Showing papers on "Eye tracking published in 1985"

Visual cells in the temporal cortex sensitive to face view and gaze direction

Abstract: The direction of eye gaze and orientation of the face towards or away from another are important social signals for man and for macaque monkey. We have studied the effects of these signals in a region of the macaque temporal cortex where cells have been found to be responsive to the sight of faces. Of cells selectively responsive to the sight of the face or head but not to other objects (182 cells) 63% were sensitive to the orientation of the head. Different views of the head (full face, profile, back or top of the head, face rotated by 45 degrees up to the ceiling or down to the floor) maximally activated different classes of cell. All classes of cell, however, remained active as the preferred view was rotated isomorphically or was changed in size or distance. Isomorphic rotation by 90-180 degrees increased cell response latencies by 10-60 ms. Sensitivity to gaze direction was found for 64% of the cells tested that were tuned to head orientation. Eighteen cells most responsive to the full face preferred eye contact, while 18 cells tuned to the profile face preferred averted gaze. Sensitivity to gaze was thus compatible with, but could be independent of, sensitivity to head orientation. Results suggest that the recognition of one type of object may proceed via the independent high level analysis of several restricted views of the object (viewer-centred descriptions).

Effects of gaze on hiring, credibility, attraction and relational message interpretation

Abstract: Two competing models of the social meaning and effects of eye gaze exist. One holds that different levels of eye gaze have clearly identifiable meanings that will yield main effects on such communication outcomes as hiring and interpersonal evaluations. The other holds that deviant levels of eye gaze are ambiguous in meaning and that interpretation depends on contextual cues such as the reward value of the violator. An experiment required 140 Ss to serve as interviewers during a structured interview in which six confederate interviewees sytematically varied three levels of eye gaze (high, normal, low) and two levels of reward (highly qualified, highly unqualified for the advertised position). Results favored a social meaning model over a violations of expectations model: Subjects were more likely to hire and rate as credible and attractive interviewees who maintained a normal or high degree of gaze than those who averted gaze. Interpretations given to higher amounts of gaze were more intimacy and similarity, more immediacy and involvement, and more composure, informality and nonarousal. “The eyes of men converse as much as their tongues, with the advantage that the ocular dialect needs no dictionary, but is understood the world over.” —Ralph Waldo Emerson “These lovely lamps, these windows of the soul.” —Guillaume de Salluste “And I have known the eyes already, known them all—The eyes that fix you in a formulated phrase ...” —T.S. Eliot

Dynamic Visual Capture: Apparent Auditory Motion Induced by a Moving Visual Target

Abstract: Apparent motion of a sound source can be induced by a moving visual target. The direction of the perceived motion of the sound source is the same as that of the visual target, but the subjective velocity of the sound source is 25–50% of that of the visual target measured under the same conditions. Eye tracking of the light target tends to enhance the apparent motion of the sound, but is not a prerequisite for its occurrence. The findings are discussed in connection with the ‘visual capture’ or ‘ventriloquism’ effect.

Smooth pursuit eye tracking, neuropsychological test performance, and computed tomography in schizophrenia.

Abstract: Smooth pursuit eye movements (SPEM) were measured in 18 patients who met Research Diagnostic Criteria for schizophrenia. Some degree of SPEM impairment was present in most patients. Deviant eye tracking was not related to rating of severity of illness, but was related to recurrent episodes of hospitalization, antipsychotic medication, and lower rating in anxiety and delusions. Worse SPEM tended to be associated with larger lateral ventricles as assessed on computed tomography. Three patients with reversed occipital asymmetry had was related to worse performance in Finger Tapping and in the Trail-Making Test, and to fewer perceived alternations of a Necker cube, suggesting that frontoparietal disturbances are related to poor pursuit eye tracking in schizophrenia.

Eye movement problems in achieving readers: an update.

Abstract: There is extant a population of subjects who have average or better than average interpretive reading skills as measured by standardized tests but who read slowly and inefficiently. Ten cases are presented where both Iowa Silent Reading Tests (ISRT) (Level III) and eye movement recordings were completed. Three of the subjects received training to improve reading efficiency. Reducing the cognitive level of the reading selections did not result in improved reading efficiency for subjects who have good interpretive skills. Substantial improvement in reading efficiency was measured in each of the three subjects selected for training.

