Pupillometry as an integrated readout of distinct attentional networks

Trends in Neurosciences, Год журнала: 2022, Номер 45(8), С. 635 - 647

Опубликована: Июнь 1, 2022

Язык: Английский

---

Cholinergic and noradrenergic axonal activity contains a behavioral-state signal that is coordinated across the dorsal cortex

eLife, Год журнала: 2023, Номер 12

Опубликована: Апрель 27, 2023

Fluctuations in brain and behavioral state are supported by broadly projecting neuromodulatory systems. In this study, we use mesoscale two-photon calcium imaging to examine spontaneous activity of cholinergic noradrenergic axons awake mice order determine the interaction between arousal/movement transitions across dorsal cortex at distances separated up 4 mm. We confirm that GCaMP6s within axonal projections both basal forebrain locus coeruleus neurons track arousal, indexed as pupil diameter, changes engagement, reflected bouts whisker movement and/or locomotion. The broad coordination even distant segments indicates these systems can communicate, part, through a global signal, especially relation state. addition coordinated activity, also find evidence subpopulation may exhibit heterogeneity appears be independent our measures By monitoring interneurons cortex, found cells state-dependent (arousal/movement) activity. These results demonstrate provide prominent synchronized signal related state, therefore contribute cortical excitability.

Язык: Английский

---

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

---

Neurobehavioral meaning of pupil size

Neuron, Год журнала: 2024, Номер 112(20), С. 3381 - 3395

Опубликована: Июнь 25, 2024

Pupil size is a widely used metric of brain state. It one the few signals originating from that can be readily monitored with low-cost devices in basic science, clinical, and home settings. is, therefore, important to investigate generate well-defined theories related specific interpretations this metric. What exactly does it tell us about brain? Pupils constrict response light dilate during darkness, but also controls pupil irrespective luminosity. fluctuations resulting ongoing "brain states" are as arousal, what pupil-linked arousal how should interpreted neural, cognitive, computational terms? Here, we discuss some recent findings these issues. We identify open questions propose answer them through combination tasks, neurocomputational models, neurophysiological probing interconnected loops causes consequences size.

Язык: Английский

---

Pupil size reveals arousal level fluctuations in human sleep

Nature Communications, Год журнала: 2025, Номер 16(1)

Опубликована: Фев. 28, 2025

Abstract Recent animal research has revealed the intricate dynamics of arousal levels that are important for maintaining proper sleep resilience and memory consolidation. In humans, changes in level believed to be a determining characteristic healthy pathological but tracking fluctuations been methodologically challenging. Here we measured pupil size, an established indicator levels, by safely taping right eye open during overnight tested whether size affects cortical response auditory stimulation. We show change as function events across different temporal scales. particular, our results inversely related occurrence spindle clusters, marker resilience. Additionally, found prior stimulation influence evoked response, most notably delta power, several restorative regenerative functions sleep. Recording provides insights into interplay between oscillations.

Язык: Английский

---

Probing locus coeruleus functional network in healthy aging and its association with Alzheimer’s disease biomarkers using pupillometry

Alzheimer s Research & Therapy, Год журнала: 2025, Номер 17(1)

Опубликована: Фев. 27, 2025

Abstract Background Alzheimer’s disease (AD) is the leading cause of dementia, and early detection disease-associated changes allows interventions. The locus coeruleus (LC) has been reported to be first brain region develop tau pathology in AD. However, functional network LC both healthy aging AD largely unknown due technical difficulties associated with small size LC. In this study, we used measurement spontaneous pupil constriction/dilation as a surrogate for activity study during aging. Methods Thirty-seven younger thirty-nine older adults were included from Emory Healthy Brain Study underwent resting-state MRI while simultaneously tracking diameter. measurements diameter dynamics reference signals connectivity analysis. identified networks was then compared between participants. Correlations regions neuropsychological assessments cerebrospinal fluid (CSF) biomarkers also evaluated. Results A 20 clusters identified, including well functionally connected found positively correlate salience negatively central executive network. Functional decreased within memory, executive, visuospatial functioning. CSF total closely correlated Conclusions Pupil provide valuable insights into LC-related processes. While they are not solely influenced by activity, constrictor/dilatory shows promise non-invasive approach probe warrants further studies evaluate its value an biomarker

Язык: Английский

---

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

---

Publication guidelines and recommendations for pupillary measurement in psychophysiological studies

Psychophysiology, Год журнала: 2022, Номер 59(4)

Опубликована: Март 22, 2022

A variety of psychological and physical phenomena elicit variations in the diameter pupil eye. Changes size are mediated by relative activation sphincter pupillae muscle (decrease diameter) dilator (increase diameter), innervated parasympathetic sympathetic branches, respectively, autonomic nervous system. The current guidelines intended to inform guide psychophysiological research involving measurement (1) summarizing important aspects concerning physiology pupil, (2) providing methodological data-analytic recommendations, (3) briefly reviewing that modulate pupillary reactivity. Because increased ease tractability measurement, goal these is promote accurate recording, analysis, reporting data research.

Язык: Английский

---

A unified model of the task-evoked pupil response

Science Advances, Год журнала: 2022, Номер 8(16)

Опубликована: Апрель 20, 2022

The pupil dilates and reconstricts following task events. It is popular to model this task-evoked response as a linear transformation of event-locked impulses, whose amplitudes are used estimates arousal. We show that incorrect propose an alternative based on the physiological finding common neural input drives saccades size. arousal from our agreed with key predictions: Arousal scaled difficulty behavioral performance but was invariant small differences in trial duration. Moreover, offers unified explanation for wide range phenomena: entrainment size timing, modulation amplitude noise difficulty, reaction time-dependent timing amplitude, constrictory time-locked saccades, task-dependent distortion saccade-locked response.

Язык: Английский

---

Pupil size reflects activation of subcortical ascending arousal system nuclei during rest

eLife, Год журнала: 2023, Номер 12

Опубликована: Июнь 27, 2023

Neuromodulatory nuclei that are part of the ascending arousal system (AAS) play a crucial role in regulating cortical state and optimizing task performance. Pupil diameter, under constant luminance conditions, is increasingly used as an index activity these AAS nuclei. Indeed, task-based functional imaging studies humans have begun to provide evidence stimulus-driven pupil-AAS coupling. However, whether there such tight coupling during rest not clear. To address this question, we examined simultaneously acquired resting-state fMRI pupil-size data from 74 participants, focusing on six nuclei: locus coeruleus, ventral tegmental area, substantia nigra, dorsal median raphe nuclei, cholinergic basal forebrain. Activation all was optimally correlated with pupil size at 0-2 s lags, suggesting spontaneous changes were almost immediately followed by corresponding BOLD-signal AAS. These results suggest occur states can be noninvasive general Importantly, nature appears vastly different relatively slow canonical hemodynamic response function has been characterize task-related

Язык: Английский

---