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positions of gaze

Céline M Gravot, Alexander G Knorr, Stefan Glasauer, Hans Straka
The maintenance of visual acuity during active and passive body motion is ensured by gaze-stabilizing reflexes that aim at minimizing retinal image slip. For the optokinetic reflex (OKR), large-field visual motion of the surround forms the essential stimulus that activates eye movements. Properties of the moving visual world influence cognitive motion perception and the estimation of visual image velocity. Therefore, the performance of brainstem-mediated visuo-motor behaviors might also depend on image scene characteristics...
November 15, 2017: Journal of Experimental Biology
Youngbin Kwak, Scott Huettel
Adaptive decision making requires analysis of available information during the process of choice. In many decisions that information is presented visually - which means that variations in visual properties (e.g., salience, complexity) can potentially influence the process of choice. In the current study, we demonstrate that variation in the left-right positioning of risky and safe decision options can influence the canonical gain-loss framing effect. Two experiments were conducted using an economic framing task in which participants chose between gambles and certain outcomes...
November 11, 2017: Acta Psychologica
Sung-Hee Kim, Ji-Soo Kim
The middle cerebellar peduncle (MCP) is a major conduit for cortico-ponto-cerebellar fibers that convey information related to eye movements. This study aims to elucidate eye movement abnormalities that arise from lesions confined to the MCP. In 23 patients with acute strokes restricted to unilateral MCPs, we investigated the clinical features and ocular motor findings including spontaneous nystagmus, saccades, smooth pursuit, ocular tilt reaction, and head impulse tests. Bithermal caloric tests and audiometry were also performed...
November 11, 2017: Acta Neurologica Belgica
Peipei Li, Angeliki Tsapanou, Razlighi R Qolamreza, Yunglin Gazes
Previous DTI studies have reported associations between white matter integrity and performance on the Stroop interference task. The current study aimed to add to these studies of inhibitory control by investigating how the differences in age and in white matter integrity relate to Stroop performance, and to examine whether the effect of age on Stroop performance is mediated by white matter integrity. 179 healthy adults from 20 to 80 years old were recruited in the study. DTI data were processed through TRACULA and the mean fractional anisotropy (FA) of 18 major white matter tracts were extracted and used for statistical analysis...
November 7, 2017: Behavioural Brain Research
Zhong Zhao, Robin N Salesse, Ludovic Marin, Mathieu Gueugnon, Benoît G Bardy
Although existing studies indicate a positive effect of interpersonal motor coordination (IMC) on likability, no consensus has been reached as for the effect of likability back onto IMC. The present study specifically investigated the causal effect of likability on IMC and explored, by tracking the natural gaze direction, the possible underlying mechanisms. Twenty-two participants were engaged in an interpersonal finger-tapping task with a confederate in three likability conditions (baseline, likable, and unlikable), while wearing an eye tracker...
2017: Frontiers in Psychology
Saki Takao, Aiko Murata, Katsumi Watanabe
A person's direction of gaze (and visual attention) can be inferred from the direction of the parallel shift of the eyes. However, the direction of gaze is ambiguous when there is a misalignment between the eyes. The use of schematic drawings of faces in a previous study demonstrated that gaze-cueing was equally effective, even when one eye looked straight and the other eye was averted. In the current study, we used more realistic computer-generated face models to re-examine if the diverging direction of the eyes affected gaze-cueing...
January 1, 2017: Perception
Laura Cornelissen, Carolina Donado, Johanna M Lee, Norah E Liang, Ian Mills, Andrea Tou, Aykut Bilge, Charles B Berde
BACKGROUND: Few studies have systematically described relationships between clinical-behavioural signs, electroencephalographic (EEG) patterns and age during emergence from anaesthesia in young children. OBJECTIVE: To identify the relationships between end-tidal sevoflurane (ETsevoflurane) concentration, age and frontal EEG spectral properties in predicting recovery of clinical-behavioural signs during emergence from sevoflurane in children 0 to 3 years of age, with and without exposure to nitrous oxide...
