TY  - JOUR
A1  - Fischer, Rico
A1  - Ventura-Bort, Carlos
A1  - Hamm, Alfons O.
A1  - Weymar, Mathias
T1  - Transcutaneous vagus nerve stimulation (tVNS) enhances conflict-triggered adjustment of cognitive control
JF  - Cognitive, affective, & behavioral neuroscience : a journal of the Psychonomic Society
N2  - Response conflicts play a prominent role in the flexible adaptation of behavior as they represent context-signals that indicate the necessity for the recruitment of cognitive control. Previous studies have highlighted the functional roles of the affectively aversive and arousing quality of the conflict signal in triggering the adaptation process. To further test this potential link with arousal, participants performed a response conflict task in two separate sessions with either transcutaneous vagus nerve stimulation (tVNS), which is assumed to activate the locus coeruleus-noradrenaline (LC-NE) system, or with neutral sham stimulation. In both sessions the N2 and P3 event-related potentials (ERP) were assessed. In line with previous findings, conflict interference, the N2 and P3 amplitude were reduced after conflict. Most importantly, this adaptation to conflict was enhanced under tVNS compared to sham stimulation for conflict interference and the N2 amplitude. No effect of tVNS on the P3 component was found. These findings suggest that tVNS increases behavioral and electrophysiological markers of adaptation to conflict. Results are discussed in the context of the potentially underlying LC-NE and other neuromodulatory (e.g., GABA) systems. The present findings add important pieces to the understanding of the neurophysiological mechanisms of conflict-triggered adjustment of cognitive control.
KW  - Conflict adaptation
KW  - Cognitive control
KW  - Transcutaneous vagus nerve stimulation
KW  - tVNS
KW  - ERP
KW  - N2
Y1  - 2018
U6  - https://doi.org/10.3758/s13415-018-0596-2
SN  - 1530-7026
SN  - 1531-135X
VL  - 18
IS  - 4
SP  - 680
EP  - 693
PB  - Springer
CY  - New York
ER  - 
TY  - JOUR
A1  - Giraudier, Manon
A1  - Ventura-Bort, Carlos
A1  - Burger, Andreas M.
A1  - Claes, Nathalie
A1  - D'Agostini, Martina
A1  - Fischer, Rico
A1  - Franssen, Mathijs
A1  - Kaess, Michael
A1  - Koenig, Julian
A1  - Liepelt, Roman
A1  - Nieuwenhuis, Sander
A1  - Sommer, Aldo
A1  - Usichenko, Taras
A1  - Van Diest, Ilse
A1  - von Leupoldt, Andreas
A1  - Warren, Christopher Michael
A1  - Weymar, Mathias
T1  - Evidence for a modulating effect of transcutaneous auricular vagus nerve stimulation (taVNS) on salivary alpha-amylase as indirect noradrenergic marker: A pooled mega-analysis
JF  - Brain Stimulation
N2  - Background
Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) has received tremendous attention as a potential neuromodulator of cognitive and affective functions, which likely exerts its effects via activation of the locus coeruleus-noradrenaline (LC-NA) system. Reliable effects of taVNS on markers of LC-NA system activity, however, have not been demonstrated yet.

Methods
The aim of the present study was to overcome previous limitations by pooling raw data from a large sample of ten taVNS studies (371 healthy participants) that collected salivary alpha-amylase (sAA) as a potential marker of central NA release.

Results
While a meta-analytic approach using summary statistics did not yield any significant effects, linear mixed model analyses showed that afferent stimulation of the vagus nerve via taVNS increased sAA levels compared to sham stimulation (b = 0.16, SE = 0.05, p = 0.001). When considering potential confounders of sAA, we further replicated previous findings on the diurnal trajectory of sAA activity.

Conclusion(s)
Vagal activation via taVNS increases sAA release compared to sham stimulation, which likely substantiates the assumption that taVNS triggers NA release. Moreover, our results highlight the benefits of data pooling and data sharing in order to allow stronger conclusions in research.
KW  - Non-invasive vagus nerve stimulation
KW  - tVNS
KW  - sAA
KW  - Noradrenaline
KW  - Biomarker
KW  - Data pooling
Y1  - 2022
U6  - https://doi.org/10.1016/j.brs.2022.09.009
SN  - 1876-4754
VL  - 15
SP  - 1378
EP  - 1388
PB  - Elsevier
CY  - New York, NY, USA
ET  - 6
ER  -