title: The role of the amygdala in the perception of positive emotions: an "intensity detector".
abstract: The specific role of the amygdala remains controversial even though the development of functional imaging techniques has established its implication in the emotional process. The aim of this study was to highlight the sensitivity of the amygdala to emotional intensity (arousal). We conducted an analysis of the modulation of amygdala activation according to variation in emotional intensity via an fMRI event-related protocol. Monitoring of electrodermal activity, a marker of psychophysiological emotional perception and a reflection of the activation of the autonomic nervous system, was carried out concurrently. Eighteen subjects (10 men; aged from 22 to 29 years) looked at emotionally positive photographs. We demonstrated that the left and right amygdalae were sensitive to changes in emotional intensity, activating more in response to stimuli with higher intensity. Furthermore, electrodermal responses were more frequent for the most intense stimuli, demonstrating the concomitant activation of the autonomic nervous system. These results highlight the sensitivity of the amygdala to the intensity of positively valenced visual stimuli, and in conjunction with results in the literature on negative emotions, reinforce the role of the amygdala in the perception of intensity.
authors.affiliation: Department of Neurology, Besancon University Hospital Besancon, France ; Department of Research in Functional Imaging, CIC 808, Besancon University Hospital Besancon, France ; Laboratory of Integrative and Clinical Neuroscience, EA 481, SFR FED 4234 UFC-CHRU-EFS Besancon, France.
authors.forename: Louise
authors.initials: L
authors.lastname: Bonnet
authors.affiliation: Department of Research in Functional Imaging, CIC 808, Besancon University Hospital Besancon, France ; Laboratory of Integrative and Clinical Neuroscience, EA 481, SFR FED 4234 UFC-CHRU-EFS Besancon, France.
authors.forename: Alexandre
authors.initials: A
authors.lastname: Comte
authors.affiliation: Department of Neurology, Besancon University Hospital Besancon, France ; Department of Research in Functional Imaging, CIC 808, Besancon University Hospital Besancon, France ; Laboratory of Integrative and Clinical Neuroscience, EA 481, SFR FED 4234 UFC-CHRU-EFS Besancon, France.
authors.forename: Laurent
authors.initials: L
authors.lastname: Tatu
authors.affiliation: Laboratory of Integrative and Clinical Neuroscience, EA 481, SFR FED 4234 UFC-CHRU-EFS Besancon, France.
authors.forename: Jean-Louis
authors.initials: JL
authors.lastname: Millot
authors.affiliation: Department of Neurology, Besancon University Hospital Besancon, France ; Department of Research in Functional Imaging, CIC 808, Besancon University Hospital Besancon, France ; Laboratory of Integrative and Clinical Neuroscience, EA 481, SFR FED 4234 UFC-CHRU-EFS Besancon, France.
authors.forename: Thierry
authors.initials: T
authors.lastname: Moulin
authors.affiliation: Department of Neurology, Besancon University Hospital Besancon, France ; Department of Research in Functional Imaging, CIC 808, Besancon University Hospital Besancon, France ; Laboratory of Integrative and Clinical Neuroscience, EA 481, SFR FED 4234 UFC-CHRU-EFS Besancon, France.
authors.forename: Elisabeth
authors.initials: E
authors.lastname: Medeiros de Bustos
keywords: IAPS; amygdala; electrodermal response; emotion; emotional intensity; fMRI