Spatial Attention Effects During Conscious and Nonconscious Processing of Visual Features and Objects.

Flanker congruency effects were measured in a masked flanker task to assess the properties of spatial attention during conscious and nonconscious processing of form, color, and conjunctions of these features. We found that (1) consciously and nonconsciously processed colored shape distractors (i.e., flankers) produce flanker congruency effects; (2) these congruency effects decrease with increasing separation between the probe and the flanking stimuli; (3) this decrease occurs even when flankers are suppressed from awareness; and (4) regardless of whether the form, color, or conjunction of these features have to be attended. Importantly, (5) flanker congruency effects decrease at nearly comparable rates when flankers are visible or masked, which suggests that for separate and conjoint features (i.e., objects), the gradient of spatial attention at the conscious and nonconscious levels of processing is almost identical, with the possibility of a slightly broader gradient for nonconsciously processed visual information. [ABSTRACT FROM AUTHOR]