Phenomenology of attention: I. Color, location, orientation, and spatial frequency.

The effect of attention on the phenomenal appearance of objects was investigated in the domains of color (hue), location, line orientation, and spatial frequency. Observers indicated the appearance of a briefly presented above-threshold stimulus by selecting a matching stimulus along a sensory continuum (e.g., color). Attention was manipulated with a dual task that involved letter identification. Attention had little effect in changing the way objects appeared in terms of observers' mean response. However, in each stimulus domain, attention reduced the variability of responses. It is argued that attention should be viewed in terms of reducing uncertainty. (PsycINFO Database Record (c) 2010 APA, all rights reserved)