Your browser doesn't support javascript.
loading
Mostrar: 20 | 50 | 100
Resultados 1 - 20 de 10.174
Filtrar
1.
PLoS One ; 15(8): e0237854, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32853262

RESUMO

Drug-induced long QT syndrome (diLQTS), characterized by a prolongation of the QT-interval on the electrocardiogram (ECG), is a serious adverse drug reaction that can cause the life-threatening arrhythmia Torsade de Points (TdP). Self-monitoring for diLQTS could therefore save lives, but detecting it on the ECG is difficult, particularly at high and low heart rates. In this paper, we evaluate whether using a pseudo-colouring visualisation technique and changing the coordinate system (Cartesian vs. Polar) can support lay people in identifying QT-prolongation at varying heart rates. Four visualisation techniques were evaluated using a counterbalanced repeated measures design including Cartesian no-colouring, Cartesian pseudo-colouring, Polar no-colouring and Polar pseudo-colouring. We used a multi-reader, multi-case (MRMC) receiver operating characteristic (ROC) study design within a psychophysical paradigm, along with eye-tracking technology. Forty-three lay participants read forty ECGs (TdP risk n = 20, no risk n = 20), classifying each QT-interval as normal/abnormal, and rating their confidence on a 6-point scale. The results show that introducing pseudo-colouring to the ECG significantly increased accurate detection of QT-interval prolongation regardless of heart rate, T-wave morphology and coordinate system. Pseudo-colour also helped to reduce reaction times and increased satisfaction when reading the ECGs. Eye movement analysis indicated that pseudo-colour helped to focus visual attention on the areas of the ECG crucial to detecting QT-prolongation. The study indicates that pseudo-colouring enables lay people to visually identify drug-induced QT-prolongation regardless of heart rate, with implications for the more rapid identification and management of diLQTS.


Assuntos
Eletrocardiografia , Frequência Cardíaca , Síndrome do QT Longo/diagnóstico por imagem , Síndrome do QT Longo/fisiopatologia , Adulto , Cor , Movimentos Oculares/fisiologia , Feminino , Fixação Ocular/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Satisfação Pessoal , Estimulação Luminosa , Psicofísica , Curva ROC , Tempo de Reação , Fatores de Risco , Sensibilidade e Especificidade , Adulto Jovem
2.
PLoS One ; 15(8): e0237717, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32810159

RESUMO

The effect of spatial contexts on attention is important for evaluating the risk of human errors and the accessibility of information in different situations. In traditional studies, this effect has been investigated using display-based and non-laboratory procedures. However, these two procedures are inadequate for measuring attention directed toward 360-degree environments and controlling exogeneous stimuli. In order to resolve these limitations, we used a virtual-reality-based procedure and investigated how spatial contexts of 360-degree environments influence attention. In the experiment, 20 students were asked to search for and report a target that was presented at any location in 360-degree virtual spaces as accurately and quickly as possible. Spatial contexts comprised a basic context (a grey and objectless space) and three specific contexts (a square grid floor, a cubic room, and an infinite floor). We found that response times for the task and eye movements were influenced by the spatial context of 360-degree surrounding spaces. In particular, although total viewing times for the contexts did not match the saliency maps, the differences in total viewing times between the basic and specific contexts did resemble the maps. These results suggest that attention comprises basic and context-dependent characteristics, and the latter are influenced by the saliency of 360-degree contexts even when the contexts are irrelevant to a task.


