RESUMEN
The interplay between the different components of emotional contagion (i.e. emotional state and facial motor resonance), both during implicit and explicit appraisal of emotion, remains controversial. The aims of this study were (i) to distinguish between these components thanks to vocal smile processing and (ii) to assess how they reflect implicit processes and/or an explicit appraisal loop. Emotional contagion to subtle vocal emotions was studied in 25 adults through motor resonance and Autonomic Nervous System (ANS) reactivity. Facial expressions (fEMG: facial electromyography) and pupil dilation were assessed during the processing and judgement of artificially emotionally modified sentences. fEMG revealed that Zygomaticus major was reactive to the perceived valence of sounds, whereas the activity of Corrugator supercilii reflected explicit judgement. Timing analysis of pupil dilation provided further insight into both the emotional state and the implicit and explicit processing of vocal emotion, showing earlier activity for emotional stimuli than for neutral stimuli, followed by valence-dependent variations and a late judgement-dependent increase in pupil diameter. This innovative combination of different electrophysiological measures shed new light on the debate between central and peripherical views within the framework of emotional contagion.
Asunto(s)
Electromiografía , Emociones , Expresión Facial , Pupila , Humanos , Masculino , Femenino , Emociones/fisiología , Pupila/fisiología , Adulto , Adulto Joven , Sonrisa/fisiología , Músculos Faciales/fisiología , Sistema Nervioso Autónomo/fisiología , Voz/fisiologíaRESUMEN
In this study we tested whether depression is associated with impaired semantic inhibition, resulting in symptoms of rumination and anhedonia. For this purpose and using the Beck Depression Inventory II (BDI-II) college students with depressive states (DEP) and matched controls (CTL) performed a Hayling's task, while EEG and pupillometry measures were recorded. Participants were asked to complete sentential contexts with either a highly associated word (initiation) or a non-related word (inhibition), in response to randomly presented trial-by-trial cues. The DEP group, compared to the CTL group, showed lower performance, and reduced frontal negativity (N450) in inhibition trials. Source analyses revealed greater activation for inhibition trials than for initiation trials in bilateral orbitofrontal cortex for the CTL group, but the difference was reduced and more left lateralized for the DEP group. In addition, the DEP group showed more pupil size reactivity to inhibition trials than the CTL group, indicating higher cognitive effort during semantic inhibition. Finally, self-reported rumination and anhedonia correlated with N450 in inhibition trials, and rumination correlated with pupil dilation. Overall, this research contributes to understanding the neural underpinnings of impaired semantic inhibition in individuals with depression, with potential clinical applications.
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Depresión , Electroencefalografía , Pupila , Estudiantes , Humanos , Femenino , Masculino , Adulto Joven , Depresión/fisiopatología , Estudiantes/psicología , Pupila/fisiología , Semántica , Adulto , Universidades , Adolescente , Anhedonia/fisiología , Inhibición PsicológicaRESUMEN
Intransitive gestures are expressive and symbolic, whereas pantomimes are object-related actions. These gestures convey different meanings depending on whether they are directed toward (TB) or away from the body (AB). TB gestures express mental states (intransitive) or hygiene/nutritional activities (pantomime), while AB gestures modify the behaviour of the observer (intransitive) or demonstrate tool use with an object (pantomime). A substantial body of literature suggests that females exhibit stronger social cue processing compared to males. Considering the social significance of gestures, this study aimed to explore the physiological gender differences in the observation of AB and TB gestures. Pupil dilation and High Frequency Heart Rate Variability (HF-HRV) were measured in 54 participants (27 female) while observing TB and AB gestures. The Interpersonal Reactivity Index (IRI) and the Vicarious Distress Questionnaire (VDQ) were used to assess social-emotional processes. Results showed greater pupil dilation in females for TB gestures, but no significant gender differences for HF-HRV. Males showed a significant correlation between increased pupil dilation to both TB and AB gestures and empathy levels (IRI). The support scale of the VDQ correlated significantly with TB gestures in males. These findings provide insight into the neurobiological basis of gender differences in perceiving social gestures.
