Verbal repetition engages a bilateral fronto-temporo-parietal network with left-hemispheric dominance
This is a meta-analysis of neuroimaging experiments in healthy adults, synthesizing neural patterns of verbal repetition. The authors found that verbal repetition engages a robust, bilaterally distributed fronto-temporo-parietal network encompassing auditory-phonological regions of the superior temporal cortex, sensorimotor cortices of the precentral and postcentral gyri, and medial frontal motor regions including the SMA and the preSMA. Hemispheric lateralization showed a predominant left-hemispheric contribution across conditions, with a stronger leftward bias for pseudoword than for word repetition. Neural engagement differed by stimulus type: pseudoword repetition involved greater involvement of auditory associative, premotor, and subcortical regions, while word repetition showed preferential engagement of primary auditory and medial frontal motor regions. The authors note methodological heterogeneity across studies as a key limitation. These findings may have diagnostic relevance in acquired and developmental language disorders, but the evidence is not causal and should be interpreted cautiously.