title: Virtual lesion of angular gyrus disrupts the relationship between visuoproprioceptive weighting and realignment.
abstract: Posterior parietal cortex is thought to be involved in multisensory processes such as sensory weighting (how much different modalities are represented in sensory integration) and realignment (recalibrating the estimates given by unisensory inputs relative to each other, e.g., when viewing the hand through prisms). Sensory weighting and realignment are biologically independent but can be correlated such that the lowest-weighted modality realigns most. This is important for movement precision because it results in the brain's estimate of hand position favoring the more reliable (higher-weighted) modality. It is unknown if this interaction is an emergent property of separate neural pathways for weighting and realignment or if it is actively mediated by a common substrate. We applied disruptive TMS to the angular gyrus near the intraparietal sulcus (PGa) before participants performed a task with misaligned visual and proprioceptive information about hand position. Visuoproprioceptive weighting and realignment were unaffected. However, the relationship between weighting and realignment, found in control conditions, was absent after TMS in the angular gyrus location. This suggests that a specific region in the angular gyrus actively mediates the interaction between visuoproprioceptive weighting and realignment and may thus play a role in the decreased movement precision associated with posterior parietal lesions.
authors.affiliation: Johns Hopkins University School of Medicine, Baltimore, MD 21205, USA.
authors.forename: Hannah
authors.initials: H
authors.lastname: Block
authors.forename: Amy
authors.initials: A
authors.lastname: Bastian
authors.forename: Pablo
authors.initials: P
authors.lastname: Celnik
mesh_terms: D000328:Adult; D000704:Analysis of Variance; D019054:Evoked Potentials, Motor / Q000502:physiology; D056228:Feedback, Sensory; D005260:Female; D006179:Gyrus Cinguli / Q000293:injuries / Q000502:physiology*; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D011434:Proprioception / Q000502:physiology*; D011597:Psychomotor Performance / Q000502:physiology*; D011712:Pyramidal Tracts / Q000502:physiology; D013028:Space Perception / Q000502:physiology*; D050781:Transcranial Magnetic Stimulation; D014584:User-Computer Interface