Evidence for Global Motion Interactions between First-Order and Second-Order Stimuli

Perception ◽  
1998 ◽  
Vol 27 (7) ◽  
pp. 761-767 ◽  
Author(s):  
George Mather ◽  
Linda Murdoch
Keyword(s):  
Motion Analysis ◽  
Visual Motion ◽  
Global Analysis ◽  
Image Features ◽  
Second Order ◽  
The Other ◽  
Global Motion ◽  
First Order ◽  
Motion Integration ◽  
Random Block

Recent research indicates that the early stages of visual-motion analysis involve two parallel neural pathways, one conveying information from luminance-defined (first-order) image features, the other conveying information from texture-defined (second-order) features. It is still not clear whether these two pathways converge during later stages of global motion integration. According to one account they remain segregated, and feed separate global analyses. In the alternative account, all responses feed a common stage of global analysis. Two perceptual phenomena are universally held to result from interactions between detector responses during global motion integration—direction repulsion and motion capture. We conducted two psychophysical experiments on these phenomena to test for segregation of first-order and second-order responses during integration. Stimuli contained two components, either two random-block patterns transparently drifting in different directions (repulsion measurements), or a drifting square-wave grating superimposed on an incoherent random-block pattern (capture measurements). Repulsion and capture effects were measured when both stimulus components were the same order, and when one component was first order and the other was second order. Both effects were obtained for all combinations of first-order and second-order patterns. Repulsion effects were stronger with first-order inducing patterns, and capture effects were stronger with second-order inducers. The presence of perceptual interactions regardless of stimulus order strongly suggests that responses in first-order and second-order pathways interact during global motion analysis.

What are the Mechanisms of Rivalrous First-Order and Second-Order Motions?

Perception ◽  
1996 ◽  
Vol 25 (1_suppl) ◽  
pp. 57-57 ◽  
Author(s):  
A Gellatly ◽  
A Blurton
Keyword(s):  
Motion Analysis ◽  
Visual Motion ◽  
Second Order ◽  
Differential Sensitivity ◽  
National Academy Of Sciences ◽  
First Order ◽  
Underlying Mechanisms ◽  
The Fourier Transform ◽  
Academy Of Sciences ◽  
Technical Guidance

There have been many reports in the visual motion literature describing how patterns of contrast reversal in bar stimuli may yield rivalrous motions in opposing directions. One of these, usually termed first-order motion, is generally explained in terms of ‘short range’ matching of same polarity edges or of standard motion analysis of the distribution of energy in the Fourier transform of the stimulus. The opposite, second-order, motion is usually explained in terms either of ‘long range’ matching of whole forms/features or of luminance signal rectification followed by standard motion analysis. It is known that the mechanisms underlying the two motions show differential sensitivity to manipulations of spatial frequency and eccentricity (Mather, Cavanagh, and Anstis, 1985 Perception14 163 – 166; Chubb and Sperling, 1989 Proceedings of the National Academy of Sciences of the USA86 2985 – 2989), and this paper reports a number of studies intended to further specify them in terms of their sensitivities and the interactions between them. The experiments employ mainly stimulus sequences in which luminance changes are unaccompanied by displacement of forms/features, and are designed to investigate the effects of manipulations involving the spacing of luminance events, modulations of directional power, camouflage, and attention. The results obtained raise questions about how the underlying mechanisms are best to be characterised. We are greatly indebted to Professor Ted Evans for technical guidance and assistance.

Neural computation of motion in the fly visual system: quadratic nonlinearity of responses induced by picrotoxin in the HS and CH cells

1995 ◽  
Vol 74 (6) ◽  
pp. 2665-2684 ◽  
Author(s):  
Y. Kondoh ◽  
Y. Hasegawa ◽  
J. Okuma ◽  
F. Takahashi
Keyword(s):  
Mean Square Error ◽  
Order Term ◽  
Mirror Image ◽  
Second Order ◽  
The Other ◽  
Linear Component ◽  
Mean Square ◽  
Nonlinear Component ◽  
First Order ◽  
Order Kernel

