Impaired mismatch negativity generation in prodromal subjects and patients with schizophrenia

Schizophr Res. 2005 Mar 1;73(2-3):297-310. doi: 10.1016/j.schres.2004.05.016.


Background: Mismatch negativity (MMN) specifically the response to tone duration deviants has consistently been shown to be reduced in schizophrenia suggesting dysfunction in auditory sensory memory. As part of a multidimensional approach to the early recognition of psychosis, MMN was investigated as a possible risk factor for later development of psychosis in subjects with a prodromal syndrome. Forty-three prodromal subjects, 31 neuroleptic-free inpatients with schizophrenia and 33 healthy controls were studied. A prodromal state was defined by a cluster 'Cognitive Disturbances' as defined by the 'Bonn Scale for the Assessment of Basic Symptoms' (BSABS), which was found highly predictive of first-episode schizophrenia. To elicit MMN, a three-tone auditory oddball paradigm with 10% 'duration deviants' and 10% 'frequency deviants' was used.

Results: MMN amplitudes to tone duration deviants were significantly reduced in the patients with schizophrenia compared to controls. The putatively prodromal subjects also showed a slight, though non-significant reduction of the MMN amplitude that was intermediate between normal controls and patients with schizophrenia, and with a larger within-group variance.

Conclusion: These results support the view that abnormalities in temporal processing are particularly pronounced in patients with schizophrenia. Prodromal subjects are a heterogeneous group with regard to outcome and time until transition to a first psychotic episode. Follow-up of these putatively prodromal subjects will show whether MMN amplitudes further reduce over time in those developing psychosis and if a reduction is state-dependent.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Acoustic Stimulation*
  • Adult
  • Auditory Perceptual Disorders / diagnosis
  • Auditory Perceptual Disorders / etiology*
  • Brain / physiopathology*
  • Cognition Disorders / diagnosis
  • Cognition Disorders / etiology*
  • Electroencephalography
  • Electrooculography
  • Female
  • Humans
  • Male
  • Memory Disorders / diagnosis
  • Memory Disorders / etiology
  • Neuropsychological Tests
  • Schizophrenia / complications*
  • Schizophrenia / diagnosis
  • Schizophrenia / physiopathology*
  • Time Perception / physiology