Changes of regional cerebral blood flow during listening to an unfamiliar spoken language

The regional cerebral blood flow (rCBF) was measured with positron emission tomography in eight normal volunteers with the purpose of measuring rCBF changes related to the comprehension of an unfamiliar spoken languages. When attempting to comprehend the meaning of words, the left hemisphere showed dominant increases in rCBF, however, when subjects attempted to evaluate the emotional tone of the same spoken passage, relatively large increases in rCBF more found in the right hemisphere. The results indicate that there may be several different auditory representations of language which involve both left and right hemispheres, both of which may contribute to the overall comprehension of spoken language.