Adaptability and specificity of inhibition processes in distractor-induced blindness.

Abstract

In a rapid serial visual presentation task, inhibition processes cumulatively impair processing of a target possessing distractor properties. This phenomenon-known as distractor-induced blindness-has thus far only been elicited using dynamic visual features, such as motion and orientation changes. In three ERP experiments, we used a visual object feature-color-to test for the adaptability and specificity of the effect. In Experiment I, participants responded to a color change (target) in the periphery whose onset was signaled by a central cue. Presentation of irrelevant color changes prior to the cue (distractors) led to reduced target detection, accompanied by a frontal ERP negativity that increased with increasing number of distractors, similar to the effects previously found for dynamic targets. This suggests that distractor-induced blindness is adaptable to color features. In Experiment II, the target consisted of coherent motion contrasting the color distractors. Correlates of distractor-induced blindness were found neither in the behavioral nor in the ERP data, indicating a feature specificity of the process. Experiment III confirmed the strict distinction between congruent and incongruent distractors: A single color distractor was embedded in a stream of motion distractors with the target consisting of a coherent motion. While behavioral performance was affected by the distractors, the color distractor did not elicit a frontal negativity. The experiments show that distractor-induced blindness is also triggered by visual stimuli predominantly processed in the ventral stream. The strict specificity of the central inhibition process also applies to these stimulus features.