Differential effects of early hemisphere damage on lexical comprehension and production

Abstract

Abstract The effects of early hemisphere damage on lexical development were investigated in 33 children with unilateral left (n = 21) or right (n = 12) hemisphere damage and 16 normal healthy controls. Single-word naming was assessed using the Expressive One-Word Picture Vocabulary Test (EOW) and lexical comprehension was assessed using the Peabody Picture Vocabulary Test-Revised (PPVT-R). Left lesion subjects (LL) performed comparable to controls in naming, but scored lower than controls on the PPVT-R. Right lesion subjects (RL) scored lower than controls and LL subjects on both the EOW and the PPVT-R. The unexpected superiority of LL in comparison to RL children on the EOW and the PPVT-R argues against a simple left hemisphere dominance for early lexical development. RL subjects' significant comprehension deficits failed to correlate with more general measures of verbal intelligence, supporting a specialized role of the right hemisphere in mediating the acquisition of word meaning.