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Eye Blink Response in Healthy Volunteers and Adults With Schizophrenia

2017年6月30日 更新者:National Institute of Mental Health (NIMH)

Investigation of Brain Function During Eyeblink Responding in Normal Volunteers and Patients With Schizophrenia (A Study of Behavior and Evoked Potentials)

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.

研究概览

地位

完全的

详细说明

Eyeblink conditioning is a paradigm that allows the study of aspects of the neural mechanism of memory in humans. This paradigm has been extensively studied in animals and human beings and its functional neuroanatomy appears to be well understood, involving the hippocampus and cerebellum. The performance on this task is most likely independent of subject motivation. Moreover, manipulation of the intervals between conditioned and unconditioned stimuli allows to study subliminal forms of mnemonic encoding ("delay" task) as well as learning that is associated with conscious awareness ("trace" task). This makes eyeblink conditioning particularly suited for study in patient populations, and particularly in schizophrenia where motivation and attention are frequently confounding factors in the study of memory processes.

Patients with schizophrenia have been reported to have hippocampal and possibly cerebellar structural and functional abnormalities, however eyeblink conditioning has been minimally studied in this patient population. We expect implicit forms of memory (cerebellum dependent) to be relatively spared as compared to declarative memory (hippocampus dependent) in schizophrenia.

We would like to test the hypothesis that patients with schizophrenia have deficits in acquiring the trace form of the task as opposed to the delay, where we assume they would be unimpaired as compared to normal controls. We would also like to study heart rate and skin conductance changes that occur during conditioning, since patients with schizophrenia have showed impaired autonomic function.

We also plan to study neurophysiological correlates of these behaviors with evoked response potentials (EP) and eventually functional magnetic resonance imaging (fMRI)

We expect EPs to show significant change in relation to development of the behavioral response. The association of awareness of the stimulus contingency with slow cortical potentials on the EEG will also be of interest.

研究类型

观察性的

注册 (实际的)

112

联系人和位置

本节提供了进行研究的人员的详细联系信息,以及有关进行该研究的地点的信息。

学习地点

    • Maryland
      • Bethesda、Maryland、美国、20892
        • National Institutes of Health Clinical Center, 9000 Rockville Pike

参与标准

研究人员寻找符合特定描述的人,称为资格标准。这些标准的一些例子是一个人的一般健康状况或先前的治疗。

资格标准

适合学习的年龄

18年 至 60年 (成人)

接受健康志愿者

有资格学习的性别

全部

描述

  • INCLUSION CRITERIA

Controls:

No psychiatric or severe chronic medical illness at the time of the study, and by history. This includes the absence of substance abuse histories, learning disabilities and all DSM IV disorders. Medical histories will be evaluated by the investigators and medical conditions that are judged not to interfere with the study may be allowed.

No use of psychotropic substances in the last 3 months.

Age 18-60.

No family history of schizophrenia by subject report and possibly also by collateral report by at least one other family member.

Patients:

Schizophrenia, any subtype or schizoaffective disorder, depressed type by DSM IV (110).

Only concomitant medications should be neuroleptics and medications directed at controlling side effects (e.g. anticholinergics). An effort will be made to recruit patients on atypical neuroleptics, therefore attempting to minimize the anticholinergics, which might interfere with the acquisition of a conditioned response. When patients on anticholinergic treatment will be recruited as inpatients, a clinical evaluation of the risks and benefits of suspending anticholinergic treatment will be made and discussed with the patient. Anticholinergics will be withdrawn for a period equivalent to 3 half lives of the drug before attempting the study, if this is judged to be achievable with a relatively low risk and the patient agrees.

Age18-60.

EXCLUSION CRITERIA

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.

学习计划

本节提供研究计划的详细信息,包括研究的设计方式和研究的衡量标准。

研究是如何设计的?

合作者和调查者

在这里您可以找到参与这项研究的人员和组织。

出版物和有用的链接

负责输入研究信息的人员自愿提供这些出版物。这些可能与研究有关。

研究记录日期

这些日期跟踪向 ClinicalTrials.gov 提交研究记录和摘要结果的进度。研究记录和报告的结果由国家医学图书馆 (NLM) 审查,以确保它们在发布到公共网站之前符合特定的质量控制标准。

研究主要日期

学习开始

1999年8月30日

研究完成

2010年6月2日

研究注册日期

首次提交

1999年11月3日

首先提交符合 QC 标准的

1999年11月3日

首次发布 (估计)

1999年11月4日

研究记录更新

最后更新发布 (实际的)

2017年7月2日

上次提交的符合 QC 标准的更新

2017年6月30日

最后验证

2010年6月2日

更多信息

与本研究相关的术语

此信息直接从 clinicaltrials.gov 网站检索,没有任何更改。如果您有任何更改、删除或更新研究详细信息的请求,请联系 register@clinicaltrials.gov. clinicaltrials.gov 上实施更改,我们的网站上也会自动更新.

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