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1.
Nat Commun ; 12(1): 2003, 2021 03 31.
Artigo em Inglês | MEDLINE | ID: mdl-33790282

RESUMO

Understanding how activity of visual neurons represents distinct components of attention and their dynamics that account for improved visual performance remains elusive because single-unit experiments have not isolated the intensive aspect of attention from attentional selectivity. We isolated attentional intensity and its single trial dynamics as determined by spatially non-selective attentional performance in an orientation discrimination task while recording from neurons in monkey visual area V4. We found that attentional intensity is a distinct cognitive signal that can be distinguished from spatial selectivity, reward expectations and motor actions. V4 spiking on single trials encodes a combination of sensory and cognitive signals on different time scales. Attentional intensity and the detection of behaviorally relevant sensory signals are well represented, but immediate reward expectation and behavioral choices are poorly represented in V4 spiking. These results provide a detailed representation of perceptual and cognitive signals in V4 that are crucial for attentional performance.


Assuntos
Algoritmos , Atenção/fisiologia , Macaca mulatta/fisiologia , Neurônios/fisiologia , Córtex Visual/fisiologia , Percepção Visual/fisiologia , Animais , Fenômenos Eletrofisiológicos , Modelos Lineares , Masculino , Estimulação Luminosa/métodos , Pupila/fisiologia , Córtex Visual/citologia
2.
Nat Commun ; 12(1): 1539, 2021 03 09.
Artigo em Inglês | MEDLINE | ID: mdl-33750784

RESUMO

Vagus nerve stimulation (VNS) is thought to affect neural activity by recruiting brain-wide release of neuromodulators. VNS is used in treatment-resistant epilepsy, and is increasingly being explored for other disorders, such as depression, and as a cognitive enhancer. However, the promise of VNS is only partially fulfilled due to a lack of mechanistic understanding of the transfer function between stimulation parameters and neuromodulatory response, together with a lack of biosensors for assaying stimulation efficacy in real time. We here develop an approach to VNS in head-fixed mice on a treadmill and show that pupil dilation is a reliable and convenient biosensor for VNS-evoked cortical neuromodulation. In an 'optimal' zone of stimulation parameters, current leakage and off-target effects are minimized and the extent of pupil dilation tracks VNS-evoked basal-forebrain cholinergic axon activity in neocortex. Thus, pupil dilation is a sensitive readout of the moment-by-moment, titratable effects of VNS on brain state.


Assuntos
Pupila/fisiologia , Nervo Vago/fisiologia , Animais , Encéfalo , Córtex Cerebelar/fisiologia , Epilepsia/fisiopatologia , Feminino , Locus Cerúleo/patologia , Masculino , Camundongos , Camundongos Endogâmicos C57BL , Estimulação do Nervo Vago , Vigília/fisiologia
3.
J Vis Exp ; (168)2021 02 13.
Artigo em Inglês | MEDLINE | ID: mdl-33645555

RESUMO

The retina transforms light signals from the environment into electrical signals that are propagated to the brain. Diseases of the retina are prevalent and cause visual impairment and blindness. Understanding how such diseases progress is critical to formulating new treatments. In vivo microscopy in animal models of disease is a powerful tool for understanding neurodegeneration and has led to important progress towards treatments of conditions ranging from Alzheimer's disease to stroke. Given that the retina is the only central nervous system structure inherently accessible by optical approaches, it naturally lends itself towards in vivo imaging. However, the native optics of the lens and cornea present some challenges for effective imaging access. This protocol outlines methods for in vivo two-photon imaging of cellular cohorts and structures in the mouse retina at cellular resolution, applicable for both acute- and chronic-duration imaging experiments. It presents examples of retinal ganglion cell (RGC), amacrine cell, microglial, and vascular imaging using a suite of labeling techniques including adeno-associated virus (AAV) vectors, transgenic mice, and inorganic dyes. Importantly, these techniques extend to all cell types of the retina, and suggested methods for accessing other cellular populations of interest are described. Also detailed are example strategies for manual image postprocessing for display and quantification. These techniques are directly applicable to studies of retinal function in health and disease.


