Related Experiment Videos
CNV, PINV and probe-evoked potentials in schizophrenics
M Wagner1, N Rendtorff, N Kathmann
1Department of Psychology, University of Konstanz, Germany.
Electroencephalography and Clinical Neurophysiology
|February 1, 1996
Summary
Schizophrenia patients show altered attention and cortical excitability. Their brain activity patterns (contingent negative variation) differ, impacting reaction times and psychopathology.
Area of Science:
- Neuroscience
- Psychiatry
- Cognitive Psychology
Background:
- Attention deficits and temporal modulation impairments are noted in schizophrenia.
- Cortical excitability changes may underlie these attentional disturbances.
Purpose of the Study:
- To investigate distractibility and temporal attention modulation in schizophrenia.
- To examine cortical excitability using auditory evoked potentials (EPs) and electroencephalography (EEG) measures like contingent negative variation (CNV).
Main Methods:
- A visual reaction time task with auditory probe stimuli was administered to schizophrenic patients, alcoholics, and normal controls.
- Midline contingent negative variation (tCNV) distribution and postimperative negative variation (PINV) amplitude were analyzed.
- Event-related potentials (ERPs) including N100 and P300 to auditory probes were measured.
Main Results:
- Schizophrenics exhibited distinct tCNV distribution, linked to psychopathology and delayed reactions.
- Auditory probes between trials decreased tCNV and PINV, but paradoxically sped up reaction times, suggesting an alerting effect.
- N100 and P300 amplitudes to probes during CNV were enhanced in all groups, indicating heightened cortical excitability.
Conclusions:
- Schizophrenia is associated with disturbed temporal and topographical regulation of cortical excitability.
- Heightened cortical excitability during CNV is not stimulus-specific and is impaired in schizophrenia.