Assuntos
Atenção/fisiologia , Processamento Espacial/fisiologia , Adulto , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Estimulação Luminosa/métodos , Tempo de Reação/fisiologia , Realidade Virtual , Adulto Jovem
3.
J Vis Exp ; (161)2020 07 21.
Artigo em Inglês | MEDLINE | ID: mdl-32773761

RESUMO

Macular degeneration typically results in heterogeneous binocular central visual defects. Currently available approaches to assess central visual field, like the microperimetry, can test only one eye at a time. Therefore, they cannot explain how the defects in each eye affect the binocular interaction and real-world function. Dichoptic stimulus presentation with a gaze-controlled system could provide a reliable measure of monocular/binocular visual fields. However, dichoptic stimulus presentation and simultaneous eye-tracking are challenging because optical devices of instruments that present stimulus dichoptically (e.g., haploscope) always interfere with eye-trackers (e.g., infrared video-based eye-trackers). Therefore, the goals were 1) to develop a method for dichoptic stimulus presentation with simultaneous eye-tracking, using 3D-shutter glasses and 3D-ready monitors, that is not affected by interference and 2) to use this method to develop a protocol for assessing central visual field in subjects with central vision loss. The results showed that this setup provides a practical solution for reliably measuring eye-movements in dichoptic viewing condition. In addition, it was also demonstrated that this method can assess gaze-controlled binocular central visual field in subjects with central vision loss.


Assuntos
Movimentos Oculares/fisiologia , Visão Binocular/fisiologia , Campos Visuais/fisiologia , Adulto , Idoso , Feminino , Humanos , Degeneração Macular/fisiopatologia , Masculino , Estimulação Luminosa , Transtornos da Visão/fisiopatologia
4.
Nat Commun ; 11(1): 3524, 2020 07 14.
Artigo em Inglês | MEDLINE | ID: mdl-32665559

RESUMO

Eye movements are inhibited prior to the onset of temporally-predictable visual targets. This oculomotor inhibition effect could be considered a marker for the formation of temporal expectations and the allocation of temporal attention in the visual domain. Here we show that eye movements are also inhibited before predictable auditory targets. In two experiments, we manipulate the period between a cue and an auditory target to be either predictable or unpredictable. The findings show that although there is no perceptual gain from avoiding gaze-shifts in this procedure, saccades and blinks are inhibited prior to predictable relative to unpredictable auditory targets. These findings show that oculomotor inhibition occurs prior to auditory targets. This link between auditory expectation and oculomotor behavior reveals a multimodal perception action coupling, which has a central role in temporal expectations.


Assuntos
Atenção/fisiologia , Movimentos Oculares/fisiologia , Músculos Oculomotores/fisiologia , Adulto , Análise de Variância , Feminino , Humanos , Tempo de Reação/fisiologia , Percepção Visual/fisiologia , Adulto Jovem
5.
Proc Natl Acad Sci U S A ; 117(31): 18799-18809, 2020 08 04.
Artigo em Inglês | MEDLINE | ID: mdl-32680968

RESUMO

We try to deploy the retinal fovea to optimally scrutinize an object of interest by directing our eyes to it. The horizontal and vertical components of eye positions acquired by goal-directed saccades are determined by the object's location. However, the eccentric eye positions also involve a torsional component, which according to Donder's law is fully determined by the two-dimensional (2D) eye position acquired. According to von Helmholtz, knowledge of the amount of torsion provided by Listing's law, an extension of Donder's law, alleviates the perceptual interpretation of the image tilt that changes with 2D eye position, a view supported by psychophysical experiments he pioneered. We address the question of where and how Listing's law is implemented in the visual system and we show that neurons in monkey area V1 use knowledge of eye torsion to compensate the image tilt associated with specific eye positions as set by Listing's law.


Assuntos
Movimentos Oculares/fisiologia , Neurônios/fisiologia , Córtex Visual , Animais , Macaca mulatta , Masculino , Estimulação Luminosa , Córtex Visual/citologia , Córtex Visual/fisiologia
6.
Nat Commun ; 11(1): 3341, 2020 07 03.
Artigo em Inglês | MEDLINE | ID: mdl-32620746

