Research of the Gaze during Perception of Textbook’s Page Elements in Bulgarian

2021 ◽  
Vol 63 (5) ◽  
pp. 467-474
Author(s):  
Despina Vasileva ◽  
Keyword(s):  
Statistical Analysis ◽  
Standard Deviation ◽  
Tracking System ◽  
Field Of View ◽  
Right Visual Field ◽  
Critical Ratio ◽  
The Gaze ◽  
Two Samples ◽  
Left And Right ◽  
The Right

A study about perception of a page from a textbook of Bulgarian is presented in the article. Participants in the experiment are 30 students of age 15 to 19 from high schools in Sofia. The study is realized through an eye tracking system. For the purposes of the study 8 stimuli (textbook pages) were constructed, containing the components as follows: “text”, “image”, and “diagram”. In each stimulus the quantity of the components differs. All possible pairs in a combination in the left and in the right field of view are presented in the stimuli. The goal of the research is to be examined the fixation of the gaze on each elements of a textbook page. To assess the characteristic of the gaze was calculated the number of saccades in the left and right visual field of the slides. The data are organized in spreadsheets. Statistical analysis is performed in two-group t-test (two samples with different variances). Mean number of saccades, standard deviation, standard error, critical ratio are calculated.

Hemispheric Asymmetries in a Signal Detection Task

1983 ◽  
Vol 57 (3) ◽  
pp. 923-929 ◽  
Author(s):  
John L. Andreassi ◽  
Charles S. Rebert ◽  
Ferol F. Larsen
Keyword(s):  
Signal Detection ◽  
Right Hemisphere ◽  
Reaction Times ◽  
Vigilance Task ◽  
Verbal Stimulus ◽  
Right Visual Field ◽  
Left And Right ◽  
The Right ◽  
Male Subjects ◽  
Central Fixation

Reaction time and signal detection performance were measured during a 78-min. vigilance task. 12 right-handed male subjects served in two experimental sessions. Subjects focused on a central fixation point and responded to signals presented at unpredictable times in one of three locations: 2.5° to right of central fixation, central, and 2.5° to the left of center. Subjects decided whether to press a response key with either the left or right hand with each presentation. Over-all vigilance performance (signal detections and response time) was similar for left and right visual-field presentations. Evidence from reaction times indicated that responses controlled by the left hemisphere were faster to a verbal stimulus (T) while reactions controlled by the right hemisphere were faster to an apparent non-verbal stimulus, an inverted T.

Riders’ perception of symmetrical pressure on their ischial tuberosities and rein contact tension whilst sitting on a static object

2017 ◽  
Vol 13 (1) ◽  
pp. 7-12 ◽  
Author(s):  
R. Guire ◽  
H. Mathie ◽  
M. Fisher ◽  
D. Fisher
Keyword(s):  
Standard Deviation ◽  
Solid Wall ◽  
Static Model ◽  
Ischial Tuberosity ◽  
Static Object ◽  
Left And Right ◽  
And Performance ◽  
The Right ◽  
Ischial Tuberosities ◽  
Paired T Test

The horse-rider system is of great interest in understanding the mechanics involved in optimising locomotor function and performance in the ridden horse. Adult riders (n=30) attending a rider conference volunteered to take part in the study. Riders were asked to mimic riding position by positioning themselves symmetrically on their seat bones (ischial tuberosities) sitting on a (Pliance) pressure mat which was placed on a static platform. Riders were also asked to mimic even rein contact using reins with gauges which were attached to a solid wall. When satisfied that they were sitting symmetrically and had an even rein contact, pressure and rein measurements were captured for 5 s and repeated three times. A paired T Test was carried out to determine differences between left and right ischial tuberosities and rein pressures. Using a static model, this study found that the riders had significantly more pressure beneath the left ischial tuberosity (mean ± standard deviation, 3.22±1.43 N/cm2) compared to the right (2.65±1.49 N/cm2) (P=0.04) and no significant differences were observed between left (6.37±2.42 N) and right rein pressure (6.38±2.66 N) (P=0.95). Whilst sitting on a static platform, differences in ischial tuberosity pressure in adult riders were observed despite these riders’ perception that their seat was symmetrically weighted. These differences observed need to be investigated further, dynamically, to determine if there is a similar trend in the ridden situation.

