Assessment of Depth Perception in Cats

Perception ◽  
1979 ◽  
Vol 8 (4) ◽  
pp. 389-396 ◽  
Author(s):  
Donald E Mitchell ◽  
Martin Kaye ◽  
Brian Timney
Keyword(s):  
Depth Perception ◽  
Binocular Viewing ◽  
Monocular Viewing

A behavioural method is described for the assessment of depth perception of kittens. Measurement is made of the smallest separation in depth that can be discriminated between two adjacent stimuli under both monocular and binocular viewing conditions. Normal animals can discriminate much smaller separations in depth when using two eyes than with monocular viewing, implying the presence of a cue to depth that is uniquely available with binocular viewing. The test provides a quick and reliable way of screening animals for stereopsis.

Binocular and Monocular Coincidence-Anticipation Timing Responses

2018 ◽  
pp. 186-199
Keyword(s):  
Standard Deviation ◽  
Binocular Viewing ◽  
Monocular Viewing ◽  
Stimulus Velocity ◽  
Time To Collision ◽  
Dominant Eye ◽  
Response Errors ◽  
And Training

Background Coincidence-anticipation timing (CAT) responses require individuals to determine the time at which an approaching object will arrive at (time to collision) or pass by (time to passage) the observer and to then make a response coincident with this time. Previous studies suggest that under some conditions time to collision estimates are more accurate when binocular and monocular cues are combined. The purpose of this study was to compare binocular and monocular coincidence anticipation timing responses with the Bassin Anticipation Timer, a device for testing and training CAT responses. Methods: Useable data were obtained from 20 participants. Coincidence-anticipation timing responses were determined using a Bassin Anticipation Timer over a range of approaching stimulus linear velocities of 5 to 40mph. Participants stood to the left side of the Bassin Anticipation track. The track was below eye height. The participants’ task was to push a button to coincide with arrival of the approaching stimulus at a location immediately adjacent to the participant. CAT responses were made under three randomized conditions: binocular viewing, monocular dominant eye viewing, and monocular non-dominant eye viewing. Results: Signed (constant), unsigned (absolute), and variable (standard deviation) CAT response errors were determined and compared across viewing conditions at each stimulus velocity. There were no significant differences in CAT errors between the conditions at any stimulus velocity, although the differences in signed and unsigned errors approached significance at 40mph. Conclusions: The addition of binocular cues did not result in a reduction in coincidence anticipation timing response errors compared to the monocular viewing conditions. There were no differences in CAT response errors between the monocular dominant eye viewing and monocular non-dominant eye viewing conditions.

Gaze-Accuracy during Monocular and Binocular Viewing

Perception ◽  
1997 ◽  
Vol 26 (1_suppl) ◽  
pp. 371-371
Author(s):  
R M Steinman ◽  
T I Forofonova ◽  
J Epelboim ◽  
M R Stepanov
Keyword(s):  
Eye Movements ◽  
Affirmative Answer ◽  
Binocular Viewing ◽  
Control Limit ◽  
Monocular Viewing ◽  
Gaze Control ◽  
The Gaze

Epelboim et al (1996 Vision Research35 3401 – 3422) reported that cyclopean gaze errors were smaller than either eye's during tapping and looking-only tasks. This raised two questions: (i) does cyclopean gaze accuracy require binocular input, and (ii) when only one eye sees, is its gaze more accurate than the patched eye's? Most oculomotorists probably expect an affirmative answer to both. Neither expectation was fulfilled. The Maryland Revolving Field Monitor recorded, with exceptional accuracy, eye movements of two unrestrained subjects tapping or only looking, in a specified order, at four randomly positioned LEDs, with monocular or binocular viewing. Subjects either tapped with their finger tips naturally, or unnaturally via a rod (2 mm diameter, 1.5 cm long), glued to a sewing thimble. Instructions were to be fast, but make no order errors. With binocular viewing, cyclopean gaze accuracy was best during looking-only. During natural tapping, gaze errors increased, becoming no smaller than success required. Both tasks were learned equally fast, but as expected, the younger subject (aged 27 years) performed ∼ 40% faster than the older subject (aged 69 years). Unnatural, monocular viewing produced odd results, eg cyclopean gaze error was smallest when only one eye could see in some conditions. Only the older subject served in the unnatural tapping task because the younger's errors were too close to his gaze control limit. The older subject, who was suitable, reduced his cyclopean gaze error by 56%, from 1.4 to 0.9 deg. These results support our claim that the gaze error allowed is adjusted to the visuomotor demands of different tasks.

