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Modulating emotional responses: effects of a neocortical network on the limbic system

Hariri, Ahmad R.1; Bookheimer, Susan Y.1,2; Mazziotta, John C.1

Motivation, Emotion, Feeding, Drinking

Humans share with animals a primitive neural system for processing emotions such as fear and anger. Unlike other animals, humans have the unique ability to control and modulate instinctive emotional reactions through intellectual processes such as reasoning, rationalizing, and labeling our experiences. This study used functional MRI to identify the neural networks underlying this ability. Subjects either matched the affect of one of two faces to that of a simultaneously presented target face (a perceptual task) or identified the affect of a target face by choosing one of two simultaneously presented linguistic labels (an intellectual task). Matching angry or frightened expressions was associated with increased regional cerebral blood flow (rCBF) in the left and right amygdala, the brain's primary fear centers. Labeling these same expressions was associated with a diminished rCBF response in the amygdalae. This decrease correlated with a simultaneous increase in rCBF in the right prefrontal cortex, a neocortical region implicated in regulating emotional responses. These results provide evidence for a network in which higher regions attenuate emotional responses at the most fundamental levels in the brain and suggest a neural basis for modulating emotional experience through interpretation and labeling.

1Brain Mapping Division, UCLA School of Medicine, Ahmanson-Lovelace Brain Mapping Center, 660 Charles E. Young Dr., Rm. 205, Los Angeles, CA 90095, USA

2Corresponding Author: Susan Y. Bookheimer

Acknowledgements: We thank N. Sicotte for assistance with neurological examinations, and J. Quintana and R.M. DuBois for comments on earlier versions of this manuscript. This study was supported in part by a National Institutes of Health grant to M. Sigman and a grant from the National Center on Research Resources, as well as donations from the Ahmanson Foundation, the Pierson-Lovelace Foundation, the Tamkin Foundation, the Jennifer Jones Simon Foundation, and the Brain Mapping Medical Research Organization. A.R.H. is supported by a fellowship from the Achievement Rewards for College Scientists (ARCS) Foundation, Inc.

Received 15 September 1999; accepted 16 October 1999

© 2000 Lippincott Williams & Wilkins, Inc.