Orientation-Specific Computation in Stereoscopic Vision

Farell, Bart

doi:10.1523/jneurosci.1100-06.2006

Cited by 10 publications

(23 citation statements)

References 59 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Also, the plaids’ contrast envelopes, despite their fixed disparities, were not useful as reference stimuli against which to judge the depth of the test plaid. The disparities appearing in this study are far smaller than the threshold disparity for an isolated grating patch, with an envelope disparity of zero, having the same carrier spatial frequency as used here (Farell, 2006). The observed values in that case are characteristic of absolute, not relative, disparity thresholds.…”

Section: Methodsmentioning

confidence: 69%

“…This is an advantage of coding disparity along a stimulus-independent direction. The visual system does not do this with 1-D stimuli like gratings, but rather codes disparity and orientation jointly (Farell, 2006; Farell et al, 2009). …”

Section: Discussionmentioning

confidence: 99%

“…It is not known what the effects might be in this study. However, an effect on disparity thresholds occurs for grating patches (Farell, 2006). Using a center-surround arrangement eliminates it.…”

Section: Methodsmentioning

confidence: 99%

See 2 more Smart Citations

The horizontal disparity direction vs. the stimulus disparity direction in the perception of the depth of two-dimensional patterns

Farell

Chai

Fernandez

2010

JOV

View full text Add to dashboard Cite

Horizontal binocular disparity has long been the conventional predictor of stereo depth. Surprisingly, an alternative predictor fairs just as well. This alternative predicts the relative depth of two stimuli from the relation between their disparity vectors, without regard to horizontal disparities. These predictions can differ; horizontal disparities accurately predict the perceived depth of a grating and a plaid only when the grating is vertical, while the vector calculation accurately predicts it at all except near-horizontal grating orientations. For spatially two-dimensional stimulus pairs, such as plaids, dots, and textures, the predictions cannot be distinguished when the stimuli have the same disparity direction or when the disparity direction of one of the stimuli is horizontal or has a magnitude of zero. These are the conditions that have prevailed in earlier studies. We tested whether the perceived depth of two-dimensional stimuli depends on relative horizontal disparity magnitudes or on relative disparity magnitudes along a disparity axis. On both measures tested—depth matches and depth-interval matches—the perceived depth of plaids varied with their horizontal disparities and not with disparity direction differences as observed for grating-plaid pairs. Differences in disparity directions as great as 120° did not affect depth judgments. This result, though opposite the grating-plaid data, is consistent with them and provides a view into the construction of orientation-invariant disparity representations.

show abstract

Section: Methodsmentioning

confidence: 69%

Section: Discussionmentioning

confidence: 99%

See 1 more Smart Citation

The horizontal disparity direction vs. the stimulus disparity direction in the perception of the depth of two-dimensional patterns

Farell

Chai

Fernandez

2010

JOV

View full text Add to dashboard Cite

show abstract

“…Horizontal disparity supplies the common metric for perceived depth in most laboratory studies and theories of stereopsis. However, two 1-D stimuli, if they have different orientations and identical horizontal disparities, will have different effective disparities: The two stimuli can appear at different depths relative to the same reference stimulus Farell, 2006;Farell, Chai, & Fernandez, 2009;Ito, 2005). By dissociating perceived depth from horizontal disparity, 1-D stimuli allow us to create a set of stimulus pairs whose depth relations, taken together, violate transitivity, despite the normal appearance of each pair when viewed individually.…”

Section: Discussionmentioning

confidence: 99%

“…The result is that stereoacuity and perceived depth for 1-D patterns vary with stimulus orientation, a fact known for many years but open to diverse interpretations (Blake, Camisa, & Antoinetti, 1976;Ebenholtz & Walchli, 1965;Farell & Ahuja, 1996;Friedman, Kaye, & Richards, 1978;Morgan & Castet, 1997;Ogle, 1955; see Howard & Rogers, 2002). In general, the psychophysical effects of 1-D stimulus orientation are consistent with an effective disparity that has a direction perpendicular to the orientation Farell, 1998Farell, , 2006Morgan & Castet, 1997;Patel, Bedell, & Sampat, 2006;Patel et al, 2003;Quaia et al, 2013), though the physiological evidence is mixed (e.g., Cumming, 2002;Durand, Celebrini, & Trotter, 2007;Maske, Yamane, & Bishop, 1986).…”

Section: Introductionmentioning

confidence: 88%

Perceived depth in non-transitive stereo displays

Farell

2014

Vision Research

View full text Add to dashboard Cite

The separation between the eyes shapes the distribution of binocular disparities and gives a special role to horizontal disparities. However, for one-dimensional stimuli, disparity direction, like motion direction, is linked to stimulus orientation. This makes the perceived depth of one-dimensional stimuli orientation dependent and generally non-veridical. It also allows perceived depth to violate transitivity. Three stimuli, A, B, and C, can be arranged such that A > B (stimulus A is seen as farther than stimulus B when they are presented together) and B > C, yet A ⩽ C. This study examines how the visual system handles the depth of A, B, and C when they are presented together, forming a pairwise inconsistent stereo display. Observers' depth judgments of displays containing a grating and two plaids resolved transitivity violations among the component stimulus pairs. However, these judgments were inconsistent with judgments of the same stimuli within depth-consistent displays containing no transitivity violations. To understand the contribution of individual disparity signals, observers were instructed in subsequent experiments to judge the depth of a subset of display stimuli. This attentional instruction was ineffective; relevant and irrelevant stimuli contributed equally to depth judgments. Thus, the perceived depth separating a pair of stimuli depended on the disparities of the other stimuli presented concurrently. This context dependence of stereo depth can be approximated by an obligatory pooling and comparison of the disparities of one- and two-dimensional stimuli along an axis defined locally by the stimuli.

show abstract

Projected disparity, not horizontal disparity, predicts stereo depth of 1-D patterns

2009

View full text Add to dashboard Cite

Binocular disparities have a straightforward geometric relation to object depth, but the computation that humans use to turn disparity signals into depth percepts is neither straightforward nor well understood. One seemingly solid result, which came out of Wheatstone’s work in the 1830’s, is that the sign and magnitude of horizontal disparity predict the perceived depth of an object: ‘Positive’ horizontal disparities yield the perception of ‘far’ depth, ‘negative’ horizontal disparities yield the perception of ‘near’ depth, and variations in the magnitude of horizontal disparity monotonically increase or decrease the perceived extent of depth. Here we show that this classic link between horizontal disparity and the perception of ‘near’ versus ‘far’ breaks down when the stimuli are one-dimensional. For these stimuli, horizontal is not a privileged disparity direction. Instead of relying on horizontal disparities to determine their depth relative to that of two-dimensional stimuli, the visual system uses a disparity calculation that is non-veridical yet well suited to deal with the joint coding of disparity and orientation.

show abstract

Orientation-Specific Computation in Stereoscopic Vision

Cited by 10 publications

References 59 publications

The horizontal disparity direction vs. the stimulus disparity direction in the perception of the depth of two-dimensional patterns

The horizontal disparity direction vs. the stimulus disparity direction in the perception of the depth of two-dimensional patterns

Perceived depth in non-transitive stereo displays

Projected disparity, not horizontal disparity, predicts stereo depth of 1-D patterns

Contact Info

Product

Resources

About