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Gestos , Humanos , Femenino , Masculino , Adulto , Adulto Joven , Frecuencia Cardíaca/fisiología , Caracteres Sexuales , Pupila/fisiología , Empatía/fisiología , Emociones/fisiología , Factores SexualesRESUMEN
This study aimed to investigate the effects of exercise on pupil dynamics, prefrontal haemodynamic, and salivary alpha-amylase (sAA) responses in 45 healthy graduate students. These participants were divided into two groups: a resting control group (CTL) and a very-light-intensity exercise group (EX). Participants in the EX-group engaged in a 10-min exercise at 30% O2 peak on a cycle ergometer. Salivary samples and pupillometry assessments were collected before the exercise, at the end of the exercise, and 5 min after the completion to evaluate changes over time. Our analysis showed that exercise induced significant changes in the secretion of salivary alpha-amylase, with elevated levels suggesting increased neuroendocrine activity linked to the arousal state triggered by exercise. In addition, functional oxyHb signals indicated greater fluctuations in the mid-left prefrontal cortex among participants in the EX-group compared to those in the CTL group, pointing to altered prefrontal haemodynamic.
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Ejercicio Físico , Hemodinámica , Corteza Prefrontal , Pupila , alfa-Amilasas Salivales , Humanos , Corteza Prefrontal/fisiología , Corteza Prefrontal/enzimología , Corteza Prefrontal/metabolismo , Masculino , Ejercicio Físico/fisiología , alfa-Amilasas Salivales/metabolismo , Hemodinámica/fisiología , Adulto Joven , Pupila/fisiología , Femenino , Adulto , Saliva/metabolismo , Saliva/enzimologíaRESUMEN
Perceiving emotions from the movements of other biological entities is critical for human survival and interpersonal interactions. Here, we report that emotional information conveyed by point-light biological motion (BM) triggered automatic physiological responses as reflected in pupil size. Specifically, happy BM evoked larger pupil size than neutral and sad BM, while sad BM induced a smaller pupil response than neutral BM. Moreover, this happy over sad pupil dilation effect is negatively correlated with individual autistic traits. Notably, emotional BM with only local motion features retained could also exert modulations on pupils. Compared with intact BM, both happy and sad local BM evoked stronger pupil responses than neutral local BM starting from an earlier time point, with no difference between the happy and sad conditions. These results revealed a fine-grained pupil-related emotional modulation induced by intact BM and a coarse but rapid modulation by local BM, demonstrating multi-level processing of emotions in life motion signals. Taken together, our findings shed new light on BM emotion processing, and highlight the potential of utilizing the emotion-modulated pupil response to facilitate the diagnosis of social cognitive disorders.
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Emociones , Pupila , Humanos , Pupila/fisiología , Emociones/fisiología , Masculino , Femenino , Adulto Joven , Adulto , Percepción de Movimiento/fisiología , Estimulación LuminosaRESUMEN
The efficacy of transcutaneous auricular vagus nerve stimulation (taVNS) as a non-invasive method to modulate physiological markers of noradrenergic activity of the Locus Coeruleus (LC), such as pupil dilation, is increasingly more discussed. However, taVNS studies show high heterogeneity of stimulation effects. Therefore, a taVNS setup was established here to test different frequencies (10 Hz and 25 Hz) and intensities (3 mA and 5 mA) during phasic stimulation (3 s) with time-synchronous recording of pupil dilation in younger adults. Specifically, phasic real taVNS and higher intensity led to increased pupil dilation, which is consistent with phasic invasive VNS studies in animals. The results also suggest that the influence of intensity on pupil dilation may be stronger than that of frequency. However, there was an attenuation of taVNS-induced pupil dilation when differences in perception of sensations were considered. Specifically, pupil dilation during phasic stimulation increased with perceived stimulation intensity. The extent to which the effect of taVNS induces pupil dilation and the involvement of sensory perception in the stimulation process are discussed here and require more extensive research. Additionally, it is crucial to strive for comparable stimulation sensations during systematic parameter testing in order to investigate possible effects of phasic taVNS on pupil dilation in more detail.