Assuntos
Fótons , Pupila/fisiologia , Retina/diagnóstico por imagem , Animais , Cálcio/metabolismo , Dependovirus/metabolismo , Processamento de Imagem Assistida por Computador , Injeções Intravítreas , Camundongos , Camundongos Transgênicos , Microglia/citologia , Células Ganglionares da Retina/citologia , Software
4.
PLoS One ; 15(12): e0244662, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33378354

RESUMO

Although behavioral studies have repeatedly demonstrated that individuals with attention-deficit/hyperactivity disorder (ADHD) have deficits in alertness, little is known about its underlying neural basis. It is hypothesized that pupil diameter reflects the firing of norepinephrine (NE) neurons in the locus coeruleus (LC), and that the LC-NE neuromodulatory system for regulating alertness may be dysfunctional in ADHD. To clinically and non-invasively examine this hypothesis, we monitored the kinetics of pupil diameter in response to stimuli and compared them between adults with ADHD (n = 17) and typically developing (TD) adults (n = 23) during an auditory continuous performance task. Individuals in the ADHD group exhibited a significantly larger tonic pupil diameter, and a suppressed stimulus-evoked phasic pupil dilation, compared to those in the TD group. These findings provide support for the idea that the aberrant regulatory control of pupil diameter in adults with ADHD may be consistent with a compromised state of alertness resulting from a hyperactivated LC-NE system.


Assuntos
Transtorno do Deficit de Atenção com Hiperatividade/psicologia , Locus Cerúleo/fisiopatologia , Norepinefrina/metabolismo , Pupila/fisiologia , Adulto , Transtorno do Deficit de Atenção com Hiperatividade/fisiopatologia , Estudos de Casos e Controles , Feminino , Humanos , Masculino , Neurônios/fisiologia , Testes Neuropsicológicos
5.
PLoS One ; 15(12): e0244017, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33382718

RESUMO

Hormonal changes such as increased cortisol level in blood plasma in response to stress and social environmental stimuli are common among vertebrates including humans and typically accompanied by other physiological processes, such as changes in body pigmentation and/or pupil dilatation. The role of pupil size variation (PSV) as a response to stress have yet to be investigated in fish. We exposed albino and pigmented European catfish to short-term stress and measured changes in pupil size and cortisol level. Albinos showed lower pupil dilatation and higher cortisol levels than did pigmented conspecifics. A clear positive relationship between pupil dilatation and cortisol concentrations was observed for both pigmented and albino specimens, suggesting that PSV can be used as a stress indicator in fish, irrespective of albino's inability to express social communication by coloring. During the follow-up, we investigated whether a penultimate contest between albino individuals would impact contestants' social stress during subsequent contact. We observed PSV during the contact of unfamiliar albino catfish with different penultimate experiences (winner (W) and/or loser (L)). Then, the following treatment combinations were tested: WW, WL and LL. Twenty-four-hour contact of two unfamiliar catfish resulted in higher pupil dilatation among individuals with previous winner experience. Among treatment combinations, a WL contest displayed the highest pupil dilatation for winners. PSV reflected socially induced stress in individuals that was accompanied by the "winner" experience and dominancy in albinos. To conclude, the present study validates pupil dilatation as a non-invasive method to evaluate stress level in pigmented as well as albino fish in various contexts.


Assuntos
Comunicação Animal , Peixes-Gato/fisiologia , Pupila/fisiologia , Estresse Psicológico/fisiopatologia , Animais , Hidrocortisona/sangue , Pigmentação da Pele , Estresse Psicológico/sangue
6.
JAMA Netw Open ; 3(12): e2022227, 2020 12 01.
Artigo em Inglês | MEDLINE | ID: mdl-33326024

