Experimental Psychology, Helmholtz Institute, Utrecht University Utrecht, Netherlands.
Front Psychol. 2011 Nov 8;2:314. doi: 10.3389/fpsyg.2011.00314. eCollection 2011.
In colour-grapheme synesthesia, non-coloured graphemes are perceived as being inherently coloured. In recent years, it is debated whether visual processing of synesthesia-inducing achromatic graphemes is similar to that of chromatic graphemes. Here, we exploit the phenomenon of binocular rivalry in which incompatible images presented dichoptically compete for conscious expression. Importantly, the competition only arises if the two images are sufficiently different; if the difference between the images is small, the images will fuse into a single mixed percept. We show that achromatic digits that induce synesthetic colour percepts increase the incidence of binocular rivalry compared to achromatic non-digits that do not evoke such percepts. That is, compared to achromatically perceived non-digits, synesthesia-inducing digits increase the predominance of binocular rivalry over binocular fusion. This finding shows that the synesthetic colour experience can provide the conditions for promoting binocular rivalry, much like stimulus features that induce rivalry in normal vision.
在颜色-文字联觉中，非彩色的文字被感知为固有颜色。近年来，人们一直在争论诱发联觉的非彩色文字的视觉处理是否与彩色文字的视觉处理相似。在这里，我们利用双眼竞争现象，其中呈现给双眼的不兼容图像会争夺有意识的表达。重要的是，如果两个图像足够不同，竞争才会出现；如果图像之间的差异很小，图像就会融合成一个单一的混合感知。我们表明，与不会引起这种感知的非彩色非数字相比，引起联觉颜色感知的非彩色数字会增加双眼竞争的发生率。也就是说，与非彩色感知的非数字相比，引起联觉的数字增加了双眼竞争相对于双眼融合的优势。这一发现表明，联觉的颜色体验可以提供促进双眼竞争的条件，就像在正常视觉中引起竞争的刺激特征一样。