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Pupila , Estimulación Eléctrica Transcutánea del Nervio , Estimulación del Nervio Vago , Humanos , Estimulación del Nervio Vago/métodos , Pupila/fisiología , Masculino , Adulto , Femenino , Estimulación Eléctrica Transcutánea del Nervio/métodos , Adulto Joven , Nervio Vago/fisiología , Locus Coeruleus/fisiologíaRESUMEN
Affective Touch is characterized by both emotional and arousing dimensions that rely on specific features of a gentle human caress. In this study, we investigated whether and how both the nature of the touching effector (Human hand vs. Artificial hand) and touch type (Dynamic vs. Static) influenced the participants' pupil dilation and their subjective experience during tactile stimulation. We observed that when participants received a dynamic touch, their pupil dilation increased more when the touch was produced by a human compared to an artificial hand. This discrimination was not present for static touch. Also, dynamic touch given by a human hand invoked a supralinear enhancement of pupil dilation indicating that the combination of these two features induced a stronger autonomic activation than the summed effects of each separately. Moreover, this specific type of touch was perceived as the most pleasant compared to all other tactile stimulations. Overall, our results suggest that pupil dilation could reflect the pleasant experience of human-to-human tactile interactions, supporting the notion that the autonomic nervous system is responsive to the emotional and hedonic aspects associated with Affective Touch as a part of a complex and holistic social experience, rather than solely reacting to its low-level sensory properties.
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Pupila , Tacto , Humanos , Pupila/fisiología , Femenino , Masculino , Adulto , Tacto/fisiología , Adulto Joven , Percepción del Tacto/fisiología , Emociones/fisiología , Afecto/fisiología , Sistema Nervioso Autónomo/fisiologíaRESUMEN
Pupillometry is widely used to measure arousal states. The primary functional role of the pupil, however, is to respond to the luminance of visual inputs. We previously demonstrated that cognitive effort-related arousal interacted multiplicatively with luminance, with the strongest pupillary effects of arousal occurring at low-to-mid luminances (< 37 cd/m2), implying a narrow range of conditions ideal for assessing cognitive arousal-driven pupillary differences. Does this generalize to other forms of arousal? To answer this, we assessed luminance-driven pupillary response functions while manipulating emotional arousal, using well-established visual and auditory stimulus sets. At the group level, emotional arousal interacted with the pupillary light response differently from cognitive arousal: the effects occurred primarily at much lower luminances (< 20 cd/m2). Analyses at the individual-participant level revealed qualitatively distinct patterns of modulation, with a sizable number of individuals displaying no arousal response to the visual or auditory stimuli, regardless of luminance. Together, our results suggest that effects of arousal on pupil size are not monolithic: different forms of arousal exert different patterns of effects. More practically, our findings suggest that lower luminances create better conditions for measuring pupil-linked arousal, and when selecting ambient luminance levels, consideration of the arousal manipulation and individual differences is critical.
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Nivel de Alerta , Emociones , Estimulación Luminosa , Pupila , Humanos , Pupila/fisiología , Nivel de Alerta/fisiología , Emociones/fisiología , Masculino , Femenino , Adulto , Adulto Joven , Luz , Estimulación AcústicaRESUMEN
We investigated the relations between self-reported math anxiety, task difficulty, and pupil dilation in adults and very young children during math tasks of varying difficulty levels. While task difficulty significantly influenced pupillary responses in both groups, the association between self-reported math anxiety and pupil dilation differed across age cohorts. The children exhibited resilience to the effects of math anxiety, hinting at additional influential factors such as formal math education experiences shaping their relations to mathematics and their impact on cognitive processes over time. Contrary to expectations, no significant association between self-reported math anxiety and pupil dilation during task anticipation was found in either group. In adults, math anxiety influenced pupil dilation exclusively during the initial phase of task processing indicating heightened cognitive load, but this influence diminished during sustained task processing. Theoretical implications emphasize the need for exploring individual differences, cognitive strategies, and the developmental trajectory of math anxiety in very young children.
