‘Squaring’ is Better at Predicting Plaid Motion than the Vector Average or Intersection of Constraints

Perception ◽  
10.1068/p5349 ◽  
2006 ◽  
Vol 35 (4) ◽  
pp. 469-481 ◽  
Author(s):  
Linda Bowns
1996 ◽  
Vol 13 (4) ◽  
pp. 615-626 ◽  
Author(s):  
David Alais ◽  
Maarten J. van der Smagt ◽  
Frans A. J. Verstraten ◽  
W. A. van de Grind

AbstractAlthough the neural location of the plaid motion coherence process is not precisely known, the middle temporal (MT) cortical area has been proposed as a likely candidate. This claim rests largely on the neurophysiological findings showing that in response to plaid stimuli, a subgroup of cells in area MT responds to the pattern direction, whereas cells in area V1 respond only to the directions of the component gratings. In Experiment 1, we report that the coherent motion of a plaid pattern can be completely abolished following adaptation to a grating which moves in the plaid direction and has the same spatial period as the plaid features (the so-called “blobs”). Interestingly, we find this phenomenon is monocular: monocular adaptation destroys plaid coherence in the exposed eye but leaves it unaffected in the other eye. Experiment 2 demonstrates that adaptation to a purely binocular (dichoptic) grating does not affect perceived plaid coherence. These data suggest several conclusions: (1) that the mechanism determining plaid coherence responds to the motion of plaid features, (2) that the coherence mechanism is monocular, and thus (3), that it is probably located at a relatively low level in the visual system and peripherally to the binocular mechanisms commonly presumed to underlie two-dimensional (2-D) motion perception. Experiment 3 examines the spatial tuning of the monocular coherence mechanism and our results suggest it is broadly tuned with a preference for lower spatial frequencies. In Experiment 4, we examine whether perceived plaid direction is determined by the motion of the grating components or the features. Our data strongly support a feature-based model.


2009 ◽  
Vol 49 (24) ◽  
pp. 2902-2910 ◽  
Author(s):  
Rumi Hisakata ◽  
Ikuya Murakami
Keyword(s):  

2007 ◽  
Vol 47 (3) ◽  
pp. 375-383 ◽  
Author(s):  
Rebecca A. Champion ◽  
Stephen T. Hammett ◽  
Peter G. Thompson
Keyword(s):  

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Yuya Hataji ◽  
Hika Kuroshima ◽  
Kazuo Fujita

Abstract Perceiving motion is a fundamental ability for animals. Primates integrate local 1D motion across orientation and space to compute a rigid 2D motion. It is unknown whether the rule of 2D motion integration is universal within the vertebrate clade; comparative studies of animals with different ecological backgrounds from primates may help answer that question. Here we investigated 2D motion integration in pigeons, using hierarchically structured motion stimuli, namely a barber-pole illusion and plaid motion. The pigeons were trained to report the direction of motion of random dots. When a barber-pole or plaid stimulus was presented, they reported the direction perpendicular to the grating orientation for barber-pole and the vector average of two component gratings for plaid motion. These results demonstrate that pigeons perceive different directions than humans from the same motion stimuli, and suggest that the 2D integrating rules in the primate brain has been elaborated through phylogenetic or ecological factors specific to the clade.


1996 ◽  
Vol 36 (19) ◽  
pp. 3061-3075 ◽  
Author(s):  
BRENT R. BEUTTER ◽  
JEFFREY B. MULLIGAN ◽  
LELAND S. STONE
Keyword(s):  

2014 ◽  
Vol 111 (2) ◽  
pp. 369-378 ◽  
Author(s):  
J. Scott McDonald ◽  
Colin W. G. Clifford ◽  
Selina S. Solomon ◽  
Spencer C. Chen ◽  
Samuel G. Solomon

We used multielectrode arrays to measure the response of populations of neurons in primate middle temporal area to the transparent motion of two superimposed dot fields moving in different directions. The shape of the population response was well predicted by the sum of the responses to the constituent fields. However, the population response profile for transparent dot fields was similar to that for coherent plaid motion and hence an unreliable cue to transparency. We then used single-unit recording to characterize component and pattern cells from their response to drifting plaids. Unlike for plaids, component cells responded to the average direction of superimposed dot fields, whereas pattern cells could signal the constituent motions. This observation provides support for a strong prediction of the Simoncelli and Heeger (1998) model of motion analysis in area middle temporal, and suggests that pattern cells have a special status in the processing of superimposed dot fields.


2010 ◽  
Vol 9 (8) ◽  
pp. 689-689
Author(s):  
R. Hisakata ◽  
I. Murakami
Keyword(s):  

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 20-20
Author(s):  
L Bowns

Yo and Wilson (1992 Vision Research32 135 – 147) reported that Type II plaids move in the vector sum (VS) direction at short durations. Bowns ( Vision Research in press) showed that the result did not generalise to all Type II plaids. Computational analysis of the stimuli revealed an alternative explanation of the result in terms of features that were shown to move in a similar direction to the VS. When features (or VS) moved in a different direction to the intersection of constraints (IOC) the plaids were often perceived to move in the direction of the feature. It is hypothesised that a feature will contribute only when there is sufficient projection of the IOC in the feature direction. The direction of the features and the IOC for the stimuli used by Bowns was computed for a set of plaids that shifted from being perceived in the feature direction to the IOC. If projection is critical, then it should decrease as the stimuli shift direction. This was confirmed. A different set of plaids comprising a feature that moved in the opposite direction to the IOC and varied in terms of the magnitude of projection was presented to subjects in a forced-choice task. The plaids moved as predicted from the hypothesis. These results show a correlation between the amount of projection of the IOC in the direction of a feature and the incidence of perceived movement in the direction of the feature. The hypothesis that perceived movement of a plaid is influenced by the degree of projection of the IOC onto another available motion signal such as a displaced feature is supported.


Sign in / Sign up

Export Citation Format

Share Document