1. A computational model accounting for motion detection in the fly was examined by comparing responses in motion-sensitive horizontal system (HS) and centrifugal horizontal (CH) cells in the fly's lobula plate with a computer simulation implemented on a motion detector of the correlation type, the Reichardt detector. First-order (linear) and second-order (quadratic nonlinear) Wiener kernels from intracellularly recorded responses to moving patterns were computed by cross correlating with the time-dependent position of the stimulus, and were used to characterize response to motion in those cells. 2. When the fly was stimulated with moving vertical stripes with a spatial wavelength of 5-40 degrees, the HS and CH cells showed basically a biphasic first-order kernel, having an initial depolarization that was followed by hyperpolarization. The linear model matched well with the actual response, with a mean square error of 27% at best, indicating that the linear component comprises a major part of responses in these cells. The second-order nonlinearity was insignificant. When stimulated at a spatial wavelength of 2.5 degrees, the first-order kernel showed a significant decrease in amplitude, and was initially hyperpolarized; the second-order kernel was, on the other hand, well defined, having two hyperpolarizing valleys on the diagonal with two off-diagonal peaks. 3. The blockage of inhibitory interactions in the visual system by application of 10-4 M picrotoxin, however, evoked a nonlinear response that could be decomposed into the sum of the first-order (linear) and second-order (quadratic nonlinear) terms with a mean square error of 30-50%. The first-order term, comprising 10-20% of the picrotoxin-evoked response, is characterized by a differentiating first-order kernel. It thus codes the velocity of motion. The second-order term, comprising 30-40% of the response, is defined by a second-order kernel with two depolarizing peaks on the diagonal and two off-diagonal hyperpolarizing valleys, suggesting that the nonlinear component represents the power of motion. 4. Responses in the Reichardt detector, consisting of two mirror-image subunits with spatiotemporal low-pass filters followed by a multiplication stage, were computer simulated and then analyzed by the Wiener kernel method. The simulated responses were linearly related to the pattern velocity (with a mean square error of 13% for the linear model) and matched well with the observed responses in the HS and CH cells. After the multiplication stage, the linear component comprised 15-25% and the quadratic nonlinear component comprised 60-70% of the simulated response, which was similar to the picrotoxin-induced response in the HS cells. The quadratic nonlinear components were balanced between the right and left sides, and could be eliminated completely by their contralateral counterpart via a subtraction process. On the other hand, the linear component on one side was the mirror image of that on the other side, as expected from the kernel configurations. 5. These results suggest that responses to motion in the HS and CH cells depend on the multiplication process in which both the velocity and power components of motion are computed, and that a putative subtraction process selectively eliminates the nonlinear components but amplifies the linear component. The nonlinear component is directionally insensitive because of its quadratic non-linearity. Therefore the subtraction process allows the subsequent cells integrating motion (such as the HS cells) to tune the direction of motion more sharply.

scholarly journals A Survey of Conceptualizations of Politeness

2015 ◽  
Vol 5 (6) ◽  
pp. 115
Author(s):  
Lei Qiu
Keyword(s):  
Second Order ◽  
The Other ◽  
Theoretical Construct ◽  
First Order ◽  
Relational Work ◽  
Other Hand ◽  
Uniform Definition

<p>Along with the general trends of research from traditional Gricean approach to postmodern approach, politeness has been conceptualized as facework, social indexing concept, relational work and interactional work. Based on examination of debates over East group-oriented and Western individual-oriented politeness, first-order and second-order politeness, as well as the universality and relativity of conceptualizations, this paper has roughly demonstrated that the tension between universality and relativity of politeness can help to explain the reason for lack of uniform definition and concept in this field. It is essential for researchers to seek a universal second-order culture-general theoretical construct on one hand, and to look at first-order culture-specific constructs on the other hand.</p>

Thermodynamics of Aluminum Deoxidization Equilibria in GCr18Mo Bearing-Steel

2018 ◽  
Vol 382 ◽  
pp. 80-85 ◽  
Author(s):  
Xin Su ◽  
Shu Qiang Guo ◽  
Meng Ran Qiao ◽  
Hong Yan Zheng ◽  
Li Bin Qin
Keyword(s):  
Bearing Steel ◽  
Second Order ◽  
The Other ◽  
Interaction Parameters ◽  
Interaction Coefficients ◽  
Concentration Region ◽  
Order Interaction ◽  
First Order ◽  
The Relationship ◽  
Reaction Equilibrium

