Evidence map›Paper›PMID 41996100›Full record

ArticlePsychophysiology2026

Pulsed taVNS-Elicited Pupil Dilation: Effects of Intermixed Stimulation, Sham Location, and Respiratory Phase.

Martin Kolnes, Sander Nieuwenhuis

Abstract read
In one paragraph

Article in Psychophysiology, 2026. The graph could read no effect estimate from its abstract, so it casts no vote on the map. Not yet cited in PubMed.

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1 · What the graph read from it

What it found

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The abstract states no effect estimate the extractor could read, or names no intervention and outcome on the map, so this paper lights no cell and moves no belief. It is still indexed, cited and linked below.

2 · The registry

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3 · Its place in the literature

Who cites it

0 citing papers in PubMed.

No citing paper in PubMed yet.

4 · The record

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5 · Who and what money

Authors and funding

2 authors.

Martin KolnesInstitute of Psychology, University of Tartu, Tartu, Estonia.ORCID https://orcid.org/0000-0003-3953-8724
Sander NieuwenhuisInstitute of Psychology, Leiden University, Leiden, the Netherlands.ORCID https://orcid.org/0000-0003-2418-3879

Funding

Eesti Teadusagentuur KOHTO16Nederlandse Organisatie voor Wetenschappelijk Onderzoek VI.C.181.032
6 · The paper itself

Abstract

Transcutaneous auricular vagus nerve stimulation (taVNS) may offer a powerful, noninvasive way to stimulate activity of brainstem arousal systems, including the locus coeruleus-norepinephrine (LC-NE) system. Pulsed taVNS is known to elicit pupil dilation, a marker of LC activity. However, studies reporting taVNS effects on pupil dilation have delivered taVNS and sham stimulation in separate blocks of trials or in separate sessions, hindering the integration of taVNS into rapid, event-related task designs of cognitive neuroscientists. In two experiments, we examined the effectiveness of pulsed taVNS in eliciting pupil dilation when active and sham stimulation were intermixed within the same blocks of trials and whether these effects depend on sham location and respiratory phase. In Experiment 1 (N = 40), intermixed taVNS and (earlobe) sham pulses of 3.4 s produced inconclusive evidence for increased taVNS-evoked pupil dilation. In contrast, in Experiment 2 (N = 60), taVNS pulses of 1.0 s had a strong effect on pupil dilation, but only in a group of participants that received sham stimulation at the earlobe; this effect was abolished in a group that received sham stimulation at the upper scapha, a non-vagal control area with a similar density of sympathetic nerve fibers as the cymba concha. Furthermore, taVNS-evoked pupil dilation was not enhanced when stimulation was delivered during exhalation, as would be expected if pupil effects were mediated by the vagus nerve-nucleus tractus solitarius-LC pathway. Together, these findings show that the effect of pulsed taVNS on pupil dilation can be preserved when taVNS and (earlobe) sham are delivered in the same blocks of trials. However, the null finding with the scapha as a sham location and the absence of an enhanced taVNS effect during exhalation call into question the assumption that taVNS-induced pupil dilation is mediated by activation of the vagal afferent pathway.

Indexed as

PupilRespirationTranscutaneous Electric Nerve StimulationVagus Nerve StimulationAdultFemaleHumansLocus CoeruleusMaleVagus NerveYoung AdultLC–NE systempupilrespirationshamtranscutaneous vagus nerve stimulationtVNS

Identifiers

PMID41996100
PMCPMC13089595

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Read under generation 80e0d062 · epoch 390. Bibliography from PubMed, PubMed Central and OpenAlex; grants from NIH RePORTER; trial links from ClinicalTrials.gov; estimates, votes and beliefs from the OpenQuestion graph.