scholarly journals A new variant of the barberpole effect: Psychophysical data and computer simulations

Psihologija ◽  
2002 ◽  
Vol 35 (3-4) ◽  
pp. 209-223
Author(s):  
Dejan Todorovic
Keyword(s):  
Receptive Fields ◽  
Vertical Component ◽  
Parallel Line ◽  
Random Fluctuation ◽  
Final State ◽  
Motion Direction ◽  
Weak Preference ◽  
New Variant ◽  
Direction Sensitivity ◽  
Perceived Motion

The classic barberpole effect shows that perceived direction of motion of parallel line segments depends on the orientation of the frame defined by segment end points. A stimulus configuration was created by crossing two oblique barberpoles. Perceived motion in the crossed portion of the configuration is bi-stable, alternating between two oblique directions defined by the two component barberpoles. Ratings of dominance of perceived motion direction in the crossed portion of two barberpoles of different width and orientation revealed a strong preference for the wider component barberpole and a weak preference for the nearer-to-vertical component barberpole. A network model is presented in which each unit inhibits units with different direction sensitivity and co-extensive receptive fields, and excites units with equal direction sensitivity and neighboring receptive fields. Simulations of the temporal evolution of the spatial activity profile exhibit the effect of barberpole width and the bi-stability of percepts. Fatigue of highly adapted units enables the gradual emergence of non-adapted units. Small initial variations can lead to profound differences in the final state of the system, explaining the quasi-random fluctuation between the two perceptual variants.

Auditory Motion Induces Directionally Dependent Receptive Field Shifts in Inferior Colliculus Neurons

1998 ◽  
Vol 79 (4) ◽  
pp. 2040-2062 ◽  
Author(s):  
Willard W. Wilson ◽  
William E. O'Neill
Keyword(s):  
Receptive Field ◽  
Inferior Colliculus ◽  
Apparent Motion ◽  
Target Location ◽  
Receptive Fields ◽  
Silent Interval ◽  
Auditory Motion ◽  
Motion Direction ◽  
Motion Sequence ◽  
And Shifts

Wilson, Willard W. and William E. O'Neill. Auditory motion induces directionally dependent receptive field shifts in inferior colliculus neurons. J. Neurophysiol. 79: 2040–2062, 1998. This research focused on the response of neurons in the inferior colliculus of the unanesthetized mustached bat, Pteronotus parnelli, to apparent auditory motion. We produced the apparent motion stimulus by broadcasting pure-tone bursts sequentially from an array of loudspeakers along horizontal, vertical, or oblique trajectories in the frontal hemifield. Motion direction had an effect on the response of 65% of the units sampled. In these cells, motion in opposite directions produced shifts in receptive field locations, differences in response magnitude, or a combination of the two effects. Receptive fields typically were shifted opposite the direction of motion (i.e., units showed a greater response to moving sounds entering the receptive field than exiting) and shifts were obtained to horizontal, vertical, and oblique motion orientations. Response latency also shifted as a function of motion direction, and stimulus locations eliciting greater spike counts also exhibited the shortest neural latency. Motion crossing the receptive field boundaries appeared to be both necessary and sufficient to produce receptive field shifts. Decreasing the silent interval between successive stimuli in the apparent motion sequence increased both the probability of obtaining a directional effect and the magnitude of receptive field shifts. We suggest that the observed directional effects might be explained by “spatial masking,” where the response of auditory neurons after stimulation from particularly effective locations in space would be diminished. The shift in auditory receptive fields would be expected to shift the perceived location of a moving sound and may explain shifts in localization of moving sources observed in psychophysical studies. Shifts in perceived target location caused by auditory motion might be exploited by auditory predators such as Pteronotus in a predictive tracking strategy to capture moving insect prey.