Improvements relating to eye-gaze-direction controlled apparatus

Abstract: Eye-gaze-direction controlled apparatus including eye-gaze-direction determining means to detect a direction of gaze of any eye of a user, which means are also adapted to determine a relative position of the direction of eye gaze with respect to a target direction (8), said means further adapted to mesure and record a plurality of eye-gaze-directions (a-h) each measure being taken between sequentially selected intervals of time and to provide an ''activate'' or ''identify for subsequent action'' signal upon at least a preselected proportion of a preselected number of sequentially measured directions being detected which are within a preselected range of positions from the target direction bounded by boundaries (9, 10, 11, 12).

Improvements relating to an apparatus and method related to control through eye gaze direction

Abstract: An eye gaze direction control arrangement using a light source (4) and a detector (5) giving the direction of eye gaze by detecting the positon on a user's eye (3) of the reflection of the light source and using such information to locate a cursor position on a video screen (2) and providing for a recalibration initiation achievable by a user to ensure consistent alignment of such a cursor with actual viewing direction. The calibration may be initiated by the user (1) providing multiple interruptions of the incident light within a predetermined time period (e.g. eye closures). The use (1) is then required to attempt to direct his gaze at various predetermined locations (7, 8, 9, 10) from which an average provides the calibration.

Real-time on-line pattern recognition of eye position and movement

Abstract: A pattern recognition technique has been successfully used as a noninvasive, accurate and sensitive method for direct on-line and real-time measurement of instantaneous eyeball positions and movements. The scheme uses a vidicon camera as the input to a microcomputer system. Both hardware and software windowing are used for tracking eye positions adaptively. The system can be applied to study both one- and two- dimensional eye movements. An error analysis of the approach is also included.

Estimating Frequency and Size of Effects Due to Experimental Manipulations in Eye Movement Research. Technical Report No. 338.

Abstract: In studies of eye movement behavior, once it has been demonstrated that an experimental manipulation has produced a reliable effect, it is often useful to try to estimate the frequency with which the effect occurred. This paper describes the Frequency of Effects Analysis and illustrates its use with data from a study on characteristics of the perceptual span of adult readers. The results of the analysis indicated that, in one instance, a manipulation which produced a 21 msec increase in fixation duration was actually producing a 151 msec increase in only 21% of the instances, and was having no effect in the remaining 79% of the cases.

Eye movements and illusions of alignment.

Abstract: Extraction of the location of a target in the visual periphery is a fundamental visual process which may be manifested both in conscious judgments of location, such as decisions about alignment, and in the processing required to execute an eye movement to a peripheral target. In both cases, location judgement is affected by the neighbouring visual configuration. An experiment is reported in which the amplitude of saccadic eye movements has been measured to study the effect of a configuration consisting of a single 'induction line'. The results demonstrate systematic effects of this line on the size of the saccade which are closely similar to those previously found in an alignment task.

The effect of video bandwith on the judgement of comfort, visual performance and eye movements using visual display units

Abstract: The dependence of comfort judgement, visual performance and eye movements on video bandwidth is demonstrated. If the bandwidth of a visual display unit (VDU) is varied, the sensory attributes sharpness and brightness contrast of the characters may both change, as bandwidth limitation also causes a luminance contrast decrease . An attempt to separate the effects of these two psychologica l attributes is described .

