title: Facilitating access to emotions: neural signature of EMDR stimulation.
abstract: BACKGROUND
  Eye Movement Desensitisation and Reprocessing (EMDR) is a method in psychotherapy effective in treating symptoms of posttraumatic stress disorder. The client attends to alternating bilateral visual, auditory or sensory stimulation while confronted with emotionally disturbing material. It is thought that the bilateral stimulation as a specific element of EMDR facilitates accessing and processing of negative material while presumably creating new associative links. We hypothesized that the putatively facilitated access should be reflected in increased activation of the amygdala upon bilateral EMDR stimulation even in healthy subjects.
  
  
  METHODS
  We investigated 22 healthy female university students (mean 23.5 years) with fMRI. Subjects were scanned while confronted with blocks of disgusting and neutral picture stimuli. One third of the blocks was presented without any additional stimulation, one third with bilateral simultaneous auditory stimulation, and one third with bilateral alternating auditory stimulation as used in EMDR.
  
  
  RESULTS
  Contrasting disgusting vs. neutral picture stimuli confirmed the expected robust effect of amygdala activation for all auditory stimulation conditions. The interaction analysis with the type of auditory stimulation revealed a specific increase in activation of the right amygdala for the bilateral alternating auditory stimulation. Activation of the left dorsolateral prefrontal cortex showed the opposite effect with decreased activation.
  
  
  CONCLUSIONS
  We demonstrate first time evidence for a putative neurobiological basis of the bilateral alternating stimulation as used in the EMDR method. The increase in limbic processing along with decreased frontal activation is in line with theoretical models of how bilateral alternating stimulation could help with therapeutic reintegration of information, and present findings may pave the way for future research on EMDR in the context of posttraumatic stress disorder.
authors.affiliation: Department of Psychiatry, Ulm University, Ulm, Germany.
authors.forename: Deborah
authors.initials: D
authors.lastname: Herkt
authors.affiliation: Department of Psychiatry, Ulm University, Ulm, Germany.
authors.forename: Visal
authors.initials: V
authors.lastname: Tumani
authors.affiliation: Department of Psychiatry, Ulm University, Ulm, Germany.
authors.forename: Georg
authors.initials: G
authors.lastname: Grön
authors.affiliation: Department of Psychiatry, Ulm University, Ulm, Germany.
authors.forename: Thomas
authors.initials: T
authors.lastname: Kammer
authors.affiliation: EMDR-Institut Deutschland, Bergisch Gladbach, Germany.
authors.forename: Arne
authors.initials: A
authors.lastname: Hofmann
authors.affiliation: Department of Psychiatry, Ulm University, Ulm, Germany.
authors.forename: Birgit
authors.initials: B
authors.lastname: Abler
mesh_terms: D000161:Acoustic Stimulation / Q000379:methods*; D000293:Adolescent; D000328:Adult; D004644:Emotions / Q000502:physiology*; D057169:Eye Movement Desensitization Reprocessing / Q000379:methods*; D005133:Eye Movements; D005260:Female; D006801:Humans; D017397:Prefrontal Cortex / Q000502:physiology*; D011795:Surveys and Questionnaires; D055815:Young Adult