RESUMO

Importance: Therapeutic inertia (TI) is the failure to escalate therapy when treatment goals are unmet and is associated with low tolerance to uncertainty and aversion to ambiguity in physician decision-making. Limited information is available on how physicians handle therapeutic decision-making in the context of uncertainty. Objective: To evaluate whether an educational intervention decreases TI by reducing autonomic arousal response (pupil dilation), a proxy measure of how physicians respond to uncertainty during treatment decisions. Design, Setting, and Participants: In this randomized clinical trial, 34 neurologists with expertise in multiple sclerosis (MS) practicing at 15 outpatient MS clinics in academic and community institutions from across Canada were enrolled. Participants were randomly assigned to receive an educational intervention that facilitates treatment decisions (active group) or to receive no exposure to the intervention (usual care [control group]) from December 2017 to March 2018. Participants listened to 20 audio-recorded simulated case scenarios as pupil responses were assessed by eye trackers. Autonomic arousal was assessed as pupil dilation in periods in which critical information was provided (first period [T1]: clinical data, second period [T2]: neurologic status, and third period [T3]: magnetic resonance imaging data). Data were analyzed from September 2018 to March 2020. Interventions: The traffic light system (TLS)-based educational intervention vs usual care (unexposed). The TLS (use of established associations between traffic light colors and actions to stop or proceed) assists participants in identifying factors associated with worse prognosis in MS care, thereby facilitating the treatment decision-making process by use of established associations between red, green, and yellow colors and risk levels, and actions (treatment decisions). Main Outcomes and Measures: Pupil assessment was the primary autonomic outcome. To test the treatment effect of the educational intervention (TLS), difference-in-differences models (also called untreated control group design with pretest and posttest) were used. Results: Of 38 eligible participants, 34 (89.4%) neurologists completed the study. The mean (SD) age was 44.6 (11.6) years; 38.3% were female and 20 (58.8%) were MS specialists. Therapeutic inertia was present in 50.0% (17 of 34) of all participants and was associated with greater pupil dilation. For every additional SD of pupil dilation, the odds of TI increased by 51% for T1 (odds ratio, 1.51; 95% CI, 1.12-2.03), by 31% for T2 (odds ratio, 1.31; 95% CI, 1.08-1.59), and by 49% for T3 (odds ratio, 1.49; 95% CI, 1.13-1.97). The intervention significantly reduced TI (risk reduction, 31.5%; 95% CI, 16.1%-47.0%). Autonomic arousal responses mediated 29.0% of the effect of the educational intervention on TI. Conclusions and Relevance: In this randomized clinical trial, the TLS intervention decreased TI as measured by pupil dilation, which suggests that individual autonomic arousal is an indicator of how physicians handle uncertainty when making live therapeutic decisions. Pupil response, a biomarker of TI, may eventually be useful in medical education. Trial Registration: ClinicalTrials.gov Identifier: NCT03134794.


Assuntos
Sistema Nervoso Autônomo/fisiologia , Tomada de Decisões/fisiologia , Neurologistas/psicologia , Pupila/fisiologia , Adulto , Canadá , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Esclerose Múltipla
7.
Nat Commun ; 11(1): 5004, 2020 10 05.
Artigo em Inglês | MEDLINE | ID: mdl-33020473

RESUMO

Adaptive brain function requires that sensory impressions of the social and natural milieu are dynamically incorporated into intrinsic brain activity. While dynamic switches between brain states have been well characterised in resting state acquisitions, the remodelling of these state transitions by engagement in naturalistic stimuli remains poorly understood. Here, we show that the temporal dynamics of brain states, as measured in fMRI, are reshaped from predominantly bistable transitions between two relatively indistinct states at rest, toward a sequence of well-defined functional states during movie viewing whose transitions are temporally aligned to specific features of the movie. The expression of these brain states covaries with different physiological states and reflects subjectively rated engagement in the movie. In sum, a data-driven decoding of brain states reveals the distinct reshaping of functional network expression and reliable state transitions that accompany the switch from resting state to perceptual immersion in an ecologically valid sensory experience.


