Binocular Summation and Peripheral Visual Response Time

Binocular summation of chromatic changes as measured by visual reaction time

“…This test also indicated for each observer that the VRT for the right and left eye did not differ significantly ( p = .78 for J.A., p = .32 for J.M., and p = .30 for J.R.). VRT was also found to be shorter for binocular than for monocular viewing, as reported in other studies (Blake et al, 1980;Gilliland & Haines, 1975;Haines, 1977;Minucci & Connors, 1964;Ueno, 1977;Westendorf & Blake, 1988).…”

The effect of pupil size on binocular summation at suprathreshold conditions

“…In accordance with a "kill the twin" procedure, [33][34][35] reactions shorter than 110 ms were discarded as false alarms while those exceeding 1500 ms were also excluded as misses. These cut-off values were similar to those used in other studies of binocular summation for luminance changes 17,25,36,37 and other studies of reaction time. 29,34,35,38 We ran a number of sessions until no fewer than 80 VRTs had been collected for each test stimulus under each experimental condition.…”

“…46 In our case, It could be argued that If cortical pupil mechanisms influence our results when artificial pupils are used, our binocular-summation values for natural pupils would be similar to those found under similar observational conditions, but when luminance is decreased. The works of Minucci & Connors, 40 Gilliand and Haines, 36 and Haines 37 present conditions similar to our experimental configuration (detection of white luminance flashes in the dark, on fovea, without spatial frequency and under natural pupils), but at low intensity levels (three of four intensity levels examined by Minucci . From the VRT tables presented in these works, we estimated binocularsummation ratios according to Expression (1).…”

“…23 Also, the preceding analysis with natural pupils but at low luminance ranges 36,37,40 suggests, on average, the influence of cortical pupil mechanisms on binocular summation. Nevertheless, not all binocular-summation values could be influenced by this factor.…”

“…For both subjects (JM and JR), a three-way analysis of variance (ANOVA) showed significant differences in the main factors between the natural and artificial pupil (JM, 17,22,25,36,37,40 On the other hand, there were no differences in VTRs between the two eyes for monocular viewing (JM, right eye vs. left eye, p = 0.70; JR, right eye vs. left eye, p = 0.81). Figure 1 presents for both subjects and for each observational condition, the total VRT average on 12 experimental conditions, for natural and artificial pupils.…”