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Showing papers on "Eye tracking published in 1983"




Journal ArticleDOI
TL;DR: Three experiments are reported that attempted to demonstrate the existence of an integrative visual buffer, a special memory store capable of fusing the visual contents of successive fixations according to their environmental coordinates, but no evidence was found in any experiment for the fusion of visual information from successive fixation in memory, leaving the status of the integrativeVisual buffer in serious doubt.
Abstract: One of the classic problems in perception concerns how we perceive a stable, continuous visual world even though we view it via a temporally discontinuous series of eye movements. Previous investigators have suggested that our perception of a stable visual environment is due to anintegrative visual buffer, a special memory store capable of fusing the visual contents of successive fixations according to their environmental coordinates. In this paper, three experiments are reported that attempted to demonstrate the existence of an integrative visual buffer. The experimental procedure required subjects to mentally fuse two halves of a dot matrix presented in the same spatial region of a display, but separated by an eye movement so that each half was viewed only during one fixation. Thus, subjects had to integrate packets of visual information that had the same environmental coordinates, but different retinal coordinates. No evidence was found in any experiment for the fusion of visual information from successive fixations in memory, leaving the status of the integrative visual buffer in serious doubt.

200 citations


Journal ArticleDOI
TL;DR: The authors found that dyslexic and normal readers did not differ in their number of saccades, percentage of regressions, or stability of fixations in the tracking task, and defective oculomotor control was not associated with or a causal factor in dyslexia, and dyslexics' abnormal eye movements in reading must be related to differences in higher cognitive processes.
Abstract: Dyslexic and normal readers' eye movements were compared while tracking a moving fixation point and in reading. Contrary to previous reports, the dyslexic and normal readers did not differ in their number of saccades, percentage of regressions, or stability of fixations in the tracking task. Thus, defective oculomotor control was not associated with or a causal factor in dyslexia, and the dyslexics' abnormal eye movements in reading must be related to differences in higher cognitive processes. However, individual differences in oculmotor efficiency, independent of reading ability, were found within both the dyslexic and normal groups, and these differences were correlated in reading and tracking tasks.

138 citations


Journal ArticleDOI
TL;DR: Eye tracking pattern appears to be under genetic control and some impairments may reflect a predisposition to functional psychosis, and the study of other oculomotor functions suggests that the locus of the central nervous system disruption is above the brainstem.
Abstract: Impairments of smooth pursuit eye movements occur in a high proportion of schizophrenic patients and in a lower but significant percentage of patients with affective psychoses, as well as patients with structural and metabolic disorders of the central nervous system. These findings have been confirmed using a wide range of tracking tasks, recording techniques, and scoring procedures, and therefore cannot be attributed to measurement artifact. The eye movement disruption in schizophrenics does not seem to result from drug treatment or simple inattention. Eye tracking pattern appears to be under genetic control and some impairments may reflect a predisposition to functional psychosis. The smooth pursuit eye movement impairment has been attributed to a central nervous system dysfunction that manifests itself in a disorder of nonvoluntary attention. The study of other oculomotor functions, such as the oculocephalic reflex, optokinetic and vestibular nystagmus, and saccadic eye movements, suggests that the locus of the central nervous system disruption is above the brainstem.

106 citations


Journal ArticleDOI
TL;DR: It is concluded that while there may be children with reading disorders secondary to visual or oculomotor deficits, dyslexia can and does exist independent of such deficits.
Abstract: We measured saccadic and smooth eye tracking movements in 34 dyslexic and 35 control subjects and were unable to show differences in any of the tasks or parameters measured. Subjects were carefully screened for neurological, optometric, audiological, and behavioral problems before admission to the study. We suggest that differences between our results and those of previous investigators are based on sampling differences. We conclude that while there may be children with reading disorders secondary to visual or oculomotor deficits, dyslexia can and does exist independent of such deficits. Because, in this and other studies, we have ruled out peripheral involvement, we feel that dyslexia is primarily a deficit of central information processing of written or spoken material.