Assuntos
Encéfalo/fisiologia , Filmes Cinematográficos , Adulto , Encéfalo/diagnóstico por imagem , Mapeamento Encefálico , Feminino , Frequência Cardíaca/fisiologia , Humanos , Imagem por Ressonância Magnética , Masculino , Filmes Cinematográficos/classificação , Filmes Cinematográficos/estatística & dados numéricos , Percepção/fisiologia , Pupila/fisiologia , Descanso/fisiologia , Inquéritos e Questionários , Adulto Jovem
8.
PLoS One ; 15(10): e0239512, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-33048934

RESUMO

In the present study, we examined the pupillary response of White participants who were asked to tell the truth or lie to White or Black partners. Research on cues to deception has assumed that lying is more cognitively demanding that truth telling. In line with this assumption, previous studies have shown that lying is associated with greater pupil dilation, a behavioral cue that typically manifests itself under conditions of stress or cognitive effort. In accordance with these results, we predicted greater pupil dilation when lying than when telling the truth. Furthermore, pupil dilation was expected to be greater when responding to White than Black partners. Finally, we hypothesized that pupil dilation would be greater when lying to White than Black partners. Participants were instructed to answer a set of questions, half truthfully and half deceptively. They were led to believe that White vs. Black partners (one male and one female) would ask the questions via computer connection. Indeed, we used feminine and masculine synthetic voices. Pupil dilation was assessed with a remote eye-tracking system. Results provided support for the first two hypotheses. However, the predicted interaction between race of partners and truth status of message (lying vs. telling the truth) was nonsignificant. Our findings highlight the importance of considering race in the study of truthful and deceptive communications.


Assuntos
Grupo com Ancestrais do Continente Africano/psicologia , Decepção , Grupo com Ancestrais do Continente Europeu/psicologia , Pupila/fisiologia , Feminino , Humanos , Masculino , Adulto Jovem
9.
J Fr Ophtalmol ; 43(8): 770-773, 2020 Oct.
Artigo em Francês | MEDLINE | ID: mdl-32819735

RESUMO

PURPOSE: To study the effect of type 2 diabetes on pupil diameter. PATIENTS AND METHODS: We carried out a case-control study at the Douala Obstetrics, Gynecology and Pediatric Hospital over a 5-month period. The cases were type 2 diabetic patients, and the controls were non-diabetic patients paired for age and gender. We studied the correlation between the duration of diabetes, fasting blood sugar and the horizontal pupil diameter. RESULTS: We included 35 patients in each group. The mean age was 56.6±10.01 years. Both groups included 17 males and 18 females. The mean duration of diabetes was 2.72±4.31 years, and the mean fasting blood sugar was 2.02±0.69g/L. The mean pupil diameter was similar in the two groups. On the right side, it was 4.75±0.73mm for controls and 4.52±0.69mm for cases (P=0.179). On the left side, it was 4.70±0.68mm and 4.42±0.73mm respectively for each group (P=0.101). The duration of diabetes was correlated to pupil diameter in the right eye (r=-0.43; P=0.01) and left eye (r=-0.45; P<0.01). No additional risk was found to be associated with diabetes for right pupil diameters (OR=0.79; P=0.33), or for left ones (OR=0.76; P=0.24). CONCLUSION: Pupil diameter is similar in diabetic and non-diabetic patients. However, the duration of diabetes appears to affect pupil diameter.


Assuntos
Glicemia/fisiologia , Diabetes Mellitus Tipo 2/patologia , Pupila/fisiologia , Adulto , Idoso , Glicemia/metabolismo , Camarões/epidemiologia , Estudos de Casos e Controles , Diabetes Mellitus Tipo 2/sangue , Diabetes Mellitus Tipo 2/diagnóstico , Diabetes Mellitus Tipo 2/epidemiologia , Retinopatia Diabética/sangue , Retinopatia Diabética/diagnóstico , Retinopatia Diabética/epidemiologia , Retinopatia Diabética/patologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Tamanho do Órgão , Reflexo Pupilar/fisiologia
10.
Nat Commun ; 11(1): 4007, 2020 08 11.
Artigo em Inglês | MEDLINE | ID: mdl-32782282

