scholarly journals Strategies of Visual Search by Novice and Experienced Drivers

1972 ◽  
Vol 14 (4) ◽  
pp. 325-335 ◽  
Author(s):  
Ronald R. Mourant ◽  
Thomas H. Rockwell
Keyword(s):  
Eye Movements ◽  
Visual Information ◽  
Control Group ◽  
Visual Behavior ◽  
Novice Drivers ◽  
Vehicle Handling ◽  
Driving Experience ◽  
Pursuit Eye Movements ◽  
Eye Fixations ◽  
The Right

Six novice drivers drove a 2.1-mi. neighborhood route and a 4.3-mi. freeway route. Eye movements (including blinks and glances to the vehicle's mirrors and speedometer) were videotaped. The visual behavior of a control group, consisting of four experienced drivers, was also videotaped on the same routes. The results showed that the novice drivers: (1) concentrated their eye fixations in a smaller area as they gained driving experience, (2) looked closer in front of the vehicle and more to the right of the vehicle's direction of travel than the experienced drivers, (3) sampled their mirrors less frequently than the experienced drivers, and (4) made pursuit eye movements on the freeway route while the experienced drivers made only eye fixations. These results suggest that the visual acquisition process of the novice drivers was unskilled and overloaded. Thus, the search and scan patterns of the novice drivers may be considered unsafe in terms of impairing the drivers’ ability to detect circumstances that have high accident potential. On this basis it is recommended that novice drivers be prohibited from driving on public roads until they achieve an acceptable level of vehicle handling control and develop skill in acquiring visual information.

Vision without Contours: Study of Visual Information from Ordinal Stimulation

1968 ◽  
Vol 26 (2) ◽  
pp. 335-351 ◽  
Author(s):  
Gunnar Johansson
Keyword(s):  
Eye Movements ◽  
Visual Information ◽  
Sensitivity Threshold ◽  
Continuous Change ◽  
Stimulus Motion ◽  
Pursuit Eye Movements ◽  
Illuminance Level ◽  
Sinusoidal Pattern ◽  
Moving Pattern ◽  
Sinusoidal Function

Continuous change of illuminance over retinal area in accordance with the sinusoidal function was studied as a stimulus for the human visual system. Its efficiency in controlling pursuit eye movements was compared with that of a stepwise luminance function (square wave). Such distributions of luminance were generated on a cathode ray screen (wavelength at the eye 9° and 3°) and were given a small translatory motion (2° – 12′). Ss were instructed to follow the moving pattern with pursuit eye movements. There is no difference in performance between the two types of brightness distributions. A stimulus motion of 24′ was sufficient to produce full evidence of eye tracking in all Ss also from the contour-free sinusoidal pattern. This means that the brightness change in every point of the CRT screen was far below the retinal sensitivity threshold at the illuminance level used. Thus a summation effect occurs. This was taken as a support for an hypothesis about “ordinal” stimulation. Arguments from modern neurophysiology are introduced and yield further support for the conclusion.

scholarly journals Selection of visual information for lightness judgements by eye movements

2013 ◽  
Vol 368 (1628) ◽  
pp. 20130056 ◽  
Author(s):  
Matteo Toscani ◽  
Matteo Valsecchi ◽  
Karl R. Gegenfurtner
Keyword(s):  
Eye Movements ◽  
Visual System ◽  
Visual Information ◽  
Selection Process ◽  
Sampling Strategy ◽  
Selection Strategy ◽  
Eye Fixations ◽  
Target Layer ◽  
Highly Correlated ◽  
Selection Of

When judging the lightness of objects, the visual system has to take into account many factors such as shading, scene geometry, occlusions or transparency. The problem then is to estimate global lightness based on a number of local samples that differ in luminance. Here, we show that eye fixations play a prominent role in this selection process. We explored a special case of transparency for which the visual system separates surface reflectance from interfering conditions to generate a layered image representation. Eye movements were recorded while the observers matched the lightness of the layered stimulus. We found that observers did focus their fixations on the target layer, and this sampling strategy affected their lightness perception. The effect of image segmentation on perceived lightness was highly correlated with the fixation strategy and was strongly affected when we manipulated it using a gaze-contingent display. Finally, we disrupted the segmentation process showing that it causally drives the selection strategy. Selection through eye fixations can so serve as a simple heuristic to estimate the target reflectance.

