title: Individual differences in trait anxiety predict the response of the basolateral amygdala to unconsciously processed fearful faces.
abstract: Responses to threat-related stimuli are influenced by conscious and unconscious processes, but the neural systems underlying these processes and their relationship to anxiety have not been clearly delineated. Using fMRI, we investigated the neural responses associated with the conscious and unconscious (backwardly masked) perception of fearful faces in healthy volunteers who varied in threat sensitivity (Spielberger trait anxiety scale). Unconscious processing modulated activity only in the basolateral subregion of the amygdala, while conscious processing modulated activity only in the dorsal amygdala (containing the central nucleus). Whereas activation of the dorsal amygdala by conscious stimuli was consistent across subjects and independent of trait anxiety, activity in the basolateral amygdala to unconscious stimuli, and subjects' reaction times, were predicted by individual differences in trait anxiety. These findings provide a biological basis for the unconscious emotional vigilance characteristic of anxiety and a means for investigating the mechanisms and efficacy of treatments for anxiety.
authors.affiliation: Center for Neurobiology and Behavior, Columbia University Medical Center, fMRI Research Center, 170 West 168th Street, Box 108, New York, New York 10032, USA. ae157@columbia.edu
authors.forename: Amit
authors.initials: A
authors.lastname: Etkin
authors.forename: Kristen C
authors.initials: KC
authors.lastname: Klemenhagen
authors.forename: Joshua T
authors.initials: JT
authors.lastname: Dudman
authors.forename: Michael T
authors.initials: MT
authors.lastname: Rogan
authors.forename: René
authors.initials: R
authors.lastname: Hen
authors.forename: Eric R
authors.initials: ER
authors.lastname: Kandel
authors.forename: Joy
authors.initials: J
authors.lastname: Hirsch
mesh_terms: D000328:Adult; D000679:Amygdala / Q000502:physiology*; D001007:Anxiety / Q000523:psychology*; D001931:Brain Mapping / Q000379:methods; D004644:Emotions / Q000502:physiology; D005149:Facial Expression; D005239:Fear / Q000502:physiology* / Q000523:psychology; D005260:Female; D006801:Humans; D007206:Individuality; D008297:Male; D010775:Photic Stimulation / Q000379:methods; D011237:Predictive Value of Tests; D011930:Reaction Time / Q000502:physiology; D014473:Unconscious, Psychology