Based on the predecessors of thermodynamic data, the relationship between aluminum contents and oxygen contents of the aluminum deoxidization reaction was calculated. And the influence of activity coefficient to the reaction equilibrium in bearing-steel is analyzed. First-order and second-order interaction coefficients were used to calculate and draw the equilibrium curves, respectively. The effects of different temperature and different interaction parameters on the deoxidization equilibrium curves were studied. And through the curve the influence of the change of aluminum contents to the activity can be known. The trend of the curve with first-order interaction parameters is consistent with the curve with first-order and second-order interaction parameters at the low Al concentration region. And the oxygen contents of curve with first-order interaction parameters are higher than the other curve at the high Al concentration region

An Energy Method for Certain Second-Order Effects With Application to Torsion of Elastic Bars Under Tension

1980 ◽  
Vol 47 (1) ◽  
pp. 75-81 ◽  
Author(s):  
R. T. Shield
Keyword(s):  
Axial Force ◽  
Strain Energy Function ◽  
Incompressible Material ◽  
Elastic Cylinder ◽  
Second Order ◽  
The Other ◽  
Circular Cylinders ◽  
Order Effects ◽  
First Order ◽  
Wide Range

When a mechanical system has a potential energy, it is a simple matter to show that if the generalized force corresponding to a coordinate p is known to first order in p for a range of the other coordinates of the system, then the other generalized forces can be found immediately to second order in p, without requiring a second-order analysis of the system. By this method the second-order change in the axial force when a finitely extended elastic cylinder is twisted is found from the first-order value of the twisting moment. Numerical results for a realistic form of the strain-energy function for an incompressible material suggest that the second-order expression for the axial force is very accurate for a wide range of twist for circular cylinders of rubber-like materials extended 100 percent or more.

A second order version of S2i and U21

1991 ◽  
Vol 56 (3) ◽  
pp. 1038-1063 ◽  
Author(s):  
Gaisi Takeuti
Keyword(s):  
Second Order ◽  
The Other ◽  
Polynomial Hierarchy ◽  
Bounded Arithmetic ◽  
Conservative Extension ◽  
First Order ◽  
Second Order Systems ◽  
Separation Problems

In [1] S. Buss introduced systems of bounded arithmetic , , , (i = 1, 2, 3, …). and are first order systems and and are second order systems. and are closely related to and respectively in the polynomial hierarchy, and and are closely related to PSPACE and EXPTIME respectively. One of the most important problems in bounded arithmetic is whether the hierarchy of bounded arithmetic collapses, i.e. whether = or = for some i, or whether = , or whether is a conservative extension of S2 = ⋃i. These problems are relevant to the problems whether the polynomial hierarchy PH collapses or whether PSPACE = PH or whether PSPACE = EXPTIME. It was shown in [4] that = implies and consequently the collapse of the polynomial hierarchy. We believe that the separation problems of bounded arithmetic and the separation problems of computational complexities are essentially the same problem, and the solution of one of them will lead to the solution of the other.

The Effect of Displacement on Sensitivity to First- and Second-Order Global Motion in 5-year-olds and Adults

2010 ◽  
Vol 23 (5) ◽  
pp. 517-532 ◽  
Author(s):  
◽  
J.-P. Guilemot ◽  
◽  
◽  
◽  
...  
Keyword(s):  
Second Order ◽  
Spatial Integration ◽  
Global Motion ◽  
First Order

AbstractWe compared the development of sensitivity to first-versus second-order global motion in 5-year-olds (n = 24) and adults (n = 24) tested at three displacements (0.1, 0.5 and 1.0°). Sensitivity was measured with Random–Gabor Kinematograms (RGKs) formed with luminance-modulated (first-order) or contrastmodulated (second-order) concentric Gabor patterns. Five-year-olds were less sensitive than adults to the direction of both first- and second-order global motion at every displacement tested. In addition, the immaturity was smallest at the smallest displacement, which required the least spatial integration, and smaller for first-order than for second-order global motion at the middle displacement. The findings suggest that the development of sensitivity to global motion is limited by the development of spatial integration and by different rates of development of sensitivity to first-versus second-order signals.

