Showing papers on "Eye tracking published in 1982"

Visual Localization and Eye Movements

Abstract: Displacement of the retinal image at the back of the eye may be produced either by eye movements, which the observer uses to redirect his gaze within the visual field, or by displacements of the visual field itself outside of the eye. Nevertheless while displacements of the visual field are normally seen to be displacements in the environment, stationary visual fields normally continue to appear stationary in the presence of eye movements. The main concern of this chapter is with the basis for this difference in visual localization.

Retinally stabilized differential resolution television display

Abstract: A remote television viewing system employing an eye tracker is disclosed, wherein a small region of the image appears in high resolution, and the remainder of the image appears in low resolution. The eye tracker monitors the position of the viewer's line of sight. The eye tracker position data is transmitted to the remote television camera and control. Both the remote camera and television display are adapted to have selectable high-resolution and low-resolution raster scan modes. The position data from the eye tracker is used to determine the point at which the high-resolution scan is to commence. The video data defining the observed image is encoded in a novel format, wherein in each data field, the data representing the position of the high-resolution region of predetermined size appears first, followed by the high-resolution zone video data and then the low-resolution region data. As the viewer's line of sight relative to the displayed image changes, the position of the high-resolution region changes to track the viewer's line of sight.

Learning patterns of eye motion for foveal pursuit.

Abstract: Two human subjects fixated a small light oscillating sinusoidally. After the light disappeared, sinusoidal post-pursuit eye motion (PPEM) continued to follow the unexpected trajectory of targets oscillating at 0.8 and 1.0 Hz. Saccades corrected differences between eye and expected target position during PPEM in complete darkness. Predictive tracking, the ability of primates to accurately fixate even rapidly moving targets, may thus involve learning specific eye movement patterns that mimic target motion.

CCD Head and eye position indicator

Abstract: A head and eye tracking apparatus utilizes a plurality of coded IR emitte mounted in a reflective surface, as a reference base. A reference lens aligned with the user's head references a limited number of the emitters within its field of view and transmits the image to a fiber optic bundle. Simultaneously, an IR reflection from the user's eye is superimposed on the image and transferred via the fiber optic bundle. A CCD array detects the IR transmission and provides a high speed read-out to a computer which can determine head and eye positions from the geometry of the emitters referenced by the lens.

The accuracy of eye‐gaze judgement: A signal detection approach

Abstract: Two studies are reported which tested the hypothesis that eye-gaze discriminability declines with increased interpersonal distance and that this decline produces an overestimation bias. Signal detection theory was used to provide separate indices of discriminability and bias. Discriminability declined with both increased distance and, in one study, with decreased lighting. The tendency of the subject to guess that gaze was occurring when it was not mirrored the changes in discriminability, supporting the hypothesis.

Eye tracking in normal twins.

Abstract: The influence of genetic factors on smooth-pursuit and saccadic eye tracking was determined using 34 pairs of monozygotic and 24 pairs of dizygotic twins. Subjects engaged in smooth-pursuit tracking of different-frequency sinusoidal targets and saccadic tracking of an abruptly moving, rectangular-wave target. Tracking error and phase lag served as dependent measures for the pursuit tasks; saccadic eye tracking performance was evaluated by measuring oculomotor reaction times. The results suggest a genetic basis for smooth-pursuit tracking error; the intraclass correlations for performance averaged over all pursuit tasks were 0.68 and 0.35 for the identical and fraternal twins, respectively. While equivocal results were found for the phase lag data, there was no evidence for the influence of genetic factors on oculomotor response times. These findings are in agreement with the results of twin studies using psychiatric patients.

Response biases in eye-gaze perception.

Abstract: Signal detection theory was used to study the impact of behaviors occurring with eye gazing on judgments of the gaze. Ten subjects judged the gaze direction of two videotaped gazers while each gazer also smiled, spoke, or displayed a thinking gesture. Results show a response bias for smiling, subjects reporting more eye gaze on those trials. The overestimation bias was independent of eye gaze discriminability.

Eye Movement and Motion Perception

Abstract: Two procedures are described with which the relative effectiveness of the three conditions of stimulation that cause motion perception can be explored, and the results of such experiments are reported.

Eye movement pattern and accuracy during perceptual-motor performance in young and old adults

Abstract: Differences between young and old adults in matching a motor response to arrival of a moving stimulus may be partially attributable to age group differences in eye movements. In Experiment 1 the eye movement patterns used by young and old adults during performance of a coincidence-anticipation task were recorded. Age group differences in preferred pattern were noted but did not appear to be linked to task performance level. In Experiment 2, eye tracking error was recorded for young adults and many of the old adults tested in Experiment 1. Age group differences were attributable to task performance rather than eye tracking error. Further, the preferred eye movement pattern did not appear to be stable over time among the subjects retested. The eye-movement reaction time of the old adults was significantly longer than that of the young adults, but this did not appear to hamper the ability of the old adults to distinguish the stimulus speeds. Little evidence was found for linking visual search to task performance error.