RESUMO

Everyday life unfolds continuously, yet we tend to remember past experiences as discrete event sequences or episodes. Although this phenomenon has been well documented, the neuromechanisms that support the transformation of continuous experience into distinct and memorable episodes remain unknown. Here, we show that changes in context, or event boundaries, elicit a burst of autonomic arousal, as indexed by pupil dilation. Event boundaries also lead to the segmentation of adjacent episodes in later memory, evidenced by changes in memory for the temporal duration, order, and perceptual details of recent event sequences. These subjective and objective changes in temporal memory are also related to distinct temporal features of pupil dilations to boundaries as well as to the temporal stability of more prolonged pupil-linked arousal states. Collectively, our findings suggest that pupil measures reflect both stability and change in ongoing mental context representations, which in turn shape the temporal structure of memory.


Assuntos
Nível de Alerta/fisiologia , Memória Episódica , Pupila/fisiologia , Percepção do Tempo/fisiologia , Adulto , Percepção Auditiva/fisiologia , Discriminação Psicológica/fisiologia , Feminino , Humanos , Masculino , Tempo de Reação , Adulto Jovem
11.
Proc Natl Acad Sci U S A ; 117(29): 17320-17329, 2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32632006

RESUMO

Second only to headache, photophobia is the most debilitating symptom reported by people with migraine. While the melanopsin-containing intrinsically photosensitive retinal ganglion cells (ipRGCs) are thought to play a role, how cone and melanopsin signals are integrated in this pathway to produce visual discomfort is poorly understood. We studied 60 people: 20 without headache and 20 each with interictal photophobia from migraine with or without visual aura. Participants viewed pulses of spectral change that selectively targeted melanopsin, the cones, or both and rated the degree of visual discomfort produced by these stimuli while we recorded pupil responses. We examined the data within a model that describes how cone and melanopsin signals are weighted and combined at the level of the retina and how this combined signal is transformed into a rating of discomfort or pupil response. Our results indicate that people with migraine do not differ from headache-free controls in the manner in which melanopsin and cone signals are combined. Instead, people with migraine demonstrate an enhanced response to integrated ipRGC signals for discomfort. This effect of migraine is selective for ratings of visual discomfort, in that an enhancement of pupil responses was not seen in the migraine group, nor were group differences found in surveys of other behaviors putatively linked to ipRGC function (chronotype, seasonal sensitivity, presence of a photic sneeze reflex). By revealing a dissociation in the amplification of discomfort vs. pupil response, our findings suggest a postretinal alteration in processing of ipRGC signals for photophobia in migraine.


Assuntos
Transtornos de Enxaqueca/metabolismo , Fotofobia/metabolismo , Células Ganglionares da Retina/fisiologia , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa , Pupila/fisiologia , Células Fotorreceptoras Retinianas Cones/fisiologia , Opsinas de Bastonetes/fisiologia
12.
Nat Protoc ; 15(8): 2301-2320, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32632319

RESUMO

The locus coeruleus (LC) is a region in the brainstem that produces noradrenaline and is involved in both normal and pathological brain function. Pupillometry, the measurement of pupil diameter, provides a powerful readout of LC activity in rodents, primates and humans. The protocol detailed here describes a miniaturized setup that can screen LC activity in rodents in real-time and can be established within 1-2 d. Using low-cost Raspberry Pi computers and cameras, the complete custom-built system costs only ~300 euros, is compatible with stereotaxic surgery frames and seamlessly integrates into complex experimental setups. Tools for pupil tracking and a user-friendly Pupillometry App allow quantification, analysis and visualization of pupil size. Pupillometry can discriminate between different, physiologically relevant firing patterns of the LC and can accurately report LC activation as measured by noradrenaline turnover. Pupillometry provides a rapid, non-invasive readout that can be used to verify accurate placement of electrodes/fibers in vivo, thus allowing decisions about the inclusion/exclusion of individual animals before experiments begin.


