When errors are present in the perceived depth between the parts of a physically stationary object, the object appears to rotate as the head is moved laterally (Gogel, 1980). This illusory rotation has been attributed either to compensation (Wallach, 1985, 1987) or to inferential-like processes (Rock, 1983). Alternatively, the perceived distances of and directions to the parts of the object are...

We examined how much depth we perceive when viewing a depiction of a slanted plane in which binocular disparity and monocular perspective provide different slant information. We exposed observers to a grid stimulus in which the monocular--and binocular-specified grid orientations were varied independently across stimulus presentations. The grids were slanted about the vertical axis and observer...

The perceived direction of different barber-pole stimuli was assessed by adjusting an arrow on the screen. The terminator ratio (TR: number of terminators moving along the long side divided by the number of terminators moving along the small side) was either one or three. In this latter case, the aperture orientation was either vertical or horizontal. The grating was either in the same plane as...

Binocular rivalry is the alternating perception that occurs when the two eyes are presented with incompatible stimuli. We have developed a new method for controlling binocular rivalry and measuring its progress. One eye views a static grating while the fellow eye views a grating that smoothly and cyclically varies between two orientations, one the same as the static grating and the other orthog...

This study investigated luminance and texture-defined spatial information processing in normal aging using an adapted Landolt-C technique. Sensitivity to C-target stimuli (optotypes) was measured for four age groups: 18-34, 35-49, 50-64, and 65+ years. Participants indicated optotype gap-opening orientations (up, down, left, or right) at different levels of luminance or texture contrast. Althou...

Binocular disparity and motion parallax provide information about the spatial structure and layout of the world. Descriptive similarities between the two cues have often been noted which have been taken as evidence of a close relationship between them. Here, we report two experiments which investigate the effect of surface orientation and modulation frequency on (i) a threshold detection task a...

In this study, we used event-related functional magnetic resonance imaging to investigate whether visual mental images retinotopically activate early visual cortex. Six participants were instructed to visualize or view horizontally or vertically oriented flashing bow-tie shaped stimuli. When compared to baseline, imagery globally activated Area V1. When the activation evoked by the stimuli at t...

Detection of a Gabor pattern is impaired in the presence of a similar pattern of orthogonal orientation, a phenomenon known as cross-orientation masking (XOM). Here we investigate the role of color in cross-orientation masking. We measured contrast detection thresholds to horizontally oriented Gabors overlaid by similar Gabors of a different orientation. Red-green chromatic masking was compared...

We investigate a measure of \dominant perceived orienta-tion" that has recently been developed to match the output of a human study involving 40 subjects. The results of this measure are compared with humans analyzing seven \teaser" images to test its eeectiveness for nding perceptually dominant orientations. The use of low-level orientation is then applied to a \quick search" problem important...