Presentation Effects and Eye-Motion Behaviors in Dynamic Visual Inspection:

Abstract: Dynamic visual inspection (DVI) occurs when objects on a moving conveyor are being individually examined for compliance with specifications. This study investigated the effect of the conveyor velocity and object interspacing on DVI performance and eye-motion behavior during this task. Nine combinations of these object presentation factors were examined where three pairs of these combinations each had a constant throughput rate (or exposure time). Horizontal eye-motion measurements were made through electrooculography recordings, and these measurements were analyzed to separately distinguish the visual acquisition time from the visual tracking time. Both of these time values tended to vary predictably with the available exposure time and consistently between people as a visual behavior strategy. Inspection errors were found to be highly correlated with the visual behavior.

Visual localization during eye tracking on steady background and during steady fixation on moving background

Abstract: Experiments were performed to clarify the role of the background motion on the retina in the phenomenon of mislocation of brief visual stimuli during smooth eye tracking. It was found that these visual stimuli were mislocated also relative to a moving background during steady eye fixation. The magnitude of mislocation during pursuit eye movements and during steady fixation was influenced by the stimulus intensity, the background/eye velocity and the place of stimulus presentation in respect to the background; the influence having the same features in both cases. However, the magnitudes of mislocation under the two conditions were quantitatively different. The validity of a hypothesis that the eye movement itself plays no role in the process of localization, and, that this process is based on retinal information only, is considered.

Voluntary ocular tracking movements in response to a sinusoidally moving intermittently active sound source.

Abstract: Voluntary eye movements in response to a sinusoidally moving, intermittently active sound source were investigated in 40 young healthy human subjects. Visual afferent input was prevented during the experiments. With increasing burst repetition rates of the sound source, different forms of eye movements were observed: a) so-called single and repetitive adversive movements consisting of saccades which occur with certain latencies in response to single bursts; b) so-called saccadic eye tracking movements which are characterized by numerous small saccades occurring in accordance with the target (sound source) movement but lacking a time correlation between the saccades and single bursts. It was found that saccadic eye tracking movements were performed instead of adversive movements when at least 4 to 10 bursts per movement period of the sound source was transmitted (with movement frequencies of the sound source from 0.1 to 0.5 Hz). Slight intersaccadic drifts, which could be regularly observed in all types of eye movements were interpreted as instability of fixation in darkness.

An automated eye movement laboratory for on-line electrooculography

Abstract: This paper describes an automated eye movement laboratory that uses electrooculography (EOG) to study people’s eye movements while they read. An on-line minicomputer processes bioelectric potentials that correspond to saccadic eye movements. Horizontal saccades larger than 1.5 deg of visual angle are detected and analyzed in real-time as they occur. The laboratory is designed for prolonged yet unobtrusive observation of human eye movements during sustained reading periods of minutes or hours. All important functions regarding data collection and data reduction are performed automatically, according to simple procedures that can be applied uniformly and without bias to nearly all subjects that we study. Results from three experiments are cited in order to quantify the performance of the laboratory with respect to four criteria: saccade detection accuracy, measurement accuracy, sensitivity, and the uniformity of these measures over different subjects.

Visual Fixation and Eye Movements

Abstract: Eye movements have two factors, that is, quick components or saccades and slow components or pursuit eye movements. A study has been made of whether visual fixation is concerned with saccades or pursuit eye movements.Visual fixation has been examined by the visual suppression test. The eye-tracking test is one of the methods for examining visual fixation, although it evaluates pursuit eye movements. Visual suppression is concerned with both saccades and pursuit eye movements.Visual fixation is composed of two factors, that is, quick eye movements or saccades and slow eye movements or pursuit eye movents.

GATHERING COMPLEX DATA An automated eye movement laboratory for on-line electrooculography

Abstract: This paper describes an automated eye movement laboratory that uses electrooculography (EOG) to study people's eye movements while they read. An on-line minicomputer processes bioelectric potentials that correspond to saccadic eye movements. Horizontal saccades larger than 1.5 deg of visual angle are detected and analyzed in real-time as they occur. The laboratory is designed for prolonged yet unobtrusive observation of human eye movements during sustained reading periods of minutes or hours. All important functions regarding data collection and data reduction are performed automatically, according to simple procedures that can be applied uniformly and without bias to nearly all subjects that we study. Results from three experiments are cited in order to quantify the performance of the laboratory with respect to four criteria: saccade detection accuracy, measurement accuracy, sensitivity, and the uniformity of these measures over different subjects.

A System for On-Line Detection and Analysis of Saccadic Eye Movements

Abstract: A mini computer based system for real-time aquisition and analysis of saccadic eye movements is described. The system incorporates a module for calibration, data aquisition, identification of saccades and extraction of the basic saccade parameters and a module for graphic display of the collected information. The software was developed and tested on a DECLAB PDP 11/03 minicomputer system (A/D converters, diskettes, 32 kB memory, kW 11 clock). All programs (including the basic signal identification routine) are written in FORTRAN while the communication with the A/D converter channels is achieved through DECLAB 03 FORTRAN Extensions Library subroutines (1) which greatly facilitates software installation and maitenance.