Correani Alessia, Scott-Samuel Nicholas E, Leonards Ute
Department of Experimental Psychology, Bristol University, Bristol BS8 1TN, UK.
Vision Res. 2006 Oct;46(22):3915-25. doi: 10.1016/j.visres.2006.05.001. Epub 2006 Jun 12.
Light-emitting objects are perceived as qualitatively different from light-reflecting objects, and the two categories elicit different cortical activity. However, it is unclear whether object luminosity is treated as an independent visual feature, comparable to orientation, motion or colour. Visual search tasks revealed that light-emitting targets led to efficient search when presented with light-reflecting distractors of similar luminance, but this efficiency was induced by the presence of luminance gradients producing the percept of luminosity rather than by luminosity itself. This implies that luminance gradients (not object luminosity) are encoded as features, questioning the existence of specific sensory mechanisms to detect light-emitting objects.
发光物体在性质上被认为与反光物体不同，并且这两类物体会引发不同的皮层活动。然而，目前尚不清楚物体的发光度是否被视为一种独立的视觉特征，可与方向、运动或颜色相媲美。视觉搜索任务表明，当发光目标与亮度相似的反光干扰物一起呈现时，能实现高效搜索，但这种效率是由产生发光度感知的亮度梯度的存在所引发的，而非发光度本身。这意味着亮度梯度（而非物体发光度）被编码为特征，这对检测发光物体的特定感觉机制的存在提出了质疑。
