title: Neuroanatomical assessment of the impact of negative emotion on implicit memory in patients with obsessive compulsive disorder.
abstract: OBJECTIVE
  We performed functional magnetic resonance imaging (fMRI) to discriminate the differential brain activation patterns in patients with obsessive compulsive disorder (OCD) and healthy controls during implicit retrieval tasks with emotionally neutral and unpleasant words.
  
  
  METHODS
  Sixteen patients with OCD (mean age: 31.4±10.1 years) and 16 healthy controls (mean age: 32.6±5.8 years) with no history of neurological or psychiatric illness underwent 3-T fMRI. The stimulation paradigm consisted of the following cycle: rest, encoding of a string of two-syllable words, rest, and retrieval of the previously encoded words with the first consonant omitted.
  
  
  RESULTS
  During the implicit retrieval task with emotionally neutral words, no distinct brain activity was observed in either the patients with OCD or healthy controls. On the other hand, during the retrieval task with unpleasant words, the patients with OCD showed predominant activity in the superior/middle temporal pole, medial superior frontal gyrus, and orbitofrontal cortex (uncorrected p<0.001, extent threshold: 30 voxels), whereas the healthy controls did not show any distinct regions of activation.
  
  
  CONCLUSIONS
  This study revealed the differential brain activation patterns between patients with OCD and healthy controls during implicit memory tasks with unpleasant words. Our results suggest that the impact of negative emotion on implicit memory task may be associated with the symptomatology of OCD. This finding may be helpful for understanding the neural mechanisms that underlie implicit memory retrieval, particularly the interaction between emotion and cognition, in patients with OCD.
authors.affiliation: 1Interdisciplinary Program of Biomedical Engineering,Chonnam National University,Gwangju,Republic of Korea.
authors.forename: Shin-Eui
authors.initials: SE
authors.lastname: Park
authors.affiliation: 2Department of Psychiatry,Chonbuk National University Medical School,Jeonju,Republic of Korea.
authors.forename: Jong-Chul
authors.initials: JC
authors.lastname: Yang
authors.affiliation: 1Interdisciplinary Program of Biomedical Engineering,Chonnam National University,Gwangju,Republic of Korea.
authors.forename: Gwang-Woo
authors.initials: GW
authors.lastname: Jeong
mesh_terms: D000328:Adult; D001931:Brain Mapping / Q000379:methods*; D016022:Case-Control Studies; D004644:Emotions / Q000502:physiology*; D005260:Female; D006801:Humans; D008279:Magnetic Resonance Imaging / Q000379:methods; D008297:Male; D008568:Memory / Q000502:physiology*; D009483:Neuropsychological Tests; D009771:Obsessive-Compulsive Disorder / Q000000981:diagnostic imaging / Q000503:physiopathology* / Q000523:psychology; D017397:Prefrontal Cortex / Q000000981:diagnostic imaging / Q000503:physiopathology*; D055815:Young Adult
keywords: functional magnetic resonance imaging (fMRI); implicit memory; obsessive compulsive disorder (OCD)