Eye Blink Response in Healthy Volunteers and Adults With Schizophrenia

Completed

Conditions studied: Healthy, Schizophrenia

In brief

The purpose of this study is to explore how the brain works during particular memory tasks in people with schizophrenia and healthy volunteers. Research has shown that patients with schizophrenia have structural and functional abnormalities in the hippocampus and cerebellum of their brains. These abnormalities are likely associated with the memory impairment experienced by these patients. Eye blink tests can provide information about memory acquisition involving the cerebellar and hippocampal regions. By altering the stimuli interval, these tests can distinguish between cerebellum-dependent memory associated with subliminal mnemonic encoding and hippocampus-dependent memory associated with conscious awareness. This study will use eyeblink tests to determine which type of memory is predominantly affected in schizophrenia. Participants in this study will be screened with a physical and psychiatric examination. Participants will have an electroencephalogram (EEG), an electrocardiogram (ECG), and an electrodermal test. Evoked potentials and magnetic resonance imaging (MRI) scans of the brain may also be taken.

Key facts

Study ID

NCT00001920

Run by

National Institute of Mental Health (NIMH)

People needed

112

Starts

1999-08-30

Expected to finish

2010-06-02

Last updated by the study team

2017-07-02

Who can join

Age: 18 and older, up to 60. Sex: any. Healthy volunteers: accepted.

You may not qualify if…

• Controls and Patients:
• Impaired hearing.
• Use of caffeine or tobacco in the 2 hours preceding the test.
• Head trauma with loss of consciousness in the last year, or any evidence of functional impairment due to and persisting after head trauma.
• All subjects who are unable to withstand the eyeblink testing will be excluded. Subjects who are not able to participate in the MRI (e.g. due to claustrophobia) will be studied to achieve a larger group for the behavioral experiments.
• Subjects who are found to have eye lesions on exam.
• Patients or healthy volunteers with a known risk from exposure to high magnetic fields (e.g. patients with pace makers) and those who have metallic implants (e.g. braces) in the head region (likely to create artifact on the MRI scans) will be excluded from participating in the MRI studies.
• Patients:
• Coexistence of another major mental illness at the time of the study. If the patients experienced other mental illnesses in the past (e.g. a learning disability or major depression), then this should be judged to be fully recovered.
• Criteria for substance abuse met in the last 6 months.
• Criteria for substance dependence met in the last year. If criteria for dependence were met in the past, then the duration of the disorder was less than 3 years, or not judged to have produced long term brain changes to allow the patient to be in the study.
• Major concurrent medical illness likely to interfere with the acquisition of the task.
• Concomitant medications which could interfere with performance on the task, excluding neuroleptics.
• Presence of diskinetic movements of the face and tongue (likely to interfere with eyeblink measures, or of gross involuntary movements of the whole body (likely to interfere with positioning in the MRI scanner).
• Pregnancy testing will be performed on women of childbearing age within the three days prior to MRI scanning.
• Siblings of Patients with Schizophrenia:
• The same inclusion criteria as normal volunteers, with the exception of family history, of course. In addition, the inclusion criteria for protocol #95-M-0150 will apply.
• The same exclusion criteria as normal volunteers will apply.

Where it is running

• National Institutes of Health Clinical Center, 9000 Rockville Pike — Bethesda, Maryland, United States

Full record on ClinicalTrials.gov

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