned with the direction of the vertical currently perceived by the subject. This study provides a demonstration that top-down processing influences lower level visual processing mechanisms. In another test condition, the subjects had all perceptual cues available and the influence was even stronger.