Left and Right Visual Field Superiority for Letter Classification

1979 ◽  
Vol 31 (3) ◽  
pp. 423-439 ◽  
Author(s):  
John Jonides
Keyword(s):  
Visual Field ◽  
Task Demands ◽  
Perceptual Processing ◽  
Right Visual Field ◽  
Left And Right ◽  
The Right ◽  
Visual Field Superiority

Two letter classification experiments examine the hypothesis that lateral asymmetries in perceptual processing are sensitive to subtle changes in task demands. The first experiment reports a right visual field superiority for an easy letter classification, but a left field superiority for a difficult classification using the same population of stimuli. Experiment II demonstrates that the right field superiority can be reversed if the easy classification trials are embedded among more difficult trials. The implications of these results for theories of hemispheric localization are discussed.

Do the Hemispheres Interact during Object Naming? Evidence from Tachistoscopic Viewing and Time-Sharing Paradigms

1991 ◽  
Vol 73 (3) ◽  
pp. 1019-1024 ◽  
Author(s):  
Michael P. Rastatter ◽  
Richard A. McGuire
Keyword(s):  
Picture Naming ◽  
Visual Fields ◽  
Finger Tapping ◽  
Right Visual Field ◽  
Time Sharing ◽  
Hemispheric Processing ◽  
Processing Resources ◽  
Left And Right ◽  
The Right ◽  
Right And Left Hands

Here we report an experiment in which 16 right-handed young adults named a series of unilaterally presented pictures during concurrent unimanual finger tapping with the right and left hands at separate times. A multivariate analysis of variance showed no significant differences in picture-naming reaction time between left versus right visual-field stimulations. Also the test for finger tapping was nonsignificant, with the magnitude of disruption being symmetrical for the right and left hands as a function of visual fields. It was proposed that the two cerebral hemispheres interact with each other at later processing stages when performing tasks requiring both left and right hemispheric processing resources.

Models of Response Time to Peripheral Stimuli

1974 ◽  
Vol 18 (5) ◽  
pp. 533-533
Author(s):  
D.S. Kochhar ◽  
T.M. Fraser
Keyword(s):  
Visual Field ◽  
Response Time ◽  
Visual Fields ◽  
Stimulus Location ◽  
Stimulus Size ◽  
Tracking Task ◽  
Right Visual Field ◽  
Simulated Driving ◽  
Left And Right ◽  
The Right

The variable contribution of peripherally presented stimuli in a A sensory motor task has been explored in terms of stimulus and environmental variables. A simulated driving task was chosen as being a representative compensatory tracking task. Empirical models have been developed using response surface methodology, statistical design and data collected on a simulator with a 240° wrap-around screen and projection systems very much like cinerama. In this research, seven factors were isolated for a study of their effects on detection latency to peripherally presented stimuli when the subject was ‘driving’. These factors were stimulus size (circular stimuli between 18′ and 60′), stimulus color (red, white and green), stimulus-background contrast (background luminance 1ft.L and stimulus luminance of 30, 60 and 90 ft.L), stimulus location along the horizontal (between ± 90°) and vertical meridians (between ± 26°), intensity of continuous white noise (between 52 and 100 dbA), and complexity of the continuous central tracking task measured in terms of the simulated driving speed. Three levels of each variable were selected in a 7 factor Box-Behnken design. Twenty undergraduates between the ages 19 and 26 participated in the experiment. It was found that, in this multivariable environment when all seven factors were simultaneously varied, the effects of noise, stimulus location in the visual field and stimulus size were the more important determinants of response latency. In addition, marked differences for the left and right visual fields were observed for the right-handed subject population. Four models have been developed: two for the left visual field, with and without the continuous central task (CCT), and two for the right visual field for the same conditions. The response was found to be of the form 1/Yr = f (xi); i= 1,2,… 7 for both the left and right visual fields in the presence of the CCT. In the absence of the CCT the model was of the form Yr = f (xr) for the left and 1/2 = f (xi) for the right visual field where Yr = response time in millisec. and Yr xi = variables in equations. Response curves have been presented to illustrate the variation of response time with each of the seven variables for regions where response time may be expected to be a minimum. The implications of these curves and the models on which they are based have been examined from the design point of view.

