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HealthyNCT00001920

Eye Blink Response in Healthy Volunteers and Adults With Schizophrenia

An observational study of Healthy and Schizophrenia, run by National Institute of Mental Health (NIMH) at 1 site in United States.

Completed

Finished. The study has ended and is not enrolling. Results may be posted on the official record.

Official record
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Trial summary

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. Read more about this study

Who is it for?
Ages 18 to 60 yearsHealthy volunteers can take part
Conditions the study is for
Healthy, Schizophrenia
How many people
112 participants
Where
1 siteUnited States
Study dates
30 Aug 1999to 2 Jun 2010
Phase
Observational
Are there results?
None posted in the registry

Key requirements

Who can take part, as listed by the sponsor. Only the study team can confirm whether you are eligible, so take this list to your doctor.

  • Ages 18 to 60 years
  • All sexes
  • Healthy volunteers accepted
  • Adult

Who may be able to join

  • 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:
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  • 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.

Who cannot join

  • 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.
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  • 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.

Trial locations and contacts

1 site in 1 country.

United States1 site

  • National Institutes of Health Clinical Center, 9000 Rockville Pike

    Bethesda, Maryland, 20892

Other trials in United States

About this study

Official title: 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.

Read the detailed description

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.

Keywords
Schizophrenia, Eyeblink, Evoked Potentials, Learning, Normal Volunteer, Healthy Volunteer
Medical subject headings
Schizophrenia

Timeline

From the start of the study to its completion; the mark is today. Estimated dates are the sponsor’s plan.

  1. First posted4 Nov 1999 (estimated)
  2. Study start30 Aug 1999
  3. Study completion2 Jun 2010

Resources

More details

For doctors and researchers: how the study is designed, who runs it, and its registry IDs.

Study design
Study type
Observational
Enrolment
112 participants (actual)
IDs, dates and publications
ClinicalTrials.gov ID
NCT00001920
Sponsor's protocol ID
990166
Other IDs
99-M-0166
Status last verified
2 Jun 2010
First submitted
3 Nov 1999
Last updated
2 Jul 2017
Results posted
No

Publications

  • Woodruff-Pak DS. Classical conditioning. Int Rev Neurobiol. 1997;41:341-66. doi: 10.1016/s0074-7742(08)60359-1.

    PubMed 9378597

  • Chen L, Bao S, Lockard JM, Kim JK, Thompson RF. Impaired classical eyeblink conditioning in cerebellar-lesioned and Purkinje cell degeneration (pcd) mutant mice. J Neurosci. 1996 Apr 15;16(8):2829-38. doi: 10.1523/JNEUROSCI.16-08-02829.1996.

    PubMed 8786457

  • Daum I, Schugens MM, Ackermann H, Lutzenberger W, Dichgans J, Birbaumer N. Classical conditioning after cerebellar lesions in humans. Behav Neurosci. 1993 Oct;107(5):748-56. doi: 10.1037//0735-7044.107.5.748.

    PubMed 8280385

Questions about this trial

What is this clinical trial studying?

An observational study of Healthy and Schizophrenia, run by National Institute of Mental Health (NIMH) at 1 site in United States.

The full registered description is in the About this study section and the official record.

Who may be eligible to take part?

The sponsor lists 9 inclusion and 18 exclusion criteria. Eligibility is decided by the study team after screening, so read the full criteria and contact a listed site.

Is this clinical trial currently recruiting?

The record says: finished, as of the sponsor's last update on 2 Jul 2017. Status can change between updates, so confirm with the study contact before making plans.

Where is the study taking place?

The record lists 1 site in United States. Whether a site is taking part right now should be confirmed with that site. See every site.

What are the possible benefits and risks?

They depend on the study and the treatment, and no study can promise a benefit. The study team explains the known risks during informed consent, before anyone joins; the record itself does not list them.

Are results available for this study?

The study is completed, but results are not available in the source record. That does not mean the treatment did or did not work.

How can a doctor refer a patient or contact the research team?

The record lists no contact. The official record names the sponsor, who can be asked directly. AzTrials does not enrol participants or take referrals.

Where can I read the original study information?

On the ClinicalTrials.gov record for NCT00001920, which also lists 3 linked publications.

Does a listing mean the treatment is approved or proven to work?

No. A listing means the study is registered. It does not show that the treatment is safe, works, or is approved by a regulator.

How often is this information updated?

AzTrials copies changed records from ClinicalTrials.gov every night and reloads the whole registry every week. The sponsor last updated this record on 2 Jul 2017.

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