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Dorsolateral prefrontal cortex and the implicit association of concepts and attributes

L. Chee, Michael W.1,3; Sriram, N2; Soon, Chun Siong1,2; Lee, Kok Ming1

Brain Imaging

The Implicit Association Test (IAT) examines the differential association of two object categories (e.g. flower and insect) with attribute categories (e.g. pleasant and unpleasant). When items from congruent categories (e.g. flower + pleasant) share a response key, performance is faster and more accurate than when items from incongruent categories (e.g. insect + pleasant) share a key. Performing incongruent word classification engages inhibitory processes to overcome the prepotent tendency to map emotionally congruent items to the same response key. Using fMRI on subjects undergoing the IAT, we show that the left dorsolateral prefrontal cortex, and to a lesser extent the anterior cingulate cortex, mediate inhibitory processes where manipulation of word association is required.

1Cognitive Neuroscience Laboratory, Singapore General Hospital, 20 College Road, Singapore 169856

2Department of Social Work and Psychology, National University of Singapore 119260, Singapore

3Corresponding Author: Michael W. L. Chee

Acknowledgements: This work was supported by the National Medical Research Council of Singapore, Grant NMRC 98/00270. We are grateful to Michael I Posner Ph.D. for helpful critique of the manuscript and to Jia Jia Hoon and Marilyn Chee, who contributed to running the experiments and processing the data.

Received 28 September 1999; accepted 3 November 1999

© 2000 Lippincott Williams & Wilkins, Inc.