Shared and distinct structure-function substrates of heterogenous distractor suppression ability between high and low...

Area of Science:

• Neuroscience
• Cognitive Psychology

Background:

• Salient stimuli capture attention bottom-up, but can be suppressed top-down.
• High working memory capacity (WMC) is linked to better suppression of salient, irrelevant distractors.
• Neural mechanisms underlying WMC-related differences in distractor suppression are not fully understood.

Purpose of the Study:

• To investigate the neuroanatomical differences associated with high versus low WMC in suppressing salient distractors.
• To explore the relationship between brain structure, functional connectivity, and distractor suppression performance across WMC groups.

Main Methods:

• Participants with high or low WMC performed a visual search task with a salient color singleton distractor.
• Structural and resting-state functional magnetic resonance imaging (fMRI) were used.
• Voxel-based morphometry and functional connectivity analyses were conducted.

Main Results:

• High-WMC individuals showed superior distractor suppression, indicated by a larger reaction time benefit (ΔRT).
• Gray matter morphology in the ventral attention network (VAN) positively correlated with ΔRT in both groups.
• Gray matter morphology in the frontoparietal (FPN)/default mode network (DMN) showed opposite correlations with ΔRT between WMC groups.
• Connectivity between DMN and VAN hubs correlated with ΔRT in high-WMC individuals only.

Conclusions:

• Shared and distinct neuroanatomical substrates underlie distractor suppression in high- and low-WMC individuals.
• Intrinsic brain network connectivity, particularly in high-WMC individuals, may underlie their enhanced ability to suppress salient distractors.