Saccadic Eye Movements of Dyslexic and Normal Reading Children

Perception ◽  
1994 ◽  
Vol 23 (1) ◽  
pp. 45-64 ◽  
Author(s):  
Monica Biscaldi ◽  
Burkhart Fischer ◽  
Franz Aiple
Keyword(s):  
Eye Movements ◽  
Reaction Times ◽  
Saccadic Eye Movements ◽  
Control Group ◽  
Express Saccades ◽  
Movement Data ◽  
Fixation Durations ◽  
Normal Reading ◽  
Single Target ◽  
The Right

Twenty-four children made saccades in five noncognitive tasks. Two standard tasks required saccades to a single target presented randomly 4 deg to the right or left of a fixation point. Three other tasks required sequential saccades from the left to the right. 75 parameters of the eye-movement data were collected for each child. On the basis of their reading, writing, and other cognitive performances, twelve children were considered dyslexic and were divided into two groups (D1 and D2). Group statistical comparisons revealed significant differences between control and dyslexic subjects. In general, in the standard tasks the dyslexic subjects had poorer fixation quality, failed more often to hit the target at once, had smaller primary saccades, and had shorter reaction times to the left as compared with the control group. The control group and group D1 dyslexics showed an asymmetrical distribution of reaction times, but in opposite directions. Group D2 dyslexics made more anticipatory and express saccades, they undershot the target more often in comparison with the control group, and almost never overshot it. In the sequential tasks group D1 subjects made fewer and larger saccades in a shorter time and group D2 subjects had shorter fixation durations than the subjects of the control group.

Eye Movements While Driving Cars around Curves

1977 ◽  
Vol 44 (3) ◽  
pp. 683-689 ◽  
Author(s):  
Amos S. Cohen ◽  
Herbert Studach
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Vehicle Control ◽  
Eye Fixation ◽  
Eye Fixations ◽  
The Future ◽  
The Mean ◽  
The Right

The eye fixations of 5 experienced and 4 inexperienced car drivers were analyzed while driving curves to the left and to the right. For experienced drivers in a curve to the left the mean duration of eye fixations was longer and the amplitude of the eye movements greater than in a curve to the right. No such difference was observed in inexperienced drivers who manifested neither uniformity within the same curves nor differentiation between the two types of curves. Mean duration of eye fixations of experienced subjects was shorter while driving in a curve to right, but their amplitude of eye movement was greater in a curve to left than those of inexperienced drivers. In Exp. 2, it was pointed out that there is already a change in the pattern of eye movements prior to entering a curve. Upon approaching the curve the mean duration of eye fixation decreased, and the fixations were mainly shifted toward the future driving path. Results are interpreted in terms of the adequacy of the eye fixations (supposedly influenced by prior long-term learning) for information at near distance for vehicle control and at longer distances for setting up proprioceptive forward programs for possible future sensomotoric activity.

Smooth pursuit eye movements in psychiatric inpatients

2017 ◽  
Vol 41 (S1) ◽  
pp. S764-S765
Author(s):  
L. Mandolesi ◽  
G. Piraccini ◽  
F. Ambrosini ◽  
F.L. Vetere ◽  
R.P. Sant’Angelo ◽  
...  
Keyword(s):  
Eye Movements ◽  
Eye Movement ◽  
Smooth Pursuit ◽  
Group Performance ◽  
Psychiatric Patients ◽  
Sampling Rate ◽  
Psychiatric Inpatients ◽  
Control Group ◽  
Maximum Speed ◽  
Pursuit Eye Movements

