Spatial Induction of Illusory Motion

Perception ◽  
1982 ◽  
Vol 11 (2) ◽  
pp. 187-199 ◽  
Author(s):  
Walter C Gogel ◽  
Bernard W Griffin
Keyword(s):  
Apparent Motion ◽  
Alternative Interpretation ◽  
Test Point ◽  
Illusory Motion ◽  
Frontoparallel Plane ◽  
Continuous Motion ◽  
Motion In Depth ◽  
Physical Motion ◽  
Induced Motion

Induced motion is not limited to continuous motions presented on a frontoparallel plane. Experiments were conducted to investigate several varieties of induced motion to which theories of induced motion must apply. The observer indicated the perceived path of motion of a vertically moving test point to which induced motion at right angles to the physical motion was added by the motion of two inducing points. In experiment 1 all motions (both apparently and physically) were in a frontoparallel plane. It was found that discrete displacement as well as continuous motion of the test and inducing points produced substantial amounts of induction. In experiment 2 the inducing points were continuously moved in stereoscopic distance rather than remaining in an apparent frontoparallel plane. A large amount of apparent motion in depth was found in the vertically moving test point and was interpreted as an induced motion in depth. In experiment 3 an alternative interpretation of the phenomenon of experiment 2, in terms of an apparent vergence for the two images of the test point, was investigated and found to be unlikely. In experiment 4, with all the points moving continuously in a frontoparallel plane, eye motions as well as induced motions were measured, with the observer fixating either the test point or an inducing point. Substantial amounts of induction were obtained under both conditions of fixation. The consequences of these findings for theories of induced motion are discussed.

Measuring Attention Using Induced Motion

Perception ◽  
1989 ◽  
Vol 18 (3) ◽  
pp. 303-320 ◽  
Author(s):  
Walter C Gogel ◽  
Thomas J Sharkey
Keyword(s):  
Apparent Motion ◽  
Test Object ◽  
The Other ◽  
Horizontal Motion ◽  
Involuntary Attention ◽  
Frontoparallel Plane ◽  
Physical Motion ◽  
Test Spot ◽  
Induced Motion

Attention was measured by means of its effect upon induced motion. Perceived horizontal motion was induced in a vertically moving test spot by the physical horizontal motion of inducing objects. All stimuli were in a frontoparallel plane. The induced motion vectored with the physical motion to produce a clockwise or counterclockwise tilt in the apparent path of motion of the test spot. Either a single inducing object or two inducing objects moving in opposite directions were used. Twelve observers were instructed to attend to or to ignore the single inducing object while fixating the test object and, when the two opposing inducing objects were present, to attend to one inducing object while ignoring the other. Tracking of the test spot was visually monitored. The tilt of the path of apparent motion of the test spot was measured by tactile adjustment of a comparison rod. It was found that the measured tilt was substantially larger when the single inducing object was attended rather than ignored. For the two inducing objects, attending to one while ignoring the other clearly increased the effectiveness of the attended inducing object. The results are analyzed in terms of the distinction between voluntary and involuntary attention. The advantages of measuring attention by its effect on induced motion as compared with the use of a precueing procedure, and a hypothesis regarding the role of attention in modifying perceived spatial characteristics are discussed.

scholarly journals Recovery of fMRI Activation in Motion Area MT Following Storage of the Motion Aftereffect

1999 ◽  
Vol 81 (1) ◽  
pp. 388-393 ◽  
Author(s):  
Jody C. Culham ◽  
Sean P. Dukelow ◽  
Tutis Vilis ◽  
Frank A. Hassard ◽  
Joseph S. Gati ◽  
...  
Keyword(s):  
Storage Period ◽  
Motion Aftereffect ◽  
Illusory Motion ◽  
Continuous Motion ◽  
Area Mt ◽  
Perceptual Effect ◽  
Static Test ◽  
Physical Motion ◽  
Stationary Test ◽  
The Relationship

