Difficulties in the definition of ?stereoscotoma? using temporal detection of thresholds of dynamic random dot stereograms

Abstract

Temporal detection thresholds are reported from two subjects to dynamic random dot stereograms (DRDSs) of both crossed and uncrossed disparity. The stimuli were 1 degree square, of 0.25 degrees disparity and were presented at 81 positions in a 9 degree square central region. In both subjects crossed disparity stimuli were detected at shorter durations. One subject displayed particularly acute stereoscopic vision and presented a pattern of temporal thresholds increasing gradually with eccentricity. The other subject displayed evidence, particularly in response to uncrossed stimuli, of a 'stereo-scotoma' which was not evident in monocular testing or ophthalmologic examination. Criteria used to define 'stereo-scotoma' are discussed. It was concluded that, although left-right field differences may be found with a large subject sample, individual factors may be more important in the distribution of stereo sensitivity throughout the portion of visual field tested.

Disparity-Tuning Characteristics of Neuronal Responses to Dynamic Random-Dot Stereograms in Macaque Visual Area V4

“…Ample psychophysical evidence indicates perceptual asymmetry between crossed and uncrossed disparity conditions. Crossed disparity requires less stimulus duration than uncrossed disparity for stereoscopic depth perception (Finlay et al 1989;Landers and Cormack 1997;Manning et al 1987;Patterson et al 1995;Tam and Stelmach 1998). Therefore for a given stimulus duration, stereo threshold is lower for crossed than uncrossed disparity.…”

“…This section formulates the responses of the disparity energy model proposed by Ohzawa et al (1990). Many of the mathematical details have been previously described for other stimuli such as sinusoidal gratings (Fleet et al 1996;Qian 1994;Qian and Zhu 1997;Zhu andQian 1996), static RDSs (Fleet et al 1996;Qian 1994;Qian and Zhu 1997;Zhu andQian 1996), dynamic RDSs (Prince et al 2002a), SFSs containing a thin static bar (Mikaelian and Qian 2000; Qian 1994), and SFSs containing a thin sweeping bar (Anzai et al 1999;Ohzawa et al 1997). Here, we derive the analytical solution for the disparity tuning of a model complex cell, in response to a dynamic RDS and a thin static bar SFS.…”

A Planar and a Volumetric Test for Stereoanomaly

“…At the very least, one needs different spatiotemporal characteristics for stereo processing over crossed and uncrossed ranges of disparity, which again leads to the more parsimonious conclusion that there are at least two separate mechanisms. Indeed, the spatiotemporal characteristics of these depth^disparity mechanisms have been estimated and are found different (Finlay et al 1989;Patterson et al 1995;Richards 1972;Schor and Wood 1983).…”

50 Years of Stereoblindness: Reconciliation of a Continuum of Disparity Detectors With Blindness for Disparity in Near or Far Depth

“…Multiple psychophysical studies ( Birch, Gwiazda, & Held, 1982 ; Breitmeyer, Julesz, & Kropfl, 1975 ; Finlay, Manning, Dunlop, & Dewis, 1989 ; Herring & Bechtoldt, 1981 ; Manning, Finlay, Neill, & Frost, 1987 ; Patterson et al., 1995 ; Regan, Erkelens & Collewijn, 1986 ; Schor & Wood, 1983 ) have reported on asymmetries in sensitivity for far and near disparities (see also reviews in Landers & Cormack, 1997 ; Mustillo, 1985 ; Regan, Frisby, Poggio, Schor, & Tyler, 1990 ). For example, developmental work showed that infants develop near stereopsis prior to far stereopsis ( Birch et al., 1982 ).…”

“…For example, developmental work showed that infants develop near stereopsis prior to far stereopsis (Birch et al, 1982). In the adult, it has been reported that there are different spatiotemporal response functions for far and near disparities (Finlay et al, 1989;Manning et al, 1987;Patterson et al, 1995;Schor & Wood, 1983).…”