Assuntos
Locus Cerúleo/fisiologia , Monitorização Fisiológica/instrumentação , Pupila/fisiologia , Animais , Camundongos , Camundongos Endogâmicos C57BL , Fatores de Tempo
14.
PLoS One ; 15(7): e0235782, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32649733

RESUMO

Individuals with hearing loss allocate cognitive resources to comprehend noisy speech in everyday life scenarios. Such a scenario could be when they are exposed to ongoing speech and need to sustain their attention for a rather long period of time, which requires listening effort. Two well-established physiological methods that have been found to be sensitive to identify changes in listening effort are pupillometry and electroencephalography (EEG). However, these measurements have been used mainly for momentary, evoked or episodic effort. The aim of this study was to investigate how sustained effort manifests in pupillometry and EEG, using continuous speech with varying signal-to-noise ratio (SNR). Eight hearing-aid users participated in this exploratory study and performed a continuous speech-in-noise task. The speech material consisted of 30-second continuous streams that were presented from loudspeakers to the right and left side of the listener (±30° azimuth) in the presence of 4-talker background noise (+180° azimuth). The participants were instructed to attend either to the right or left speaker and ignore the other in a randomized order with two different SNR conditions: 0 dB and -5 dB (the difference between the target and the competing talker). The effects of SNR on listening effort were explored objectively using pupillometry and EEG. The results showed larger mean pupil dilation and decreased EEG alpha power in the parietal lobe during the more effortful condition. This study demonstrates that both measures are sensitive to changes in SNR during continuous speech.


Assuntos
Auxiliares de Audição , Pupila/fisiologia , Percepção da Fala , Idoso , Idoso de 80 Anos ou mais , Percepção Auditiva , Eletroencefalografia , Feminino , Audição , Testes Auditivos , Humanos , Masculino , Pessoa de Meia-Idade , Razão Sinal-Ruído
15.
J Vis ; 20(6): 21, 2020 06 03.
Artigo em Inglês | MEDLINE | ID: mdl-32589197

RESUMO

Continuously tracking cognitive demands via pupil dilation is a desirable goal for the monitoring and investigation of cognitive performance in applied settings where the exact time point of mental engagement in a task is often unknown. Yet, hitherto no experimentally validated algorithm exists for continuously estimating cognitive demands based on pupil size. Here, we evaluated the performance of a continuously operating algorithm that is agnostic of the onset of the stimuli and derives them by way of retrospectively modeling attentional pulses (i.e., onsets of processing). We compared the performance of this algorithm to a standard analysis of stimulus-locked pupil data. The pupil data were obtained while participants performed visual search (VS) and visual working memory (VWM) tasks with varying cognitive demands. In Experiment 1, VS was performed during the retention interval of the VWM task to assess interactive effects between search and memory load on pupil dilation. In Experiment 2, the tasks were performed separately. The results of the stimulus-locked pupil data demonstrated reliable increases in pupil dilation due to high VWM load. VS difficulty only affected pupil dilation when simultaneous memory demands were low. In the single task condition, increased VS difficulty resulted in increased pupil dilation. Importantly, online modeling of pupil responses was successful on three points. First, there was good correspondence between the modeled and stimulus locked pupil dilations. Second, stimulus onsets could be approximated from the derived attentional pulses to a reasonable extent. Third, cognitive demands could be classified above chance level from the modeled pupil traces in both tasks.


Assuntos
Memória de Curto Prazo/fisiologia , Pupila/fisiologia , Percepção Visual/fisiologia , Adulto , Atenção/fisiologia , Feminino , Humanos , Masculino , Estudos Retrospectivos , Adulto Jovem
16.
PLoS Biol ; 18(6): e3000677, 2020 06.
Artigo em Inglês | MEDLINE | ID: mdl-32530910

