FUNCTION OF THE LEFT PLANUM TEMPORALE IN AUDITORY AND LINGUISTIC PROCESSING

Previous research suggests that the human left planum temporale (PT) p lays an important role in language. To test this hypothesis, functiona l MRT (fMRI) data were collected from 12 normal right-handed subjects during passive and active listening to words and tone sequences. Sever al left hemisphere areas, including the superior temporal sulcus, midd le temporal gyrus, angular gyrus and lateral frontal lobe showed stron ger activation during the word conditions. This was not true of the PT which responded equally to tones and words during passive listening a nd more strongly to tones during active listening. The PT is likely to be involved in early auditory processing, while specifically linguist ic functions are mediated by multimodal association areas distributed elsewhere in the left hemisphere.