Processing sentences with literal versus figurative use of verbs: An ERP study with children with language impairments, nonverbal impairments, and typical development

Forty native Italian children (age 6-15) performed a sentence plausibility judgment task. ERP recordings were available for 12 children with specific language impairment (SLI), 11 children with nonverbal learning disabilities (NVLD), and 13 control children. Participants listened to verb-object combinations and judged them as acceptable or unacceptable. Stimuli belonged to four conditions, where concreteness and congruency were manipulated. All groups made more errors responding to abstract and to congruent sentences. Moreover, SLI participants performed worse than NVLD participants with abstract sentences. ERPs were analyzed in the time window 300-500 ms. SLI children show atypical, reversed effects of concreteness and congruence as compared to control and NVLD children, respectively. The results suggest that linguistic impairments disrupt abstract language processing more than visual-motor impairments. Moreover, ROI and SPM analyses of ERPs point to a predominant involvement of the left rather than the right hemisphere in the comprehension of figurative expressions.