Mixed evidence for the potential of non-invasive transcutaneous vagal nerve stimulation to improve the extinction and retention of fear. (October 2017)

• Record Type: Journal Article
• Authors: Burger, A.M.; Verkuil, B.; Fenlon, H.; Thijs, L.; Cools, L.; Miller, H.C.; Vervliet, B.; Van Diest, I.
• Is Part Of: Behaviour research and therapy. Volume 97(2017)
• Page Start: 64
• Page End: 74
• Publication Date: 2017-10
• Subjects: Transcutaneous vagus nerve stimulation -- Fear extinction -- Memory -- Anxiety; Cognitive therapy -- Periodicals; Psychotherapy -- Periodicals; 616.891
• DOI: 10.1016/j.brat.2017.07.005
• Languages: English
• ISSNs: 0005-7967

Abstract

Abstract: Extinction memories are fragile and their formation has been proposed to partially rely on vagus nerve activity. We tested whether stimulating the auricular branch of the vagus (transcutaneous VNS; tVNS) accelerates extinction and reduces spontaneous recovery of fear. Forty-two healthy students participated in a 3-day fear conditioning study, where we tested fear acquisition (day 1), fear extinction (day 2) and the retention of the extinction memory (day 3). During extinction, participants were randomly allocated to receive tVNS or sham stimulation concurrently with each CS presentation. During the acquisition and retention phases, all participants received sham stimulation. Indexes of fear included US-expectancy, startle blink EMG and skin conductance responses. Results showed successful acquisition and extinction of fear in all measures. tVNS facilitated the extinction of declarative fear (US expectancy ratings), but did not promote a stronger retention of the declarative extinction memory. No clear effects of tVNS on extinction and retention of extinction were found for the psychophysiological indexes. The present findings provide tentative indications that tVNS could be a promising tool to improve fear extinction and call for larger scale studies to replicate these effects. Highlights: First study to assess effects of tVNS on psychophysiological indices of fear extinction in humans. tVNS accelerates declarative fear extinction. tVNS does not affect declarative fear retention. No clear evidence for effects of tVNS on psychophysiological fear extinction.