Inception of the cupule of Quercus macrocarpa and Fagus grandifolia

1979 ◽  
Vol 57 (17) ◽  
pp. 1777-1782 ◽  
Author(s):  
Alastair D. Macdonald
Keyword(s):  
Female Flower ◽  
Fagus Grandifolia ◽  
Second Order ◽  
The Other ◽  
Third Order ◽  
Quercus Macrocarpa ◽  
First Order ◽  
Female Inflorescence ◽  
Inflorescence Axis ◽  
Morphological Nature

The female inflorescence of Fagus grandifolia comprises two flowers; one flower terminates the first-order inflorescence axis, the other flower terminates the second-order inflorescence axis. Each flower is flanked by two cupular valves each of which arise in the axil of a bract. The two valves flanking the flower terminating the first-order inflorescence axis represent second-order inflorescence axes and the two valves flanking the flower terminating the second-order inflorescence axis represent third-order inflorescence axes. The four valves remain discrete. Each female flower of Quercus macrocarpa terminates a second-order inflorescence axis and is surrounded by a continuous cupule. The cupule first forms as two primordia in the axils of each of the two transversal second-order bracts. These cupular primordia represent third-order inflorescence branches. The cupule primordia become continuous about the pedicel by meristem extension. The cupules of Fagus and Quercus are homologous to the extent that they are modified axes of the inflorescence. This serves as a model to interpret the morphological nature of the fagaceous cupule.

Processing of first-order motion in marmoset visual cortex is influenced by second-order motion

2006 ◽  
Vol 23 (5) ◽  
pp. 815-824 ◽  
Author(s):  
NICK BARRACLOUGH ◽  
CHRIS TINSLEY ◽  
BEN WEBB ◽  
CHRIS VINCENT ◽  
ANDREW DERRINGTON
Keyword(s):  
Visual Cortex ◽  
Low Frequency ◽  
Second Order ◽  
The Other ◽  
Motion Processing ◽  
Single Neurons ◽  
First Order ◽  
The Third ◽  
Early Visual Cortex ◽  
Direction Sensitivity

We measured the responses of single neurons in marmoset visual cortex (V1, V2, and the third visual complex) to moving first-order stimuli and to combined first- and second-order stimuli in order to determine whether first-order motion processing was influenced by second-order motion. Beat stimuli were made by summing two gratings of similar spatial frequency, one of which was static and the other was moving. The beat is the product of a moving sinusoidal carrier (first-order motion) and a moving low-frequency contrast envelope (second-order motion). We compared responses to moving first-order gratings alone with responses to beat patterns with first-order and second-order motion in the same direction as each other, or in opposite directions to each other in order to distinguish first-order and second-order direction-selective responses. In the majority (72%, 67/93) of cells (V1 73%, 45/62; V2 70%, 16/23; third visual complex 75%, 6/8), responses to first-order motion were significantly influenced by the addition of a second-order signal. The second-order envelope was more influential when moving in the opposite direction to the first-order stimulus, reducing first-order direction sensitivity in V1, V2, and the third visual complex. We interpret these results as showing that first-order motion processing through early visual cortex is not separate from second-order motion processing; suggesting that both motion signals are processed by the same system.

Reflections on the concept of symmetry

2005 ◽  
Vol 13 (S2) ◽  
pp. 3-11 ◽  
Author(s):  
KUNO LORENZ
Keyword(s):  
Binary Relation ◽  
Second Order ◽  
The Other ◽  
First Order ◽  
Broken Symmetries ◽  
Other Hand ◽  
Logical Notion ◽  
The One ◽  
Ancient Usage

The concept of symmetry is omnipresent, although originally, in Greek antiquity, distinctly different from the modern logical notion. In logic a binary relation R is called symmetric if xRy implies yRx. In Greek, ‘being symmetric’ in general usage is synonymous with ‘being harmonious’, and in technical usage, as in Euclid's Elements, it is synonymous with ‘commensurable’. Due to the second meaning, which is close to the etymology of συ´μμετρoς, ‘with measure’ has likewise to be read as ‘being [in] rational [ratios]’ and displays the origin of the concept of rationality of establishing a proportion. Heraclitus can be read as a master of such connections. Exercising rationality is a case of simultaneously finding and inventing symmetries. On that basis a proposal is made of how to relate the modern logical notion of symmetry, a second-order concept, on the one hand with modern first-order usages of the term symmetric in geometry and other fields, and on the other hand with the notion of balance that derives from the ancient usage of symmetric. It is argued that symmetries as states of balance exist only in theory, in practice they function as norms vis-à-vis broken symmetries.

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