RESUMO

The oculomotor system keeps the eyes steady in expectation of visual events. Here, recording microsaccades while people performed a tactile, frequency discrimination task enabled us to test whether the oculomotor system shows an analogous preparatory response for unrelated tactile events. We manipulated the temporal predictability of tactile targets using tactile cues, which preceded the target by either constant (high predictability) or variable (low predictability) time intervals. We find that microsaccades are inhibited prior to tactile targets and more so for constant than variable intervals, revealing a tight crossmodal link between tactile temporal expectation and oculomotor action. These findings portray oculomotor freezing as a marker of crossmodal temporal expectation. Moreover, microsaccades occurring around the tactile target presentation are associated with reduced task performance, suggesting that oculomotor freezing mitigates potential detrimental, concomitant effects of microsaccades and revealing a crossmodal coupling between tactile perception and oculomotor action.


Assuntos
Movimentos Oculares/fisiologia , Desempenho Psicomotor/fisiologia , Percepção do Tempo/fisiologia , Percepção do Tato/fisiologia , Tato/fisiologia , Percepção Visual/fisiologia , Adulto , Sinais (Psicologia) , Feminino , Humanos , Masculino , Músculos Oculomotores/inervação , Músculos Oculomotores/fisiologia , Estimulação Luminosa , Tempo de Reação/fisiologia , Movimentos Sacádicos/fisiologia , Adulto Jovem
7.
Nat Hum Behav ; 4(9): 928-936, 2020 09.
Artigo em Inglês | MEDLINE | ID: mdl-32690919

RESUMO

Toddlers exhibit behaviours that suggest judicious responses to states of uncertainty (for example, turning to adults for help), but little is known about the informational basis of these behaviours. Across two experiments, of which experiment 2 was a preregistered replication, 160 toddlers (aged 25 to 32 months) identified a target from two partially occluded similar (for example, elephant versus bear) or dissimilar (for example, elephant versus broccoli) images. Accuracy was lower for the similar trials than for the dissimilar trials. By fitting drift-diffusion models to response times, we found that toddlers accumulated evidence more slowly but required less evidence for similar trials compared with dissimilar trials. By analysing eye movements, we found that toddlers took longer to settle on the selected image during inaccurate trials and switched their gaze between response options more frequently during inaccurate trials and accurately identified similar items. Exploratory analyses revealed that the evidence-accumulation parameter correlated positively with the use of uncertainty language. Overall, these findings inform theories on the emergence of evidence accumulation under uncertainty.


Assuntos
Atenção/fisiologia , Movimentos Oculares/fisiologia , Desempenho Psicomotor/fisiologia , Tempo de Reação/fisiologia , Incerteza , Pré-Escolar , Feminino , Fixação Ocular/fisiologia , Humanos , Masculino , Percepção Visual/fisiologia
8.
PLoS One ; 15(6): e0235342, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32598385

RESUMO

This report elaborates on adaptations of the eyes of the whale shark Rhincodon typus (Elasmobranchii, Rhincodontidae), including the discovery that they are covered with dermal denticles, which is a novel mechanism of eye protection in vertebrates. The eye denticle differs in morphology from that of the dermal denticles distributed over the rest of the body, consistent with a different function (abrasion resistance). We also demonstrate that the whale shark has a strong ability to retract the eyeball into the eye socket. The retraction distance was calculated to be approximately half the diameter of the eye, which is comparable to those of other vertebrates that are known to have highly retractable eyes. These highly protective features of the whale shark eye seem to emphasize the importance of vision for environmental perception, which contradicts the general, though poorly established, notion of low reliance on vision in this species.


