title: Symbolic online exposure for spider fear: habituation of fear, disgust and physiological arousal and predictors of symptom improvement.
abstract: OBJECTIVE
  This research compared the effects of real versus hyper-real images on anxiety, disgust, and physiological arousal during internet-delivered exposure in high spider-fearfuls. Hyper-real images were digitally altered to highlight fearful aspects. A further aim was to examine self-reported and behavioural therapeutic outcomes and exposure-related predictors of these outcomes.
  
  
  METHODS
  Twenty-eight females were randomised to real (n = 14) or hyper-real (n = 14) treatment groups and nine participants were subsequently allocated to a wait-list control group. Treatment groups viewed an 8-stage exposure hierarchy of real or hyper-real spider images. Subjective anxiety and disgust ratings were taken during each stage (0, 60, 120, 180 s) with heart rate and skin conductance recorded throughout.
  
  
  RESULTS
  Anxiety, disgust and physiological arousal habituated within each exposure stage, with no differential effect of real compared to hyper-real images. Both treatment groups but not controls demonstrated significant reductions in behavioural avoidance and self-reported phobic symptoms from pre-treatment to post-treatment with large effect sizes noted. The change in within-stage habituation of anxiety, disgust and heart rate, between the first and last stage, predicted improvement in behavioural avoidance at post-treatment. This suggests that generalisation of habituation to multiple images is an important predictor of improvement.
  
  
  CONCLUSIONS
  While findings in relation to therapeutic outcome should be considered preliminary, clear relationships were found between exposure-related variables and outcome among those who undertook treatment.
  
  
  CONCLUSIONS
  Findings provide evidence in support of the efficacy of online image-based exposure and have implications for informing further research into the underlying mechanisms of image-based exposure treatment.
authors.affiliation: Division of Psychology, School of Medicine, University of Tasmania, Private Bag 30, Hobart, TAS 7001, Australia. Electronic address: Allison.Matthews@utas.edu.au.
authors.forename: Allison
authors.initials: A
authors.lastname: Matthews
authors.affiliation: Division of Psychology, School of Medicine, University of Tasmania, Private Bag 30, Hobart, TAS 7001, Australia.
authors.forename: Nishma
authors.initials: N
authors.lastname: Naran
authors.affiliation: School of Medicine, University of Tasmania, Private Bag 27, Hobart, TAS 7001, Australia.
authors.forename: Kenneth C
authors.initials: KC
authors.lastname: Kirkby
mesh_terms: D000293:Adolescent; D000328:Adult; D000818:Animals; D001143:Arousal / Q000502:physiology; D001362:Avoidance Learning / Q000502:physiology; D005239:Fear / Q000523:psychology*; D005260:Female; D005712:Galvanic Skin Response / Q000502:physiology; D006185:Habituation, Psychophysiologic; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D010698:Phobic Disorders / Q000523:psychology* / Q000628:therapy*; D010775:Photic Stimulation / Q000379:methods; D013112:Spiders; D011795:Surveys and Questionnaires; D016896:Treatment Outcome; D014796:Visual Perception; D055815:Young Adult
keywords: Emotional processing theory; Habituation; Heart rate; Online exposure; Skin conductance; Spider phobia