Table 1.
32 adapt-test pairings, grouped into sixteen conditions according to angular difference and ocular presentation mode.
Figure 1.
An example of the spatial configuration of adaptor and test stimuli.
Four conditions are shown (clockwise from left): monoptic 0°, dichoptic 0°, dichoptic 90° and monoptic 90°. The figure provides an example of possible adaptor stimuli configurations, and the two possible configurations of target stimuli.
Figure 2.
Individual and mean monoptic threshold elevation estimates as a function of angular difference between adaptor and test stimuli.
The data points are fitted with a standard von Mises model (Equation 1; black dashed lines) and a von Mises model with an isotropic amplitude component included (Equation 2; solid lines). Chi-square estimates of each fit are included for individual subjects and averaged data. Differences in chi-square greater than 3.84 are deemed statistically significant (p<.05, 1 degree of freedom).
Figure 3.
Individual and mean dichoptic threshold elevation estimates as a function of angular difference between adaptor and test stimuli.
The data points are fitted with a standard von Mises model (Equation 1; black dashed lines) and a von Mises model with an additive isotropic amplitude component (Equation 2; solid lines). Chi-square estimates of each fit are included for individual subjects and averaged data. Differences in chi-square greater than 3.84 are deemed statistically significant (p<.05, 1 degree of freedom).
Figure 4.
Comparison of circular variance (κ) as a function of spatial frequency.
Data represent threshold elevation averaged across subjects in the 2 c.p.d. monoptic condition. In one case, Equation 2 is fit with two free parameters (κ and α; solid curve) while in the other it is fit with only one free parameter (α), with κ was fixed at the value found in the 0.25 c.p.d. monoptic condition (dashed curve). The difference between these fits fails to exceed the critical value of 3.84 (p>.05; 1 degree of freedom), indicating no significant difference in bandwidths (circular variance) across spatial frequency.
Table 2.
Parametric, bandwidth and chi-square and estimates for each spatial frequency and ocular mode of presentation using Von Mises Equations 1 and 2.
Figure 5.
Effect of ocular presentation mode on bandwidths.
(a) Comparison of circular variance (κ) as a function of ocular presentation mode. Data represent threshold elevation averaged across subjects in the 0.25 c.p.d. dichoptic condition. In one case, Equation 2 is fit with two free parameters (κ and α; solid curve) while in the other it is fit with only one free parameter (α), with κ was fixed at the value found in the 0.25 c.p.d. monoptic condition (dashed curve). The difference between these fits exceeds the critical value of 3.84 (p>.05; 1 degree of freedom), indicating broader bandwidths (smaller estimates of κ) in the dichoptic condition. (b) Average estimates of bandwidth (HWHA) measured under monoptic and dichoptic adaptation conditions (0.25 c.p.d.) using Equation 1 for the dichoptic and Equation 2 (κ and α both free to vary) for the monoptic condition.