Assuntos
Movimentos Oculares/fisiologia , Olho/anatomia & histologia , Olho/fisiopatologia , Tubarões/anatomia & histologia , Tubarões/fisiologia , Animais
9.
PLoS One ; 15(6): e0233915, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32484819

RESUMO

Cognitive control and incentive sensitivity are related to overeating and obesity. Optimal white matter integrity is relevant for an efficient interaction among reward-related brain regions. However, its relationship with sensitivity to incentives remains controversial. The aim of this study was to assess the incentive sensitivity and its relationship to white matter integrity in normal-weight and overweight groups. Seventy-six young adults participated in this study: 31 were normal-weight (body mass index [BMI] 18.5 to < 25.0 kg/m2, 14 females) and 45 were overweight (BMI ≥ 25.0 kg/m2, 22 females). Incentive sensitivity was assessed using an antisaccade task that evaluates the effect of incentives (neutral, reward, and loss avoidance) on cognitive control performance. Diffusion tensor imaging studies were performed to assess white matter integrity. The relationship between white matter microstructure and incentive sensitivity was investigated through tract-based spatial statistics. Behavioral antisaccade results showed that normal-weight participants presented higher accuracy (78.0 vs. 66.7%, p = 0.01) for loss avoidance incentive compared to overweight participants. Diffusion tensor imaging analysis revealed a positive relationship between fractional anisotropy and loss avoidance accuracy in the normal-weight group (p < 0.05). No relationship reached significance in the overweight group. These results support the hypothesis that white matter integrity is relevant for performance in an incentivized antisaccade task.


Assuntos
Encéfalo/diagnóstico por imagem , Sistema Nervoso Central/fisiopatologia , Cognição/fisiologia , Obesidade/fisiopatologia , Adulto , Anisotropia , Índice de Massa Corporal , Encéfalo/fisiologia , Mapeamento Encefálico , Sistema Nervoso Central/diagnóstico por imagem , Chile/epidemiologia , Imagem de Tensor de Difusão , Movimentos Oculares/fisiologia , Feminino , Humanos , Masculino , Obesidade/diagnóstico por imagem , Obesidade/epidemiologia , Perda de Peso/fisiologia , Substância Branca/diagnóstico por imagem , Substância Branca/fisiologia , Adulto Jovem
10.
Stud Health Technol Inform ; 270: 287-291, 2020 Jun 16.
Artigo em Inglês | MEDLINE | ID: mdl-32570392

RESUMO

Eye tracking studies have demonstrated deficits in attention in individuals with Autism Spectrum Disorder (ASD) for a range of different social attention-based tasks. Here we examined social attention skills in a large sample of ASD participants (n = 120), using eye tracking data from a social information processing task, and compared them with a typically developing (TD) group (n = 35). Assuming eye movement parameters are random variables generated by an underlying stochastic process, we modeled the fixation sequences of participants in ASD and TD groups with a Hidden Markov Model. The Regions of Interests (ROIs), modeled as hidden states, corresponded to the true ROIs with a prediction accuracy of >90% for each group. The transition between ROIs revealed bias towards a specific area in the scene in ASD group, which deviated from the TD group. Objective time-dynamic measures of gaze patterns can potentially serve as useful endpoints in ASD diagnosis. Clinical Trial Registration: NCT02299700.


Assuntos
Atenção/fisiologia , Transtorno do Espectro Autista/diagnóstico , Transtorno do Espectro Autista/fisiopatologia , Movimentos Oculares/fisiologia , Fixação Ocular/fisiologia , Aprendizagem/fisiologia , Estudos de Casos e Controles , Humanos , Cadeias de Markov , Comportamento Social , Habilidades Sociais , Processos Estocásticos
11.
J Vis Exp ; (159)2020 05 29.
Artigo em Inglês | MEDLINE | ID: mdl-32538905

RESUMO

Researchers usually theorize media exposure based on assumptions of legacy media. However, a new interactive video viewing format, in this case barrage video where viewers' comments are overlaid over visual content, challenges past perspectives. This study proposes an activation and match satisfaction model to study viewing behaviors of lonely people and to challenge previous claims. It presents a protocol to examine the mechanism of how loners use barrage videos by combining eye tracking and self-report measures. Eye tracking documents the audience's conscious and subconscious watching behaviors in real time and allows for inference of the amount of allocated cognitive resources in response to rational and emotional content. The self-report gauges the amount of satisfaction obtained. Overall, results from the measures supported an activation and match satisfaction model regarding loners and their barrage video viewing behaviors. Implications are discussed.