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Ansiedad , Matemática , Pupila , Humanos , Femenino , Masculino , Ansiedad/psicología , Pupila/fisiología , Adulto , Niño , Adulto Joven , Cognición/fisiología , PreescolarRESUMEN
Purpose: To use finite element (FE) analysis to assess what morphologic and biomechanical factors of the iris and anterior chamber are more likely to influence angle narrowing during pupil dilation. Methods: The study consisted of 1344 FE models comprising the cornea, sclera, lens, and iris to simulate pupil dilation. For each model, we varied the following parameters: anterior chamber depth (ACD = 2-4 mm) and anterior chamber width (ACW = 10-12 mm), iris convexity (IC = 0-0.3 mm), iris thickness (IT = 0.3-0.5 mm), stiffness (E = 4-24 kPa), and Poisson's ratio (v = 0-0.3). We evaluated the change in (â³â ) and the final dilated angles (â f) from baseline to dilation for each parameter. Results: The final dilated angles decreased with a smaller ACD (â f = 53.4° ± 12.3° to 21.3° ± 14.9°), smaller ACW (â f = 48.2° ± 13.5° to 26.2° ± 18.2°), larger IT (â f = 52.6° ± 12.3° to 24.4° ± 15.1°), larger IC (â f = 45.0° ± 19.2° to 33.9° ± 16.5°), larger E (â f = 40.3° ± 17.3° to 37.4° ± 19.2°), and larger v (â f = 42.7° ± 17.7° to 34.2° ± 18.1°). The change in angles increased with larger ACD (â³â = 9.37° ± 11.1° to 15.4° ± 9.3°), smaller ACW (â³â = 7.4° ± 6.8° to 16.4° ± 11.5°), larger IT (â³â = 5.3° ± 7.1° to 19.3° ± 10.2°), smaller IC (â³â = 5.4° ± 8.2° to 19.5° ± 10.2°), larger E (â³â = 10.9° ± 12.2° to 13.1° ± 8.8°), and larger v (â³â = 8.1° ± 9.4° to 16.6° ± 10.4°). Conclusions: The morphology of the iris (IT and IC) and its innate biomechanical behavior (E and v) were crucial in influencing the way the iris deformed during dilation, and angle closure was further exacerbated by decreased anterior chamber biometry (ACD and ACW).
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Análisis de Elementos Finitos , Iris , Pupila , Humanos , Iris/anatomía & histología , Pupila/fisiología , Fenómenos Biomecánicos , Glaucoma de Ángulo Cerrado/fisiopatología , Presión Intraocular/fisiología , Cámara Anterior/diagnóstico por imagen , Cámara Anterior/anatomía & histología , Córnea/fisiología , Córnea/anatomía & histología , EscleróticaRESUMEN
Throughout history, various odors have been harnessed to invigorate or relax the mind. The mechanisms underlying odors' diverse arousal effects remain poorly understood. We conducted five experiments (184 participants) to investigate this issue, using pupillometry, electroencephalography, and the attentional blink paradigm, which exemplifies the limit in attentional capacity. Results demonstrated that exposure to citral, compared to vanillin, enlarged pupil size, reduced resting-state alpha oscillations and alpha network efficiency, augmented beta-gamma oscillations, and enhanced the coordination between parietal alpha and frontal beta-gamma activities. In parallel, it attenuated the attentional blink effect. These effects were observed despite citral and vanillin being comparable in perceived odor intensity, pleasantness, and nasal pungency, and were unlikely driven by semantic biases. Our findings reveal that odors differentially alter the small-worldness of brain network architecture, and thereby brain state and arousal. Furthermore, they establish arousal as a unique dimension in olfactory space, distinct from intensity and pleasantness.
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Nivel de Alerta , Electroencefalografía , Odorantes , Percepción Olfatoria , Humanos , Masculino , Femenino , Percepción Olfatoria/fisiología , Adulto , Nivel de Alerta/fisiología , Adulto Joven , Olfato/fisiología , Corteza Cerebral/fisiología , Parpadeo Atencional/fisiología , Monoterpenos Acíclicos , Pupila/fisiología , BenzaldehídosRESUMEN
Intercepting moving targets is a fundamental skill in human behavior, influencing various domains such as sports, gaming, and other activities. In these contexts, precise visual processing and motor control are crucial for adapting and navigating effectively. Nevertheless, there are still some gaps in our understanding of how these elements interact while intercepting a moving target. This study explored the dynamic interplay among eye movements, pupil size, and interceptive hand movements, with visual and motion uncertainty factors. We developed a simple visuomotor task in which participants used a joystick to interact with a computer-controlled dot that moved along two-dimensional trajectories. This virtual system provided the flexibility to manipulate the target's speed and directional uncertainty during chase trials. We then conducted a geometric analysis based on optimal angles for each behavior, enabling us to distinguish between simple tracking and predictive trajectories that anticipate future positions of the moving target. Our results revealed the adoption of a strong interception strategy as participants approached the target. Notably, the onset and amount of optimal interception strategy depended on task parameters, such as the target's speed and frequency of directional changes. Furthermore, eye-tracking data showed that participants continually adjusted their gaze speed and position, continuously adapting to the target's movements. Finally, in successful trials, pupillary responses predicted the amount of optimal interception strategy while exhibiting an inverse relationship in trials without collisions. These findings reveal key interactions among visuomotor parameters that are crucial for solving complex interception tasks.
