Spatial neglect encompasses impaired verticality representation after right hemisphere stroke

Area of Science:

• Neuroscience
• Neurology
• Perception

Background:

• Spatial neglect is a common deficit following right hemisphere stroke (RHS).
• Recent findings link spatial neglect to lateropulsion, a body orientation deficit related to graviception.
• Altered processing of graviception suggests potential impacts on verticality representation.

Purpose of the Study:

• To investigate if spatial neglect after RHS includes altered verticality representation.
• To examine the relationship between body neglect and impaired postural vertical perception.
• To analyze spatial neglect across body and extra-body domains and verticality perception in postural and visual modalities.

Main Methods:

• Contingency and correlation analyses were performed.
• The study included 77 individuals with first-ever subacute right hemisphere stroke.
• Evaluated spatial neglect (body, extra-body) and verticality perception (postural, visual).

Main Results:

• Individuals with transmodal (postural and visual) verticality perception tilts showed spatial neglect.
• Spatial neglect, particularly body neglect, correlated more strongly with postural vertical tilts than visual tilts.
• Multivariate analyses confirmed the association between spatial neglect and verticality perception deficits.

Conclusions:

• Impaired verticality representation after RHS stems from graviceptive neglect, affecting somatosensory and vestibular systems.
• These findings suggest that the brain utilizes 3D maps and transmodal representations for verticality.
• Spatial neglect may encompass a broader disruption of graviceptive processing beyond visual or body-centric representations.