Prefrontal dimension change-related activation differs for visual search in sparse and dense displays

Area of Science:

• Neuroscience
• Cognitive Psychology
• Visual Perception

Background:

• Anterior prefrontal cortex activation increases with changes in target-defining feature dimensions.
• Previous studies predominantly observed this activation in the left lateral frontopolar cortex.
• A discrepancy exists, with one study reporting right anterior prefrontal activation using sparse displays.

Purpose of the Study:

• To investigate if display density influences the laterality of anterior prefrontal cortex activation during attentional dimension changes.
• To explore differing neural processes in efficient (dense) versus inefficient (sparse) visual search.

Main Methods:

• Participants performed visual search tasks using both dense and sparse displays.
• Brain activity in the anterior prefrontal cortex was monitored during target-defining feature dimension changes.
• Functional magnetic resonance imaging (fMRI) or electroencephalography (EEG) likely used to measure brain activation.

Main Results:

• Changes in the target-defining feature dimension selectively activated the right frontopolar cortex during sparse display search.
• The reverse pattern was observed in the left frontopolar cortex during dense display search.
• This indicates that display density modulates the neural correlates of dimension change detection.

Conclusions:

• Different neural processes underlie visual search in sparse and dense displays.
• The laterality of anterior prefrontal cortex activation is dependent on display density.
• This resolves the apparent discrepancy in previous findings regarding dimension change-related activation.