Distractor rejection in visual search breaks down with more than a single distractor feature

Area of Science:

• Cognitive Psychology
• Visual Perception
• Attention

Background:

• Color distractors interfere with visual search for shape singletons but not in feature search.
• Previous models suggest feature search relies on a single feature map, preventing interference.

Purpose of the Study:

• To investigate the impact of random color variation on visual search interference.
• To test whether interference occurs in feature search under conditions of unpredictable color.

Main Methods:

• Replication of previous findings on singleton detection vs. feature search.
• Introduction of random color variation for target and distractor stimuli.
• Experiment 2 manipulated fixed vs. variable target/distractor colors.

Main Results:

• Random color variation increased interference in both singleton detection and feature search.
• Interference in feature search occurred with variable distractor color when target color was fixed.
• Interference was absent when target color varied but distractor color was fixed.

Conclusions:

• Random variation of an irrelevant feature (color) forces attention to that feature, causing interference in feature search.
• The absence of interference in traditional feature search may be due to a single distractor feature.
• Current models may need revision to account for interference caused by variable irrelevant features.