Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 3.566
Filtrar
1.
J. optom. (Internet) ; 16(1)January - March 2023. ilus, tab, graf
Artigo em Inglês | IBECS | ID: ibc-CR-673

RESUMO

Purpose: The intrinsically photosensitive retinal ganglion cells (ipRGCs) regulate pupil size and circadian rhythms. Stimulation of the ipRGCs using short-wavelength blue light causes a sustained pupil constriction known as the post-illumination pupil response (PIPR). Here we examined the effects of ipRGC stimulation on axial length changes to imposed optical defocus in young adults.Materials and methodsNearly emmetropic young participants were given either myopic (+3 D, n = 16) or hyperopic (-3 D, n = 17) defocus in their right eye for 2 h. Before and after defocus, a series of axial length measurements for up to 180 s were performed in the right eye using the IOL Master following exposure to 5 s red (625 nm, 3.74 × 1014 photons/cm2/s) and blue (470 nm, 3.29 × 1014 photons/cm2/s) stimuli. The pupil measurements were collected from the left eye to track the ipRGC activity. The 6 s and 30 s PIPR, early and late area under the curve (AUC), and time to return to baseline were calculated.ResultsThe PIPR with blue light was significantly stronger after 2 h of hyperopic defocus as indicated by a lower 6 and 30 s PIPR and a larger early and late AUC (all p<0.05). Short-wavelength ipRGC stimulation also significantly exaggerated the ocular response to hyperopic defocus, causing a significantly greater increase in axial length than that resulting from the hyperopic defocus alone (p = 0.017). Neither wavelength had any effect on axial length with myopic defocus.ConclusionsThese findings suggest an interaction between myopiagenic hyperopic defocus and ipRGC signaling. (AU)


Assuntos
Humanos , Adulto Jovem , Hiperopia , Luz , Miopia/terapia , Estimulação Luminosa , Pupila/fisiologia , Células Ganglionares da Retina
2.
Agri ; 35(1): 22-27, 2023 Jan.
Artigo em Inglês | MEDLINE | ID: mdl-36625194

RESUMO

OBJECTIVES: Pain is a subjective experience. Besides, sensory, affective and behavioral responses, and autonomic response are part of pain response to noxious stimuli. Evaluation of pupil diameter by pupillometry has been used as an alternative method for pain assessment. In algologic procedures like interventional headache management have not been addressed in the literature. Herein, we investigated changes in pupil diameter during interventional headache management as an objective method for pain assessment. METHODS: Demographic data of the patients were collected before the bilateral major occipital nerve blockage (MONB) procedure. Numeric rating score (NRS) and pupil diameter measurements by pupillometer were recorded before MONB. Standard MONB procedure was applied to all patients. Pain assessment and pupillary diameter measurements were obtained after nerve blockage. RESULTS: Twenty-eight patients were included in this study. Mean age was 41.03+-12.63 years. There is no difference between the hemodynamic parameters before and after the procedure. Post-procedure NRS and pupil diameter values were significantly lower than pre-procedure values. There was a positive correlation between changes in NRS scores and changes in the right and left pupil diameters. CONCLUSION: There was a significant correlation between NRS score and pupil diameter in patients who underwent MONB. Monitoring of pupil diameter can be used for pain assessment during headache treatment. Evaluation of pupil diameter is a new approach in pain palliation. Future research is needed to study the effect of other parameters, that is, gender, age, origin of pain, acute, and chronic pain on pupil diameter and to evaluate its application in different algological procedures.


