Motion Parallax Driven by Head Movements: Conditions for Visual Stability, Perceived Depth, and Perceived Concomitant Motion

Perception ◽  
10.1068/p5221 ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 477-490 ◽  
Author(s):  
Hiroshi Ono ◽  
Hiroyasu Ujike

Yoking the movement of the stimulus on the screen to the movement of the head, we examined visual stability and depth perception as a function of head-movement velocity and parallax. In experiment 1, for different head velocities, observers adjusted the parallax to find (a) the depth threshold and (b) the concomitant-motion threshold. Between these thresholds, depth was seen with no perceived motion. In experiment 2, for different head velocities, observers adjusted the parallax to produce the same perceived depth. A slower head movement required a greater parallax to produce the same perceived depth as faster head movements. In experiment 3, observers reported the perceived depth for different parallax magnitudes. Perceived depth covaried with smaller parallax without motion perception, but began to decrease with larger parallax and concomitant motion was seen. Only motion was seen with the larger parallax.

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 163-163
Author(s):  
H Ujike ◽  
S Saida

Motion parallax has been shown to be a principal cue for depth perception under monocular viewing. The simulated depth of stimuli in previous studies has been constant in both magnitude and direction. In the present study we addressed the question how the visual system detects parallactic depth change. To answer this we investigated the temporal characteristics of parallactic depth change and the effect of a motion signal on them. The stimulus consisted of four bands of 15-cycle sinusoidal gratings and parallactic depth was simulated between each band. In experiment 1, we measured the amount of perceived depth change with different frequencies (0.125 to 10 Hz) of simulated depth change and with different velocities (2.5 to 40 cm s−1) of head movements. The result showed the perceived depth change decreased with frequency of depth change, and it increased with head velocity when the frequency was constant. In experiment 2, we measured the motion threshold with different velocities of head movement. The result showed the threshold was constant across different head velocities. In experiment 3, we measured the amount of perceived depth using apparent motion stimuli with the head moving. The result showed depth decreased with SOA of apparent motion stimuli, but there was no effect of different head velocities. The results of these three experiments indicate that parallactic depth change is determined by the duration of simulated depth, which corresponds to the integration time of motion, as well as by the extent of head movement. We conclude that parallactic depth is integrated in two stages: first, integration of motion and, second, integration of motion parallax.


Perception ◽  
2019 ◽  
Vol 48 (4) ◽  
pp. 338-345
Author(s):  
Soyogu Matsushita ◽  
Hiroshi Ono

We examined whether the thresholds of motion and depth perception produced by motion parallax could be specified by the concept of a disparity gradient. We manipulated both the motion parallax amplitude and the angular separation of two dots and calculated the percentages of trials in which participants perceived motion or depth. The results showed that the amplitude of motion parallax for the threshold increased as the separation became larger with the gradients of 0.023, 0.072, and 0.430 for the lower depth, the lower motion, and the upper depth thresholds, respectively. These findings indicate that the gradient is a useful concept to specify the motion and depth thresholds together rather than parallax amplitude alone.


2001 ◽  
Vol 41 (22) ◽  
pp. 2835-2843 ◽  
Author(s):  
Hiroyasu Ujike ◽  
Hiroshi Ono

i-Perception ◽  
10.1068/ic393 ◽  
2011 ◽  
Vol 2 (4) ◽  
pp. 393-393
Author(s):  
Masahiro Ishii ◽  
Masashi Fujita ◽  
Masayuki Sato

Perception ◽  
10.1068/p5232 ◽  
2005 ◽  
Vol 34 (10) ◽  
pp. 1263-1273 ◽  
Author(s):  
Hiroshi Ono ◽  
Nicholas J Wade

Motion parallax was described as a cue to depth over 300 years ago and as producing apparent motion over 150 years ago. In recent years, experimental interest in motion parallax has increased, following the rediscovery of the idea that stimulus motion can be yoked to head movement. We compare the historical descriptions with some contemporary research, which indicates how depth and motion perception are dependent on the conditions of stimulation.


2000 ◽  
Vol 9 (6) ◽  
pp. 638-647 ◽  
Author(s):  
Hanfeng Yuan ◽  
W. L. Sachtler ◽  
Nat Durlach ◽  
Barbara Shinn-Cunningham

Experiments were conducted to determine how the ability to detect and discriminate head-motion parallax depth cues is degraded by time delays between head movement and image update. The stimuli consisted of random-dot patterns that were programmed to appear as one cycle of a sinusoi dal grating when the subject's head moved. The results show that time delay between head movement and image update has essentially no effect on the ability to discrimi nate between two such gratings with different depth char acteristics when the delay is less than or equal to roughly 265 ms.


2020 ◽  
Vol 27 (2) ◽  
pp. 206-225 ◽  
Author(s):  
Sirisilp Kongsilp ◽  
Matthew N. Dailey

Since one of the most important aspects of a Fish Tank Virtual Reality (FTVR) system is how well it provides the illusion of depth to users, we present a study that evaluates users' depth perception in FTVR systems using three tasks. The tasks are based on psychological research on human vision and depth judgments common in VR applications. We find that participants do not perform well under motion parallax cues only, when compared with stereo only or a combination of both kinds of cues. Measurements of participants' head movement during each task prove valuable in explaining the experimental findings. We conclude that FTVR users rely on stereopsis for depth perception in FTVR environments more than they do on motion parallax, especially for tasks requiring depth acuity.


1999 ◽  
Vol 58 (3) ◽  
pp. 170-179 ◽  
Author(s):  
Barbara S. Muller ◽  
Pierre Bovet

Twelve blindfolded subjects localized two different pure tones, randomly played by eight sound sources in the horizontal plane. Either subjects could get information supplied by their pinnae (external ear) and their head movements or not. We found that pinnae, as well as head movements, had a marked influence on auditory localization performance with this type of sound. Effects of pinnae and head movements seemed to be additive; the absence of one or the other factor provoked the same loss of localization accuracy and even much the same error pattern. Head movement analysis showed that subjects turn their face towards the emitting sound source, except for sources exactly in the front or exactly in the rear, which are identified by turning the head to both sides. The head movement amplitude increased smoothly as the sound source moved from the anterior to the posterior quadrant.


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