Assuntos
Movimentos Oculares/fisiologia , Solidão/psicologia , Gravação em Vídeo/métodos , Adolescente , Adulto , Humanos , Adulto Jovem
12.
PLoS One ; 15(5): e0233909, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32470054

RESUMO

Regular Mouthing Movements (RMMs) are movements in which lips and lower jaw movements occur regularly and can be observed in the fetus using transabdominal ultrasonic tomography. In near term infants, it is known that RMMs form clusters during the quiet sleep period. The notation of RMMs is not uniform, and is described as spontaneous sucking movement or non-nutritive sucking in newborns. Non-nutritive sucking is used to evaluate neurological function after birth, but there are no fetal indicators. The purpose of this study was to clarify the changes in the RMM clusters in fetuses at 24-39 weeks of gestation, and to investigate the relationship with the non-eye movement (NEM) period, which corresponds to the quiet sleep period after birth. Subjects included 83 normal single pregnancy cases. Fetal RMMs and eye movement (EM) were observed for 60 minutes using ultrasonic tomography and recorded as moving image files. We created time series data of eye movements and mouth movements from video recordings, and calculated RMM clusters per minute within effective observation time, RMM clusters per minute in EM period, RMM clusters per minute in NEM period, mouthing movements per cluster and ratio of number of RMM clusters per minute between NEM and EM periods and analyzed using linear regression analysis. As a result, critical points were detected in at two time points, at 32-33 weeks and 36-37 weeks of gestation, in RMM clusters per minute within the effective observation time and RMM clusters per minute in NEM period, respectively. RMM clusters in human fetuses increased from 32-33 to 36-37 weeks. This change is thought to represent fetal sleep development and central nervous system development.


Assuntos
Movimentos Oculares/fisiologia , Feto/fisiologia , Idade Gestacional , Boca/fisiologia , Feminino , Humanos , Gravidez
13.
Proc Natl Acad Sci U S A ; 117(20): 11178-11183, 2020 05 19.
Artigo em Inglês | MEDLINE | ID: mdl-32358186

RESUMO

It is known that attention shifts prior to a saccade to start processing the saccade target before it lands in the foveola, the high-resolution region of the retina. Yet, once the target is foveated, microsaccades, tiny saccades maintaining the fixated object within the fovea, continue to occur. What is the link between these eye movements and attention? There is growing evidence that these eye movements are associated with covert shifts of attention in the visual periphery, when the attended stimuli are presented far from the center of gaze. Yet, microsaccades are primarily used to explore complex foveal stimuli and to optimize fine spatial vision in the foveola, suggesting that the influences of microsaccades on attention may predominantly impact vision at this scale. To address this question we tracked gaze position with high precision and briefly presented high-acuity stimuli at predefined foveal locations right before microsaccade execution. Our results show that visual discrimination changes prior to microsaccade onset. An enhancement occurs at the microsaccade target location. This modulation is highly selective and it is coupled with a drastic impairment at the opposite foveal location, just a few arcminutes away. This effect is strongest when stimuli are presented closer to the eye movement onset time. These findings reveal that the link between attention and microsaccades is deeper than previously thought, exerting its strongest effects within the foveola. As a result, during fixation, foveal vision is constantly being reshaped both in space and in time with the occurrence of microsaccades.


