Statistical Learning of Frequent Distractor Locations in Visual Search Involves Regional Signal Suppression in Early...

Area of Science:

• Cognitive Neuroscience
• Neuroimaging
• Visual Attention

Background:

• Observers learn to suppress distractors at frequently encountered locations.
• Mechanisms of distractor suppression in visual and attention networks are not fully understood.

Purpose of the Study:

• Investigate neural implementation of distractor suppression based on location learning.
• Differentiate neural mechanisms for same- vs. different-dimension distractors.

Main Methods:

• Functional magnetic resonance imaging (fMRI) with a regional distractor-location learning paradigm.
• Used same- (orientation) and different- (color) dimension distractors relative to the target.

Main Results:

• Reduced BOLD signals in early visual cortex for frequent vs. rare distractor locations, stronger for same-dimension distractors.
• Behavioral interference correlated with visual activity for same-dimension distractors only.
• Different-dimension distractors activated fusiform gyrus color-processing areas differently based on location frequency.

Conclusions:

• Statistical learning of frequent distractor locations involves regional suppression in early visual cortex.
• Differential neural mechanisms underlie distractor handling for same- vs. different-dimension distractors.