57 citations


Book ChapterDOI
01 Jan 1983
TL;DR: Although this analysis makes use almost entirely of behavioral observations on human subjects, the explanatory concepts used are, in many cases, derived from neurophysiological knowledge of the visual and oculomotor systems.
Abstract: The appearance of a target in the human peripheral visual field frequently leads to the response of a saccadic eye movement to that target. In many cases this appears to have a reflex nature, whereas in others the movement may best be described as voluntary target following. It is suggested later that a dichotomous classification into reflex and voluntary responses is oversimplified, but for the most part the analysis in this chapter ignores this question and concentrates on the details of the process whereby the visual information about the target position leads to an accurate saccade at a particular time. Although this analysis makes use almost entirely of behavioral observations on human subjects, the explanatory concepts used are, in many cases, derived from neurophysiological knowledge of the visual and oculomotor systems.

56 citations



Journal ArticleDOI
TL;DR: A differential effect with the elderly men demonstrating significantly better tracking performance than elderly women is revealed, which largely explains the existing controversy as to whether age or sex variables influence tracking performance.

36 citations


Journal ArticleDOI
01 Dec 1983
TL;DR: Both a critical tracking and a stationary single-axis tracking task were conducted with and without velocity quickening, and in the critical tracking tasks the visual displays were superior; however, the quickened KT display was approximately equal to the unquickened visual display.
Abstract: Research on manual tracking with a kinesthetic-tactual (KT) display suggests that under certain conditions it can be an effective alternative or supplement to visual displays. In order to better understand how KT tracking compares with visual tracking, both a critical tracking and a stationary single-axis tracking task were conducted with and without velocity quickening. In the critical tracking tasks, the visual displays were superior; however, the quickened KT display was approximately equal to the unquickened visual display. In stationary tracking tasks, subjects adopted lag equalization with the quickened KT and visual displays, and mean-squared error scores were approximately equal. With the unquickened displays, subjects adopted lag-lead equalization, and the visual displays were superior.

15 citations


Journal ArticleDOI
TL;DR: Rhesus monkeys were trained to track a moving disk using a procedure in which responses on a lever were reinforced with water delivery only when the disk, oscillating in a horizontal plane on a screen at a frequency of 0.4 Hz in a visual angle of 20°, dimmed for a brief period, to show the effects of drug effects on eye movements.
Abstract: Rhesus monkeys were trained to track a moving disk using a procedure in which responses on a lever were reinforced with water delivery only when the disk, oscillating in a horizontal plane on a screen at a frequency of 0.4 Hz in a visual angle of 20°, dimmed for a brief period. Pursuit eye movements were recorded by electrooculography (EOG). IM phencyclidine, secobarbital, and diazepam injections decreased the number of reinforced lever presses in a dose-related manner. Both secobarbital and diazepam produced episodic jerky-pursuit eye movements, while phencyclidine had no consistent effects on eye movements. Lever pressing was disrupted at doses which had little effect on the quality of smooth-pursuit eye movements in some monkeys. This separation was particularly pronounced with diazepam. The similarities of the drug effects on smooth-pursuit eye movements between the present study and human studies indicate that the present method using rhesus monkeys may be useful for predicting drug effects on eye tracking and oculomotor function in humans.

Journal ArticleDOI
TL;DR: A review of numerous subsequent studies suggests that ETD is not specific to schizophrenia, but is restricted to functional psychosis.
Abstract: Based on eye tracking studies in psychiatric patients, normal controls, and first-degree relatives of patients, Holzman, Proctor, and Levy et al. (1974) state that eye tracking dysfunction (ETD) is specific to schizophrenia and may be a genetic marker of that disorder. A review of numerous subsequent studies, however, suggests that ETD is not specific to schizophrenia, but is restricted to functional psychosis. Evidence that ETD is a genetic marker of functional psychosis is, as yet, inconclusive.

