Attentional capacity is undifferentiated: Concurrent discrimination of form, color, and motion

We report a series of experiments on the concurrent discrimination of form, color, and motion attributes. All tasks involved joint discrimination of a ttributes, and positions and were highly demanding of attention. We quantif ied interference between concurrent discriminations by establishing the att ention-operating characteristic. Interference was indistinguishable for sim ilar and dissimilar task combinations (form-form, color-color, motion-motio n, and color-form, color-motion, motion-color, and motion-form, respectivel y). These results suggest strongly that different visual discriminations dr aw on the same attentional capacity-in other words, that the capacity of vi sual attention is undifferentiated.