Spatio-temporal EEG waves in first episode schizophrenia

Clin Neurophysiol. 2009 Sep;120(9):1667-82. doi: 10.1016/j.clinph.2009.06.020. Epub 2009 Jul 30.

Abstract

Objective: Schizophrenia is characterized by a deficit in context processing, with physiological correlates of hypofrontality and reduced amplitude P3b event-related potentials. We hypothesized an additional physiological correlate: differences in the spatio-temporal dynamics of cortical activity along the anterior-posterior axis of the scalp.

Methods: This study assessed latency topographies of spatio-temporal waves under task conditions that elicit the P3b. EEG was recorded during separate auditory and visual tasks. Event-related spatio-temporal waves were quantified from scalp EEG of subjects with first episode schizophrenia (FES) and matched controls.

Results: The P3b-related task conditions elicited a peak in spatio-temporal waves in the delta band at a similar latency to the P3b event-related potential. Subjects with FES had fewer episodes of anterior to posterior waves in the 2-4 Hz band compared to controls. Within the FES group, a tendency for fewer episodes of anterior to posterior waves was associated with high Psychomotor Poverty symptom factor scores.

Conclusions: Subjects with FES had altered global EEG dynamics along the anterior-posterior axis during task conditions involving context update.

Significance: The directional nature of this finding and its association with Psychomotor Poverty suggest this result is related to findings of hypofrontality in schizophrenia.

MeSH terms

  • Acoustic Stimulation
  • Adolescent
  • Adult
  • Data Interpretation, Statistical
  • Delta Rhythm
  • Electroencephalography*
  • Evoked Potentials / physiology
  • Female
  • Frontal Lobe / physiopathology
  • Humans
  • Male
  • Memory, Short-Term / physiology
  • Photic Stimulation
  • Psychiatric Status Rating Scales
  • Psychomotor Performance / physiology
  • Reaction Time / physiology
  • Schizophrenia / physiopathology*
  • Schizophrenic Psychology
  • Young Adult