title: Amygdala responses to averted vs direct gaze fear vary as a function of presentation speed.
abstract: We examined whether amygdala responses to rapidly presented fear expressions are preferentially tuned to averted vs direct gaze fear and conversely whether responses to more sustained presentations are preferentially tuned to direct vs averted gaze fear. We conducted three functional magnetic resonance imaging (fMRI) studies to test these predictions including: Study 1: a block design employing sustained presentations (1 s) of averted vs direct gaze fear expressions taken from the Pictures of Facial Affect; Study 2: a block design employing rapid presentations (300 ms) of these same stimuli and Study 3: a direct replication of these studies in the context of a single experiment using stimuli selected from the NimStim Emotional Face Stimuli. Together, these studies provide evidence consistent with an early, reflexive amygdala response tuned to clear threat and a later reflective response tuned to ambiguous threat.
authors.affiliation: Department of Psychology, The Pennsylvania State University, University Park, PA 16802, USA. radams@psu.edu
authors.forename: Reginald B
authors.initials: RB
authors.lastname: Adams
authors.forename: Robert G
authors.initials: RG
authors.lastname: Franklin
authors.forename: Kestutis
authors.initials: K
authors.lastname: Kveraga
authors.forename: Nalini
authors.initials: N
authors.lastname: Ambady
authors.forename: Robert E
authors.initials: RE
authors.lastname: Kleck
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Whalen
authors.forename: Nouchine
authors.initials: N
authors.lastname: Hadjikhani
authors.forename: Anthony J
authors.initials: AJ
authors.lastname: Nelson
mesh_terms: D000293:Adolescent; D000328:Adult; D000679:Amygdala / Q000098:blood supply / Q000502:physiology*; D004644:Emotions / Q000502:physiology*; D004924:Escape Reaction / Q000502:physiology*; D005149:Facial Expression; D005239:Fear / Q000502:physiology*; D005260:Female; D005403:Fixation, Ocular; D006801:Humans; D007091:Image Processing, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D010100:Oxygen / Q000097:blood; D010775:Photic Stimulation; D055815:Young Adult
chemical_list: D010100:Oxygen