scholarly journals Second-order motion without awareness: Passive adaptation to second-order motion produces a motion aftereffect

2007 ◽  
Vol 47 (4) ◽  
pp. 569-579 ◽  
Author(s):  
David Whitney ◽  
David W. Bressler
Keyword(s):  
Motion Aftereffect ◽  
Second Order

The Duration of the Motion Aftereffect following Adaptation to First-Order and Second-Order Motion

Perception ◽  
1994 ◽  
Vol 23 (10) ◽  
pp. 1211-1219 ◽  
Author(s):  
Timothy Ledgeway ◽  
Andrew T Smith
Keyword(s):  
Motion Aftereffect ◽  
Second Order ◽  
Adaptation Stimulus ◽  
Motion Patterns ◽  
First Order ◽  
Parallel Motion ◽  
Significant Difference ◽  
Cross Adaptation ◽  
Identification Threshold ◽  
Direction Opposite

The magnitude of the motion aftereffect (MAE) obtained following adaptation to first-order or to second-order motion was measured by estimating its duration. The second-order adaptation stimulus was composed of contrast-modulated noise produced by multiplying two-dimensional (2-D) noise by a drifting 1 cycle deg−1 sine grating. The first-order adaptation stimulus was composed of luminance-modulated noise produced by summing, rather than multiplying, the noise and the sine grating. The test stimuli were directionally ambiguous motion patterns composed of either two oppositely drifting sine gratings added to noise or the contrast-modulated equivalent. The adaptation and test stimuli were equated for visibility by presenting them at the same multiple of direction-identification threshold. All possible combinations of first-order and second-order adaptation and test stimuli were examined in order to compare the magnitudes of the MAEs obtained following same adaptation and cross adaptation. After adaptation the test stimuli always appeared to drift coherently in the direction opposite to that of adaptation and the magnitudes of this MAE were very similar for all conditions examined. Statistical analyses of the results showed that there was no significant difference between the durations of the MAEs obtained in the same-adaptation and cross-adaptation conditions. The cross-adaptation effects suggest that either first-order or second-order motion are detected by a common low-level mechanism, or that separate parallel motion-detecting mechanisms exist, for the two types of motion, that interact at some later stage of processing.

scholarly journals Separate motion-detecting mechanisms for first- and second-order patterns revealed by rapid forms of visual motion priming and motion aftereffect

2009 ◽  
Vol 9 (11) ◽  
pp. 27-27 ◽  
Author(s):  
A. Pavan ◽  
G. Campana ◽  
M. Guerreschi ◽  
M. Manassi ◽  
C. Casco
Keyword(s):  
Visual Motion ◽  
Motion Aftereffect ◽  
Second Order

scholarly journals Asymmetric transfer of the dynamic motion aftereffect between first- and second-order cues and among different second-order cues

10.1167/7.8.1 ◽  
2007 ◽  
Vol 7 (8) ◽  
pp. 1 ◽  
Author(s):  
Andrew J. Schofield ◽  
Timothy Ledgeway ◽  
Claire V. Hutchinson
Keyword(s):  
Motion Aftereffect ◽  
Second Order ◽  
Dynamic Motion

scholarly journals Motion Aftereffect of Combined First-Order and Second-Order Motion

Perception ◽  
10.1068/p2899 ◽  
1999 ◽  
Vol 28 (11) ◽  
pp. 1397-1411 ◽  
Author(s):  
Maarten J van der Smagt ◽  
Frans A J Verstraten ◽  
Eric B P Vaessen ◽  
Thomas van Londen ◽  
Wim A van de Grind
Keyword(s):  
Motion Aftereffect ◽  
Second Order ◽  
First Order

Disappearance Voltage Determinations Using a Convergent Beam

1971 ◽  
Vol 29 ◽  
pp. 184-185
Author(s):  
W. L. Bell
Keyword(s):  
Second Order ◽  
Objective Method ◽  
Uniform Thickness ◽  
Rocking Curve ◽  
Crystal Perfection ◽  
Kikuchi Line ◽  
Central Maximum ◽  
Diffraction Patterns ◽  
Convergent Beam ◽  
Beam Technique

Disappearance voltages for second order reflections can be determined experimentally in a variety of ways. The more subjective methods, such as Kikuchi line disappearance and bend contour imaging, involve comparing a series of diffraction patterns or micrographs taken at intervals throughout the disappearance range and selecting that voltage which gives the strongest disappearance effect. The estimated accuracies of these methods are both to within 10 kV, or about 2-4%, of the true disappearance voltage, which is quite sufficient for using these voltages in further calculations. However, it is the necessity of determining this information by comparisons of exposed plates rather than while operating the microscope that detracts from the immediate usefulness of these methods if there is reason to perform experiments at an unknown disappearance voltage.The convergent beam technique for determining the disappearance voltage has been found to be a highly objective method when it is applicable, i.e. when reasonable crystal perfection exists and an area of uniform thickness can be found. The criterion for determining this voltage is that the central maximum disappear from the rocking curve for the second order spot.

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