scholarly journals A stereo illusion induced by binocularly presented gratings: Effects of number of eyes stimulated, spatial frequency, orientation, field size, and viewing distance

1987 ◽  
Vol 42 (2) ◽  
pp. 140-149 ◽  
Author(s):  
J. Vernon Odom ◽  
Gung-Mei Chao
Keyword(s):  
Spatial Frequency ◽  
Field Size ◽  
Viewing Distance ◽  
Orientation Field

Dependence of Anomaloscope Matching on Viewing Distance or Field Size

Nature ◽  
1947 ◽  
Vol 160 (4053) ◽  
pp. 23-24 ◽  
Author(s):  
R. G. HORNER ◽  
E. T. PURSLOW
Keyword(s):  
Field Size ◽  
Viewing Distance

Receptive Field Size and Response Latency Are Correlated Within the Cat Visual Thalamus

2005 ◽  
Vol 93 (6) ◽  
pp. 3537-3547 ◽  
Author(s):  
Chong Weng ◽  
Chun-I Yeh ◽  
Carl R. Stoelzel ◽  
Jose-Manuel Alonso
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Response Latency ◽  
Time Course ◽  
Frequency Tuning ◽  
Receptive Fields ◽  
Cortical Cell ◽  
Field Size ◽  
Receptive Field Size ◽  
Spatial Frequency Tuning

Each point in visual space is encoded at the level of the thalamus by a group of neighboring cells with overlapping receptive fields. Here we show that the receptive fields of these cells differ in size and response latency but not at random. We have found that in the cat lateral geniculate nucleus (LGN) the receptive field size and response latency of neighboring neurons are significantly correlated: the larger the receptive field, the faster the response to visual stimuli. This correlation is widespread in LGN. It is found in groups of cells belonging to the same type (e.g., Y cells), and of different types (i.e., X and Y), within a specific layer or across different layers. These results indicate that the inputs from the multiple geniculate afferents that converge onto a cortical cell (approximately 30) are likely to arrive in a sequence determined by the receptive field size of the geniculate afferents. Recent studies have shown that the peak of the spatial frequency tuning of a cortical cell shifts toward higher frequencies as the response progresses in time. Our results are consistent with the idea that these shifts in spatial frequency tuning arise from differences in the response time course of the thalamic inputs.

Viewing Distance Affects Stereoscopic Tilt Created with Spatial Frequency Disparity

1989 ◽  
Vol 66 (8) ◽  
pp. 554-557
Author(s):  
ROBERT PATTERSON ◽  
GREGORY BURNS ◽  
SANDRA MOONEY
Keyword(s):  
Spatial Frequency ◽  
Viewing Distance

The Sensitivity of Binocular Rivalry Suppression to Changes in Orientation Assessed by Reaction-Time and Forced-Choice Techniques

Perception ◽  
1981 ◽  
Vol 10 (3) ◽  
pp. 283-293 ◽  
Author(s):  
Robert P O'Shea ◽  
Boris Crassini
Keyword(s):  
Reaction Time ◽  
Spatial Frequency ◽  
Binocular Rivalry ◽  
Luminance Contrast ◽  
Forced Choice ◽  
Field Size ◽  
Correct Performance ◽  
Orientation Change ◽  
Choice Procedure ◽  
Forced Choice Procedure

Binocular rivalry was induced between two orthogonal square-wave gratings of the same spatial frequency, luminance, contrast, and field size, presented dichoptically. One of the gratings could be instantly replaced by a third grating differing only in orientation. In one experiment subjects were required to respond as soon as an orientation change was noticed, and to withold response to catch trials (no orientation change). When orientation changes were made to the visible grating, reaction time was found to be a U-shaped function of the magnitude of orientation change. When orientation changes were made to the grating undergoing binocular-rivalry suppression, an overall increase in reaction time was found with the increase being greater for large orientation changes (an asymmetrical U-shaped function). In another experiment subjects were required to detect the direction of a change in orientation in a two-alternative forced-choice procedure. Thresholds were thus obtained for 75% correct performance. It was found that thresholds for orientation changes made to the visible and invisible fields were identical from 20° to 70° orientation change. Outside this range thresholds were higher when orientation changes were made to the field suppressed by binocular rivalry. It is argued that the orientation functions obtained in the two experiments may represent incomplete suppression of either form or transient information during binocular rivalry.

Spatial and temporal properties of neurons of the lateral suprasylvian cortex of the cat

1986 ◽  
Vol 56 (4) ◽  
pp. 969-986 ◽  
Author(s):  
M. C. Morrone ◽  
M. Di Stefano ◽  
D. C. Burr
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Second Harmonic ◽  
Temporal Frequency ◽  
Field Size ◽  
Contrast Threshold ◽  
Receptive Field Size ◽  
Contrast Gain ◽  
Lateral Suprasylvian Cortex ◽  
Suprasylvian Cortex

