Magnussen S, Greenlee M W
Department of Psychology, University of Oslo, Norway.
J Exp Psychol Hum Percept Perform. 1997 Dec;23(6):1603-16. doi: 10.1037//0096-1523.23.6.1603.
Discrimination thresholds for spatial frequency and contrast tested individually were compared with dual discrimination of contrast and spatial frequency, and dual discrimination of 2 contrast or spatial frequency components. The components were presented overlapping, forming a compound grating or as side-by-side simple gratings. When observers had to judge contrast and spatial frequency simultaneously, discrimination thresholds increased by an amount predicted by a model of stimulus uncertainty for orthogonal dimensions (1.7); when they had to judge 2 frequency or contrast components, discrimination thresholds increased by a factor of 3-6 compared with the single-judgment task. The relative spatial location of the components did not interact with task complexity. The results are consistent with a model assuming a set of parallel special-purpose attentional mechanisms.
将单独测试的空间频率和对比度的辨别阈值与对比度和空间频率的双重辨别，以及两个对比度或空间频率成分的双重辨别进行了比较。这些成分以重叠的方式呈现，形成一个复合光栅，或者作为并排的简单光栅。当观察者必须同时判断对比度和空间频率时，辨别阈值增加的幅度由一个针对正交维度的刺激不确定性模型预测（1.7）；当他们必须判断两个频率或对比度成分时，与单判断任务相比，辨别阈值增加了3至6倍。成分的相对空间位置与任务复杂性没有相互作用。结果与假设一组并行专用注意机制的模型一致。