Assuntos
Dor , Pupila , Humanos , Adulto , Pessoa de Meia-Idade , Pupila/fisiologia , Medição da Dor/métodos , Cefaleia/diagnóstico
3.
Transl Vis Sci Technol ; 12(1): 15, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36622687

RESUMO

Purpose: A scene consisting of a white stimulus on a black background incorporates strong luminance contrast. When both stimulus and background receive different colors, luminance contrast decreases but color contrast increases. Here, we sought to characterize the pattern of stimulus salience across varying trade-offs of color and luminance contrasts by using the pupil light response. Methods: Three experiments were conducted with 17, 16, and 17 healthy adults. For all experiments, a flickering stimulus (2 Hz; alternating color to black) was presented superimposed on a background with a complementary color to the stimulus (i.e., opponency colors in human color perception: blue and yellow for Experiment 1, red and green for Experiment 2, and equiluminant red and green for Experiment 3). Background luminance varied between 0% and 45% to trade off luminance and color contrast with the stimulus. By comparing the locus of the optimal trade-off between color and luminance across different color axes, we explored the generality of the trade-off. Results: The strongest pupil responses were found when a substantial amount of color contrast was present (at the expense of luminance contrast). Pupil response amplitudes increased by 15% to 30% after the addition of color contrast. An optimal pupillary responsiveness was reached at a background luminance setting of 20% to 35% color contrast across several color axes. Conclusions: These findings suggest that a substantial component of pupil light responses incorporates color processing. More sensitive pupil responses and more salient stimulus designs can be achieved by adding subtle levels of color contrast between stimulus and background. Translational Relevance: More robust pupil responses will enhance tests of the visual field with pupil perimetry.


Assuntos
Luz , Pupila , Adulto , Humanos , Pupila/fisiologia , Visão Ocular , Campos Visuais , Percepção de Cores/fisiologia
4.
Transl Vis Sci Technol ; 12(1): 9, 2023 Jan 03.
Artigo em Inglês | MEDLINE | ID: mdl-36607622

RESUMO

Purpose: To present FIAT, a novel optical instrument and analysis package that is designed to elicit and optically record accommodation in human eyes. Methods: FIAT employs a Shack-Hartmann wavefront sensor and a retro-illumination pupil camera that records from a single eye at video rates. It is effective at eliciting accommodation by offering the subject a full-field binocular view of an alternating distant target and a near-eye display. FIAT analysis software computes wave aberrations for each video frame over full- or subpupil sizes and computes accommodative dynamics and accommodative range. Results: The system is validated by showing accurate refraction measurements in model eyes and human eyes with trial lenses. Robust accommodative responses are shown for young eyes, and a lack of accommodative response is shown for a known presbyopes. Accommodative stimulus-response curves from five phakic subjects over a range of ages show expected results. Results from two individuals with monofocal intraocular lenses are shown. Conclusions: FIAT is an effective instrument for making accurate, objective measures of accommodation in phakic and pseudophakic eyes. Translational Relevance: We present a device that can play an important role in the development and testing of accommodating intraocular lenses.


Assuntos
Lentes Intraoculares , Pseudofacia , Humanos , Acomodação Ocular , Pupila/fisiologia
5.
Int Ophthalmol ; 42(2): 385-391, 2022 Feb.
Artigo em Inglês | MEDLINE | ID: mdl-34613562

RESUMO

AIM: To compare pupillary responses in patients with Coronavirus disease-2019 (COVID-19) during active infection and at 3rd months post-infection. METHODS: This study included 58 COVID-19 cases (mean age 47.23 ± 1.1 years). The scotopic, mesopic and photopic diameters were noted. Pupil diameters were noted at the 0, 1st, 2nd, 4th, 6th, 8th, and 10th seconds in reflex pupil dilation after the termination of a light. The average dilation speed was calculated at the 1st, 2nd, 4th, 6th, 8th, and 10th seconds. Pupil responses measured during COVID-19 infection and 3 months later were compared. RESULTS: The mean scotopic and mesopic pupil diameter value of during COVID-19 infection was found lower than the 3rd month post-infection. (p = 0.001, p = 0.023; respectively). No statistically significant difference was found in the mean photopic pupil diameter and the mean pupil diameter at 0 s between measurements (p > 0.05, p = 0.734; respectively). The mean pupil diameter was significantly lower during COVID-19 infection at the 1st, 2nd, 4th, 6th, 8th and 10th seconds (p < 0.01, for each). The average dilation speed measurements at every second measured were lower in during COVID-19 infection than the 3rd months later (p = 0.001; p < 0.01 for each). CONCLUSIONS: Pupil responses were found significantly different in COVID-19 cases when compared with the measurements taken three months later.