Assuntos
Atenção/fisiologia , Movimentos Oculares/fisiologia , Fóvea Central/fisiologia , Movimentos Sacádicos/fisiologia , Visão Ocular/fisiologia , Adolescente , Adulto , Feminino , Humanos , Masculino , Estimulação Luminosa , Percepção Visual , Adulto Jovem
14.
PLoS One ; 15(4): e0232246, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32353030

RESUMO

INTRODUCTION: Observational gait analysis is a widely used skill in physical therapy. Meanwhile, the skill has not been investigated using objective assessments. The present study investigated the differences in eye movement between professionals and trainees, while observing gait analysis. METHODS: The participants included in this study were 26 professional physical therapists and 26 physical therapist trainees. The participants, wearing eye tracker systems, were asked to describe gait abnormalities of a patient as much as possible. The eye movement parameters of interest were fixation count, average fixation duration, and total fixation duration. RESULTS: The number of gait abnormalities described was significantly higher in professionals than in trainees, overall and in limbs of the patient. The fixation count was significantly higher in professionals when compared to trainees. Additionally, the average fixation duration and total fixation duration were significantly shorter in professionals. Conversely, in trunks, the number of gait abnormalities and eye movements showed no significant differences between groups. CONCLUSIONS: Professionals require shorter fixation durations on areas of interest than trainees, while describing a higher number of gait abnormalities.


Assuntos
Movimentos Oculares/fisiologia , Marcha/fisiologia , Feminino , Fixação Ocular/fisiologia , Análise da Marcha/métodos , Humanos , Masculino , Apoio ao Desenvolvimento de Recursos Humanos/métodos
15.
Invest Ophthalmol Vis Sci ; 61(5): 4, 2020 05 11.
Artigo em Inglês | MEDLINE | ID: mdl-32392313

RESUMO

Purpose: Acceleration plays a great impact on the vestibular system, but is attributed little influence over vision. This study aims to explore how visual and vestibular acceleration affect roll-plane oculomotor responses, including their addiative effect. Methods: Seated in a mechanical sled, 13 healthy volunteers (7 men, 6 women; mean age 25 years) were exposed to a series of visual (VIS) optokinetic, vestibular (VES) whole-body, and combined (VIS + VES) rotations. This was carried out at two acceleration intensities. Subjects wore a video-based eye tracker, enabling analysis of torsional and skewing eye movement responses, which were used to evaluate the individual response to each trial. The tracker also contained accelerometers allowing head tracking. Results: Both ocular torsion and vertical skewing were sensitive to acceleration intensities for VES and VIS + VES. For VIS only, skewing exhibited such a response. An increased acceleration yielded a decreased torsion-skewing ratio for VIS, explained by the change in skewing, but remained unchanged for VES and VIS + VES. Torsion exhibited particularly reliable summative effect, yielding a relative contribution of 32% VIS and 75% VES during low acceleration, and 19% and 85%, respectively, during high acceleration. Conclusions: The change in the skewing response to different intensities indicates that the visual system is more sensitive to visual accelerations than previously described. Eye movements showed reliable summative effects, indicating a robust visual-vestibular integration that indicates their integrative priorities for each acceleration, with the visual system being more involved during low accelerations. Such objective quantifications could hold clinical utility when assessing sensory mismatch in vertiginous patients.


Assuntos
Aceleração , Movimentos Oculares/fisiologia , Reflexo Vestíbulo-Ocular/fisiologia , Adulto , Feminino , Voluntários Saudáveis , Humanos , Masculino , Percepção de Movimento/fisiologia , Estimulação Luminosa , Rotação , Vestíbulo do Labirinto/fisiologia
16.
PLoS One ; 15(5): e0223941, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32469952

RESUMO

Expert behavior is characterized by rapid information processing abilities, dependent on more structured schemata in long-term memory designated for their domain-specific tasks. From this understanding, expertise can effectively reduce cognitive load on a domain-specific task. However, certain tasks could still evoke different gradations of load even for an expert, e.g., when having to detect subtle anomalies in dental radiographs. Our aim was to measure pupil diameter response to anomalies of varying levels of difficulty in expert and student dentists' visual examination of panoramic radiographs. We found that students' pupil diameter dilated significantly from baseline compared to experts, but anomaly difficulty had no effect on pupillary response. In contrast, experts' pupil diameter responded to varying levels of anomaly difficulty, where more difficult anomalies evoked greater pupil dilation from baseline. Experts thus showed proportional pupillary response indicative of increasing cognitive load with increasingly difficult anomalies, whereas students showed pupillary response indicative of higher cognitive load for all anomalies when compared to experts.