RESUMO

A key feature of most social relationships is that we like seeing good things happen to others. Research has implicated the anterior cingulate cortex (ACC) in attaching value to social outcomes. For example, single neurons in macaque ACC selectively code reward delivery to the self, a partner, both monkeys, or neither monkey. Here, we assessed whether the ACC's contribution to social cognition is causal by testing rhesus monkeys (Macaca mulatta) on a vicarious reinforcement task before and after they sustained ACC lesions. Prior to surgery, actors learned that 3 different visual cues mapped onto 3 distinct reward outcomes: to self ("Self"), to the other monkey ("Other"), or to neither monkey ("Neither"). On each trial, actors saw a cue that predicted one of the 3 juice offers and could accept the offer by making a saccade to a peripheral target or reject the offer by breaking fixation. Preoperatively, all 6 actors displayed prosocial preferences, indicated by their greater tendency to give reward to Other relative to Neither. Half then received selective, bilateral, excitotoxic lesions of the ACC, and the other half served as unoperated controls. After surgery, all monkeys retained the social preferences they had demonstrated with the preoperatively learned cues, but this preference was reduced in the monkeys with ACC lesions. Critically, none of the monkeys in the ACC lesion group acquired social preferences with a new set of cues introduced after surgery. These data indicate that the primate ACC is necessary for acquisition of prosocial preferences from vicarious reinforcement.


Assuntos
Comportamento de Escolha , Giro do Cíngulo/fisiologia , Reforço Psicológico , Comportamento Social , Animais , Macaca mulatta , Masculino , Pupila/fisiologia
17.
PLoS One ; 15(6): e0233982, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32479559

RESUMO

BACKGROUND: The aim of this study was to investigate the effects on subjective and objective sleepiness of a stay above a large struck singing bowl compared to a relaxation period in a silent singing bowl. METHODS: Fifty-eight healthy subjects were recruited for the study, 48 participated on two days, one week apart, during the same timeslot. The Karolinska sleepiness scale was used to evaluate current subjective sleepiness, and the relative pupillary unrest index to assess objective sleepiness. In this randomized cross-over study, the intervention consisted of a 20-minute stay in a hammock while the singing bowl, positioned beneath, was struck seven times. The controlled comparator was a 20-minute stay in the same hammock above the singing bowl, but without being struck. After these two interventions subjective and objective sleepiness were re-evaluated. RESULTS: The mean relative pupillary unrest index values after relaxation in the struck and silent singing bowl groups were 0.74 and respectively 0.71 (p = 0.460). The median Karolinska sleepiness scale value after relaxation with the struck singing bowl was 3 compared with 4 (p = 0.041) for the silent singing bowl. DISCUSSION: This study evaluated the influence of a struck singing bowl on sleepiness during daytime. Subjective sleepiness was significantly lower after relaxation above a struck singing bowl. After gender stratification, the difference was still significant in women. Objective sleepiness was not different in both groups. Finally, we can only speculate if women may be more susceptible to subjective improvements in case of sleepiness and show another perception of relaxation in a struck singing bowl compared to men.


Assuntos
Estimulação Acústica/instrumentação , Distúrbios do Sono por Sonolência Excessiva/reabilitação , Relaxamento/fisiologia , Sonolência , Vigília/fisiologia , Estimulação Acústica/métodos , Adulto , Estudos Cross-Over , Distúrbios do Sono por Sonolência Excessiva/diagnóstico , Distúrbios do Sono por Sonolência Excessiva/fisiopatologia , Feminino , Voluntários Saudáveis , Humanos , Masculino , Pessoa de Meia-Idade , Polissonografia , Estudos Prospectivos , Pupila/fisiologia , Fases do Sono/fisiologia , Adulto Jovem
18.
Expert Rev Med Devices ; 17(6): 591-597, 2020 Jun.
Artigo em Inglês | MEDLINE | ID: mdl-32425075

RESUMO

PURPOSE: To assess the repeatability of ocular biometric parameters using a high-resolution imaging device. METHODS: 74 healthy right eyes were included in this study. Five-repeated measurements were taken with ANTERION high-resolution swept-source optical coherence tomographer (SS-OCT) to measure: corneal thickness (central and at 2, 4 and 6-mm diameters), aqueous depth (AD), lens thickness (LT), anterior chamber volume (ACV), axial length (AL), and pupil (diameter and position). The intrasubject standard deviation (Sw), coefficient of repeatability (CoR) and intraclass correlation coefficient (ICC) were calculated. Bland-Altman method was applied to analyze the difference between the first and the last measurement. The average and the difference between both measurements were calculated for all parameters. RESULTS: We have not found statistically significant differences between repeated measurements (p > 0.05). The mean difference for corneal thickness was between -0.08 and 0.28 µm. For AD and LT was 0.004 and -0.004 µm, respectively. ACV mean difference was -0.03 mm3 and for AL was 0.001 mm. Pupil diameter and position mean differences ranged between -0.008 and 0.009 mm. Overall, most ocular parameters had a Sw <1 and a CoR <2 in their respective units, and an ICC >0.92. CONCLUSIONS: The ANTERION high-resolution SS-OCT device provides good repeatability for different ocular biometric measurements.