November 8, 2017: European Journal of Anaesthesiology
Praveen Jeyaseelan, Tulika Kar, P Vijayalakshmi
Periventricular leukomalacia (PVL) is coagulation necrosis of white matter seen in preterm, low birth weight (LBW) infants and associated with a range of ocular manifestations. We report a case of 2½ months old (47 weeks gestational age) female infant with PVL associated with bilateral high myopia (-16 DS). On examination, child had difficulty in tracking objects and inferior field defect with preference for superior gaze. She was prescribed spectacles and visual stimulation exercises to preserve existing vision and prevent amblyopia...
September 2017: Oman Journal of Ophthalmology
Manabu Miyata, Kiyo Shibata, Ichiro Hamasaki, Masayuki Hata, Yuki Muraoka, Munemitsu Yoshikawa, Satoshi Hasebe, Hiroshi Ohtsuki
PURPOSE: To identify preoperative factors associated with the surgical corrective effect of contralateral inferior rectus recession (IRR) for vertical deviation in patients with congenital superior oblique palsy (SOP). METHODS: This retrospective study included 20 treatment-naïve patients with unilateral congenital SOP (age range, 6-79 years) who underwent contralateral IRR according to our basic policy to select IRR for paretic eye fixation. The corrective effect (°/mm) of IRR was defined as the difference in the vertical deviation at the primary gaze position between before and 6-18 months after surgery per distance of recession...
November 7, 2017: Graefe's Archive for Clinical and Experimental Ophthalmology
Lars O M Rothkegel, Hans A Trukenbrod, Heiko H Schütt, Felix A Wichmann, Ralf Engbert
When watching the image of a natural scene on a computer screen, observers initially move their eyes toward the center of the image-a reliable experimental finding termed central fixation bias. This systematic tendency in eye guidance likely masks attentional selection driven by image properties and top-down cognitive processes. Here, we show that the central fixation bias can be reduced by delaying the initial saccade relative to image onset. In four scene-viewing experiments we manipulated observers' initial gaze position and delayed their first saccade by a specific time interval relative to the onset of an image...
November 1, 2017: Journal of Vision
Sanni Somppi, Heini Törnqvist, József Topál, Aija Koskela, Laura Hänninen, Christina M Krause, Outi Vainio
The neuropeptide oxytocin plays a critical role in social behavior and emotion regulation in mammals. The aim of this study was to explore how nasal oxytocin administration affects gazing behavior during emotional perception in domestic dogs. Looking patterns of dogs, as a measure of voluntary attention, were recorded during the viewing of human facial expression photographs. The pupil diameters of dogs were also measured as a physiological index of emotional arousal. In a placebo-controlled within-subjects experimental design, 43 dogs, after having received either oxytocin or placebo (saline) nasal spray treatment, were presented with pictures of unfamiliar male human faces displaying either a happy or an angry expression...
2017: Frontiers in Psychology
Calandra Speirs, Zorry Belchev, Amanda Fernandez, Stephanie Korol, Christopher Sears
Two experiments examined age differences in the effect of a sad mood induction (MI) on attention to emotional images. Younger and older adults viewed sets of four images while their eye gaze was tracked throughout an 8-s presentation. Images were viewed before and after a sad MI to assess the effect of a sad mood on attention to positive and negative scenes. Younger and older adults exhibited positively biased attention after the sad MI, significantly increasing their attention to positive images, with no evidence of an age difference in either experiment...
October 30, 2017: Neuropsychology, Development, and Cognition. Section B, Aging, Neuropsychology and Cognition
Ping Huang, Jianyan Huang, Tudor Tepelus, Jyotsna Maram, Srinivas Sadda, Olivia L Lee
PURPOSE: To determine the reliability and agreement of a new comprehensive pterygium grading scale for use in clinical research and clinical trials. METHODS: Thirty eyes with pterygia were enrolled in this study. Primary gaze position and lateral gaze position images were taken of each eye with a modified single-lens reflex camera system. Our grading scale includes five parameters: two hyperemia parameters of pterygia on two different gaze position images and three size parameters, quantifying length, width, and area of the cornea encroachment of pterygium, using ImageJ software...
