White matter networks dissociate semantic control from semantic knowledge representations: Evidence from voxel-based...

Area of Science:

• Neuroscience
• Cognitive Science
• Neurolinguistics

Background:

• The semantic system comprises distinct processes: semantic knowledge and semantic control.
• Understanding the neuroanatomical dissociation between these processes is crucial but remains unclear.

Purpose of the Study:

• To investigate the white matter neuroanatomy underlying semantic knowledge and semantic control.
• To identify specific white matter networks associated with deficits in semantic knowledge and semantic control.

Main Methods:

• Recruited patients with semantic dementia (SD) and semantic aphasia (SA), exhibiting selective deficits in semantic knowledge and control, respectively.
• Utilized regression models to correlate white matter damage with semantic performance in each patient group.
• Conducted voxel-based analysis to identify additional semantic-relevant white matter tracts.

Main Results:

• Semantic knowledge deficits in SD patients were linked to the left medial temporal white matter network.
• Semantic control deficits in SA patients were associated with damage to left frontal-temporal/occipital and frontal-subcortical networks.
• Additional semantic-relevant white matter tracts were identified through voxel-based analysis.

Conclusions:

• Semantic knowledge and semantic control rely on dissociable white matter networks.
• Findings specify different processing principles within the semantic system based on distinct neuroanatomical substrates.