Examining the effects of stimulus location and monocular-binocular viewing on the sound-induced flash illusion

2020 ◽  
Author(s):  
Jenna Cao ◽  
Nickolas F. Goenadi ◽  
Emma L. Neto ◽  
Isabel R. Shapiro
Keyword(s):  
Visual Stimulus ◽  
Representative Sample ◽  
Stimulus Location ◽  
Audiovisual Integration ◽  
Binocular Viewing ◽  
Monocular Viewing ◽  
Viewing Condition ◽  
Integration Model ◽  
Future Studies ◽  
Data Analyses

The present study aimed to determine whether stimulus location (central or peripheral) or eye viewing condition (binocular, dominant monocular, or non-dominant monocular) had a greater magnitude of effect on perception of the sound-induced flash illusion (SIFI). Both the fission illusion (when one flash paired with two beeps is perceived as two flashes) and the fusion illusion (when two flashes paired with one beep are perceived as one flash) were measured in all location and eye viewing conditions. Analyses revealed significant fission and fusion illusions in all conditions. Additionally, we found significant differences in central and peripheral criterion levels that were driven by differences between binocular and monocular viewing conditions. Data analyses demonstrated that location of the visual stimulus had a greater magnitude of effect on the illusion than eye viewing condition. Our findings add to the growing literature supporting the mechanisms underlying central-peripheral eccentricity, and contradict the optimal integration model of the SIFI. The implications of these results would help better our understanding of the SIFI and audiovisual integration. Future studies must be conducted to confirm these results in a more representative sample.

scholarly journals Optokinetic stimulation induces vertical vergence, possibly through a non-visual pathway

2020 ◽  
Vol 10 (1) ◽  
Author(s):  
Tobias Wibble ◽  
Tony Pansell
Keyword(s):  
Eye Movements ◽  
Head Tilt ◽  
Visual Pathway ◽  
Binocular Viewing ◽  
Visual Scene ◽  
Monocular Viewing ◽  
Optokinetic Stimulation ◽  
Eye Tracker ◽  
Ocular Torsion ◽  
Erect Position

Abstract Vertical vergence is generally associated with one of three mechanisms: vestibular activation during a head tilt, induced by vertical visual disparity, or as a by-product of ocular torsion. However, vertical vergence can also be induced by seemingly unrelated visual conditions, such as optokinetic rotations. This study aims to investigate the effect of vision on this latter form of vertical vergence. Eight subjects (4m/4f) viewed a visual scene in head erect position in two different viewing conditions (monocular and binocular). The scene, containing white lines angled at 45° against a black background, was projected at an eye-screen distance of 2 m, and rotated 28° at an acceleration of 56°/s2. Eye movements were recorded using a Chronos Eye-Tracker, and eye occlusions were carried out by placing an infrared-translucent cover in front of the left eye during monocular viewing. Results revealed vergence amplitudes during binocular viewing to be significantly lower than those seen for monocular conditions (p = 0.003), while torsion remained unaffected. This indicates that vertical vergence to optokinetic stimulation, though visually induced, is visually suppressed during binocular viewing. Considering that vertical vergence is generally viewed as a vestibular signal, the findings may reflect a visually induced activation of a vestibular pathway.

