RECEPTIVE AND EXPRESSIVE LANGUAGE ACTIVATIONS FOR SENTENCES - A PET STUDY

MOST language mapping studies have focussed on activations for single- word tasks. We examined activations for verbal auditory and generation tasks using sentence stimuli. [O-15]-water PET was performed in 4 fem ale and 5 male normal adults. Listening to sentences (minus rest) acti vated the superior and middle temporal gyri bilaterally, but mean acti vation was significantly stronger on the left. The strongest activatio n for sentence generation (minus repetition) was seen in the left midd le and inferior frontal gyri (area 46). This focus appears to be anter ior to activations reported for single-word generation, possibly due t o greater verbal working memory demands of the sentential task. Additi onal activation of the left inferior temporal lobe can be attributed t o lexicosemantic processing.