scholarly journals Cooperation of Accommodation and Motion Detection Mechanisms for Perceiving Multiple Apparent Motion

2005 ◽  
Vol 59 (9) ◽  
pp. 1343-1351 ◽  
Author(s):  
Toshikazu Matsu
Keyword(s):  
Apparent Motion ◽  
Motion Detection ◽  
Detection Mechanisms

Local-Level and Global-Level Form Characteristics in Apparent-Motion Correspondence

Perception ◽  
1995 ◽  
Vol 24 (11) ◽  
pp. 1233-1245 ◽  
Author(s):  
Terry Palmer ◽  
Ovid J L Tzeng ◽  
Sheng He
Keyword(s):  
Apparent Motion ◽  
Motion Detection ◽  
Local Level ◽  
The Other ◽  
Correspondence Problem ◽  
Global Level ◽  
Global Precedence ◽  
Detection Mechanism ◽  
Motion Display ◽  
Motion Correspondence

This study addressed the ‘correspondence’ problem of apparent-motion (AM) perception in which parts of a scene must be matched with counterparts separated in time and space. Given evidence that AM correspondence can be mediated by two distinct processes—one based on a low-level motion-detection mechanism (the Reichardt process), the other involving the tracking of objects by visual attention (the attention-based process)—the present study explored how these processes interact in the perception of apparent motion between hierarchically structured figures. In three experiments, hierarchical figures were presented in a competition motion display so that, across frames, figures were identical at either the local or the global level. In experiment 1 it was shown that AM occurred between locally identical figures. Furthermore, with the Reichardt AM component eliminated in experiments 3 and 4, no preference was obtained for either level. While evidence from previous studies suggests that form extraction for hierarchically structured figures proceeds from the global to the local level, the present results indicate the irrelevance of such a global precedence in AM correspondence. In addition, it is suggested that Reichardt AM correspondence between local elements constrains attention-based AM correspondence between global figures so that both components move in the same direction. It is argued that this constraining process represents an elegant means of achieving AM correspondence between objects undergoing complex transformations.

Two-Stroke Apparent Motion

2017 ◽  
Author(s):  
George Mather
Keyword(s):  
Receptive Field ◽  
Visual System ◽  
Apparent Motion ◽  
Motion Detection ◽  
Human Visual System ◽  
Motion Aftereffect ◽  
Temporal Response ◽  
Motion Sensing ◽  
Receptive Field Properties ◽  
Directional Motion

“Two-stroke” apparent motion is a powerful illusion of directional motion generated by alternating just two animation frames, which occurs when a brief blank interframe interval is inserted at alternate frame transitions. This chapter discusses this illusion, which can be explained in terms of the receptive field properties of motion-sensing neurons in the human visual system. The temporal response of these neurons contains both an excitatory phase and an inhibitory phase; when the timing of the interframe interval just matches the switch in response sign, the illusion occurs. Concepts covered in this chapter include four-stroke as well as two-stroke apparent motion, motion aftereffect, and motion detection.

scholarly journals Tuning for temporal interval in human apparent motion detection

10.1167/7.1.2 ◽  
2007 ◽  
Vol 7 (1) ◽  
pp. 2 ◽  
Author(s):  
Roger J. E. Bours ◽  
Sanne Stuur ◽  
Martin J. M. Lankheet
Keyword(s):  
Apparent Motion ◽  
Motion Detection ◽  
Temporal Interval

Temporal Properties of Apparent Motion in Subjective Figures

Perception ◽  
1988 ◽  
Vol 17 (6) ◽  
pp. 729-736 ◽  
Author(s):  
George Mather
Keyword(s):  
Apparent Motion ◽  
Motion Detection ◽  
Time Interval ◽  
Temporal Properties ◽  
Motion Process ◽  
Motion Percept ◽  
High Level ◽  
Level Process

In ‘Kanizsa’ figures, vivid subjective shapes are seen in the absence of explicit contours to define them. When two or more such figures are presented sequentially, so that the subjective shape occupies different positions, good apparent motion of the shape is usually reported. This motion percept must be mediated by a high-level process, in which form extraction precedes motion detection. Some spatial and temporal properties of this motion process are investigated. A major finding is that motion is only perceived when the time interval between successive frames falls below about 500 ms, and the duration of each frame exceeds about 80 ms.

