Visual orientation of the flyMusca domestica towards a horizontal stripe

Chr Wehrhahn; W. Reichardt

doi:10.1007/bf00599440

The influence of visual orientation on apparent bodily rotation following actual rotation. (Proj. Rep. No. NM 001 063.01.23).

PsycEXTRA Dataset ◽

10.1037/e465312004-001 ◽

1952 ◽

Author(s):

F. E. Guedry ◽

J. T. Ray ◽

J. I. Niven

Keyword(s):

Visual Orientation

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ANALYSIS OF REGULATIONS REGARDING THE SETTLEMENT OF ISSUES ON THE REMOVAL AND RECOVERY OF PLANTATIONS IN THE RIGHT-OF-WAY OF PUBLIC ROADS

Avtoshliakhovyk Ukrayiny ◽

10.33868/0365-8392-2020-1-261-55-60 ◽

2020 ◽

pp. 55-60

Author(s):

Nataliia Kharytonova ◽

Olha Mykolaienko ◽

Tetyana Lozova

Keyword(s):

Traffic Safety ◽

Climatic Factors ◽

Visual Orientation ◽

Right Of Way ◽

Adverse Weather ◽

Overhead Power Lines ◽

The Right ◽

Neck Diameter ◽

Proper Operation

Greening of roads contributes to the protection of roads and their elements from influence of adverse weather and climatic factors; it includes the measures for improvement and landscaping of roads, ensures the protection of roadside areas from transport pollution, provides visual orientation of drivers. The solution of these issues will ensure creation and maintenance of safe and comfortable conditions for travelers. Green plantings in the right-of-way road area include woody, bushy, flower and grass vegetation of natural and artificial origin. For proper operation of public roads and satisfaction of other needs of the industry, there may be the need in removing the greenery. The reason for the removal of greenery in the right-of-way road area may be due to the following factors: construction of the architectural object, widening of the motor road, repair works in the security zone of overhead power lines, water supply, drainage, heating, telecommunications facilities, cutting of hazardous, dry and fautal trees, as well as self-grown and brushwood trees with a root neck diameter not exceeding 5 cm, elimination of the consequences of natural disasters and emergencies. The removal of plantations in the right-of-way area is executed in order to ensure traffic safety conditions and to improve the quality of plantations composition and their protective properties. Nowadays, in Ukraine there is no clear procedure for issuing permits for removing of such plantations. In order to resolve this issue, there is a need in determining the list of regulations in the area of forest resources of Ukraine and, if needed, the list of regulatory acts that have to be improved; to prepare a draft of the regulatory legal act that would establish the procedure of plantations cutting, the methodology of their condition determination, recovery costs determination, the features of cutting. Keywords: plantations, cutting, right-of-way, woodcutting permit, order.

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The effects of contrast on visual orientation and spatial frequency discrimination: a comparison of single cells and behavior

Journal of Neurophysiology ◽

10.1152/jn.1987.57.3.773 ◽

1987 ◽

Vol 57 (3) ◽

pp. 773-786 ◽

Cited By ~ 186

Author(s):

B. C. Skottun ◽

A. Bradley ◽

G. Sclar ◽

I. Ohzawa ◽

R. D. Freeman

Keyword(s):

Spatial Frequency ◽

Striate Cortex ◽

Frequency Tuning ◽

Single Cells ◽

Frequency Discrimination ◽

Frequency Selectivity ◽

Response Amplitude ◽

Visual Orientation ◽

Characteristic Analysis ◽

Response Variance

We have compared the effects of contrast on human psychophysical orientation and spatial frequency discrimination thresholds and on the responses of individual neurons in the cat's striate cortex. Contrast has similar effects on orientation and spatial frequency discrimination: as contrast is increased above detection threshold, orientation and spatial frequency discrimination performance improves but reaches maximum levels at quite low contrasts. Further increases in contrast produce no further improvements in discrimination. We measured the effects of contrast on response amplitude, orientation and spatial frequency selectivity, and response variance of neurons in the cat's striate cortex. Orientation and spatial frequency selectivity vary little with contrast. Also, the ratio of response variance to response mean is unaffected by contrast. Although, in many cells, response amplitude increases approximately linearly with log contrast over most of the visible range, some cells show complete or partial saturation of response amplitude at medium contrasts. Therefore, some cells show a clear increase in slope of the orientation and spatial frequency tuning functions with increasing contrast, whereas in others the slopes reach maximum values at medium contrasts. Using receiver operating characteristic analysis, we estimated the minimum orientation and spatial frequency differences that can be signaled reliably as a response change by an individual cell. This analysis shows that, on average, the discrimination of orientation or spatial frequency improves with contrast at low contrasts more than at higher contrasts. Using the optimal stimulus for each cell, we estimated the contrast threshold of 48 neurons. Most cells had contrast thresholds below 5%. Thresholds were only slightly higher for nonoptimal stimuli. Therefore, increasing the contrast of sinusoidal gratings above approximately 10% will not produce large increases in the number of responding cells. The observed effects of contrast on the response characteristics of nonsaturating cortical cells do not appear consistent with the psychophysical results. Cells that reach their maximum response at low-to-medium contrasts may account for the contrast independence of psychophysical orientation and spatial frequency discrimination thresholds at medium and high contrasts.

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