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Movimientos Oculares , Desempeño Psicomotor , Humanos , Masculino , Femenino , Desempeño Psicomotor/fisiología , Adulto , Movimientos Oculares/fisiología , Adulto Joven , Pupila/fisiología , Percepción de Movimiento/fisiología , Tecnología de Seguimiento Ocular , Mano/fisiología , Movimiento/fisiologíaRESUMEN
For individuals with hearing loss, even successful speech communication comes at a cost. Cochlear implants transmit degraded information, specifically for voice pitch, which demands extra and sustained listening effort. The current study hypothesized that abnormal pitch patterns contribute to the additional listening effort, even in non-tonal language native speaking normally hearing listeners. We manipulated the fundamental frequency (F0) within and across words, while participants listen and repeat (simple intelligibility task), or listen, repeat, and later recall (concurrent encoding task) the words. In both experiments, the F0 manipulations resulted in small changes in intelligibility but no difference in free recall or subjective effort ratings. Pupillary metrics were yet sensitive to these manipulations: pupil dilations were larger when words were monotonized (flat contour) or inverted (the natural contour flipped upside-down), and larger when successive words were organized into a melodic pattern. The most likely interpretation is that the natural or expected F0 contour of a word contributes to its identity and facilitate its matching and retrieval from the phonological representation stored in long-term memory. Consequently, degrading words' F0 contour can result in extra listening effort. Our results call for solutions to improve pitch saliency and naturalness in future development of cochlear implants' signal processing strategies, even for non-tonal languages.
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Memoria a Corto Plazo , Percepción de la Altura Tonal , Percepción del Habla , Humanos , Femenino , Memoria a Corto Plazo/fisiología , Masculino , Adulto , Percepción del Habla/fisiología , Percepción de la Altura Tonal/fisiología , Adulto Joven , Pupila/fisiología , LenguajeRESUMEN
Pupillometry has gained attention as a valuable tool for assessing autonomic nervous system activity and studying phasic changes in pupil size to comprehend underlying neurocognitive mechanisms. However, knowledge regarding pupillary responses to social processing in autism is limited. We conducted a systematic review and meta-analysis, examining research studies on pupil size changes that compare social and non-social stimuli in autism. Electronic searches were performed for articles up to September 2023 and relevant studies were evaluated following PRISMA guidelines. Out of 284 articles screened, 14 studies were eligible for systematic review. The results indicated that non-autistic individuals showed larger pupil size for social compared to non-social stimuli (g = 0.54; 95â¯% CI [0.25, 0.82]), whereas autistic individuals seemed to exhibit no differences between the two conditions. However, high heterogeneity was observed between studies in autistic populations, compromising interpretability. Despite such limitations, pupillary responses may constitute an objective physiological marker of social processing in autism. This review emphasizes the need for further investigations into pupillary responses in autism across different life stages.
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Trastorno Autístico , Pupila , Percepción Social , Humanos , Trastorno Autístico/fisiopatología , Trastorno Autístico/psicología , Pupila/fisiología , Percepción Social/psicologíaRESUMEN
PURPOSE: To evaluate the impact of pharmacologic pupil dilation on axial length (AL) measurement in patients with dense cataracts and previous failed AL measurements carried out without pupil dilation. DESIGN: Retrospective case series. METHODS: All participants underwent swept-source optical coherence tomography (SS-OCT) biometry. Patients with unsuccessful AL measurements due to dense cataract underwent an additional SS-OCT biometric evaluation after pupil dilation, and the SS-OCT AL measurement was compared to the immersion ultrasound. RESULTS: The study included 3668 eyes of 3668 patients who underwent SS-OCT between October 2021 and March 2023. Of them, 102 eyes (2.8%) had failed AL measurements because of dense cataract. Eighty-seven of those 102 eyes underwent a repeat SS-OCT biometric exam following pharmacologic pupil dilation, after which AL measurements were successfully achieved in 27 (31.0%) of the 87 eyes. These measurements were found to be consistent with immersion ultrasound, supporting the validity of SS-OCT biometer measurements post dilation. CONCLUSIONS: Pharmacologic pupil dilation improved the rate of successful SS-OCT biometrically measured AL in patients with failed AL measurement due to dense cataract.