Depth perception and evoked brain activity: The influence of horizontal disparity and visual field location

1997 ◽  
Vol 14 (3) ◽  
pp. 527-532 ◽  
Author(s):  
Wolfgang Skrandies
Keyword(s):  
Visual Field ◽  
Visual Information ◽  
Evoked Potential ◽  
Brain Activity ◽  
Right Visual Field ◽  
Functional Difference ◽  
Horizontal Disparity ◽  
Random Dot Stereograms ◽  
Left And Right ◽  
The Right

AbstractThe perception of dynamic random-dot stereograms (RDS) depends on the physiological fusion of horizontally disparate binocular visual input. Thus, the use of RDS offers the possibility to study selectively cortical processing of visual information in man. We investigated the influence of horizontal disparity on the scalp topography of RDS evoked brain activity in 33 healthy subjects. Stereoscopic checkerboard patterns were presented in the center or lateralized in the left or right visual field with horizontal disparities changing at temporal frequencies of six or eight depth reversals/s using different disparity values ranging from 3.5 to 28 min of arc. In 11 subjects evoked potential fields were recorded from 16 electrodes, and 21 subjects participated in 30-channel recordings with electrodes located over the parietal and occipital brain areas. Stimulation frequency-related brain activity was obtained with all disparity values; however, with large or small disparities the potential field strength decreased significantly while largest responses were obtained with intermediate disparities. Significant differences were observed in RDS evoked brain activity when central and lateralized stimulus locations were compared. With lateral stimuli (extending from the fovea to 17.1-deg eccentricity) maximal amplitudes were obtained at larger disparities than with central stimuli. In addition there were pronounced differences between brain activity evoked with stimuli presented in the left or right visual field; however, there were very similar evoked potential signals recorded from electrodes located over the left and right hemispheres. Our findings indicate that the processing of disparity information with lateralized stimuli is different from the processing in the center of the visual field. In addition, lateralized stimulation yields a significant disparity tuning mainly with stereoscopic targets occurring to the right from the fixation point (but not with stimuli to the left) suggesting a functional difference between the visual half-fields.

Lateralized Visual-Field Inattention in Schizophrenia

1994 ◽  
Vol 79 (1) ◽  
pp. 699-702 ◽  
Author(s):  
Daniel S. Lobel ◽  
Rex M. Swanda ◽  
Miklos F. Losonczy
Keyword(s):  
Visual Field ◽  
Cerebral Hemisphere ◽  
Right Visual Field ◽  
Verbal Processing ◽  
Cognitive Research ◽  
Schizophrenic Patients ◽  
Hemispheric Functioning ◽  
Left And Right ◽  
Verbal Functioning ◽  
The Right

Numerous studies have shown impaired verbal functioning in schizophrenic patients as compared with normals. The verbal deficits are generally attributed to damage of the left cerebral hemisphere. This attribution is based on literature which suggests that verbal processing is primarily mediated by the left hemisphere in right-handed humans. This study explored left-hemispheric integrity directly by assessing sustained attention in both the left and right hemispheres of 40 schizophrenic patients with the Weintraub Cancellation Tasks. Patients made significantly more errors of omission on the right visual field than on the left. These results are consistent with cognitive research in schizophrenia by demonstrating selective left-hemispheric impairment relative to right-hemispheric functioning.

scholarly journals The field of view available to the ventral occipito-temporal reading circuitry

2016 ◽  
Author(s):  
Rosemary Le ◽  
Nathan Witthoft ◽  
Michal Ben-Shachar ◽  
Brian Wandell
Keyword(s):  
Visual Field ◽  
Temporal Cortex ◽  
Relevant Information ◽  
Field Of View ◽  
Right Visual Field ◽  
Small Subset ◽  
Central Visual Field ◽  
Size And Shape ◽  
Word Forms ◽  
The Right