The Effect of Temporal Phase on the Perception of Apparent Motion

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 68-68
Author(s):  
H S Hock ◽  
K Kogan ◽  
N Lodes
Keyword(s):  
Apparent Motion ◽  
Motion Detection ◽  
Discrimination Task ◽  
Luminance Contrast ◽  
Background Luminance ◽  
Motion Direction ◽  
Direction Discrimination ◽  
Temporal Phase ◽  
The Difference ◽  
Perceived Speed

In classical apparent motion, a spot of light is presented in alternation such that the waveforms describing the varying luminance at each of two locations are 180° out of phase. However, when the luminance variation at each location is approximately sinusoidal, and the perceiver's task is to discriminate motion direction, the optimum temporal phase is 90° (van Santen and Sperling, 1984 Journal of the Optical Society of America A1 451 – 473). The results reported in this study suggest that the optimality of the 90° temporal phase may be specific to the direction-discrimination task. Our experiments were based on a new procedure for measuring classical apparent motion thresholds (Hock, Kogan, and Espinoza, 1996, paper presented at ARVO). Two horizontally displaced dots are presented simultaneously against a darker background. The luminance ( L1) of one dot is always greater than that of the other ( L2), and the luminance values for the dots are exchanged on successive frames. Whether motion or stationarity is perceived depends on the background-relative luminance contrast (BRLC): ( L1- L2) divided by the difference between the average [( L1+ L2)/2] and background luminance. We found in the current study that motion thresholds depend on the temporal phase of the luminance variation at each location (rather than temporal asynchrony); the greater the phase difference (from 41° to 180°) the less the BRLC required for motion perception. At suprathreshold BRLC values, the perceived speed of apparent motion decreases with increased differences in temporal phase. The results are discussed in terms of Reichardt-type motion detection models.

scholarly journals Range perception through apparent image speed in freely flying honeybees

1991 ◽  
Vol 6 (5) ◽  
pp. 519-535 ◽  
Author(s):  
M. V. Srinivasan ◽  
M. Lehrer ◽  
W. H. Kirchner ◽  
S. W. Zhang
Keyword(s):  
Apparent Motion ◽  
Motion Detection ◽  
Longitudinal Axis ◽  
Angular Speed ◽  
Spatial Period ◽  
Narrow Gap ◽  
Optomotor Response ◽  
Feeding Site ◽  
Gap Balancing ◽  
Ocular Tracking

AbstractWhen negotiating a narrow gap, honeybees tend to fly through the middle of the gap, balancing the distances to the boundary on either side. To investigate the basis of this “centering response,” bees were trained to fly through a tunnel on their way to a feeding site and back, while their flight trajectories were filmed from above. The wall on either side carried a visual pattern. When the patterns were stationary vertical gratings, bees tended to fly through the middle of the tunnel, i.e. along its longitudinal axis. However, when one of the gratings was in motion, bees flying in the same direction as the moving grating tended to fly closer to while bees flying in the opposite direction tended to fly closer to the stationary grating. This demonstrates, directly and unequivocally, that flying bees estimate the distances of surfaces in terms of the apparent motion of their images. A series of further experiments revealed that the distance to the gratings is gauged in terms of their apparent angular speeds, and that the visual system of the bee is capable of measuring angular speed largely independently of the spatial period, intensity profile, or contrast of the grating. Thus, the motion-sensitive mechanisms mediating range perception appear to be qualitatively different from those that mediate the well-known optomotor response in insects, or those involved in motion detection and ocular tracking in man.

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