Assuntos
Cognição/fisiologia , Movimentos Oculares/fisiologia , Memória de Curto Prazo/fisiologia , Percepção Visual/fisiologia , Adulto , Atenção/fisiologia , Feminino , Humanos , Aprendizagem/fisiologia , Masculino , Pessoa de Meia-Idade , Pupila/fisiologia , Radiografia Dentária/psicologia , Radiografia Panorâmica/psicologia
17.
Int J Comput Assist Radiol Surg ; 15(5): 837-845, 2020 May.
Artigo em Inglês | MEDLINE | ID: mdl-32323208

RESUMO

PURPOSE: Eye gaze tracking is proving to be beneficial in many biomedical applications. The performance of systems based on eye gaze tracking is very much dependent on how accurate their calibration is. It has been reported that the gaze tracking accuracy deteriorates cumulatively and significantly with usage time. This impedes the wide use of gaze tracking in user interfaces. METHODS: Explicit re-calibration, typically requiring the user's active attention, is time-consuming and can interfere with the user's main activity. Therefore, we propose an implicit re-calibration method, which can rectify the deterioration of the gaze tracking accuracy without bringing about the user's deliberate attention. We make use of hand-eye coordination, with the reasonable assumption that the eye gaze follows the pointer during a selection task, to acquire additional calibration points during normal usage of a gaze-contingent system. We construct a statistical model for the calibration and the hand-eye coordination and apply the Gaussian process regression framework to perform the re-calibration. RESULTS: To validate our model and method, we performed a user study on ultrasonography tasks on a gaze-contingent interface for ultrasound machines. Results suggest that our method can rectify the tracking accuracy deterioration for [Formula: see text] of all cases where deterioration occurs in our user study. With another benchmark dataset, our method can redress tracking accuracy to a level comparable to the initial calibration in more than [Formula: see text] of the cases. CONCLUSIONS: Our implicit re-calibration method is a practical and convenient fix for tracking accuracy deterioration in gaze-contingent user interfaces, and in particular for gaze-contingent ultrasound machines.


Assuntos
Atenção/fisiologia , Fixação Ocular/fisiologia , Modelos Estatísticos , Ultrassonografia/métodos , Calibragem , Movimentos Oculares/fisiologia , Humanos
18.
Am J Ophthalmol ; 216: 186-192, 2020 08.
Artigo em Inglês | MEDLINE | ID: mdl-32247775

RESUMO

PURPOSE: Magnetic resonance imaging was used to determine the effect of axial length (AL) on globe rotational axis and horizontal extraocular muscle leverage during horizontal duction. DESIGN: Prospective observational case series. METHODS: At a single academic center, 36 orthophoric adults with a wide range of ALs underwent high-resolution axial orbital magnetic resonance imaging in target-controlled adduction and abduction. ALs were measured in planes containing maximum globe cross-sections. Area centroids were calculated to determine globe centers. Rotational axes in orbital coordinates were calculated from displacements of lens centers and globe-optic nerve attachments. Lever arms were calculated as distances between published extraocular muscle insertions and rotational axes. RESULTS: ALs averaged 26.3 ± 0.3 mm (standard error [range 21.5-33.4 mm]). Rotational axes from adduction to abduction averaged 1.1 ± 0.2 mm medial and 1.1 ± 0.2 mm anterior to the globe's geometric center in adduction. Linear regression demonstrated no significant correlation between AL and rotational axis horizontal (R2 = 0.06) or anteroposterior (R2 = 0.07) position. Medial rectus (MR) lever arms averaged 12.0 ± 0.2 mm and lateral rectus (LR) lever arms averaged 12.8 ± 0.2 mm. Both MR (R2 = 0.24, P < .001) and LR (R2 = 0.32, P < .001) lever arms significantly increased by about 0.3 mm per 1.0-mm of increased AL, with a corresponding reduction in predicted per-millimeter effect of surgical repositioning of their insertions. CONCLUSIONS: Regardless of AL, the globe rotates about a point nasal and anterior to its geometric center, giving the LR more leverage than the MR. This eccentricity may diminish the effect of tendon repositioning in moderate to highly myopic patients, with reductions in per-mill imeter dose/response predicted with longer AL.


