title: Mismatch negativity of sad syllables is absent in patients with major depressive disorder.
abstract: BACKGROUND
  Major depressive disorder (MDD) is an important and highly prevalent mental disorder characterized by anhedonia and a lack of interest in everyday activities. Additionally, patients with MDD appear to have deficits in various cognitive abilities. Although a number of studies investigating the central auditory processing of low-level sound features in patients with MDD have demonstrated that this population exhibits impairments in automatic processing, the influence of emotional voice processing has yet to be addressed. To explore the automatic processing of emotional prosodies in patients with MDD, we analyzed the ability to detect automatic changes using event-related potentials (ERPs).
  
  
  METHODS
  This study included 18 patients with MDD and 22 age- and sex-matched healthy controls. Subjects were instructed to watch a silent movie but to ignore the afferent acoustic emotional prosodies presented to both ears while continuous electroencephalographic activity was synchronously recorded. Prosodies included meaningless syllables, such as "dada" spoken with happy, angry, sad, or neutral tones. The mean amplitudes of the ERPs elicited by emotional stimuli and the peak latency of the emotional differential waveforms were analyzed.
  
  
  RESULTS
  The sad MMN was absent in patients with MDD, whereas the happy and angry MMN components were similar across groups. The abnormal sad emotional MMN component was not significantly correlated with the HRSD-17 and HAMA scores, respectively.
  
  
  CONCLUSIONS
  The data indicate that patients with MDD are impaired in their ability to automatically process sad prosody, whereas their ability to process happy and angry prosodies remains normal. The dysfunctional sad emotion-related MMN in patients with MDD were not correlated with depression symptoms. The blunted MMN of sad prosodies could be considered a trait of MDD.
authors.affiliation: Department of Neurology and Psychiatry, First Affiliated Hospital, Dalian Medical University, Liaoning Province, China; Research Institute of Integrated Traditional and Western Medicine, Dalian Medical University, Liaoning Province, China.
authors.forename: Xiaomei
authors.initials: X
authors.lastname: Pang
authors.affiliation: Department of Neurology and Psychiatry, First Affiliated Hospital, Dalian Medical University, Liaoning Province, China; Research Institute of Integrated Traditional and Western Medicine, Dalian Medical University, Liaoning Province, China.
authors.forename: Jing
authors.initials: J
authors.lastname: Xu
authors.affiliation: Department of Neurology and Psychiatry, First Affiliated Hospital, Dalian Medical University, Liaoning Province, China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Chang
authors.affiliation: Department of Neurology and Psychiatry, First Affiliated Hospital, Dalian Medical University, Liaoning Province, China; Research Institute of Integrated Traditional and Western Medicine, Dalian Medical University, Liaoning Province, China.
authors.forename: Di
authors.initials: D
authors.lastname: Tang
authors.affiliation: Department of Psychology, Dalian Medical University, Liaoning Province, China.
authors.forename: Ya
authors.initials: Y
authors.lastname: Zheng
authors.affiliation: Department of Neurology and Psychiatry, First Affiliated Hospital, Dalian Medical University, Liaoning Province, China.
authors.forename: Yanhua
authors.initials: Y
authors.lastname: Liu
authors.affiliation: Department of Neurology and Psychiatry, First Affiliated Hospital, Dalian Medical University, Liaoning Province, China.
authors.forename: Yiming
authors.initials: Y
authors.lastname: Sun
mesh_terms: D000161:Acoustic Stimulation; D000328:Adult; D059445:Anhedonia; D003865:Major Depressive Disorder / Q000503:physiopathology*; D004569:Electroencephalography; D004644:Emotions; D005260:Female; D006801:Humans; D008297:Male; D008606:Mental Processes