Brain regions supporting intentional and incidental memory: ... : NeuroReport (original) (raw)

Learning and Memory

a PET study

Rugg, M D.1,3; Fletcher, P C.2; Frith, C D.2; Frackowiak, R S. J.2; Dolan, R J.2

1Wellcome Brain Research Group, School of Psychology, University of St Andrews, St Andrews, Fife KY16 9JU

2Wellcome Department of Cognitive Neurology, Institute of Neurology, Queen Square, London WC1N 3BG, UK

3Corresponding Author: M. D. Rugg

ACKNOWLEDGEMENTS: M.D.R. is supported by a programme grant and research leave fellowship from the Wellcome Trust. P.C.F., C.D.F., R.S.J.F. and R.J.D. are supported by the Wellcome Trust.

Received 12 November 1996; accepted 17 January 1997

Abstract

REGIONAL brain activity associated with intentional and incidental memory retrieval was studied with PET. Previously studied and new words were presented in either an intentional or an incidental memory task. Type of task was crossed with an encoding manipulation (‘deep’ vs ‘shallow’) which varied the probability that studied items would be remembered. In both tasks, deeply encoded items were associated with greater activation in the left hippocampus than were items that had received shallow encoding, suggesting that the involvement of the hippocampus in memory retrieval is independent of whether remembering is intentional or incidental. Right prefrontal and bilateral parietal cortex were more activated during the intentional task than during the incidental task, irrespective of encoding condition. Thus, these regions play a more extensive role in memory retrieval when remembering is intentional.