title: Looking under the hood of the dot-probe task: an fMRI study in anxious youth.
abstract: BACKGROUND
  Anxious youth have shown altered behavioral performance on the dot-probe task, but neural activation patterns provoked by the task remain poorly understood. In particular, neural mechanisms of threat disengagement, a clinically relevant construct, have been inadequately explored.
  
  
  METHODS
  During fMRI acquisition, 121 youth (ages 9-13; 90 with Generalized Anxiety Disorder, Separation Anxiety Disorder, and/or Social Phobia; 31 nonanxious controls) completed a dot-probe task, which required participants to identify the location of a dot replacing either a neutral or fearful face in a pair containing both faces. We assessed neural substrates of threat disengagement by comparing congruent trials (in which the dot replaces the fearful face) to incongruent trials (in which the dot replaces the neutral face).
  
  
  RESULTS
  Across subjects, decreased rostrodorsal anterior cingulate cortex (rdACC) activity was observed specifically during incongruent trials. Nonanxious youth showed a convergent pattern in bilateral parahippocampal and hippocampal regions, whereas anxious youth showed an opposing pattern in these limbic areas, suggesting less integration of response across cortical and limbic areas relevant to threat appraisal. Reduced functional connectivity between rdACC and left parahippocampus/hippocampus was associated with greater anxiety.
  
  
  CONCLUSIONS
  In the largest dot-probe fMRI sample to date, both anxious and nonanxious youth showed a neural pattern consistent with successful disengagement of threat reactivity in the rdACC. However, anxious youth showed evidence of abnormal disengagement in bilateral parahippocampal/hippocampal clusters when attention was directed away from threat. Early interventions targeting neural mechanisms of threat disengagement may be beneficial, for example, by increasing integration across rdACC and limbic regions.
authors.affiliation: Department of Psychiatry, University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania.
authors.forename: Rebecca B
authors.initials: RB
authors.lastname: Price
authors.forename: Greg J
authors.initials: GJ
authors.lastname: Siegle
authors.forename: Jennifer S
authors.initials: JS
authors.lastname: Silk
authors.forename: Cecile D
authors.initials: CD
authors.lastname: Ladouceur
authors.forename: Ashley
authors.initials: A
authors.lastname: McFarland
authors.forename: Ronald E
authors.initials: RE
authors.lastname: Dahl
authors.forename: Neal D
authors.initials: ND
authors.lastname: Ryan
mesh_terms: D000293:Adolescent; D001008:Anxiety Disorders / Q000503:physiopathology*; D001010:Anxiety, Separation / Q000503:physiopathology; D001288:Attention / Q000502:physiology; D054022:Cerebrum / Q000503:physiopathology*; D002648:Child; D063132:Connectome / Q000295:instrumentation / Q000379:methods; D005149:Facial Expression; D005239:Fear / Q000502:physiology*; D005260:Female; D059907:Functional Neuroimaging / Q000295:instrumentation / Q000379:methods*; D006179:Gyrus Cinguli / Q000503:physiopathology; D006624:Hippocampus / Q000503:physiopathology; D006801:Humans; D008279:Magnetic Resonance Imaging; D008297:Male; D009415:Nerve Net / Q000503:physiopathology; D009483:Neuropsychological Tests; D020534:Parahippocampal Gyrus / Q000503:physiopathology; D010364:Pattern Recognition, Visual / Q000502:physiology; D010698:Phobic Disorders / Q000503:physiopathology*
keywords: anxiety; attentional bias; dot-probe task; fMRI; pediatric