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Longitud Axial del Ojo , Biometría , Catarata , Midriáticos , Pupila , Tomografía de Coherencia Óptica , Humanos , Estudios Retrospectivos , Catarata/fisiopatología , Catarata/diagnóstico , Catarata/complicaciones , Masculino , Femenino , Tomografía de Coherencia Óptica/métodos , Pupila/fisiología , Biometría/métodos , Longitud Axial del Ojo/diagnóstico por imagen , Anciano , Persona de Mediana Edad , Midriáticos/administración & dosificación , Reproducibilidad de los ResultadosRESUMEN
Purpose: This study aimed to investigate the changes in ocular refraction and pupillary diameter during fixation on augmented reality (AR) images using a Maxwellian display. Methods: Twenty-two healthy young volunteers (average age, 20.7 ± 0.5 years) wore a Maxwellian display device in front of their right eye and fixated on an asterisk displayed on both a liquid-crystal display (real target) and a Maxwellian display (AR target) for 29 seconds (real as a baseline for 3 seconds, AR for 13 seconds, and real for 13 seconds) at distances of 5.0, 0.5, 0.33, and 0.2 meters. A binocular open-view autorefractometer was used to measure the ocular refraction and pupillary diameter of the left eye. Results: Accommodative (5.0 meters, 0.28 ± 0.29 diopter [D]; 0.5 meter, -0.12 ± 0.35 D; 0.33 meter, -0.43 ± 0.57 D; 0.2 meter, -1.20 ± 0.82 D) and pupillary (5.0 meters, 0.07 ± 0.22 mm; 0.5 meter, -0.08 ± 0.17 mm; 0.33 meter, -0.16 ± 0.20 mm; 0.2 meter, -0.25 ± 0.24 mm) responses were negative when the real target distances were farther away. The accommodative response was significantly and positively correlated with the pupillary response during fixation on the AR target (R2 = 0.187, P < 0.001). Conclusions: Fixating on AR images using a Maxwellian display induces accommodative and pupillary responses. Accommodative responses depend on the distance between real objects. Overall, the Maxwellian display does not completely eliminate accommodation in real space.
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Acomodación Ocular , Realidad Aumentada , Fijación Ocular , Pupila , Refracción Ocular , Humanos , Acomodación Ocular/fisiología , Masculino , Femenino , Adulto Joven , Pupila/fisiología , Fijación Ocular/fisiología , Refracción Ocular/fisiología , Voluntarios Sanos , Visión Binocular/fisiología , AdultoRESUMEN
Human facial features (eyes, nose, and mouth) allow us to communicate with others. Observing faces triggers physiological responses, including pupil dilation. Still, the relative influence of social and motion content of a visual stimulus on pupillary reactivity has never been elucidated. A total of 30 adults aged 18-33 years old were recorded with an eye tracker. We analysed the event-related pupil dilation in response to stimuli distributed along a gradient of social salience (non-social to social, going from objects to avatars to real faces) and dynamism (static to micro- to macro-motion). Pupil dilation was larger in response to social (faces and avatars) compared to non-social stimuli (objects), with surprisingly a larger response for avatars. Pupil dilation was also larger in response to macro-motion compared to static. After quantifying each stimulus' real quantity of motion, we found that the higher the quantity of motion, the larger the pupil dilated. However, the slope of this relationship was not higher for social stimuli. Overall, pupil dilation was more sensitive to the real quantity of motion than to the social component of motion, highlighting the relevance of ecological stimulations. Physiological response to faces results from specific contributions of both motion and social processing.
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Reconocimiento Facial , Percepción de Movimiento , Pupila , Humanos , Pupila/fisiología , Adulto Joven , Adulto , Masculino , Femenino , Adolescente , Percepción de Movimiento/fisiología , Reconocimiento Facial/fisiología , Percepción Social , Estimulación Luminosa/métodos , Cara/fisiología , Tecnología de Seguimiento OcularRESUMEN
One mechanism by which transcranial direct current stimulation (tDCS) has been proposed to improve attention is by transcutaneous stimulation of cranial nerves, thereby activating the locus coeruleus (LC). Specifically, placement of the electrodes over the frontal bone and mastoid is thought to facilitate current flow across the face as a path of least resistance. The face is innervated by the trigeminal nerve, and the trigeminal nerve is interconnected with the LC. In this study, we tested whether stimulating the trigeminal nerve impacts indices of LC activity and performance on a sustained attention task. We replicated previous research that shows deterioration in task performance, increases in the rate of task-unrelated thoughts, and reduced pupil responses due to time on task irrespective of tDCS condition (sham, anodal, and cathodal stimulation). Importantly, tDCS did not influence pupil dynamics (pretrial or stimulus-evoked), self-reported attention state, nor task performance in active versus sham stimulation conditions. The findings reported here are consistent with theories about arousal centered on a hypothesized link between LC activity indexed by pupil size, task performance, and self-reported attention state but fail to support hypotheses that tDCS over the trigeminal nerve influences indices of LC function.