Assuntos
Comprimento Axial do Olho/anatomia & histologia , Movimentos Oculares/fisiologia , Músculos Oculomotores/fisiologia , Tendões/fisiologia , Adulto , Idoso , Comprimento Axial do Olho/diagnóstico por imagem , Feminino , Voluntários Saudáveis , Humanos , Imagem por Ressonância Magnética , Masculino , Pessoa de Meia-Idade , Músculos Oculomotores/diagnóstico por imagem , Estudos Prospectivos
19.
Anim Sci J ; 91(1): e13373, 2020.
Artigo em Inglês | MEDLINE | ID: mdl-32301197

RESUMO

The difference in the frequency of the occurrence of reflexes/reactions in 355 cows (average weight 505.5 ± 7.9 kg) and 262 bulls (average weight 735.6 ± 8.4 kg) following stunning with a Matador SS 3,000 B trigger-activated captive bolt gun (Termet) was determined. The stun shot more than 2 cm from the ideal position was found in 79.6% of animals. Vocalization, corneal reflex, rhythmic breathing, blinking, eyeball rotation and the absence of tongue protrusion occurred more frequently in bulls (p < .05). Spontaneous limb movements and nystagmus occurred more frequently in cows (p < .05). No difference between bulls and cows was determined in the occurrence of a response to painful stimuli or attempts to regain normal posture. No dependency was determined between the frequency of the occurrence of a reflex/reaction and the distance of the stun shot from the ideal point on the skull for any of the monitored signs. This study shows that the occurrence of reflexes/reactions following the stunning of cattle with a captive bolt is not only dependent on the position of the shot if placed within a 9 cm radius from the ideal point on the cattle skull.


Assuntos
Matadouros , Criação de Animais Domésticos/métodos , Bovinos/fisiologia , Eletrochoque/efeitos adversos , Eletrochoque/veterinária , Reflexo/fisiologia , Animais , Piscadela/fisiologia , Córnea/fisiologia , Movimentos Oculares/fisiologia , Feminino , Masculino , Respiração , Vocalização Animal/fisiologia
20.
Proc Natl Acad Sci U S A ; 117(11): 6246-6254, 2020 03 17.
Artigo em Inglês | MEDLINE | ID: mdl-32123109

RESUMO

The ability to recall a detailed event from a simple reminder is supported by pattern completion, a cognitive operation performed by the hippocampus wherein existing mnemonic representations are retrieved from incomplete input. In behavioral studies, pattern completion is often inferred through the false endorsement of lure (i.e., similar) items as old. However, evidence that such a response is due to the specific retrieval of a similar, previously encoded item is severely lacking. We used eye movement (EM) monitoring during a partial-cue recognition memory task to index reinstatement of lure images behaviorally via the recapitulation of encoding-related EMs or gaze reinstatement. Participants reinstated encoding-related EMs following degraded retrieval cues and this reinstatement was negatively correlated with accuracy for lure images, suggesting that retrieval of existing representations (i.e., pattern completion) underlies lure false alarms. Our findings provide evidence linking gaze reinstatement and pattern completion and advance a functional role for EMs in memory retrieval.


Assuntos
Movimentos Oculares/fisiologia , Rememoração Mental/fisiologia , Reconhecimento Psicológico/fisiologia , Adulto , Sinais (Psicologia) , Medições dos Movimentos Oculares , Feminino , Humanos , Masculino , Estimulação Luminosa , Adulto Jovem
SELEÇÃO DE REFERÊNCIAS
DETALHE DA PESQUISA