Computation of motion direction by quail retinal ganglion cells that have a nonconcentric receptive field

2000 ◽  
Vol 17 (2) ◽  
pp. 263-271 ◽  
Author(s):  
HIROYUKI UCHIYAMA ◽  
TAKAHIDE KANAYA ◽  
SHOICHI SONOHATA
Keyword(s):  
Receptive Field ◽  
Retinal Ganglion Cells ◽  
Japanese Quail ◽  
Ganglion Cells ◽  
Receptive Fields ◽  
Object Motion ◽  
Directional Selectivity ◽  
Retinal Ganglion ◽  
Motion Direction ◽  
Neuronal Mechanisms

One type of retinal ganglion cells prefers object motion in a particular direction. Neuronal mechanisms for the computation of motion direction are still unknown. We quantitatively mapped excitatory and inhibitory regions of receptive fields for directionally selective retinal ganglion cells in the Japanese quail, and found that the inhibitory regions are displaced about 1–3 deg toward the side where the null sweep starts, relative to the excitatory regions. Directional selectivity thus results from delayed transient suppression exerted by the nonconcentrically arranged inhibitory regions, and not by local directional inhibition as hypothesized by Barlow and Levick (1965).

scholarly journals Choice-induced biases in perception

2016 ◽  
Author(s):  
Long Luu ◽  
Alan A Stocker
Keyword(s):  
Discrimination Task ◽  
Sensory Information ◽  
Motion Direction ◽  
Great Opportunity ◽  
Perceptual Illusion ◽  
Psychophysical Data ◽  
Observer Model ◽  
Discrimination Judgment ◽  
Perceived Motion ◽  
The Brain

AbstractIllusions provide a great opportunity to study how perception is affected by both the observer's expectations and the way sensory information is represented1,2,3,4,5,6. Recently, Jazayeri and Movshon7 reported a new and interesting perceptual illusion, demonstrating that the perceived motion direction of a dynamic random dot stimulus is systematically biased when preceded by a motion discrimination judgment. The authors hypothesized that these biases emerge because the brain predominantly relies on those neurons that are most informative for solving the discrimination task8, but then is using the same neural weighting profile for generating the percept. In other words, they argue that these biases are “mistakes” of the brain, resulting from using inappropriate neural read-out weights. While we were able to replicate the illusion for a different visual stimulus (orientation), our new psychophysical data suggest that the above interpretation is likely incorrect: Biases are not caused by a read-out profile optimized for solving the discrimination task but rather by the specific choices subjects make in the discrimination task on any given trial. We formulate this idea as a conditioned Bayesian observer model and show that it can explain the new as well as the original psychophysical data. In this framework, the biases are not caused by mistake but rather by the brain's attempt to remain ‘self-consistent’ in its inference process. Our model establishes a direct connection between the current perceptual illusion and the well-known phenomena of cognitive consistency and dissonance9,10.

scholarly journals Seeing Global Motion in a Random Dot Image Sequence

i-Perception ◽  
2020 ◽  
Vol 11 (5) ◽  
pp. 204166952096110
Author(s):  
Chien-Chung Chen ◽  
Hiroshi Ashida ◽  
Xirui Yang ◽  
Pei-Yin Chen
Keyword(s):  
Random Walk ◽  
Image Sequence ◽  
Image Sequences ◽  
Spatial Context ◽  
Coherent Motion ◽  
Global Motion ◽  
Motion Direction ◽  
Motion Energy ◽  
Random Image ◽  
Perceived Motion

In a stimulus with multiple moving elements, an observer may perceive that the whole stimulus moves in unison if (a) one can associate an element in one frame with one in the next (correspondence) and (b) a sufficient proportion of correspondences signal a similar motion direction (coherence). We tested the necessity of these two conditions by asking the participants to rate the perceived intensity of linear, concentric, and radial motions for three types of stimuli: (a) random walk motion, in which the direction of each dot was randomly determined for each frame, (b) random image sequence, which was a set of uncorrelated random dot images presented in sequence, and (c) global motion, in which 35% of dots moved coherently. The participants perceived global motion not only in the global motion conditions but also in the random image sequences, though not in random walk motion. The type of perceived motion in the random image sequences depends on the spatial context of the stimuli. Thus, although there is neither a fixed correspondence across different frames nor a coherent motion direction, observers can still perceive global motion in the random image sequence. This result cannot be explained by motion energy or local aperture border effects.