IntroductionEye movements are used in several studies as a biomarker in order to evaluate cortical alterations in psychiatric disorders. Pursuit eye movements’ deficits were found both in schizophrenia and in affective disorder patients. Nevertheless, these findings are still controversial.ObjectivesSet up a system to record and evaluate the eye movements in psychiatric patients.AimsTo verify the applicability of a smooth pursuit task in a sample of psychiatric inpatients and to prove its efficiency in discriminating patient and control group performance.MethodsA sample of psychiatric inpatients was tested at psychiatric service of diagnosis and care of AUSL Romagna-Cesena. Eye movement measures were collected at a sampling rate of 60 Hz using the eye tribe tracker, a bar plugged into a PC, placed below the screen and containing both webcam and infrared illumination. Subjects underwent to a smooth pursuit eye movement task. They had to visually follow a white dot target moving horizontally on a black background with a sinusoidal velocity. At the end of the task, a chart of the eye movements done is shown on the screen. Data are off-line analyzed to calculate several eye movement parameters: gain, eye movement delay with respect to the movement of the target, maximum speed and number of saccades exhibited during pursuit.ResultsPatients compared to controls showed higher delay and lower gain values.ConclusionsFindings confirm the adequacy of this method in order to detect eye movement differences between psychiatric patients and controls in a smooth pursuit task.Disclosure of interestThe authors have not supplied their declaration of competing interest.

Correlation of Metabolic Risk Factors with Sessile Serrated Lesions

2020 ◽  
Vol 29 (2) ◽  
pp. 175-179
Author(s):  
Melania Macarie ◽  
Simona Bataga ◽  
Simona Mocan ◽  
Monica Pantea ◽  
Razvan Opaschi ◽  
...  
Keyword(s):  
Risk Factors ◽  
Statistical Significance ◽  
Interval Cancer ◽  
Metabolic Risk Factors ◽  
Control Group ◽  
Anatomical Site ◽  
Metabolic Risk ◽  
Right Colon ◽  
Serrated Lesions ◽  
The Right

Background and Aims: The importance of sessile serrated lesions (SSLs) in the pathogenesis of colorectal carcinoma has been recently established. These are supposed to cause the so-called “interval cancer”, having a rapidly progressive growth and being difficult to detect and to obtain an endoscopic complete resection. We aimed to establish the most important metabolic risk factors for sessile serrated lesions. Methods: We performed a retrospective case-control study, on a series of 2918 consecutive patients who underwent colonoscopy in Gastroenterology and Endoscopy Unit, County Clinical Emergency Hospital, Târgu-Mureș, Romania between 1 st of January 2015-31 th of December 2017. In order to evaluate the metabolic risk factors for polyps’ development, enrolled participants were stratified in two groups, a study group, 33 patients with SSLs lesions, and a control group, 138 patients with adenomatous polyps, selected by systematic sampling for age and anatomical site. Independent variables investigated were: gender, smoking, alcohol consumption, obesity, arterial hypertension, diabetes, hypercholesterolemia, hypertriglyceridemia, hyperuricemia, nonalcoholic liver disease. Results: For SSLs the most common encountered localization was the right colon in 30.55% of cases. By comparative bivariate analysis between SSLs group and control group, it was observed that hypertension (p=0.03, OR 2.33, 95 %CI 1.03-5.24), obesity (p=0.03, OR 2.61, 95 %CI 1.08-6.30), hyperuricemia (p=0.04, OR 2.72, 95 %CI 1.28-7.55), high cholesterol (p=0.002, OR 3.42; 95 %CI 1.48-7.87), and high triglycerides level (p=0.0006, OR 5.75; 95 %CI 1.92-17.2) were statistically associated with SSLs development. By multivariate analysis hypertension and hypertriglyceridemia retained statistical significance. Conclusions: Our study showed that the highest prevalence of SSLs was in the right colon and hypertension and increased triglycerides levels were associated with the risk of SSLs development. These risk factors are easy to detect in clinical practice and may help identifying groups with high risk for colorectal cancer, where screening is recommended.

