PET STUDIES OF LANGUAGE - AN ASSESSMENT OF THE RELIABILITY OF THE TECHNIQUE

In order to understand the basis of language in the brain, we must be able to describe the neurological systems that are used in language co mprehension and production. In this paper, one technique for functiona l neuroimaging is discussed: measurement of blood flow change using po sitron emission tomography (PET). Two experiments were carried out inv estigating the usefulness of this method. One experiment examined the, intrinsic time limitations of blood flow change as a measure of cogni tive activity. A second issue considered is the replicability of the r esults obtained using this method. A comparison of two experiments con taining the same conditions suggested that the results are replicable, when the experiments and method are similar. One case is discussed wh ere the experiments differ; it is suggested that this is due to a diff erence in the materials used in the experiments, and that the differen ce has a principled basis.