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Does Transcutaneous Vagal Nerve Stimulation Improves Fear Extinction in Humans (t-VNSext)

The recruitment status of this study is unknown. The completion date has passed and the status has not been verified in more than two years.
Verified April 2014 by Universitaire Ziekenhuizen Leuven.
Recruitment status was:  Not yet recruiting
Katholieke Universiteit Leuven
Information provided by (Responsible Party):
Ilse Van Diest, Universitaire Ziekenhuizen Leuven Identifier:
First received: April 10, 2014
Last updated: April 11, 2014
Last verified: April 2014

A recent study with rats showed that electrical stimulation of the vagus nerve (VNS) facilitates extinction of fear (Pena, Engineer, & McIntyre, Biological Psychiatry, 2013). The hypothesized mechanism is that VNS both enhances memory consolidation (by increasing noradrenergic neurotransmission) and reduces anxiety (thus: preventing fear responses to the CS which may re-consolidate the fear memory). The effect was only apparent when VNS occurred during exposure of the fear conditioned stimulus (CS), and not when stimulation was given immediately following exposure. These results may have implications for the treatment of anxiety disorders in humans. However, until recently, the only means to investigate the effects of VNS on human fear learning would have required the invasive implantation of vagus nerve stimulators. This has fortunately changed, as a non-invasive transcutaneous VNS device has been approved for use in the E.U. for the treatment of psychological disorders.

This study proposes to use a t-VNS to investigate its effects on fear learning and extinction in (healthy) humans. Previous research has only investigated the effects it has on human mood and memory. The results obtained suggest that it reduces negative affect and enhances memory, findings which are consistent with those reported for rats. It is thus reasonable to expect that t-VNS will facilitate the extinction of fear in humans.

The present study aims to answer the following research questions:

Does t-VNS during extinction training:

  1. accelerates extinction curves
  2. reduces spontaneous recovery of previously extinguished fear
  3. reduce re-acquisition of fear
  4. reduce generalization of fear to other stimuli that resemble the CS+?
  5. facilitates the generalization of inhibitory learning to stimuli that resemble the CS-?

Condition Intervention
Healthy Adults
Device: t-VNS
Device: sham stimulation

Study Type: Interventional
Study Design: Allocation: Randomized
Intervention Model: Parallel Assignment
Masking: Single Blind (Participant)
Primary Purpose: Basic Science
Official Title: Does Transcutaneous Vagal Nerve Stimulation Improves Fear Extinction in Humans

Further study details as provided by Universitaire Ziekenhuizen Leuven:

Primary Outcome Measures:
  • fear response [ Time Frame: 3 test days ]
    startle blink EMG skin conductance response ECG respiration self-reports

Estimated Enrollment: 50
Study Start Date: July 2014
Estimated Primary Completion Date: December 2015 (Final data collection date for primary outcome measure)
Arms Assigned Interventions
Experimental: t-VNS

electrical stimulation of the concha of the ear

30sec trains of 0.25msec-duration monophasic square wave pulses at 25Hz, with a stimulation intensity not exceeding 0.5 mA

Device: t-VNS
The device that will be used is approved for systematic use by those with epilepsy and depression in the European Union. It has been used in studies of acute stimulation with healthy participants with no significant changes in heart rate or breathing (Kraus et al., 2007; Busch et al., 2013).
Other Name: NEMOS®, Cerbomed, Erlangen, Germany
Sham Comparator: sham t-VNS

Sham stimulation of the earlobe will be conducted by positioning the electrode upside down

30sec trains of 0.25msec-duration monophasic square wave pulses at 25Hz, with a stimulation intensity not exceeding 0.5 mA

Device: sham stimulation
electrodes will be put upside down
Other Name: NEMOS®, Cerbomed, Erlangen, Germany


Ages Eligible for Study:   16 Years to 50 Years   (Child, Adult)
Sexes Eligible for Study:   All
Accepts Healthy Volunteers:   Yes

Inclusion Criteria:

  • healthy men and women aged 16 - 50 years

Exclusion Criteria:

  • current or past psychiatric or neurological disorder
  • use of psychopharmaca
  • use of medication that affects autonomic nervous functioning (e.g., bèta-blockers)
  • current cardiac or respiratory disorder
  • pregnancy
  Contacts and Locations
Choosing to participate in a study is an important personal decision. Talk with your doctor and family members or friends about deciding to join a study. To learn more about this study, you or your doctor may contact the study research staff using the Contacts provided below. For general information, see Learn About Clinical Studies.

Please refer to this study by its identifier: NCT02113306

Contact: Ilse Van Diest, PhD +32 16 32 60 29

Faculty of Psychology and Educational Science Not yet recruiting
Leuven, Belgium, 3000
Contact: Ilse Van Diest, PhD         
Sub-Investigator: Holly Miller, PhD         
Sub-Investigator: Holly Fenlon, Ba         
Sponsors and Collaborators
Universitaire Ziekenhuizen Leuven
Katholieke Universiteit Leuven
Principal Investigator: Ilse Van Diest, PhD Katholieke Universiteit Leuven
  More Information

Responsible Party: Ilse Van Diest, Professor, Universitaire Ziekenhuizen Leuven Identifier: NCT02113306     History of Changes
Other Study ID Numbers: t-VNS extinction
Study First Received: April 10, 2014
Last Updated: April 11, 2014 processed this record on May 23, 2017