Journal ArticleDOI
TL;DR: Ten patients with disequilibrium, ataxia, and cerebrovascular abnormalities were studied using computer aided eye tracking and vestibular function tests.
Abstract: Ten patients with disequilibrium, ataxia, and cerebrovascular abnormalities were studied using computer aided eye tracking and vestibular function tests. The patients had severe abnormalities in smooth pursuit (decreased gain) and saccade tests (increased delay, decreased accuracy). Optokinetic responses were less affected. The gain of the vestibulo-oculomotor reflex was sometimes affected. Patients with eye tracking abnormalities frequently had symptoms of difficulty reading and watching television. When the lesion was asymmetrical, abnormal eye tracking tests usually pointed to the side of the lesion. Computer aided eye tracking tests are a useful adjunct to the evaluation of the patient with suspected vascular disease. They help to locate areas of central nervous system dysfunction, and produce an objective measurement of the severity of impairment. Conversely, when impairment of the smooth pursuit or saccade system is detected in patients being evaluated for disequilibrium, an assessment of the patients' cerebrovascular system should be considered.


Journal ArticleDOI
TL;DR: Results indicated there was both an elimination of discrete saccades and a shortening of eye movement paths in an experiment in which they simultaneously visually tracked a jumpwise moving target and identified randomly generated auditory dots and dashes.
Abstract: Ten adult male subjects participated in an experiment in which they simultaneously visually tracked a jumpwise moving target and identified randomly generated auditory dots and dashes. Results indicated there was both an elimination of discrete saccades and a shortening of eye movement paths. It was also observed that the difficulty of the visual tracking task and the concurrent auditory task showed effects that were not independent of each other. Results could be construed to support both a divided attention and an opponent-process visual processing model.


Journal ArticleDOI
TL;DR: An eye movement recorder, based on an optoelectronic method, can be used in closed or open eye situations and is well adapted for the studies of eye movement in after-image phenomena.
Abstract: An eye movement recorder, based on an optoelectronic method, can be used in closed or open eye situations. Three photodiodes are used as proximity sensors. This eye tracker is well adapted for the studies of eye movement in after-image phenomena.

Journal ArticleDOI
TL;DR: In this article, the effects of concurrent auditory dot/dash identification tasks on pursuit eye movements were investigated using a two-part experiment with 10 naive adult male subjects, and the results indicated that there was a significant (20 percent) but transitory task-induced restriction of the range of both an 18 deg horizontal and a 14 deg vertical pursuit eye movement visual angle.
Abstract: A two-part experiment was performed using 10 naive adult male subjects to determine the effects of a concurrent auditory dot/dash identification task on pursuit eye movements. Results indicated there was a significant (20 percent) but transitory task-induced restriction of the range of both an 18 deg horizontal and a 14 deg vertical pursuit eye movement visual angle. Furthermore, doubling the presentation rate of the concurrent task accounted for an additional 5 percent restriction of pursuit eye movement range. Results also indicated that the eye movement range is unaffected by both prior knowledge of the task and four consecutive practice trials. It is suggested that both the rapidity of target movement and the presence of concurrent mental tasks could significantly shrink an operator's pursuit eye movement ranges during viewing of dynamic visual displays such as airborne low-level television and forward-looking infrared.

01 Jan 1983



01 Jan 1983
TL;DR: In this paper, over 700 references describing past work related to eye movements and visual search are listed and qualified using a keyword system, intended as the starting point for a research program on visual search for military targets viewed through electro-optical imaging systems.
Abstract: : Over 700 references describing past work related to eye movements and visual search are listed and qualified using a keyword system. The bibliography is intended as the starting point for a research programme on visual search for military targets viewed through electro-optical imaging systems.

01 Sep 1983
TL;DR: In this paper, the authors consider possible bases for the saccade initiation decision during reading and suggest that the decision is made without consideration of information from the current fixation or that the eyes are moved when processing is finished.
Abstract: At some time during the period of a fixation a decision is made to move the eyes. This paper considers possible bases for this saccade initiation decision during reading. Two extreme theoretical positions seem unlikely: that the decision is made without consideration of information from the current fixation or that the eyes are moved when processing of information from that fixation is finished. Alternative explanations which suggest that the eyes are moved after some but not all processing is complete are considered and tested against recent data.