A Transparent Motion Aftereffect Contingent on Binocular Disparity

Perception ◽  
1994 ◽  
Vol 23 (10) ◽  
pp. 1181-1188 ◽  
Author(s):  
Frans A J Verstraten ◽  
Reinder Verlinde ◽  
R Eric Fredericksen ◽  
Wim A van de Grind
Keyword(s):  
Binocular Disparity ◽  
Motion Aftereffect ◽  
Stimulus Configuration ◽  
Retinal Disparity ◽  
Transparent Motion ◽  
Stationary Test ◽  
Vector Sum ◽  
Moving Patterns

Under transparent motion conditions overlapping surfaces are perceived simultaneously, each with its own direction. The motion aftereffect (MAE) of transparent motion, however, is unidirectional and its direction is opposite to that of a sensitivity-weighted vector sum of both inducing vectors. Here we report a bidirectional and transparent MAE contingent on binocular disparity. Depth (from retinal disparity) was introduced between two patterns. A fixation dot was presented at zero disparity, that is, located between the two adaptation patterns. After adaptation to such a stimulus configuration testing was carried out with two stationary test patterns at the same depths as the preceding moving patterns. For opposite directions a clear transparent MAE was perceived. However, if the adaptation directions were orthogonal the chance of a transparent MAE being perceived decreased substantially. This was subject dependent. Some subjects perceived an orthogonal transparent MAE whereas others saw the negative vector sum—an integrated MAE. In addition the behaviour of the MAE when the distance in depth between adapting and test patterns was increased was investigated: it was found that the visibility of the MAE then decreased. Visibility is defined in this paper as: (i) the percentage of the trials in which MAEs are perceived and (ii) the average MAE duration. Both measures decreased with increasing distance. The results suggest that segregation and integration may be mediated by direction-tuned channels that interact with disparity-tuned channels.

scholarly journals A new form of motion aftereffect in transparent motion adaptation

2011 ◽  
Vol 11 (11) ◽  
pp. 702-702
Author(s):  
A. L. F. Lee ◽  
H. Lu
Keyword(s):  
Motion Aftereffect ◽  
Motion Adaptation ◽  
Transparent Motion ◽  
New Form

The Effect of Stationary Patterns on Adaptation for Movement: Evidence for Inhibitory Interaction

Perception ◽  
1975 ◽  
Vol 4 (3) ◽  
pp. 311-329 ◽  
Author(s):  
John E W Mayhew
Keyword(s):  
Test Pattern ◽  
Threshold Elevation ◽  
Inhibitory Interaction ◽  
Movement Aftereffect ◽  
Specific Adaptation ◽  
Neural Processes ◽  
Stationary Test ◽  
Simple Movement ◽  
Moving Patterns ◽  
Moving Pattern

Contingent movement aftereffects (CMAEs) can be demonstrated by adapting to a red pattern rotating clockwise (cw) alternating with a green pattern rotating counterclockwise (ccw). After 5 min subjects typically report stationary test patterns as apparently rotating clockwise when they are green and counterclockwise when they are red. Also, luminance thresholds for motion now depend on both the colour and direction of the moving pattern. The thresholds for red—cw and green—ccw motion will be relatively greater than for the opposite colour motion pairings. This is called contingent threshold elevation. When stationary dots the same colour as the moving patterns are added to the adapting stimuli, subjects report weak CMAEs but no contingent threshold elevation can be demonstrated. When stationary dots opposite in colour to the moving patterns are added to the adapting stimuli, neither CMAEs nor contingent threshold elevation can be demonstrated. And yet colour specific adaptation does occur, and can be demonstrated in the colour specificity of the simple movement aftereffect. When stationary dots are added to the adapting pattern, the simple movement aftereffect though reduced, is greatest on a test pattern of the same colour as the moving dots. These findings suggest that the CMAE, contingent threshold elevation, and the colour specificity of the movement aftereffect involves neural processes differentially sensitive to the presence of stationary patterns.

scholarly journals Does Binocular Disparity Facilitate the Detection of Transparent Motion?

