Tonic and phasic transcutaneous auricular vagus nerve stimulation (taVNS) both evoke rapid and transient pupil dilation

Brain stimulation, Год журнала: 2024, Номер 17(2), С. 233 - 244

Опубликована: Фев. 28, 2024

BackgroundTranscutaneous auricular vagus nerve stimulation (tVNS or taVNS) is a non-invasive method of electrical the afferent pathway nerve, suggested to drive changes in putative physiological markers noradrenergic activity, including pupil dilation.ObjectiveHowever, it unknown whether different taVNS modes can map onto phasic and tonic activity. The effects on dilation humans are inconsistent, largely due differences protocols. Here, we attempted address these issues.MethodsWe investigated under (1 s) (30 taVNS, pre-registered, single-blind, sham-controlled, within-subject cross-over design, absence behavioural task.ResultsPhasic induced rapid increase size over baseline, significantly greater than sham stimulation, which rapidly declined after offset. Tonic similarly (and larger sham) returning baseline within 5 s, despite ongoing stimulation. Thus, both active closely resembled effect. There were no size, sustained size.ConclusionsThese results suggest that phasic- tonic-like standard parameters may modulate primarily mode as indexed by evoked dilation, above somatosensory effects. This result sheds light temporal profile with implications for their applicability further research.

Язык: Английский

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The impact of transcutaneous vagus nerve stimulation on anterior cingulate cortex activity in a cognitive control task

Psychophysiology, Год журнала: 2025, Номер 62(1)

Опубликована: Янв. 1, 2025

Abstract Transcutaneous vagus nerve stimulation (tVNS) offers a non‐invasive method to enhance noradrenergic neurotransmission in the human brain, thereby increasing cognitive control. Here, we investigate if changes control induced by tVNS are mediated through locus coeruleus‐induced modifications of neural activity anterior cingulate cortex. Young healthy participants engaged simple task focusing on response inhibition and more complex that involved both working memory, inside magnetic resonance imaging scanner. The tasks were executed using randomized within‐subject design, with undergoing auricular sham separate sessions. significantly changed performance reflected greater propensity respond. Furthermore, observed significant increase cortex during under tVNS. Functional connectivity analyses revealed positive coupling between coeruleus cortex, however, this was not modulated findings suggest can modulate While these effects an impact key region conflict monitoring control, behavioral indicative shift bias rather than enhanced

Язык: Английский

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Does transcutaneous auricular vagus nerve stimulation alter pupil dilation? A living Bayesian meta-analysis

Brain stimulation, Год журнала: 2025, Номер 18(2), С. 148 - 157

Опубликована: Янв. 29, 2025

Язык: Английский

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Three Hundred Hertz Transcutaneous Auricular Vagus Nerve Stimulation (taVNS) Impacts Pupil Size Non‐Linearly as a Function of Intensity

Psychophysiology, Год журнала: 2025, Номер 62(2)

Опубликована: Фев. 1, 2025

ABSTRACT Transcutaneous auricular vagus nerve stimulation (taVNS) is a neuromodulatory technique that may have numerous potential health and human performance benefits. However, optimal parameters for maximizing taVNS efficacy are unknown. Progress impeded by disagreement on the identification of biomarker reliably indexes activation systems targeted taVNS, including locus coeruleus‐norepinephrine (LC‐NE) system. Pupil size varies with LC‐NE activity one has shown inconsistent sensitivity to in prior studies. The present study examined relationship between pupil using promising behavioral effects studies but received comparatively little attention. Participants trains 50 μs pulses delivered continuously below perceptual threshold at 300 Hz left external acoustic meatus (EAM) while was recorded during pupillary light reflex task. Analysis generalized additive mixed modeling (GAMM) revealed non‐linear intensity diameter. Active increased participants who 2 approximately 4.8 mA, not higher‐intensity (up 8.1 mA). In addition, persisted subsequent blocks, mitigating decreases over course These findings suggest activates system when applied EAM, its be counteracted higher intensities.

Язык: Английский

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Transcutaneous Auricular Vagus Nerve Stimulation Does Not Accelerate Fear Extinction: A Randomized, Sham‐Controlled Study

Psychophysiology, Год журнала: 2025, Номер 62(1)

Опубликована: Янв. 1, 2025

ABSTRACT Transcutaneous auricular vagus nerve stimulation (taVNS) has been tested as a strategy to facilitate fear extinction learning based on the hypothesis that taVNS increases central noradrenergic activity. Four studies out of six found enhance especially at beginning extinction. Facilitatory effects were mainly observed in US expectancy, less fear‐potentiated startle (FPS), and not skin conductance response (SCR). Suboptimal parameters may explain reported mixed results. Also, variability selected conditioning paradigms statistical power impedes comparability between studies. This study sought further test whether accelerates indexed by FPS, SCR. Similar most previous studies, we employed differential paradigm. The left ear 79 healthy participants was stimulated with either sham (earlobe) or (cymba concha) during learning. To maximize beneficial taVNS, cymba concha administered continuously maximum level below pain threshold. Results pre‐registered frequentist exploratory Bayesian analyses indicate did accelerate any outcomes. null results commonly used does reliably optimize More research is needed if protocol determines efficacy optimizing