AbstractSkilled reading requires rapidly recognizing letters and word forms; people learn this skill best for words presented in the central visual field. Measurements over the last decade have shown that when children learn to read, responses within ventral occipito-temporal cortex (VOT) become increasingly selective to word forms. We call these regions the VOT reading circuitry (VOTRC). The portion of the visual field that evokes a response in the VOTRC is called the field of view (FOV). We measured the FOV of the VOTRC and found that it is a small subset of the entire field of view available to the human visual system. For the typical subject, the FOV of the VOTRC in each hemisphere is contralaterally and foveally biased. The FOV of the left VOTRC extends ~9° into the right visual field and ~4° into the left visual field along the horizontal meridian. The FOV of the right VOTRC is roughly mirror symmetric to that of the left VOTRC. The size and shape of the FOV covers the region of the visual field that contains relevant information for reading English. It may be that the size and shape of the FOV, which varies between subjects, will prove useful in predicting behavioral aspects of reading.

Measurement of left and right ventricular volume from implanted radiopaque markers

1981 ◽  
Vol 240 (6) ◽  
pp. H896-H900
Author(s):  
W. P. Santamore ◽  
R. Carey ◽  
D. Goodrich ◽  
A. A. Bove
Keyword(s):  
Standard Deviation ◽  
Left Ventricle ◽  
Right Ventricle ◽  
Right Ventricular ◽  
Ventricular Volume ◽  
Left Ventricular ◽  
Ventricular Volumes ◽  
Radiopaque Markers ◽  
Left And Right ◽  
The Right

To better understand biventricular mechanics, an algorithm was developed to simultaneously calculate right and left ventricular volumes from randomly placed subendocardial radiopaque markers. Mathematically, the ventricle is represented as a stack of circular discs. The radius R of each disc is calculated as the distance from the subendocardial radiopaque marker to a computer generated base-to-apex line, and the height H of each disc is determined by the projected distance between radiopaque markers along the base-to-apex line. Accordingly, the volume (V) is calculated as V = pi . sigma Hi . Ri2. The validity of this algorithm was tested on 10 canine left ventricular casts, on 10 human right ventricular casts, and in five experiments. For the left ventricle, the regression line between the casts (VT) and calculated (VC) volumes was VC = 0.55 VT + 6.6, with r = 0.95, standard error of estimate (Sy) = 1.9 ml, and the standard deviation of percent error = 12.6%. For the right ventricle, VC = 1.75 VT = 42.5, with r = 0.86, Sy = 16.2 ml, and the standard deviation of percent error = 24.8%. In five animal experiments, radiopaque markers were implanted into the endocardium of the left and right ventricles and comparisons were made between angiographic- and marker-determined ventricular volumes. For the five experiments, the mean correlation coefficient, relating the marker volumes to the angiographic volumes, were 0.92 +/- 0.01 for the left ventricle and 0.89 +/- 0.02 for the right ventricle. The results, which are similar to other volume-determination methods, indicate that this method can be applied to determine right and left ventricular volume. Once implanted, fluoroscopy of these markers provides a noninvasive means of calculating ventricular volume.

Lateralization of defence mechanisms: Differing influences on perception with left and right visual field presentation of anxiety‐arousing stimulation

1989 ◽  
Vol 3 (3) ◽  
pp. 167-179 ◽  
Author(s):  
Ingegerd Carlsson
Keyword(s):  
Visual Field ◽  
Undergraduate Students ◽  
Right Hemisphere ◽  
Right Visual Field ◽  
Defence Mechanisms ◽  
Psychoanalytic Literature ◽  
Contrast Technique ◽  
Left And Right ◽  
The Right ◽  
Perceptual Styles

Forty‐five undergraduate students were randomly divided into two groups and tested with the Meta‐Contrast Technique (MCT), in the left or right visual field (VF). In the MCT, the presentation of a subliminal threatening picture is intended to evoke anxiety and ego mechanisms of defence against it. More signs of repressive plus isolating defences were found in the left hemisphere (LH) group. Signs of projection plus regression tended to be more common in the right hemisphere (RH) group. The total number of anxiety signs in the MCT protocols did not differ between the groups. A clear sex difference was noticed, namely that the female LH and RH groups showed significant lateralization, while the male groups did not differ significantly on a combined defensive score. The data suggest that the left and right hemispheres may show differing perceptual styles, which are described as ego mechanisms of defence in the psychoanalytic literature.

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