Quantitative Measurement of Saccade by at Random Skipping Eye Tracking Test

Abstract: 不規則跳躍視標追跡検査 (At Random Skipping Eye Tracking Test) を施行し, 小型電算機 (PDP 11/40) を用いて saccade の定量分析を行った. 検査の刺激条件としては, 点燈視標位置, 視標点燈時間を共に不規則とした検査法が適切であった. また高域遮断周波数とサンプリング周波数が分析結果に大きな影響を与える事が判明した.正常被験者および疾患部位別の分析結果は以下の如くであった.〈正常例〉18才から27才までの正常被験者12例について分析を行った.潜時: 視標振幅とは無関係で, 潜時平均は225.3msec, 標準偏差43.0msecであった.最大眼球速度: Y=57.227×X0.6707の指数関数で近似された.眼球偏位量: 視標振幅と極めて高い相関を示した. 眼球偏位量の視標振幅に対する回帰分析では, Y=0.1340+0.9514Xとほぼ1:1の関係が得られた.〈疾患別〉中枢および末梢性疾患104例について検討を加えた.潜時: 脊髄小脳変性症, 有機水銀中毒症, 重症筋無力症で潜時の延長 (P<0.05) がみられた.最大眼球速度: 脳幹障害で著明な速度の低下がみられた. 脊髄小脳変性症, 有機水銀中毒症, 小脳障害, 重症筋無力症では, 症例により速度低下がみられた.眼球偏位量: 大脳, 基底核部障害, 脊髄小脳変性症, 有機水銀中毒症などで hypotonia と不正確な眼球偏位がみられた.saccade の分析には, 今回施行した定量分析の他, 最大眼球速度に関しては速度パターンの検討が, また眼球偏位量に関しては, 定性分析が必要であると思われた.

High-speed helmet-mounted eye tracker

Abstract: We have developed a compact high-speed eye position monitor for use in helmet-mounted eye tracking applications. The system provides real-time digital readout of gaze direction over a 30° (half-angle) field with ±1° accuracy at 1000 scans/sec. It also detects small head movements, or head-to-helmet slip, and reads these out separately from actual eye movements.

INSTRUMENTATION & TECHNIQUES Artificial eye for assessing corneal-reflection eye trackers

Abstract: An artificial eye for assessing corneal-reflection eye trackers is described. The "eye" simulates an adult human eye and consists of a contact lens of the same curvature as the cornea. To assess the performance of an eye tracker, it is neces­ sary to present it with a precisely known input. For a corneal-reflection eye tracker with a bright-pupil (e.g., Hainline, 1981; Young & Sheena, 1975), this can be provided only by a device that simulates the optics of the human cornea and pupil. Such a device is shown in Figure 1. This" artificial eye" consists of a contact lens of the same curvature as the human cornea; the image of the illuminator that is reflected by this surface provides one of the two required images for the eye tracker. The second image, the bright-pupil, is provided by an aper­ ture situated at the correct optical distance behind the "corneal" pole; this aperture is backed by white paper that serves as a diffuse reflector to simulate the fundus. The arrangement is rotated about a point, equivalent to the center of rotation of the human eye, by a fast high­ torque galvanometer motor. The motor is specified in Figure 1; however, a pen motor from a good chart recorder would suffice. The shaft of the motor is also con­ nected with a zero-backlash coupling to a linear poten­ tiometer, which provides a precise and continuous readout of the angular position of the device. This is a simple and inexpensive arrangement and can be driven by a signal generator or a computer-generated signal. An outline of the artificial eye is shown in Figure lao All surfaces in the field of view of the eye tracker are painted flat black. The optical geometry shown in Figure 1b is based on a simplified schematic eye of the adult human (see Bennett & Francis, 1962). The meniscus contact lens has zero power and the same curvature as the real cornea. (Un­ fortunately, a plano-convex lens, although cheaper, also produces a very bright reflected image from its second surface, and this image confuses the image-processing electronics of the eye tracker.) Since this lens has no di­ optric power, it is necessary to position the sharp-edged "pupil" 3.05 mm behind the pole, rather than 3.6 mm,

Knowledge base enhancement of visual tracking

Abstract: A proposed system for a visual tracker is presented that relies on information developed from previous tracking scenarios stored in a knowledge base to enhance tracking performance. The system is comprised of a centroid tracker front end that supplies segmented image features to a data reduction algorithm and subsequently to a track processor operating under one of two modes, learn or track. While in learn mode, a human operator provides identification cues for membership in a long-term storage relation within a knowledge base. In track mode the system operates autonomously with a cognitive processing algorithm replacing the human operator. The autonomous system functions as a correlation tracker by comparing processed input to data that was stored in the knowledge base during learn mode. Results determined from the classification generate tracker directives that either enhance the current track or cause the tracker to search for alternate targets based on a global target tracking list.