Ocular Dominance and Field of View in Monocular and Binocular Optical Systems

1980 ◽  
Vol 22 (2) ◽  
pp. 189-199 ◽  
Author(s):  
Joseph E. Swistak ◽  
John A. Allen
Keyword(s):  
Ocular Dominance ◽  
Binocular Viewing ◽  
Monocular Viewing ◽  
Field Of View ◽  
Optical Systems ◽  
Eye Dominance

An experiment was conducted in which the effects of ocular dominance and field-or-view restrictions on judgments of centricity were examined. Thirty subjects (J 5 left-eye dominant and 15 right-eye dominant) were asked to make midpoint estimates in five experimental tasks under all possible combinations of the following conditions: (a) monocular vs. binocular viewing; (b) total covering of either the dominant or nondominant eye; and (c) field-or-view restrictions of either 20, 40, or 60 degrees. While no evidence was found to suggest that, by themselves, eye dominance or field-or-view restrictions seriously affect observers' midpoint judgments, under monocular viewing conditions the direction of errors by right- and left-eye dominant subjects was found to depend on which eye was the viewing eye (i.e., dominant or nondominant). The results are discussed in terms of previous research in the area, and implications for the design and use of optical systems are presented.

Accuracy Demands, Environmental Structure and Viewing Conditions in Interception Tasks

1998 ◽  
Vol 87 (2) ◽  
pp. 715-721 ◽  
Author(s):  
Alain Kossoko ◽  
Reinoud J. Bootsma
Keyword(s):  
Binocular Vision ◽  
Binocular Viewing ◽  
Monocular Viewing ◽  
Environmental Structure ◽  
Per Se

30 subjects performed an interception task in which the accuracy demands were varied under binocular vs monocular viewing conditions and under different conditions of environmental structure. The pattern of results suggests that the advantage of binocular viewing is due to the concordance of information detected by both eyes rather than to binocular vision per se. The presence of static environmental structure enhances performance because it provides a stable external basis against which optical changes can be evaluated.

Proprioceptive and Retinal Afference Modify Postsaccadic Ocular Drift

1999 ◽  
Vol 82 (2) ◽  
pp. 551-563 ◽  
Author(s):  
Richard F. Lewis ◽  
David S. Zee ◽  
Herschel P. Goldstein ◽  
Barton L. Guthrie
Keyword(s):  
Binocular Viewing ◽  
Monocular Viewing ◽  
Inferior Rectus ◽  
Binocular Fusion ◽  
Viewing Condition ◽  
Retinal Disparity ◽  
Retinal Slip ◽  
New Findings ◽  
Before And After ◽  
Superior Oblique

Drift of the eyes after saccades produces motion of images on the retina (retinal slip) that degrades visual acuity. In this study, we examined the contributions of proprioceptive and retinal afference to the suppression of postsaccadic drift induced by a unilateral ocular muscle paresis. Eye movements were recorded in three rhesus monkeys with a unilateral weakness of one vertical extraocular muscle before and after proprioceptive deafferentation of the paretic eye. Postsaccadic drift was examined in four visual states: monocular viewing with the normal eye (4-wk period); binocular viewing (2-wk period); binocular viewing with a disparity-reducing prism (2-wk period); and monocular viewing with the paretic eye (2-wk period). The muscle paresis produced vertical postsaccadic drift in the paretic eye, and this drift was suppressed in the binocular viewing condition even when the animals could not fuse. When the animals viewed binocularly with a disparity-reducing prism, the drift in the paretic eye was suppressed in two monkeys (with superior oblique pareses) but generally was enhanced in one animal (with a tenotomy of the inferior rectus). When drift movements were enhanced, they reduced the retinal disparity that was present at the end of the saccade. In the paretic-eye–viewing condition, postsaccadic drift was suppressed in the paretic eye and was induced in the normal eye. After deafferentation in the normal-eye–viewing state, there was a change in the vertical postsaccadic drift of the paretic eye. This change in drift was idiosyncratic and variably affected the amplitude and velocity of the postsaccadic drift movements of the paretic eye. Deafferentation of the paretic eye did not affect the postsaccadic drift of the normal eye nor did it impair visually mediated adaptation of postsaccadic drift. The results demonstrate several new findings concerning the roles of visual and proprioceptive afference in the control of postsaccadic drift: disconjugate adaptation of postsaccadic drift does not require binocular fusion; slow, postsaccadic drift movements that reduce retinal disparity but concurrently increase retinal slip can be induced in the binocular viewing state; postsaccadic drift is modified by proprioception from the extraocular muscles, but these modifications do not serve to minimize retinal slip or to correct errors in saccade amplitude; and visually mediated adaptation of postsaccadic drift does not require proprioceptive afference from the paretic eye.