Assuntos
COVID-19 , Visão de Cores , Humanos , Pessoa de Meia-Idade , Pupila/fisiologia , SARS-CoV-2
6.
PLoS Comput Biol ; 18(12): e1010785, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36548401

RESUMO

Supplementation with the catecholamine precursor L-Tyrosine might enhance cognitive performance, but overall findings are mixed. Here, we investigate the effect of a single dose of tyrosine (2g) vs. placebo on two catecholamine-dependent trans-diagnostic traits: model-based control during reinforcement learning (2-step task) and temporal discounting, using a double-blind, placebo-controlled, within-subject design (n = 28 healthy male participants). We leveraged drift diffusion models in a hierarchical Bayesian framework to jointly model participants' choices and response times (RTS) in both tasks. Furthermore, comprehensive autonomic monitoring (heart rate, heart rate variability, pupillometry, spontaneous eye blink rate) was performed both pre- and post-supplementation, to explore potential physiological effects of supplementation. Across tasks, tyrosine consistently reduced participants' RTs without deteriorating task-performance. Diffusion modeling linked this effect to attenuated decision-thresholds in both tasks and further revealed increased model-based control (2-step task) and (if anything) attenuated temporal discounting. On the physiological level, participants' pupil dilation was predictive of the individual degree of temporal discounting. Tyrosine supplementation reduced physiological arousal as revealed by increases in pupil dilation variability and reductions in heart rate. Supplementation-related changes in physiological arousal predicted individual changes in temporal discounting. Our findings provide first evidence that tyrosine supplementation might impact psychophysiological parameters, and suggest that modeling approaches based on sequential sampling models can yield novel insights into latent cognitive processes modulated by amino-acid supplementation.


Assuntos
Desvalorização pelo Atraso , Humanos , Masculino , Teorema de Bayes , Tirosina/farmacologia , Reforço Psicológico , Nível de Alerta , Pupila/fisiologia
7.
J Neural Eng ; 19(6)2022 12 30.
Artigo em Inglês | MEDLINE | ID: mdl-36583387

RESUMO

Objective:recently, pupil oscillations synchronized with steady visual stimuli were used as input for an interface. The proposed system, inspired by a brain-computer interface based on steady-state visual evoked potentials, does not require contact with the participant. However, the pupil oscillation mechanism limits the stimulus frequency to 2.5 Hz or less, making it hard to enhance the information transfer rate (ITR).Approach:here, we compared multiple conditions for stimulation to increase the ITR of the pupil vibration-based interface, which were called monocular-single, monocular-superposed, and binocular-independent conditions. The binocular-independent condition stimulates each eye at different frequencies respectively and mixes them by using the visual stereoscopic perception of users. The monocular-superposed condition stimulates both eyes by a mixed signal of two different frequencies. We selected the shape of the stimulation signal, evaluated the amount of spectral leakage in the monocular-superposed and binocular-independent conditions, and compared the power spectrum density at the stimulation frequency. Moreover, 5, 10, and 15 patterns of stimuli were classified in each condition.Main results:a square wave, which causes an efficient pupil response, was used as the stimulus. Spectral leakage at the beat frequency was higher in the monocular-superposed condition than in the binocular-independent one. The power spectral density of stimulus frequencies was greatest in the monocular-single condition. Finally, we could classify the 15-stimulus pattern, with ITRs of 14.4 (binocular-independent, using five frequencies), 14.5 (monocular-superimposed, using five frequencies), and 23.7 bits min-1(monocular-single, using 15 frequencies). There were no significant differences for the binocular-independent and monocular-superposed conditions.Significance:this paper shows a way to increase the number of stimuli that can be simultaneously displayed without decreasing ITR, even when only a small number of frequencies are available. This could lead to the provision of an interface based on pupil oscillation to a wider range of users.


