Previous research suggests that the human left planum temporale
(PT) plays an important role in language. To test this hypothesis,
functional MRI (fMRI) data were collected from 12 normal right-handed
subjects during passive and active listening to words and tone
sequences. Several left hemisphere areas, including the superior
temporal sulcus, middle temporal gyrus, angular gyrus and lateral
frontal lobe showed stronger activation during the word
conditions. This was not true of the PT, which responded equally to
tones and words during passive listening and more strongly to tones
during active listening. The PT is likely to be involved in early
auditory processing, while specifically linguistic functions are
mediated by multimodal association areas distributed elsewhere in the
left hemisphere.