Eye movements in sports research and practice: Immersive technologies as optimal environments for the study of gaze behaviour

2020 ◽  
Author(s):  
David Harris ◽  
Mark Wilson ◽  
Tim Holmes ◽  
Toby de Burgh ◽  
Samuel James Vine
Keyword(s):  
Virtual Reality ◽  
Eye Movements ◽  
Eye Tracking ◽  
Visual Information ◽  
Successful Performance ◽  
Experimental Control ◽  
Research And Practice ◽  
Gaze Behaviour ◽  
Immersive Technologies

Head-mounted eye tracking has been fundamental for developing an understanding of sporting expertise, as the way in which performers sample visual information from the environment is a major determinant of successful performance. There is, however, a long running tension between the desire to study realistic, in-situ gaze behaviour and the difficulties of acquiring accurate ocular measurements in dynamic and fast-moving sporting tasks. Here, we describe how immersive technologies, such as virtual reality, offer an increasingly compelling approach for conducting eye movement research in sport. The possibility of studying gaze behaviour in representative and realistic environments, but with high levels of experimental control, could enable significant strides forward for eye tracking in sport and improve understanding of how eye movements underpin sporting skills. By providing a rationale for virtual reality as an optimal environment for eye tracking research, as well as outlining practical considerations related to hardware, software and data analysis, we hope to guide researchers and practitioners in the use of this approach.

Visual asymmetries during face encoding Increased dwell time and fixations in the upper and left hemifields

2018 ◽  
Author(s):  
Fatima Maria Felisberti
Keyword(s):  
Face Recognition ◽  
Eye Movements ◽  
Visual Field ◽  
Face Processing ◽  
Dwell Time ◽  
The Other ◽  
Environmental Cues ◽  
Reading Habits ◽  
The Right

Visual field asymmetries (VFA) in the encoding of groups rather than individual faces has been rarely investigated. Here, eye movements (dwell time (DT) and fixations (Fix)) were recorded during the encoding of three groups of four faces tagged with cheating, cooperative, or neutral behaviours. Faces in each of the three groups were placed in the upper left (UL), upper right (UR), lower left (LL), or lower right (LR) quadrants. Face recognition was equally high in the three groups. In contrast, the proportion of DT and Fix were higher for faces in the left than the right hemifield and in the upper rather than the lower hemifield. The overall time spent looking at the UL was higher than in the other quadrants. The findings are relevant to the understanding of VFA in face processing, especially groups of faces, and might be linked to environmental cues and/or reading habits.

Early Predictive Biochemical, Electrocardiographic and Echocardiographic Markers for Cardiac Damage in Patients with Pulmonic Silicosis

2019 ◽  
Vol 70 (1) ◽  
pp. 63-68 ◽  
Author(s):  
Venera Cristina Dinescu ◽  
Ileana Puiu ◽  
Sorin Nicolae Dinescu ◽  
Diana Rodica Tudorascu ◽  
Elena Catalina Bica ◽  
...  
Keyword(s):  
Heart Disease ◽  
Right Ventricle ◽  
Control Group ◽  
Cardiac Damage ◽  
Right Heart ◽  
Pulmonary Heart Disease ◽  
Upper Limit ◽  
Echocardiographic Parameters ◽  
The Right ◽  
Chronic Pulmonary Heart Disease

The aim of this study was to identify correlations between electrocardiographic and echocardiographic changes in patients with silicosis prior to the occurrence of chronic pulmonary heart disease. We conducted a prospective, descriptive, analytical study, in which we included a group of 67 patients consecutively admitted to the Health Promotion and Occupational Medicine Clinic between December 2016 and January 2018, aged 47 to 78 years.There was a biochemical and electrocardiographic evaluation for each patient as well as a right ventricle echocardiographic evaluation (diameters, volumes, function). A control group, including 25 patients with benign minor diseases that required a cardiologist consultation, was also used. From the electrocardiographic point of view, slight changes were observed regarding the waves of electrical activity of the right ventricle. Taking into account the degree of ventilatory dysfunction (depending on FEV1), changes in right heart echocardiographic parameters were identified. Thus, in what the most important right ventricular parameters, including the tricuspid annular plane systolic excursion (TAPSE) or the RV index of myocardial performance (RVMPI) were concerned, values at the upper limit of normality were recorded in most patients with moderate and severe ventilatory dysfunction. Values of echocardiographic parameters of the right heart at the upper limit of normality, correlated with the degree of ventilatory dysfunction, are early markers for cardiovascular damage in patients with pulmonary silicosis prior to the occurrence of chronic pulmonary heart disease also known ascor pulmonale.

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