October 27, 2017: International Ophthalmology
Jaana Ahonniska-Assa, Orli Polack, Einat Saraf, Judy Wine, Tamar Silberg, Andreea Nissenkorn, Bruria Ben-Zeev
BACKGROUND: While many individuals with severe developmental impairments learn to communicate with augmentative and alternative communication (AAC) devices, a significant number of individuals show major difficulties in the effective use of AAC. Recent technological innovations, i.e., eye-tracking technology (ETT), aim to improve the transparency of communication and may also enable a more valid cognitive assessment. OBJECTIVES: To investigate whether ETT in forced-choice tasks can enable children with very severe motor and speech impairments to respond consistently, allowing a more reliable evaluation of their language comprehension...
October 10, 2017: European Journal of Paediatric Neurology: EJPN
Sascha Weber, Rebekka S Schubert, Stefan Vogt, Boris M Velichkovsky, Sebastian Pannasch
Nowadays, the use of eyetracking to determine 2-D gaze positions is common practice, and several approaches to the detection of 2-D fixations exist, but ready-to-use algorithms to determine eye movements in three dimensions are still missing. Here we present a dispersion-based algorithm with an ellipsoidal bounding volume that estimates 3D fixations. Therefore, 3D gaze points are obtained using a vector-based approach and are further processed with our algorithm. To evaluate the accuracy of our method, we performed experimental studies with real and virtual stimuli...
October 26, 2017: Behavior Research Methods
John M Franchak, Kari S Kretch, Karen E Adolph
Face-to-face interaction between infants and their caregivers is a mainstay of developmental research. However, common laboratory paradigms for studying dyadic interaction oversimplify the act of looking at the partner's face by seating infants and caregivers face to face in stationary positions. In less constrained conditions when both partners are freely mobile, infants and caregivers must move their heads and bodies to look at each other. We hypothesized that face looking and mutual gaze for each member of the dyad would decrease with increased motor costs of looking...
October 26, 2017: Developmental Science
Amar Bhochhibhoya, Srijana Mishra, Suraj Mathema, Binod Acharya, Brijesh Maskey
Accurate positioning of the iris is critical for the success of an ocular prosthesis. Precise duplication of size and location of the iris is essential for the establishment of realism, symmetry, and a natural-appearing gaze. This article explores an alternative procedure for positioning the iris in a custom-made ocular prosthesis using a pupillary distance ruler (PD ruler). The orientation and mediolateral dimension of the iris of the natural eye was measured from the graduated scale on a PD ruler and transferred on to the sculpted scleral wax pattern...
October 25, 2017: Journal of Prosthodontics: Official Journal of the American College of Prosthodontists
A Favre-Felix, C Graversen, T Dau, T Lunner
Cognitive control of a hearing aid is the topic for several ongoing studies. The relevance of these studies should be seen in the light of inadequate steering of current hearing aids. While most studies are concerned with auditory attention tracking from the electroencephalogram (EEG), a complimentary approach may be to use visual attention tracking to steer the devices. Visual attention may be characterized by gaze direction, which can be obtained by electrooculography (EOG). EOG may be recorded from electrodes placed in the ear canal, termed EarEOG...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Huiying Liu, Yanwu Xu, Damon Wong, Ai Ping Yow, Augustinus Laude, Tock Han Lim
Age Related Macular Degeneration (AMD) is the third leading cause of blindness and the first one in the elderly. AMD usually causes central blindness due to loss of photoreceptor cell . In this paper, we propose to detect AMD caused vision impairment from gaze data. Compared with the current methods, e.g., Amsler grid, Microperimetry and Preferential Hyperacuity Perimetry, to detect vision impairments, the proposed method has several advantages. 1) It does not require the patient to stare at a fixed position throughout the test...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
Indu P Bodala, Nida I Abbasi, Yu Sun, Anastasios Bezerianos, Hasan Al-Nashash, Nitish V Thakor
Eye tracking offers a practical solution for monitoring cognitive performance in real world tasks. However, eye tracking in dynamic environments is difficult due to high spatial and temporal variation of stimuli, needing further and thorough investigation. In this paper, we study the possibility of developing a novel computer vision assisted eye tracking analysis by using fixations. Eye movement data is obtained from a long duration naturalistic driving experiment. Source invariant feature transform (SIFT) algorithm was implemented using VLFeat toolbox to identify multiple areas of interest (AOIs)...
July 2017: Conference Proceedings: Annual International Conference of the IEEE Engineering in Medicine and Biology Society
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