Assuntos
Pupila , Visão Binocular , Humanos , Pupila/fisiologia , Visão Binocular/fisiologia , Potenciais Evocados Visuais , Visão Monocular/fisiologia , Reflexo , Estimulação Luminosa
8.
Sensors (Basel) ; 22(23)2022 Dec 02.
Artigo em Inglês | MEDLINE | ID: mdl-36502099

RESUMO

Eye-gaze direction-tracking technology is used in fields such as medicine, education, engineering, and gaming. Stability, accuracy, and precision of eye-gaze direction-tracking are demanded with simultaneous upgrades in response speed. In this study, a method is proposed to improve the speed with decreases in the system load and precision in the human pupil orbit model (HPOM) estimation method. The new method was proposed based on the phenomenon that the minor axis of the elliptical-deformed pupil always pointed toward the rotational center presented in various eye-gaze direction detection studies and HPOM estimation methods. Simulation experimental results confirmed that the speed was improved by at least 74 times by consuming less than 7 ms compared to the HPOM estimation. The accuracy of the eye's ocular rotational center point showed a maximum error of approximately 0.2 pixels on the x-axis and approximately 8 pixels on the y-axis. The precision of the proposed method was 0.0 pixels when the number of estimation samples (ES) was 7 or less, which showed results consistent with those of the HPOM estimation studies. However, the proposed method was judged to work conservatively against the allowable angle error (AAE), considering that the experiment was conducted under the worst conditions and the cost used to estimate the final model. Therefore, the proposed method could estimate HPOM with high accuracy and precision through AAE adjustment according to system performance and the usage environment.


Assuntos
Fixação Ocular , Pupila , Humanos , Pupila/fisiologia , Cabeça , Simulação por Computador
9.
Transl Vis Sci Technol ; 11(11): 6, 2022 11 01.
Artigo em Inglês | MEDLINE | ID: mdl-36342706

RESUMO

Purpose: To analyze natural variability in pupillary contractility with dynamic volume-rendered optical coherence tomography (OCT) pupillometry regarding iris color, age, and sex in healthy Caucasian participants. Methods: The intrapupillary spaces (IPSs) derived from anterior segment swept-source OCT of 71 healthy eyes were retrospectively analyzed. Baseline scotopic and photopic volumes and the functional parameters of pupillary ejection fraction (PEF), three-dimensional (3D) contractility, and relative light response (RLR) were measured on the swept-source OCT volumes. The effect on these parameters of iris color (brown, green, and blue), age, and sex was assessed. Results: More pigmented irises were more contractile than less pigmented irises. Iris color significantly affected scotopic baseline IPSs (brown, 10.39 ± 4.86 mm3; green, 9.68 ± 3.31 mm3; blue, 6.75 ± 4.27 mm3; P = 0.018), PEF (brown, 90.8% ± 2.7%; green, 89.1% ± 2.5%; blue, 85.0% ± 9.3%; P = 0.010), 3D contractility (brown, 9.52 ± 4.59 mm3; green, 8.66 ± 3.07 mm3; blue, 6.44 ± 4.87 mm3; P = 0.016), and RLR (brown, 11.90 ± 4.03; green, 9.75 ± 2.73; blue, 8.52 ± 3.88; P = 0.026). Absolute scotopic volume (P = 0.022) and 3D contractility (P = 0.024) decreased with age. Sex showed no correlations. Conclusions: The natural variability of pupillary contractility can be analyzed with dynamic OCT pupillometry. Iris color and age can impact pupillary response with this method. Translational Relevance: Iris contractility parameters can be measured using a commercially available OCT system, allowing for quantification of the aqueous humor volume inside the pupil.