Culham, Jody C., Sean P. Dukelow, Tutis Vilis, Frank A. Hassard, Joseph S. Gati, Ravi S. Menon, and Melvyn A. Goodale. Recovery of fMRI activation in motion area MT following storage of the motion aftereffect. J. Neurophysiol. 81: 388–393, 1999. We used functional magnetic resonance imaging (fMRI) during storage of the motion aftereffect (MAE) to examine the relationship between motion perception and neural activity in the human cortical motion complex MT+ (including area MT and adjacent motion-selective cortex). MT+ responds not only to physical motion but also to illusory motion, as in the MAE when subjects who have adapted to continuous motion report that a subsequent stationary test stimulus appears to move in the opposite direction. In the phenomenon of storage, the total decay time of the MAE is extended by inserting a dark period between adaptation and test phases. That is, when the static test pattern is presented after a storage period equal in duration to the normal MAE, the illusory motion reappears for almost as long as the original effect despite the delay. We examined fMRI activation in MT+ during and after storage. Seven subjects viewed continuous motion, followed either by an undelayed stationary test (immediate MAE) or by a completely dark storage interval preceding the test (stored MAE). Like the perceptual effect, activity in MT+ dropped during the storage interval then rebounded to reach a level much higher than after the same delay without storage. Although MT+ activity was slightly enhanced during the storage period following adaptation to continuous motion (compared with a control sequence in which the adaptation grating oscillated and no MAE was perceived), this enhancement was much less than that observed during the perceptual phenomenon. These results indicate that following adaptation, activity in MT+ is pronounced only with the presentation of an appropriate visual stimulus, during which the MAE is perceived.

scholarly journals Motion Induced Colours Fusion

2019 ◽  
Author(s):  
Ahmad Yousef
Keyword(s):  
Opposite Direction ◽  
Illusory Motion ◽  
Physical Motion ◽  
Optimal Fusion ◽  
Motion Reversal

This article provides evidence that motion has the ability to stably fuse two different colored ‘spatially separated’ stimuli without impairments against the shape of those separated stimuli. Based on our observations, dilated pupils promote colours fusion; and the optimal fusion happens when the stimuli are moving in opposite direction of the actual physical motion, namely, when there is illusory motion reversal. The previous observations suggested that retinal peripheries have main contributions on the present illusion which we called; motion induced colours fusion ‘MICF’ illusion.

4. Motion perception

2017 ◽  
pp. 50-58
Author(s):  
Brian Rogers
Keyword(s):  
Motion Perception ◽  
Apparent Motion ◽  
Time To Contact ◽  
Motion System ◽  
Visual Systems ◽  
Temporal Process ◽  
The World ◽  
Induced Motion ◽  
After Effect ◽  
Spatio Temporal

The ability to detect motion is one of the most important properties of our visual system and the visual systems of nearly every other species. Motion perception is not just important for detecting the movement of objects—both for catching prey and for avoiding predators—but it is also important for providing information about the 3-D structure of the world, for maintaining balance, determining our direction of heading, segregating the scene and breaking camouflage, and judging time-to-contact with other objects in the world. ‘Motion perception’ describes the spatio-temporal process of motion perception and the perceptual effects that tell us something about the characteristics of the motion system: apparent motion, the motion after-effect, and induced motion.

The role of brachial muscle spindle signals in assignment of visual direction

1993 ◽  
Vol 70 (4) ◽  
pp. 1578-1584 ◽  
Author(s):  
P. DiZio ◽  
C. E. Lathan ◽  
J. R. Lackner
Keyword(s):  
Apparent Motion ◽  
Muscle Spindle ◽  
Target Location ◽  
Biceps Brachii ◽  
Visual Target ◽  
Visual Direction ◽  
Muscle Vibration ◽  
Illusory Motion ◽  
The Stability

1. In the oculobrachial illusion, a target light attached to the unseen stationary hand is perceived as moving and changing spatial position when illusory motion of the forearm is elicited by brachial muscle vibration. Our goal was to see whether we could induce apparent motion and displacement of two retinally fixed targets in opposite directions by the use of oculobrachial illusions. 2. We vibrated both biceps brachii, generating illusory movements of the two forearms in opposite directions, and measured any associated changes in perceived distance between target lights on the unseen stationary hands. The stability of visual fixation of one of the targets was also measured. 3. The seen distance between the stationary targets increased significantly when vibration induced an illusory increase in felt distance between the hands, both with binocular and monocular viewing. 4. Subjects maintained fixation accuracy equally well during vibration-induced illusory increases in visual target separation and in a no-vibration control condition. Fixation errors were not correlated with the extent or direction of illusory visual separation. 5. These findings indicate that brachial muscle spindle signals can contribute to an independent representation of felt target location in head-centric coordinates that can be interrelated with a visual representation of target location generated by retinal and oculomotor signals. 6. A model of how these representations are interrelated is proposed, and its relation to other intersensory interactions is discussed.