Perception ◽  
10.1068/p2742 ◽  
1999 ◽  
Vol 28 (2) ◽  
pp. 183-191 ◽  
Author(s):  
Paul B Hibbard ◽  
Mark F Bradshaw
Keyword(s):  
Binocular Disparity ◽  
Transparent Motion

Movement Aftereffects Contingent on Binocular Disparity

Perception ◽  
1974 ◽  
Vol 3 (2) ◽  
pp. 153-168 ◽  
Author(s):  
S M Anstis ◽  
J P Harris
Keyword(s):  
Binocular Disparity ◽  
Total Duration ◽  
Test Field ◽  
Movement Aftereffect ◽  
Elapsed Time ◽  
Uncrossed Disparity ◽  
Stationary Test ◽  
Time Movement

Five subjects adapted for 30 min to a textured disc lying in front of the fixation point with 0·1 deg(1) crossed disparity, which rotated clockwise at 4 rev/min, alternating with a disc behind the fixation point, with 0·1 deg of arc uncrossed disparity, which rotated anticlockwise. A stationary test field then appeared to rotate anticlockwise when it lay in front of the fixation point, and clockwise when it lay behind. Conversely, a test field in the plane of fixation briefly appeared to lie a few millimetres behind the fixation plane when it rotated clockwise, and in front when it rotated anticlockwise. The movement aftereffect contingent on disparity reappeared each time the test disparity was reversed, but the total duration of each successive aftereffect in the series decreased exponentially with elapsed time. Movement aftereffects contingent on disparity were very much stronger than those contingent on colour and won out over them when disparity was pitted against colour.

Binocular Disparity and Head-Up Displays

1980 ◽  
Vol 22 (4) ◽  
pp. 435-444 ◽  
Author(s):  
Christopher P. Gibson
Keyword(s):  
Visual System ◽  
Binocular Disparity ◽  
Spatial Location ◽  
Retinal Disparity ◽  
Visual Discomfort ◽  
Perceptual Effect ◽  
Depth Cues

Collimation errors present in displays such as the head-up display (HUD) will produce retinal disparity on the retinae of the observer and will have the effect of altering the spatial location of the display. It is apparent that this can, in some instances, give rise to visual discomfort. Psychophysical methods were used to examine the sensitivity and the tolerances of the visual system to binocular disparity in HUDs. It was shown that, when left to their own devices, subjects preferred a small positive disparity to exist between the HUD and the outside world and that even small amounts of negative disparity can have a disturbing perceptual effect. The effect is discussed in relation to the contradictory depth cues which can exist in this kind of electro-optical display.

scholarly journals The motion aftereffect of transparent motion: Two temporal channels account for perceived direction

2005 ◽  
Vol 45 (4) ◽  
pp. 403-412 ◽  
Author(s):  
David Alais ◽  
Frans A.J. Verstraten ◽  
David C. Burr
Keyword(s):  
Motion Aftereffect ◽  
Transparent Motion

Strength of Motion Aftereffect Varies with Segregation of Test Field and Surround

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 64-64 ◽  
Author(s):  
J P Harris ◽  
D Sullivan
Keyword(s):  
Visual Motion ◽  
Test Pattern ◽  
Motion Aftereffect ◽  
Auditory Signal ◽  
Test Field ◽  
Rectangular Window ◽  
Stationary Test ◽  
Two Measures ◽  
Motion Detectors ◽  
Good Agreement

It is widely accepted that the motion aftereffect (MAE) results from the adaptation of visual motion detectors. However, recent work suggests that how the effects of that adaptation are expressed (the nature of the perceived MAE) depends on the nature of the inducing and test fields. We investigated how the strength of the MAE varied with the nature of the boundary between the test field and the surround. The surround (18.5 deg wide × 13.5 deg high) to the adapting and test fields was an area of vertical square-wave grating of 0.7 cycle deg−1. During adaptation, vertical stripes of the same spatial frequency as the background moved horizontally at a speed of 2 deg s−1 for 14 s within a central rectangular window of 9.7 deg wide × 7.6 deg high. At the end of adaptation, one of six different test fields was presented in the central window. In three of these, the stationary test stripes were exactly aligned with the surrounding stripes, and in the other three they were offset by half a stripe width. For two of these conditions (one aligned, one offset), a black outline was drawn around the edge of the adapting window (and so was visible only where it crossed white areas), and for two others (one aligned, one offset) the outline was red, and so visible in its entirety. The strength of MAEs in twelve subjects was assessed both by ratings at an auditory signal which occurred 0.5 s after the end of adaptation and also by measurement of their durations. There was good agreement between these two measures. MAEs were significantly stronger on the offset than on the aligned test fields. The presence of an outline increased MAE strength compared with no outline, but these outline effects were much weaker than those of offsetting the test stripes from the surround. We suggest that the MAE depends in part on the presence of a visually separable test pattern to which motion may be allocated.

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.

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