Assuntos
Visão de Cores , Tomografia de Coerência Óptica , Humanos , Tomografia de Coerência Óptica/métodos , Estudos Retrospectivos , Iris/diagnóstico por imagem , Pupila/fisiologia
10.
Nat Commun ; 13(1): 6760, 2022 Nov 09.
Artigo em Inglês | MEDLINE | ID: mdl-36351937

RESUMO

The human light modulation response allows humans to perceive objects clearly by receiving the appropriate amount of light from the environment. This paper proposes a biomimetic ocular prosthesis system that mimics the human light modulation response capable of pupil and corneal reflections. First, photoinduced synaptic properties of the quantum dot embedded photonic synapse and its biosimilar signal transmission is confirmed. Subsequently, the pupillary light reflex is emulated by incorporating the quantum dot embedded photonic synapse, electrochromic device, and CMOS components. Moreover, a solenoid-based eyelid is connected to the pupillary light reflex system to emulate the corneal reflex. The proposed ocular prosthesis system represents a platform for biomimetic prosthesis that can accommodate an appropriate amount of stimulus by self-regulating the intensity of external stimuli.


Assuntos
Pupila , Reflexo Pupilar , Humanos , Pupila/fisiologia , Reflexo Pupilar/fisiologia , Olho Artificial , Biomimética , Sistema Nervoso Autônomo
11.
Trends Hear ; 26: 23312165221134003, 2022.
Artigo em Inglês | MEDLINE | ID: mdl-36426573

RESUMO

Pupillometry data are commonly reported relative to a baseline value recorded in a controlled pre-task condition. In this study, the influence of the experimental design and the preparatory processing related to task difficulty on the baseline pupil size was investigated during a speech intelligibility in noise paradigm. Furthermore, the relationship between the baseline pupil size and the temporal dynamics of the pupil response was assessed. The analysis revealed strong effects of block presentation order, within-block sentence order and task difficulty on the baseline values. An interaction between signal-to-noise ratio and block order was found, indicating that baseline values reflect listener expectations arising from the order in which the different blocks were presented. Furthermore, the baseline pupil size was found to affect the slope, delay and curvature of the pupillary response as well as the peak pupil dilation. This suggests that baseline correction might be sufficient when reporting pupillometry results in terms of mean pupil dilation only, but not when a more complex characterization of the temporal dynamics of the response is considered. By clarifying which factors affect baseline pupil size and how baseline values interact with the task-evoked response, the results from the present study can contribute to a better interpretation of the pupillary response as a marker of cognitive processing.


Assuntos
Ruído , Pupila , Humanos , Pupila/fisiologia , Ruído/efeitos adversos , Inteligibilidade da Fala/fisiologia , Razão Sinal-Ruído
12.
Sensors (Basel) ; 22(19)2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36236784

RESUMO

The purpose of this review is to aggregate technical information on existent optomechanical eye models (OME) described in the literature, for image quality assessment in different applications. Several physical eye models have been reviewed from peer-reviewed papers and patent applications. A typical eye model includes an artificial cornea, an intraocular lens or other lens to simulate the crystalline lens, an aperture as the pupil, and a posterior retinal surface, which may be connected to a light sensor. The interior of the eye model may be filled with a fluid to better emulate physiological conditions. The main focus of this review is the materials and physical characteristics used and the dimensional aspects of the main components including lenses, apertures, chambers, imaging sensors and filling medium. Various devices are described with their applications and technical details, which are systematically tabulated highlighting their main characteristics and applications. The models presented are detailed and discussed individually, and the features of different models are compared when applicable, highlighting strengths and limitations. In the end there is a brief discussion about the potential use of artificial eye models for industrial applications.


