Distinct neural substrates underlying target facilitation and distractor suppression: A combined voxel-based...

Area of Science:

• Neuroscience
• Cognitive Neuroscience
• Neuroimaging

Background:

• Selective attention involves prioritizing relevant information (target facilitation) and suppressing irrelevant information (distractor suppression).
• While distinct mechanisms are suggested, the neural substrates for these two attention processes remain unclear.
• Understanding these substrates is crucial for cognitive neuroscience and understanding attentional disorders.

Purpose of the Study:

• To investigate the distinct neural substrates underlying target facilitation and distractor suppression.
• To explore the relationship between structural brain differences (gray matter volume) and functional connectivity with behavioral performance in attention tasks.
• To provide neural evidence for separate structural and functional bases of target facilitation and distractor suppression.

Main Methods:

• Acquired structural and resting-state magnetic resonance imaging (rs-fMRI) scans and behavioral data from a modified Posner cueing task.
• Employed voxel-based morphometry (VBM) to analyze gray matter volume (GMV) and resting-state functional connectivity (rsFC) to assess brain network interactions.
• Used multiple linear regression to determine the combined explanatory power of GMV and rsFC on attentional benefits.

Main Results:

• Behavioral data showed faster responses in target cue (TC) and distractor cue (DC) conditions compared to baseline.
• VBM revealed distinct frontoparietal gray matter volume correlates for TC-benefit (superior frontal gyrus, postcentral gyrus) and DC-benefit (superior parietal lobe, middle frontal gyrus, angular gyrus).
• rsFC analysis indicated that TC-benefit correlated with distributed SFG connections (ventral attention, somato-motor networks), while DC-benefit correlated with centralized SFG connections (frontoparietal, dorsal/ventral attention networks).

Conclusions:

• Target facilitation and distractor suppression are supported by distinct structural and functional neural substrates within the frontoparietal cortex.
• Gray matter volume and resting-state functional connectivity jointly explain individual differences in attentional performance.
• These findings offer significant neural evidence differentiating the underlying mechanisms of focusing on targets versus ignoring distractors.