The Moon Illusion: A Test of the Vestibular Hypothesis under Monocular Viewing Conditions

1977 ◽  
Vol 45 (3_suppl) ◽  
pp. 1127-1130 ◽  
Author(s):  
David S. Carter
Keyword(s):  
Depth Perception ◽  
Real Life ◽  
Vestibular Function ◽  
Forced Choice ◽  
Monocular Viewing ◽  
The Moon ◽  
Moon Illusion ◽  
The Real ◽  
The Poor

The results of earlier monocular experiments on the moon illusion have been either negative or confounded. To test the role of vestibular function, 24 subjects made forced-choice distance comparisons between stimuli mounted in translucent tubes. The stimulus tube for standard distance could be positioned in three viewing angles (45° up, horizontal, and 45° down). A comparison tube adjustable for distance was mounted horizontally. There was a greater perception of depth in the downward looking condition. The relatively weak effects are discussed in terms of a two-hypothesis explanation of the real-life moon illusion and the poor cues for depth perception in monocular viewing.

Disparity-induced and blur-induced convergence eye movement and accommodation in the monkey

1986 ◽  
Vol 55 (5) ◽  
pp. 896-914 ◽  
Author(s):  
B. G. Cumming ◽  
S. J. Judge
Keyword(s):  
Eye Movement ◽  
Dimensional Space ◽  
Dynamic Control ◽  
Three Dimensional ◽  
Open Loop ◽  
Binocular Viewing ◽  
Monocular Viewing ◽  
Target Movement ◽  
Low Frequencies ◽  
First Case

The dynamics of vergence eye movement and of ocular accommodation were studied in two monkeys trained to track a haploscopically presented target that appeared to move in depth. The target was presented under four conditions: monocular viewing, normal binocular viewing, accommodation-open-loop binocular viewing, and "conflict" viewing, in which the accommodation and vergence stimuli did not correspond to those produced by any real target in three-dimensional space. The first and third conditions were chosen because in each case only one of the two primary cues that guide accommodation and vergence was operative: blur in the first case and disparity in the third. We usually studied responses to apparent target movement directly toward or away from the right eye, in which accommodation was measured. The latencies of the accommodation responses to steps toward the monkey were approximately 180 and 240 ms in the two monkeys, while in both monkeys the latencies of convergence were approximately 160 ms. Neither the vergence latencies nor the accommodation latencies were greatly different in monocular and binocular viewing. Responses to a sinusoidally moving target (frequencies 0.1-1.2 Hz; peak-to-peak amplitude 0.5-4 diopters or meter-angles) were studied in the first three of the above viewing conditions. In binocular viewing, even with accommodation open-loop, vergence and accommodation showed much smaller phase lags than in monocular viewing. Furthermore, in response to step changes, both vergence and accommodation velocities were higher in binocular viewing than in monocular viewing. Thus the dynamic control of both vergence and accommodation relies predominantly on disparity signals. At low frequencies (0.2 or 0.3 Hz) the monkeys showed only a modest ability to separate their accommodation and vergence responses when presented with conflicting blur and disparity cues. A simple linear calculation based on the data above was used to predict the responses in such situations. The predicted and observed responses were in reasonable agreement.

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