Effect of Element Size on Stereoscopic Apparent Motion

2003 ◽  
Vol 96 (3_suppl) ◽  
pp. 1187-1193 ◽  
Author(s):  
Hiroyuki Ito
Keyword(s):  
Motion Perception ◽  
Apparent Motion ◽  
Forced Choice ◽  
Spatial Displacement ◽  
Motion Direction ◽  
Element Size ◽  
Random Dot Stereograms ◽  
Perceived Motion

Spatial displacement limits in stereoscopic (cyclopean) apparent motion were measured from sequentially presented two-frame random-depth configurations. Each depth configuration was defined by stereoscopically near or far elements of various sizes. The limits were compared with those in luminance-defined apparent motion. The subject's task was 2-alternative forced-choice of the perceived motion direction of the sequentially presented two-frame random-dot stereograms. The spatial displacement limit below which correct motion perception arose with stereoscopic configurations was larger in proportion to increases in size of elements. The values were almost consistent with those measured by luminance-defined configurations with the same element sizes. This result suggests that the strategy for discrimination of motion direction of random configurations is similar in both stereoscopic and luminance-defined apparent motion.

scholarly journals The interaction between orientation and motion signals in moving oriented Glass patterns

2017 ◽  
Vol 34 ◽  
Author(s):  
ANDREA PAVAN ◽  
LUCY M. BIMSON ◽  
MARTIN G. GALL ◽  
FILIPPO GHIN ◽  
GEORGE MATHER
Keyword(s):  
Excitatory Input ◽  
Motion Sensors ◽  
Motion Information ◽  
Spatial Motion ◽  
Dipole Orientation ◽  
Motion Direction ◽  
Oriented Texture ◽  
Orientation Information ◽  
Glass Patterns ◽  
Perceived Motion

AbstractPrevious psychophysical evidence suggests that motion and orientation processing systems interact asymmetrically in the human visual system, with orientation information having a stronger influence on the perceived motion direction than vice versa. To investigate the mechanisms underlying this motion-form interaction we used moving and oriented Glass patterns (GPs), which consist of randomly distributed dot pairs (dipoles) that induce the percept of an oriented texture. In Experiment 1 we varied the angle between dipole orientation and motion direction (conflict angle). In separate sessions participants either judged the orientation or motion direction of the GP. In addition, the spatiotemporal characteristics of dipole motion were manipulated as a way to limit (Experiment 1) or favor (Experiment 2) the availability of orientation signals from motion (motion streaks). The results of Experiment 1 showed that apparent GP motion direction is attracted toward dipole orientation, and apparent GP orientation is repulsed from GP motion. The results of Experiment 2 showed stronger repulsion effects when judging the GP orientation, but stronger motion streaks from the GP motion can dominate over the signals provided by conflicting dipole orientation. These results are consistent with the proposal that two separate mechanisms contribute to our perception of stimuli which contain conflicting orientation and motion information: (i) perceived GP motion is mediated by spatial motion-direction sensors, in which signals from motion sensors are combined with excitatory input from orientation-tuned sensors tuned to orientations parallel to the axis of GP motion, (ii) perceived GP orientation is mediated by orientation-tuned sensors which mutually inhibit each other. The two mechanisms are revealed by the different effects of conflict angle and dipole lifetime on perceived orientation and motion direction.

A New Variant of the Ouchi Illusion Reveals Fourier-Component-Based Processing

Perception ◽  
10.1068/p5060 ◽  
2005 ◽  
Vol 34 (4) ◽  
pp. 381-390 ◽  
Author(s):  
Hiroshi Ashida ◽  
Akiyoshi Kitaoka ◽  
Kenzo Sakurai
Keyword(s):  
Line Element ◽  
Physiological Mechanism ◽  
Fourier Component ◽  
Quantitative Prediction ◽  
Checkerboard Pattern ◽  
Two Dimensional ◽  
Local Motion ◽  
Motion Direction ◽  
One Dimensional ◽  
New Variant

We report that anomalous motion illusion in a new variant of the Ouchi figure is well predicted by the strength of its Fourier fundamentals and harmonics. The original Ouchi figure consists of a rectangular checkerboard pattern surrounded by an orthogonal rectangular checkerboard pattern, in which illusory relative motion between the two regions is perceived. Although this illusion has been explained in terms of biases in integrating one-dimensional motion signals to determine the two-dimensional motion direction, the physiological mechanism has not been clarified. With our new stimuli, which consisted of thin lines instead of rectangles, we found that the perceived illusion is drastically reduced when the position of each line element is randomly shifted. This is not predicted by simple models of local motion integration along the visible edges. We demonstrate that the relative amplitude of the relevant Fourier fundamentals and harmonics leads to a quantitative prediction. Our analysis was successfully applied to other variants of the Ouchi figure (Khang and Essock 1997 Perception26 585–597), closely predicting the reported rating. The results indicate that the underlying physiological mechanism is sensitive to the Fourier components of the stimuli rather than the visible edges.

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