The Effect of Intravenous Anesthetics on Fear Learning and Memory

Phobias Clinical Trial

Official title:

The Effect of Intravenous Anesthetics on Fear Learning and Memory

Clinical Trial Details — Status: Completed

Administrative data

• NCT number: NCT00767767
• Other study ID #: 0710009434
• Secondary ID: K08GM083213
• Status: Completed
• Phase: N/A
• Start date: October 2008
• Est. completion date: May 2011

Study information

• Verified date: April 2019
• Source: Weill Medical College of Cornell University
• Contact: n/a
• Is FDA regulated: No
• Study type: Interventional

Clinical Trial Summary

People often develop fearful responses to things, but have no conscious control over the fear. This is a basic form of unconscious memory, called "fear conditioning." Intravenous anesthetic drugs have remarkable effects on conscious memory, but it is unknown whether they have similar effects on these unconscious fear memories.

To address this question, the investigators will study 114 healthy adult volunteer subjects. The subject is given a very low dose of an anesthetic drug intravenously (i.e. through the bloodstream). The dose is so low that the subject might not even be able tell if they are getting the drug. While they are receiving the drug, the subject will perform a series of memory tests and a fear conditioning experiment, which are set up like a very simple computer game. To create the "fear response", subjects will occasionally receive a mildly uncomfortable shock to their arm. The subject is able to determine the highest level of shock that they will receive.

The investigators are doing this study because the investigators wish to know exactly how the drugs affect the way people process fear and emotion. This knowledge might one day be used in the treatment of some psychiatric disorders.

Description:

People often develop fearful responses to things, but have no conscious control over the fear (e.g. phobias). This is a basic form of unconscious memory, called "fear conditioning." Intravenous anesthetic drugs have remarkable effects on conscious memory, but it is unknown whether they have similar effects on these unconscious fear memories.

To address this question, the investigators will study 114 healthy adult volunteer subjects. The subject is given a very low dose of an anesthetic drug intravenously (i.e. through the bloodstream). The dose is so low that the subject might not even be able tell if they are getting the drug. While they are receiving the drug, the subject will perform a series of memory tests and a fear conditioning experiment, which are set up like a very simple computer game. To create the "fear response", subjects will occasionally receive a mildly uncomfortable shock to their arm. The subject is able to determine the highest level of shock that they will receive.

The investigators are doing this study because the investigators wish to know exactly how the drugs affect the way people process fear and emotion. This knowledge might one day be used in the treatment of some psychiatric disorders.

Recruitment information / eligibility

• Status: Completed
• Enrollment: 67
• Est. completion date: May 2011
• Est. primary completion date: May 2011
• Accepts healthy volunteers: Accepts Healthy Volunteers
• Gender: All
• Age group: 18 Years to 50 Years

Eligibility

Inclusion Criteria:

• age between 18 and 50

• minimum of high school education

• fluent in English

• normal vocabulary

Exclusion Criteria:

• any significant medical or psychiatric comorbidity (e.g. asthma, diabetes, hypertension, depression, high anxiety)--subjects must be in excellent health such that they would be classified as American Society of Anesthesiologists Physical Status Class I

• deficit in vision or hearing that would impede the study

• allergies to any of the study drugs, to soybeans, or to eggs

• a history of head trauma

• a family history of major psychiatric illness

• body mass index > 30 kg/m2

• a recent history of recreational drug use

• prior exposure to the study materials

• pregnancy

• a personal or family history of any porphyria

• failure to exhibit a skin conductance response to deep inspiration

• the ability to read Chinese characters

• assessment by the investigators that the subject may be unable to cooperate or comply with the study requirements.

Related Conditions & MeSH terms

• Phobias

Intervention

Drug:
• Placebos
IV Saline infusion for 2 hours.
• Propofol 0.45mcg/mL
IV Propofol infusion for 2 hours.
• Propofol 0.90mcg/mL
IV Propofol infusion for 2 hours.
• Thiopental 1.5mcg/mL
IV Thiopental 1.5mcg/mL infusion for 2 hours
• Thiopental 3mcg/mL
IV Thiopental 3mcg/mL infusion for 2 hours

Locations

Country	Name	City	State
United States	Weill Cornell Medical College/New York Presbyterian Hospital	New York	New York

Sponsors (3)

Lead Sponsor	Collaborator
Weill Medical College of Cornell University	National Institute of General Medical Sciences (NIGMS), National Institutes of Health (NIH)

Country where clinical trial is conducted

United States, 

Outcome

Type	Measure	Description	Time frame	Safety issue
Primary	GSR Trial 1	Galvanic skin repose (GSR) to the first habituation trial (yes/no). Coding: Yes (0) and No (1)	First Trial, for up to 1 day