Post-stroke lesion correlates of errors in verbal and spatial production tasks

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Traditional models of stroke-induced impairments often assign verbal deficits to the left hemisphere and spatial deficits to the right hemisphere.
• However, performance monitoring, crucial after stroke, may involve both domain-general and domain-specific neural components.
• The error-monitoring hypothesis suggests domain-incongruent lateralization, predicting left hemisphere dominance for spatial errors and right hemisphere dominance for verbal errors.

Purpose of the Study:

• To investigate the neural correlates of performance monitoring in acute stroke patients.
• To examine the validity of traditional lateralization models in the context of error monitoring.
• To test the error-monitoring hypothesis regarding domain-incongruent specialization in post-stroke cognitive deficits.

Main Methods:

• Voxel-based lesion-behavior mapping was conducted in 110 acute stroke patients.
• Patients completed a cognitively demanding, error-prone spatial design fluency task and a verbal word-fragment completion task.
• Lesion locations were correlated with error rates in both tasks.

Main Results:

• Significant correlations were found between lesion location and error rates for both spatial fluency (r=0.36) and verbal completion (r=0.31).
• Right inferior frontal lesions were associated with errors in both tasks.
• Left frontal white matter (WM) lesions correlated with spatial errors, while right frontal WM lesions correlated with verbal errors, even after controlling for demographics.

Conclusions:

• Post-stroke performance monitoring involves at least two distinct neural systems: a domain-general system (likely right inferior frontal) for overall accuracy and a reverse lateralized system for domain-specific accuracy.
• Left hemisphere lesions are associated with spatial accuracy deficits, and right hemisphere lesions with verbal accuracy deficits.
• These findings challenge traditional lateralization models, suggesting more complex hemispheric interactions in performance monitoring after stroke.