Neurons in the posteromedial lateral suprasylvian cortex (PMLS) of cats were recorded extracellularly to investigate their response to stimulation by bars and by sinusoidal gratings. Two general types of cells were identified: those that modulated in synchrony with the passage of drifting bars and gratings and those that responded with an unmodulated increase in discharge. Both types responded to contrast reversed gratings with a modulation of activity: the cells that modulated to drifting gratings modulated to the first harmonic of contrast reversed gratings (at appropriate spatial phase and frequency), whereas those that did not modulate to drifting gratings always modulated to the second harmonic of contrast reversed gratings. No cell had a clear null point. Nearly all cells were selective for spatial frequency. The preferred frequency ranged from 0.1 to 1 cycles per degree (cpd), and selectivity bandwidths (full width at half height) were around two octaves. Preferred spatial frequency was not correlated with receptive field size, but bandwidth and receptive field size were positively correlated. Preferred spatial frequency decreased with eccentricity, at about 0.05 octaves/deg. The response of all cells increased as a function of grating contrast up to a saturation level. The contrast threshold for response to a grating of optimal parameters was approximately 1% for most cells and the saturation contrast approximately 10%. The contrast gain was approximately 25 spikes/s per log unit of contrast. All cells were tuned for temporal frequency, preferring frequencies from approximately 3 to 10 Hz, with a selectivity bandwidth approximately 2 octaves. For some cells, the spatial selectivity did not depend on the temporal frequency and vice versa. Others were spatiotemporally coupled, with the preferred temporal frequency being lower at high than at low spatial frequencies, and the preferred spatial frequency lower at high than at low temporal frequencies. Previous results showing broad velocity tuning to a bar were replicated and found to be predictable from the combined spatial and temporal tuning of PMLS cells and the Fourier spectrum of a bar. Preferred temporal frequency steadily decreased with eccentricity, at 0.025 octaves/deg. The results for PMLS cells are compared with those of other visual areas. Acuity and spatial preference and selectivity bandwidth is comparable to all areas except area 17, where they are a factor of about two higher. Temporal selectivity in PMLS is as fine as observed in other areas. The possibility that PMLS cells may be involved with motion detection and detection of motion in depth is discussed.

Contrast-Dependent Changes in Spatial Frequency Tuning of Macaque V1 Neurons: Effects of a Changing Receptive Field Size

2002 ◽  
Vol 88 (3) ◽  
pp. 1363-1373 ◽  
Author(s):  
Michael P. Sceniak ◽  
Michael J. Hawken ◽  
Robert Shapley
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Frequency Tuning ◽  
Fundamental Property ◽  
Spatial Summation ◽  
Field Size ◽  
Stimulus Contrast ◽  
Tuning Curves ◽  
Spatial Frequency Tuning ◽  
Receptive Field Organization

Previous studies on single neurons in primary visual cortex have reported that selectivity for orientation and spatial frequency tuning do not change with stimulus contrast. The prevailing hypothesis is that contrast scales the response magnitude but does not differentially affect particular stimuli. Models where responses are normalized over contrast to maintain constant tuning for parameters such as orientation and spatial frequency have been proposed to explain these results. However, our results indicate that a fundamental property of receptive field organization, spatial summation, is not contrast invariant. We examined the spatial frequency tuning of cells that show contrast-dependent changes in spatial summation and have found that spatial frequency selectivity also depends on stimulus contrast. These results indicate that contrast changes in the spatial frequency tuning curves result from spatial reorganization of the receptive field.

scholarly journals Distance-dependent pattern blending can camouflage salient aposematic signals

2017 ◽  
Vol 284 (1858) ◽  
pp. 20170128 ◽  
Author(s):  
James B. Barnett ◽  
Innes C. Cuthill ◽  
Nicholas E. Scott-Samuel
Keyword(s):  
Spatial Frequency ◽  
Relative Rate ◽  
Colour Pattern ◽  
Viewing Distance ◽  
Resolution Limit ◽  
Avian Predation ◽  
Spatial Frequencies ◽  
Close Range ◽  
Aposematic Signals ◽  
Colour Patterns

The effect of viewing distance on the perception of visual texture is well known: spatial frequencies higher than the resolution limit of an observer's visual system will be summed and perceived as a single combined colour. In animal defensive colour patterns, distance-dependent pattern blending may allow aposematic patterns, salient at close range, to match the background to distant observers. Indeed, recent research has indicated that reducing the distance from which a salient signal can be detected can increase survival over camouflage or conspicuous aposematism alone. We investigated whether the spatial frequency of conspicuous and cryptically coloured stripes affects the rate of avian predation. Our results are consistent with pattern blending acting to camouflage salient aposematic signals effectively at a distance. Experiments into the relative rate of avian predation on edible model caterpillars found that increasing spatial frequency (thinner stripes) increased survival. Similarly, visual modelling of avian predators showed that pattern blending increased the similarity between caterpillar and background. These results show how a colour pattern can be tuned to reveal or conceal different information at different distances, and produce tangible survival benefits.

Dependence of Anomaloscope Matching on Viewing Distance or Field Size

Nature ◽  
1947 ◽  
Vol 160 (4076) ◽  
pp. 831-832 ◽  
Author(s):  
H. HARTRIDGE
Keyword(s):  
Field Size ◽  
Viewing Distance

scholarly journals The effect of spatial frequency and field size on the spread of exclusive visibility in binocular rivalry

1997 ◽  
Vol 37 (2) ◽  
pp. 175-183 ◽  
Author(s):  
Robert P. O'Shea ◽  
Adam J.H. Sims ◽  
Donovan G. Govan
Keyword(s):  
Spatial Frequency ◽  
Binocular Rivalry ◽  
Field Size
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