Short-Term and Long-Term Verbal Memory: A Positron Emission Tomography Study

• Published in: Proceedings of the National Academy of Sciences - PNAS Vol. 92; no. 11; pp. 5111 - 5115
• Main Authors: Andreasen, Nancy C., O'Leary, Daniel S., Arndt, Stephan, Cizadlo, Ted, Hurtig, Richard, Rezai, Karim, Watkins, G. Leonard, Laura L. Boles Ponto, Hichwa, Richard D.
• Format: Journal Article
• Language: English
• Published: United States National Academy of Sciences of the United States of America 23.05.1995; National Acad Sciences; National Academy of Sciences
• Subjects: Adult; Blood flow; Brain - anatomy & histology; Brain - diagnostic imaging; Brain - physiology; Brain Mapping; Cerebellum; Female; Humans; Image analysis; Language; Lesions; Magnetic Resonance Imaging - methods; Male; Memory; Memory recall; Memory, Short-Term; Oxygen Radioisotopes; Positron emission tomography; Psychology; Reference Values; Retention (Psychology); Speech; Temporal lobe; Tomography, Emission-Computed - methods
• ISSN: 0027-8424; 1091-6490
• DOI: 10.1073/pnas.92.11.5111

Short-term and long-term retention of experimentally presented words were compared in a sample of 33 healthy normal volunteers by the [15O]I2O method with positron emission tomography (PET). The design included three conditions. For the long-term condition, subjects thoroughly studied 18 words 1 week before the PET study. For the short-term condition, subjects were shown another set of 18 words 60 sec before imaging, with instructions to remember them. For the baseline condition, subtracted from the two memory conditions, subjects read a third set of words that they had not previously seen in the experiment. Similar regions were activated in both short-term and long-term conditions: large right frontal areas, biparietal areas, and the left cerebellum. In addition, the short-term condition also activated a relatively large region in the left prefrontal region. These complex distributed circuits appear to represent the neural substrates for aspects of memory such as encoding, retrieval, and storage. They indicate that circuitry involved in episodic memory has much larger cortical and cerebellar components than has been emphasized in earlier lesion studies