Interaction between spatial neglect and attention deficit in patients with right hemisphere damage

Area of Science:

• Neuroscience
• Cognitive Psychology
• Neurology

Background:

• Unilateral spatial neglect (USN) is increasingly understood as a disruption within the broader attention network, not solely a parietal lobe issue.
• Existing evaluations often do not fully disentangle spatial neglect from non-spatial attention deficits.

Purpose of the Study:

• To develop and validate a novel evaluation approach for USN by analyzing the spatial distribution of reaction times.
• To investigate the interaction between spatial neglect and non-spatial attention deficits.

Main Methods:

• 174 right hemisphere damage patients were categorized based on USN severity using the Behavioral Inattention Test (BIT).
• A touch panel pointing task was used to record reaction times to targets arranged on a PC monitor.
• Reaction time metrics (RTmean for overall attention, L/R ratio for neglect) were calculated and analyzed using voxel-based lesion-symptom mapping and cluster analysis.

Main Results:

• RTmean and L/R ratio serve as independent parameters for assessing attention deficits and neglect symptoms, respectively.
• Voxel-based lesion mapping identified brain regions associated with attention (e.g., middle temporal gyrus) and neglect (e.g., superior temporal gyrus).
• Cluster analysis revealed six distinct USN states, highlighting an interaction between neglect and attention deficits, and suggesting recovery pathways.

Conclusions:

• The proposed evaluation method, characterizing the interaction between RTmean and L/R ratio, effectively distinguishes neglect symptoms from attention deficits.
• This approach offers valuable insights into the pathological features of USN and its recovery process.