Early- and late-latency gamma auditory steady-state response in schizophrenia during closed eyes: Does hallucination status matter?
- Griskova-Bulanova I Department of Neurobiology and Biophysics, Vilnius University, Vilnius, Lithuania; Republican Vilnius Psychiatric Hospital, Vilnius, Lithuania. Electronic address: i.griskova@gmail.com.
- Hubl D Translational Research Center, University Hospital of Psychiatry, University of Bern, Switzerland.
- van Swam C Translational Research Center, University Hospital of Psychiatry, University of Bern, Switzerland.
- Dierks T Translational Research Center, University Hospital of Psychiatry, University of Bern, Switzerland.
- Koenig T Translational Research Center, University Hospital of Psychiatry, University of Bern, Switzerland.
- 2016-04-14
Published in:
- Clinical neurophysiology : official journal of the International Federation of Clinical Neurophysiology. - 2016
Auditory steady-state response
Gamma activity
Hallucinations
Schizophrenia
Adult
Brain
Brain Mapping
Electroencephalography
Evoked Potentials, Auditory
Female
Hallucinations
Humans
Male
Middle Aged
Schizophrenia
English
OBJECTIVES
Auditory steady-state responses are larger in patients experiencing auditory verbal hallucinations (AVH) than in never hallucinating subjects (NH) when recorded with open eyes. Compensatory effects were shown for schizophrenic patients when recorded with closed eyes. This effect has not been evaluated in respect to hallucination status.
METHODS
Gamma responses to 40Hz stimulation were recorded in 15AVH patients, 25 healthy controls and 11NH patients with closed eyes. Mean and peak evoked amplitude and phase-locking index, peak time and maximal frequency were extracted for early- and late-latency responses and compared between groups.
RESULTS
Phase-locking of early, but not late-latency gamma was diminished in schizophrenic patients independently on hallucination status. Peak entrainment time was delayed in hallucinating patients. Magnitude and frequency of early-latency response correlated to negative symptoms.
CONCLUSIONS
In AVH patients, entrainment at gamma frequency was "normal" when eyes were closed. In contrast to never hallucinating subjects, entrainment to stimulation was delayed in AVH. The early-latency gamma response, standing for early sensory stimulus processing, on the contrary, was impaired in SZ irrespective of prevalence of hallucinations and was not modulated by subjects' general state; however its magnitude might be related to the expression of negative symptomatology.
SIGNIFICANCE
Evaluation of auditory entrainment in both open eyes and closed eyes conditions is informative. Frequency and timing information of both early-latency and late-latency responses helps to uncover different aspects of impairment in schizophrenia patients.
Auditory steady-state responses are larger in patients experiencing auditory verbal hallucinations (AVH) than in never hallucinating subjects (NH) when recorded with open eyes. Compensatory effects were shown for schizophrenic patients when recorded with closed eyes. This effect has not been evaluated in respect to hallucination status.
METHODS
Gamma responses to 40Hz stimulation were recorded in 15AVH patients, 25 healthy controls and 11NH patients with closed eyes. Mean and peak evoked amplitude and phase-locking index, peak time and maximal frequency were extracted for early- and late-latency responses and compared between groups.
RESULTS
Phase-locking of early, but not late-latency gamma was diminished in schizophrenic patients independently on hallucination status. Peak entrainment time was delayed in hallucinating patients. Magnitude and frequency of early-latency response correlated to negative symptoms.
CONCLUSIONS
In AVH patients, entrainment at gamma frequency was "normal" when eyes were closed. In contrast to never hallucinating subjects, entrainment to stimulation was delayed in AVH. The early-latency gamma response, standing for early sensory stimulus processing, on the contrary, was impaired in SZ irrespective of prevalence of hallucinations and was not modulated by subjects' general state; however its magnitude might be related to the expression of negative symptomatology.
SIGNIFICANCE
Evaluation of auditory entrainment in both open eyes and closed eyes conditions is informative. Frequency and timing information of both early-latency and late-latency responses helps to uncover different aspects of impairment in schizophrenia patients.
- Language
-
- English
- Open access status
- bronze
- Identifiers
-
- DOI 10.1016/j.clinph.2016.02.009
- PMID 27072092
- Persistent URL
- https://sonar.rero.ch/global/documents/169834
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