Abstract(s)
Objective—To investigate the neural correlates of verbal and non-verbal semantic processing in
neurodegenerative disease.
Background—Semantic memory is often impaired in neurodegenerative disease.
Neuropsychological and functional neuroimaging studies suggest that the semantic processing of
verbal and non-verbal stimuli may depend on partially distinct brain networks.
Methods—We examined this possibility using voxel-based morphometry to correlate performance
on verbal and non-verbal versions of a semantic association task with regional gray matter atrophy
in 144 individuals with a variety of neurodegenerative diseases.
Results—Results showed that, regardless of stimulus type, semantic processing correlated with
atrophy in both temporal lobes. In addition, material-specific correlations were found in left temporal
regions for verbal stimuli and the right fusiform gyrus for non-verbal stimuli.
Conclusions—These results provide evidence for a differential role of the left and right
hemispheres in the extraction of semantic information from verbal and pictorial representations.
Areas in the right inferior temporal lobe may be necessary to access structural descriptions of visually
presented objects