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Nivel de Alerta , Atención , Pupila , Estimulación Transcraneal de Corriente Directa , Nervio Trigémino , Humanos , Atención/fisiología , Masculino , Femenino , Adulto Joven , Nervio Trigémino/fisiología , Adulto , Nivel de Alerta/fisiología , Pupila/fisiología , Locus Coeruleus/fisiología , AdolescenteRESUMEN
OBJECTIVES: Vasospasm is a complication of aneurysmal subarachnoid hemorrhage (aSAH) that can change the trajectory of recovery and is associated with morbidity and mortality. Earlier detection of vasospasm could improve patient outcomes. Our objective is to evaluate the accuracy of smartphone-based quantitative pupillometry in the detection of radiographic vasospasm and delayed cerebral ischemia (DCI) after aSAH. MATERIALS AND METHODS: We prospectively collected pupillary light reflex (PLR) parameters from patients with aSAH admitted to a neurocritical care unit at a single hospital twice daily using quantitative smartphone pupillometry recordings. PLR parameters included: Maximum pupil diameter, minimum pupil diameter, percent change in pupil diameter, latency in beginning of pupil constriction to light, mean constriction velocity, maximum constriction velocity, and mean dilation velocity. Two-tailed t-tests for independent samples were performed to determine changes in average concurrent PLR parameter values between the following comparisons: (1) patients with and without radiographic vasospasm (defined by angiography with the need for endovascular intervention) and (2) patients with and without DCI. RESULTS: 49 subjects with aSAH underwent 323 total PLR recordings. For PLR recordings taken with (n=35) and without (n=241) radiographic vasospasm, significant differences were observed in MIN (35.0 ± 7.5 pixels with vasospasm versus 31.6 ± 6.2 pixels without; p=0.002). For PLR recordings taken with (n=43) and without (n=241) DCI, significant differences were observed in MAX (48.9 ± 14.3 pixels with DCI versus 42.5 ± 9.2 pixels without; p<0.001). CONCLUSIONS: Quantitative smartphone pupillometry has the potential to be used to detect radiographic vasospasm and DCI after aSAH.
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Valor Predictivo de las Pruebas , Reflejo Pupilar , Teléfono Inteligente , Hemorragia Subaracnoidea , Vasoespasmo Intracraneal , Humanos , Hemorragia Subaracnoidea/complicaciones , Hemorragia Subaracnoidea/fisiopatología , Hemorragia Subaracnoidea/diagnóstico , Vasoespasmo Intracraneal/etiología , Vasoespasmo Intracraneal/diagnóstico , Vasoespasmo Intracraneal/diagnóstico por imagen , Vasoespasmo Intracraneal/fisiopatología , Masculino , Persona de Mediana Edad , Femenino , Estudios Prospectivos , Anciano , Adulto , Reproducibilidad de los Resultados , Pupila/fisiología , Factores de Tiempo , Técnicas de Diagnóstico Oftalmológico/instrumentación , Isquemia Encefálica/diagnóstico , Isquemia Encefálica/fisiopatología , Isquemia Encefálica/etiología , Isquemia Encefálica/complicacionesRESUMEN
Different empathic responses are often reported in autism but remain controversial. To investigate which component of empathy is most affected by autism, we examined the affective, cognitive, and motivational components of empathy in 25 5- to 8-year-old autistic and 27 neurotypical children. Participants were presented with visual stimuli depicting people's limbs in painful or nonpainful situations while their eye movements, pupillary responses, and verbal ratings of pain intensity and empathic concern were recorded. The results indicate an emotional overarousal and reduced empathic concern to others' pain in autism. Compared with neurotypical children, autistic children displayed larger pupil dilation accompanied by attentional avoidance to others' pain. Moreover, even though autistic children rated others in painful situations as painful, they felt less sorry than neurotypical children. Interestingly, autistic children felt more sorry in nonpainful situations compared with neurotypical children. These findings demonstrated an emotional overarousal in response to others' pain in autistic children, and provide important implications for clinical practice aiming to promote socio-emotional understanding in autistic children.