Assuntos
Lentes Intraoculares , Córnea , Humanos , Pupila/fisiologia
13.
Dev Psychobiol ; 64(7): e22324, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36282740

RESUMO

In childhood, higher levels of temperamental fear-an early-emerging proclivity to distress in the face of novelty-are associated with lower social responsivity and greater social anxiety. While the early emergence of temperamental fear in infancy is poorly understood, it is theorized to be driven by individual differences in reactivity and self-regulation to novel stimuli. The current study used eye tracking to capture infants' (N = 124) reactions to a video of a smiling stranger-a common social encounter-including infant gaze aversions from the stranger's face (indexing arousal regulation) and pupil dilation (indexing physiological reactivity), longitudinally at 2, 4, 6, and 8 months of age. Multilevel mixed-effects models indicated that more fearful infants took more time to look away from a smiling stranger's face than less fearful infants, suggesting that high-fear infants may have slower arousal regulation. At 2 and 4 months, more fearful infants also exhibited greater and faster pupil dilation before gaze aversions, consistent with greater physiological reactivity. Together, these findings suggest that individual differences in infants' gaze aversions and pupil dilation can index the development of fearful temperament in early infancy, facilitating the identification of, and interventions for, risk factors to social disruptions.


Assuntos
Pupila , Sorriso , Lactente , Humanos , Pupila/fisiologia , Medo , Temperamento/fisiologia , Afeto
14.
Neural Comput ; 34(12): 2388-2407, 2022 11 08.
Artigo em Inglês | MEDLINE | ID: mdl-36283044

RESUMO

Locus coeruleus (LC) overactivity, especially in the right hemisphere, is a recognized pathophysiology of attention-deficit/hyperactivity disorder (ADHD) and may be related to inattention. LC activity synchronizes with the kinetics of the pupil diameter and reflects neural activity related to cognitive functions such as attention and arousal. Recent studies highlight the importance of the complexity of the temporal patterns of pupil diameter. Moreover, asymmetrical pupil diameter, which correlates with the severity of inattention, impulsivity, and hyperactivity in ADHD, might be attributed to a left-right imbalance in LC activity. We recently constructed a computational model of pupil diameter based on the newly discovered contralateral projection from the LC to the Edinger-Westphal nucleus (EWN), which demonstrated mechanisms for the complex temporal patterns of pupil kinetics; however, it remains unclear how LC overactivity and its asymmetry affect pupil diameter. We hypothesized that a neural model of pupil diameter control featuring left-right differences in LC activity and projections onto two opponent sides may clarify the role of pupil behavior in ADHD studies. Therefore, we developed a pupil diameter control model reflecting LC overactivity in the right hemisphere by incorporating a contralateral projection from the LC to EWN and evaluated the complexity of the temporal patterns of pupil diameter generated by the model. Upon comparisons with experimentally measured pupil diameters in adult patients with ADHD, the parameter region of interest of the neural model was estimated, which was a region in the two-dimensional plot of complexity versus left-side LC baseline activity and that of the right. A region resulting in relatively high right-side complexity, which corresponded to the pathophysiological indexes, was identified. We anticipate that the discovery of lateralization of complexity in pupil diameter fluctuations will facilitate the development of biomarkers for accurate diagnosis of ADHD.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade , Locus Cerúleo , Adulto , Humanos , Locus Cerúleo/fisiologia , Pupila/fisiologia , Cognição , Biomarcadores
15.
J Opt Soc Am A Opt Image Sci Vis ; 39(8): 1505-1512, 2022 Aug 01.
Artigo em Inglês | MEDLINE | ID: mdl-36215596

RESUMO

The pupil light reflex (PLR) can serve as a biomarker of the photoreceptor function. Protocols for chromatic PLR consider mostly pulsed stimulation. A more sophisticated and promising technique is based on the PLR to flickering stimulation. Our aim was to compare flickering PLR (fPLR) and pulsed PLR (pPLR) parameters to validate the fPLR paradigm. Two different experiments were carried out in young participants to compare parameters of chromatic pupillary measurements under flickering and pulsed conditions. We found that the fPLR amplitude parameter was significantly associated with the pPLR transient constriction parameter. Also, for some conditions, pulse parameters can be identified directly in the fPLR recordings.


