mise à jour du
16 mai 2002
The Journal of Neuroscience, 1996; 16; 23; 7678-7687
Cortical Systems for the Recognition of Emotion in Facial Expressions
Ralph Adolphs, Hanna Damasio, Daniel Tranel, Antonio Damasio
Department of Neurology, Division of Cognitive Neuroscience, University of Iowa College of Medicine, Iowa City, and The Salk Institute for Biological Studies, La Jolla, California
 Human Facial Expressions as Adaptations: Evolutionary Questions in Facial Expression Research
Yawning: an evolutionary perspective Smith EO
The perception-behavior expressway:automatic effects of social perception on social behavior
Response properties of neurons in temporal cortical visual areas of infant monkeys Rodman HR
This study is part of an effort to map neural systems involved in the processing of emotion, and it focuses on the possible cortical components of the process of recognizing facial expressions. We hypothesized that the cortical systems most responsible for the recognition of emotional facial expressions would draw on discrete regions of right higher-order sensory cortices and that the recognition of specific emotions would depend on partially distinct system subsets of such cortical regions. We tested these hypotheses using lesion analysis in 37 subjects with focal brain damage. Subjects were asked to recognize facial expressions of six basic emotions: happiness, surprise, fear, anger, disgust, and sadness. Data were analyzed with a novel technique, based on three-dimensional reconstruction of brain images, in which anatomical description of surface lesions and task performance scores were jointly mapped onto a standard brain-space. We found that all subjects recognized happy expressions normally but that some subjects were impaired in recognizing negative emotions, especially fear and sadness. The cortical surface regions that best correlated with impaired recognition of emotion were in the right inferior parietal cortex and in the right mesial anterior infracalcarine cortex. We did not find impairments in recognizing any emotion in subjects with lesions restricted to the left hemisphere. These data provide evidence for a neural system important to processing facial expressions of some emotions, involving discrete visual and somatosensory cortical sectors in right hemisphere.
A neuromodulatory role for the human amygdala in processing emotional facial expressions Brain (1998), 121, 47-57

J. S. Morris, K. J. Friston, C. Buchel, C. D. Frith, A. W. Young, A. J. Calder and R. J. Dolan Wellcome Department of Cognitive Neurology, Royal Free and University College Hospitals School of Medicine, London and MRC Applied Psychology Unit, Cambridge, UK Correspondence to: Professor R. J. Dolan, Wellcome Department of Cognitive Neurology, 12 Queen Square, London WC1N 3BG, UK

Localized amygdalar lesions in humans produce deficits in the recognition of fearful facial expressions. We used functional neuroimaging to test two hypotheses:

(1) that the amygdala and some of its functionally connected structures mediate specific neural responses to fearful expressions;

(2) that the early visual processing of emotional faces can be influenced by amygdalar activity. Normal subjects were scanned using PET while they performed a gender discrimination task involving static grey-scale images of faces expressing varying degrees of fear or happiness.

In support of the first hypothesis, enhanced activity in the left amygdala, left pulvinar, left anterior insula and bilateral anterior cingulate gyri was observed during the processing of fearful faces. Evidence consistent with the second hypothesis was obtained by a demonstration that amygdalar responses predict expressionspecific neural activity in extrastriate cortex.

Verbal and Nonverbal Emotional Memory Following Unilateral Amygdala Damage Learning Memory Vol. 8, No. 6, pp. 326-335, November/December 2001

Tony W. Buchanan,1 Natalie L. Denburg, Daniel Tranel, and Ralph Adolphs Department of Neurology, Division of Cognitive Neuroscience, University of Iowa, College of Medicine, Iowa City, Iowa 52242, USA

The amygdala is involved in the normal facilitation of memory by emotion, but the separate contributions of the left and right amygdala to memory for verbal or nonverbal emotional material have not been investigated. Fourteen patients with damage to the medial temporal lobe including the amygdala (seven left, seven right), 18 brain-damaged, and 36 normal controls were exposed to emotional and neutral pictures accompanied by verbal narratives. Memory for both narratives and pictures was assessed with a free recall test 24 h later. Subjects with left amygdala damage failed to show the normally robust enhancement of memory for verbal and nonverbal emotional stimuli. The group with right amygdala damage showed the normal pattern of facilitation of memory by emotion for both verbal and nonverbal stimuli despite an overall reduction in memory performance. Furthermore, subjects with left amygdala damage were disproportionately impaired on memory for emotional narratives as compared with memory for emotional pictures. The latter finding offers partial support for a lateralized and material-specific pattern of the amygdala's contribution to emotional memory.

The Role of the Primate Amygdala in Conditioned Reinforcement The Journal of Neuroscience, October 1, 2001, 21(19):7770-7780

John A. Parkinson, Harriet S. Crofts, Mike McGuigan, Davorka L. Tomic, Barry J. Everitt, and Angela C. Roberts Departments of Anatomy and Experimental Psychology, University of Cambridge, Cambridge CB2 3DY, United Kingdom

Conditioned reinforcement refers to the capacity of a conditioned stimulus to support instrumental behavior by acquiring affective properties of the primary reinforcer with which it is associated. Conditioned reinforcers maintain behavior over protracted periods of time in the absence of, and potentially in conflict with, primary reinforcers and as such may play a fundamental role in complex social behavior. A relatively large body of evidence supports the view that the amygdala (and in particular the basolateral area) contributes to conditioned reinforcement by maintaining a representation of the affective value of conditioned stimuli. However, a recent study in primates (Malkova et al., 1997), using a second-order visual discrimination task, suggests that the amygdala is not critical for the conditioned reinforcement process.

In the present study, excitotoxic lesions of the amygdala in a new world primate, the common marmoset, resulted in a progressive impairment in responding under a second-order schedule of food reinforcement. In addition, the responding of amygdala-lesioned animals was insensitive to the omission of the conditioned reinforcer, unlike that of control animals, for which responding was markedly reduced. In contrast, lesioned animals were unimpaired when responding on a progression of fixed-ratio schedules of primary reinforcement. These data confirm that the amygdala is critical for the conditioned reinforcement process in primates, and taken together with other recent work in monkeys, these results suggest that the contribution of the amygdala is to provide the affective value of specific reinforcers as accessed by associated conditioned stimuli.