Assuntos
Biometria/instrumentação , Olho/anatomia & histologia , Tomografia de Coerência Óptica/instrumentação , Adulto , Idoso , Câmara Anterior/anatomia & histologia , Feminino , Humanos , Cristalino/anatomia & histologia , Masculino , Pessoa de Meia-Idade , Pupila/fisiologia , Reprodutibilidade dos Testes , Adulto Jovem
19.
PLoS One ; 15(4): e0226792, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353028

RESUMO

Mind wandering (MW) refers to the shift of attention away from a primary task and/or external environment towards thoughts unrelated to the task. Recent evidence has shown that pupillometry can be used as an objective marker of the onset and maintenance of externally-driven MW episodes. In the present study we aimed to further investigate pupillary changes associated with the onset and duration of self-reported MW episodes. We used a modified version of the joint behavioural-pupillometry paradigm we recently introduced. Participants were asked to perform a monotonous vigilance task which was intermixed with task-irrelevant cue-phrases (visually presented verbal cues); they were instructed to interrupt the task whenever a thought came to mind (self-caught method) and to indicate the trigger of their thought, if any. We found systematic pupil dilation after the presentation of verbal cues reported to have triggered MW, compared with other verbal cues presented during a supposedly on-task period (i.e., the period immediately following the resuming of the task after a self-caught interruption and MW report). These results confirm that pupil diameter is sensitive to the changes associated with the onset of MW and its unfolding over time. Moreover, by computing the latency between the trigger presentation and the task interruption (self-catch), we could also estimate the duration of MW episodes triggered by verbal cues. However, a high variability was found, implying very large inter-event variability, which could not be explained by any of the MW properties we acquired (including: temporal focus, specificity, emotional valence). Our behavioural and pupillometry findings stress the need for objective measures about the temporal unfolding of MW (while most studies focus on arbitrary time-window preceding self-reports of MW).


Assuntos
Atenção/fisiologia , Pupila/fisiologia , Pensamento/fisiologia , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Testes Neuropsicológicos , Autorrelato , Fatores de Tempo , Adulto Jovem
20.
Proc Natl Acad Sci U S A ; 117(21): 11356-11363, 2020 05 26.
Artigo em Inglês | MEDLINE | ID: mdl-32385152

RESUMO

Loss-averse decisions, in which one avoids losses at the expense of gains, are highly prevalent. However, the underlying mechanisms remain controversial. The prevailing account highlights a valuation bias that overweighs losses relative to gains, but an alternative view stresses a response bias to avoid choices involving potential losses. Here we couple a computational process model with eye-tracking and pupillometry to develop a physiologically grounded framework for the decision process leading to accepting or rejecting gambles with equal odds of winning and losing money. Overall, loss-averse decisions were accompanied by preferential gaze toward losses and increased pupil dilation for accepting gambles. Using our model, we found gaze allocation selectively indexed valuation bias, and pupil dilation selectively indexed response bias. Finally, we demonstrate that our computational model and physiological biomarkers can identify distinct types of loss-averse decision makers who would otherwise be indistinguishable using conventional approaches. Our study provides an integrative framework for the cognitive processes that drive loss-averse decisions and highlights the biological heterogeneity of loss aversion across individuals.


Assuntos
Fixação Ocular/fisiologia , Pupila/fisiologia , Assunção de Riscos , Adolescente , Adulto , Tomada de Decisões/fisiologia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Modelos Psicológicos , Experimentação Humana não Terapêutica , Adulto Jovem
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