Abstract
Purpose: :
To investigate the possibility of a gender difference in peripheral colour vision, using an asymmetric matching paradigm.
Methods: :
19 male (aged 29 ± 10years; mean ± s.d.) and 19 female (aged 24 ± 6 years) observers participated in the study. All the 38 observers were tested for colour vision deficiency using the 100 Hue Farnsworth-Munsell colour vision test, the Ishihara plates (38-plate edition, 1979) and the Nagel Anomaloscope and found to be colour normal. They performed an asymmetric colour-matching paradigm, in which a 1o probe (at 1o eccentricity) and a 3o test spot (at 18o eccentricity) were presented simultaneously, in the nasal visual field, for 380ms. The colour (chromatic axis) of the probe was changed in 24 directions in CIE 1931 colour space, in 15o steps. All stimuli had the same starting purity in terms of vector length, so that they formed a circle in CIE colour space. The white point (purity = 0) was illuminant C at 12.5cd/m2 (x=0.31, y=0.316). The observers matched the test spot with the probe, for hue and saturation.
Results: :
In the males mean saturation loss in the green-yellow region of the colour space was 0.21±0.29 (42%). For females mean saturation loss in the green-yellow region was 0.11±0.21 (22%). The male-female difference was statistically significant in the green-yellow region of the colour space (p<0.001, independent sample t-test). No statistically significant difference for saturation loss was found between the two groups in the red and blue region of colour space. All subjects demonstrated the chromatic axis-dependent distortion in hue that we have previously reported (Parry et al. 2006, JOSA A, 23, p1586-97) but there was no significant sex difference.
Conclusions: :
In the peripheral visual field all observers experience reduced saturation in the green region of colour space. Female observers with normal colour vision experience less saturation loss in the periphery when compared with the male observers.
Keywords: color vision • color appearance/constancy • color pigments and opsins