Figure 2. Involvement of the Wernicke area in speech production.

Example data indicate a prominent role for the Wernicke area in speech production. (A) A summary of 14 functional neuroimaging studies shows peak locations where activation was related to phonologic retrieval independent of semantic processing, speech articulation, or auditory perception (see appendix e-1 for a description of these studies). (B) The lesion location in 40 left hemisphere stroke patients where damage was associated with failure to retrieve phonologic information without other (semantic or articulation) deficits (adapted with permission from reference 7). (C) Sites where electrical stimulation of the cortex in 14 patients produced phonologic production errors during reading aloud (adapted with permission from reference 8).