The functional neuroanatomy of verbal memory was investigated using verbal free recall during H2 (15) O positron emission tomography (PET). Twelve young (25-40 years old) normal control subjects participated in eight scans during a single scanning session during which they performed three memory tasks differing by word list length. Four subjects also had scans during a "rest" condition. Temporal lobe activation was observed during all tasks, including single-word repetition. The frontal cortices, specifically Brodmann areas 9 and 10, were activated only when the recall word lists exceeded the memory spans (i. e., 12 and 15 words). Activation was also observed in the anterior cingulate cortex (BA24 and BA32). These data, obtained using a within-subject design, extend previously reported findings that used mixed within-and between-subject designs and demonstrate important functional components of normal auditoryverbal short-term memory. © 1994 Wiley-Liss, Inc.
Keywords: PET; activation; frontal cortex; memory; memory circuit; parallel processing.
Copyright © 1994 Wiley-Liss, Inc.