Induced Motion Considered as a Visually Induced Oculogyral Illusion

Perception ◽  
1986 ◽  
Vol 15 (2) ◽  
pp. 131-138 ◽  
Author(s):  
Robert B Post
Keyword(s):  
Optokinetic Nystagmus ◽  
Optokinetic Stimulation ◽  
Fixation Target ◽  
Illusory Motion ◽  
Reverse Phase ◽  
Ocular Pursuit ◽  
Stationary Stimulus ◽  
Oculogyral Illusion ◽  
Induced Motion ◽  
Perceived Motion

The possibility that nystagmus suppression contributes to illusory motion was investigated by measuring perceived motion of a stationary stimulus following the removal of an optokinetic stimulus. This was done because optokinetic nystagmus typically outlasts cessation of an optokinetic stimulus. Therefore, it would be expected that a stationary fixated stimulus should appear to move after removal of an optokinetic stimulus if illusory motion results from nystagmus suppression. Illusory motion was reported for a stationary fixation target following optokinetic stimulation. This motion was reported first in the same direction as the preceding induced motion, then in the opposite direction. The two directions of illusory motion following optokinetic stimulation are interpreted as resulting from the use of smooth ocular pursuit to suppress first one phase of optokinetic afternystagmus and then the reverse phase. Implications for the origins of induced motion are discussed.

scholarly journals Apparent Motion and the Pulfrich Effect

Perception ◽  
1975 ◽  
Vol 4 (1) ◽  
pp. 3-18 ◽  
Author(s):  
Michael J Morgan ◽  
Peter Thompson
Keyword(s):  
Apparent Motion ◽  
Target Position ◽  
Moving Object ◽  
Continuous Motion ◽  
Depth Effect ◽  
Pairing Effect ◽  
Moving Stimuli ◽  
Pulfrich Effect

The Pulfrich pendulum effect, obtained by viewing a moving object with a filter over one eye, was examined with target stimuli in apparent, rather than continuous, motion. The filter-induced depth effect persisted until a certain degree of intermittency in the presentations of the target was reached, and then it broke down. The degree of intermittency that could be tolerated before the depth effect broke down increased with the density of the filter. It could be argued that the filter determined a shift in the pairing of successive inputs to the eyes, such that the target position in the unfiltered eye was fused with the preceding target position in the filtered eye. However, it appears that the shifted-pairing effect cannot account for the depth impression seen when the target intermittency is less than about 30 ms. Below this value of intermittency a filter can produce a depth effect even when the delay it introduces is small in comparison to the intermittency of the input. The depth effect seen with intermittencies less than 30 ms appears to be of the same magnitude as that obtained with stimuli in continuous motion. It is concluded that a filter can cause two different kinds of depth shift with apparently moving stimuli.

An MEG study into the visual perception of apparent motion in depth

2006 ◽  
Vol 403 (1-2) ◽  
pp. 40-45 ◽  
Author(s):  
Chia-Yen Yang ◽  
Jen-Chuen Hsieh ◽  
Yin Chang
Keyword(s):  
Visual Perception ◽  
Apparent Motion ◽  
Motion In Depth

scholarly journals Nonrigid Illusory Motion in Depth Induced by Translational Motion of Static Images

i-Perception ◽  
10.1068/i0434 ◽  
2011 ◽  
Vol 2 (2) ◽  
pp. 154-158 ◽  
Author(s):  
Sung-Ho Kim ◽  
Thomas V Papathomas
Keyword(s):  
Translational Motion ◽  
Illusory Motion ◽  
Motion In Depth ◽  
Static Images
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