title: Relationship between cardiac vagal activity and mood congruent memory bias in major depression.
abstract: BACKGROUND
  Previous studies suggest that autonomic reactivity during encoding of emotional information could modulate the neural processes mediating mood-congruent memory. In this study, we use a point-process model to determine dynamic autonomic tone in response to negative emotions and its influence on long-term memory of major depressed subjects.
  
  
  METHODS
  Forty-eight patients with major depression and 48 healthy controls were randomly assigned to either neutral or emotionally arousing audiovisual stimuli. An adaptive point-process algorithm was applied to compute instantaneous estimates of the spectral components of heart rate variability [Low frequency (LF), 0.04-0.15 Hz; High frequency (HF), 0.15-0.4 Hz]. Three days later subjects were submitted to a recall test.
  
  
  RESULTS
  A significant increase in HF power was observed in depressed subjects in response to the emotionally arousing stimulus (p=0.03). The results of a multivariate analysis revealed that the HF power during the emotional segment of the stimulus was independently associated with the score of the recall test in depressed subjects, after adjusting for age, gender and educational level (Coef. 0.003, 95%CI, 0.0009-0.005, p=0.008).
  
  
  CONCLUSIONS
  These results could only be interpreted as responses to elicitation of specific negative emotions, the relationship between HF changes and encoding/recall of positive stimuli should be further examined.
  
  
  CONCLUSIONS
  Alterations on parasympathetic response to emotion are involved in the mood-congruent cognitive bias observed in major depression. These findings are clinically relevant because it could constitute the mechanism by which depressed patients maintain maladaptive patterns of negative information processing that trigger and sustain depressed mood.
authors.affiliation: Martinos Center for Biomedical Imaging, Department of Radiology, Massachusetts General Hospital, Harvard Medical School, Charlestown, MA, USA.|Division of Women's Health, Department of Medicine, Brigham and Women's Hospital, Harvard Medical School, Boston, MA, USA.|Masira Research Institute, School of Medicine, Universidad de Santander (UDES), Bucaramanga, Colombia.
authors.forename: Ronald G
authors.initials: RG
authors.lastname: Garcia
authors.affiliation: Research Center E. Piaggio, School of Engineering, University of Pisa, Pisa, Italy.|Department of Anesthesia, Critical Care & Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Gaetano
authors.initials: G
authors.lastname: Valenza
authors.affiliation: Laboratory of Neuroscience and Behavior, Universidade de Brasilia, Brasilia D.F., Brazil.
authors.forename: Carlos A
authors.initials: CA
authors.lastname: Tomaz
authors.affiliation: Department of Anesthesia, Critical Care & Pain Medicine, Massachusetts General Hospital, Harvard Medical School, Boston, MA, USA.
authors.forename: Riccardo
authors.initials: R
authors.lastname: Barbieri
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D000339:Affect; D016022:Case-Control Studies; D003865:Major Depressive Disorder / Q000503:physiopathology* / Q000523:psychology*; D005260:Female; D006339:Heart Rate; D006801:Humans; D008297:Male; D008568:Memory; D011939:Mental Recall; D008875:Middle Aged; D010775:Photic Stimulation; D014630:Vagus Nerve / Q000503:physiopathology*
keywords: Autonomic nervous system; Emotional memory; Heart rate variability; Major depression; Point-process; Vagus nerve