Assuntos
Pupila , Reflexo Pupilar , Humanos , Luz , Pupila/fisiologia , Transtornos da Visão , Visão Ocular
16.
J Neurophysiol ; 128(5): 1224-1243, 2022 Nov 01.
Artigo em Inglês | MEDLINE | ID: mdl-36197019

RESUMO

Pupil diameter, under constant illumination, is known to reflect individuals' internal states, such as surprise about observation and environmental uncertainty. Despite the growing use of pupillometry in cognitive learning studies as an additional measure for examining internal states, few studies have used pupillometry in human motor learning studies. Here, we provide the first detailed characterization of pupil diameter changes in a short-term reach adaptation paradigm. We measured pupil changes in 121 human participants while they adapted to abrupt, gradual, or switching force field conditions. Sudden increases in movement error caused by the introduction/reversal of the force field resulted in strong phasic pupil dilation during movement accompanied by a transient increase in tonic premovement baseline pupil diameter in subsequent trials. In contrast, pupil responses were reduced when the force field was gradually introduced, indicating that large, unexpected errors drove the changes in pupil responses. Interestingly, however, error-induced pupil responses gradually became insensitive after experiencing multiple force field reversals. We also found an association between baseline pupil diameter and incidental knowledge of the gradually introduced perturbation. Finally, in all experiments, we found a strong co-occurrence of larger baseline pupil diameter with slower reaction and movement times after each rest break. Collectively, these results suggest that tonic baseline pupil diameter reflects one's belief about environmental uncertainty, whereas phasic pupil dilation during movement reflects surprise about a sensory outcome (i.e., movement error), and both effects are modulated by novelty. Our results provide a new approach for nonverbally assessing participants' internal states during motor learning.NEW & NOTEWORTHY Pupil diameter is known as a noninvasive window into individuals' internal states. Despite the growing use of pupillometry in cognitive learning studies, it receives little attention in motor learning studies. Here, we characterized the pupil responses in a short-term reach adaptation paradigm by measuring pupil diameter of human participants while they adapted to abrupt, gradual, or switching force field conditions. Our results demonstrate how surprise and uncertainty reflected in pupil diameter develop during motor adaptation.


Assuntos
Atenção , Pupila , Humanos , Pupila/fisiologia , Estimulação Luminosa , Atenção/fisiologia , Adaptação Fisiológica , Movimento
17.
Hum Mov Sci ; 86: 103015, 2022 Dec.
Artigo em Inglês | MEDLINE | ID: mdl-36242826

RESUMO

The purpose of the present study was to investigate the effects of attentional focus and cognitive-load on motor performance, quiet-eye-duration, and pupil dilation. 18 participants completed a dart throwing task under four conditions, internal or external focus with high or low cognitive-load. Cognitive-load was created by a secondary tone detection task. During each trial participants pupil size and eye movements were recorded along with accuracy data of the dart throw. Results revealed that decreased cognitive-load increased accuracy while high load increased pupil size (p's < 0.05). An external focus resulted in the greatest accuracy while an external focus with high cognitive-load resulted in the longest quiet-eye-durations (p's < 0.05). Based on these findings an increase in pupil size is related to greater cognitive-load but doesn't explain the improvement in task performance. Likewise, an external focus of attention improved performance but was not strongly related to quiet-eye-duration. Results are further discussed in the article.