Язык: Английский

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Transcutaneous Auricular Vagus Nerve Stimulation Enhances Emotional Processing and Long‐Term Recognition Memory: Electrophysiological Evidence Across Two Studies

Psychophysiology, Год журнала: 2025, Номер 62(3)

Опубликована: Март 1, 2025

ABSTRACT Recently, we found that continuous transcutaneous auricular vagus nerve stimulation (taVNS) facilitates the encoding and later recollection of emotionally relevant information, as indicated by differences in late positive potential (LPP), memory performance, ERP Old/New effect. Here, aimed to conceptually replicate extend these findings investigating effects different time‐dependent taVNS protocols. In Study 1, an identical paradigm our previous study was employed with interval (30‐s on/off). Participants viewed unpleasant neutral scenes on two consecutive days while receiving or sham completed a recognition test 1 week later. Replicating results, images encoded under taVNS, compared stimulation, elicited larger amplitudes earlier window LPP during encoding, well more pronounced differences. However, no performance were found. 2, followed up synchronizing cycle image presentation determine for off cycles. We could enhancing brain potentials (early differences) improved recollection‐based both images, independently cycle. Overall, results suggest increases electrophysiological correlates emotional retrieval time‐independent manner, substantiating nerve's role processing formation, opening new venues improving mnemonic processes clinical non‐clinical populations.

Язык: Английский

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Transcutaneous Auricular Vagus Nerve Stimulation to Improve Emotional State

Biomedicines, Год журнала: 2024, Номер 12(2), С. 407 - 407

Опубликована: Фев. 9, 2024

Emotional experiences are a part of our lives. The maladaptive functioning an individual's emotional field can lead to disturbances various kinds, such as anxiety and depression. Currently, there is increasing prevalence disorders that cause great human suffering high socioeconomic costs. processing has biological basis. major neuroscientific theories emotion based on functioning, all them take into account the anatomy function tenth cranial nerve: vagus nerve. nerve connects subdiaphragmatic supradiaphragmatic areas modulates basis interoceptive functioning. Auricular stimulation new innovative neuromodulation technique Several interventions have shown this neurostimulation very promising resource for treating disorders. In paper, we summarise three emotion, explain what transcutaneous auricular is, present arguments its use continued research.

Язык: Английский

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Effects of Transcutaneous Auricular Vagus Nerve Stimulation on the P300: Do Stimulation Duration and Stimulation Type Matter?

Brain Sciences, Год журнала: 2024, Номер 14(7), С. 690 - 690

Опубликована: Июль 10, 2024

Non-invasive transcutaneous auricular vagus nerve stimulation (taVNS) has attracted increasing interest as a neurostimulation tool with potential applications in modulating cognitive processes such attention and memory, possibly through the modulation of locus–coeruleus noradrenaline system. Studies examining P300 brain-related component correlate noradrenergic activity, however, have yielded inconsistent findings, due to differences parameters, thus necessitating further investigation. In this event-related study involving 61 participants, therefore, we examined how changes taVNS specifically type (interval vs. continuous stimulation) duration, influence amplitudes during visual novelty oddball task. Although no effects were found over whole cluster time window P300, cluster-based permutation tests revealed distinct impact on response for small electrode cluster, characterized by larger observed easy targets (i.e., stimuli that are easily discernible from standards) following compared sham stimulation. Notably, our findings suggested significantly modulated showing (taVNS sham) hard standards interval We interaction duration target-related P300. While align previous research, investigation is warranted fully elucidate its utility reliable marker neuromodulation field.

Язык: Английский

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Tonic and Event-Related Phasic Transcutaneous Auricular Vagus Nerve Stimulation Alters Pupil Responses in the Change-Detection Task

Neuromodulation Technology at the Neural Interface, Год журнала: 2025, Номер unknown

Опубликована: Фев. 1, 2025

Язык: Английский

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Ready for translation: non-invasive auricular vagus nerve stimulation inhibits psychophysiological indices of stimulus-specific fear and facilitates responding to repeated exposure in phobic individuals

Translational Psychiatry, Год журнала: 2025, Номер 15(1)

Опубликована: Апрель 9, 2025

Abstract Recent laboratory research showed that vagus nerve stimulation promotes fear extinction, the inhibitory core mechanism of exposure treatment, presumably via activation noradrenergic brain system. However, a translation this technique to clinical practice is lacking. We therefore investigated potential vagal inhibit excessive responses and facilitate responding in-vivo in individuals with specific phobia. Spider-phobic participants were subjected three standardized exposures towards living tarantula, complemented by an vitro (between vivo I II). Transcutaneous auricular (taVNS) was applied during in-vitro exposure, presenting pictures exposed other spiders neutral tools laboratory. Fear assessed self-reports behavioral avoidance (in-vivo exposures), amygdala-mediated autonomic components (exposure vitro). Vagal facilitated reduction across repeated exposures. During taVNS inhibited tachycardia corrugator muscle activity specifically response previously tarantula – effect became stronger increasing duration. Psychophysiological indices transmission basolateral amygdala elevated correlated subsequent attenuation avoidance. Our results suggest, exerts stimulus-specific dose-dependent inhibition multiple automatic fear, highlighting as valuable adjunct exposure-based treatment. A translational action supported, proposing exhibits its effects extinction circuitry, particularly targeting amygdala.

Язык: Английский

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