Assuntos
Atenção , Pupila , Humanos , Atenção/fisiologia , Pupila/fisiologia , Análise e Desempenho de Tarefas , Movimentos Oculares , Cognição/fisiologia
18.
Opt Express ; 30(21): 37193-37212, 2022 Oct 10.
Artigo em Inglês | MEDLINE | ID: mdl-36258312

RESUMO

The spatio-angular resolution of a light field (LF) display is a crucial factor for delivering adequate spatial image quality and eliciting an accommodation response. Previous studies have modelled retinal image formation with an LF display and evaluated whether accommodation would be evoked correctly. The models were mostly based on ray-tracing and a schematic eye model, which pose computational complexity and inaccurately represent the human eye population's behaviour. We propose an efficient wave-optics-based framework to model the human eye and a general LF display. With the model, we simulated the retinal point spread function (PSF) of a point rendered by an LF display at various depths to characterise the retinal image quality. Additionally, accommodation responses to the rendered point were estimated by computing the visual Strehl ratio based on the optical transfer function (VSOTF) from the PSFs. We assumed an ideal LF display that had an infinite spatial resolution and was free from optical aberrations in the simulation. We tested points rendered at 0-4 dioptres of depths having angular resolutions of up to 4x4 viewpoints within a pupil. The simulation predicted small and constant accommodation errors, which contradict the findings of previous studies. An evaluation of the optical resolution on the retina suggested a trade-off between the maximum achievable resolution and the depth range of a rendered point where in-focus resolution is kept high. The proposed framework can be used to evaluate the upper bound of the optical performance of an LF display for realistically aberrated eyes, which may help to find an optimal spatio-angular resolution required to render a high quality 3D scene.


Assuntos
Acomodação Ocular , Visão Ocular , Humanos , Pupila/fisiologia , Retina/fisiologia , Óptica e Fotônica
19.
Atten Percept Psychophys ; 84(8): 2472-2482, 2022 Nov.
Artigo em Inglês | MEDLINE | ID: mdl-36138300

RESUMO

There exists an intricate relationship between attention and working memory. Recent work has further established that attention and working memory fluctuate synchronously, by tightly interleaving sustained attention and working memory tasks. This work has raised many open questions about physiological signatures underlying these behavioral fluctuations. Across two experiments, we explore pupil dynamics using real-time triggering in conjunction with an interleaved sustained attention and working memory task. In Experiment 1, we use behavioral real-time triggering and replicate recent findings from our lab (deBettencourt et al., 2019) that sustained attention fluctuates concurrently with the number of items maintained in working memory. Furthermore, highly attentive moments, detected via behavior, also exhibited larger pupil sizes. In Experiment 2, we develop a novel real-time pupil-triggering technique to track pupil size fluctuations in real time and trigger working memory probes. We show that this pupil triggering procedure reveals differences in sustained attention, as indexed by response time. These experiments reflect methodological advances in real-time triggering and further disentangle the relationship among general arousal, sustained attention, and working memory.


Assuntos
Atenção , Memória de Curto Prazo , Humanos , Memória de Curto Prazo/fisiologia , Atenção/fisiologia , Pupila/fisiologia , Nível de Alerta/fisiologia , Tempo de Reação
20.
J Physiol Sci ; 72(1): 23, 2022 Sep 24.
Artigo em Inglês | MEDLINE | ID: mdl-36153491

RESUMO

Although it has been hypothesized that moderate to vigorous exercise immediately modulates cognition via ascending arousal system activation, such activation during very-light to light exercise has remained uncertain. Here, we aimed to uncover the exact exercise intensity necessary for ascending arousal system activation using pupillometry. The pupil diameter, psychological arousal, and ventilation during graded exercise of 26 young males were analyzed based on %[Formula: see text]. Pupils dilated with very-light exercise compared to rest, stabilized, and then drastically increased again with moderate exercise and above. Pupil dilation with very-light exercise was positively correlated with increases in psychological arousal. Thus, we have shown that there are two phases of pupil dilation during graded exercise: one with very-light exercise coinciding with psychological arousal response, and the other with moderate exercise or above similar to the ventilation increase pattern. This unique pupil dilation pattern provides physiological evidence of ascending arousal system activation with very-light exercise.


Assuntos
Nível de Alerta , Pupila , Nível de Alerta/fisiologia , Cognição , Humanos , Masculino , Pupila/fisiologia
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA
...