Spatial frequency tuning and contrast threshold of striate neurons in Siamese cats

1984 ◽  
Vol 56 (2) ◽  
Author(s):  
Y.M. Chino ◽  
M.S. Shansky ◽  
W.L. Jankowski
Keyword(s):  
Spatial Frequency ◽  
Frequency Tuning ◽  
Contrast Threshold ◽  
Spatial Frequency Tuning ◽  
Striate Neurons

scholarly journals Adaptation to a ‘Spatial-Frequency Doubled’ Stimulus

Perception ◽  
1980 ◽  
Vol 9 (5) ◽  
pp. 523-528 ◽  
Author(s):  
Peter Thompson ◽  
Brian J Murphy
Keyword(s):  
Spatial Frequency ◽  
Visual System ◽  
Frequency Tuning ◽  
Low Frequency ◽  
Frequency Doubling ◽  
Contrast Threshold ◽  
Threshold Elevation ◽  
Temporal Parameters ◽  
Spatial Frequency Tuning ◽  
Sinusoidal Gratings

The perceived spatial frequency of low-frequency sinusoidal gratings is elevated when the gratings are temporally modulated sufficiently rapidly. Although this phenomenon is usually called ‘spatial-frequency doubling’, the magnitude of this spatial-frequency elevation depends on the spatial and temporal parameters of the grating and may be less than or greater than doubling. Adaptation to such a pattern produces contrast-threshold elevation whose spatial-frequency tuning is centred upon the grating's real rather than perceived spatial frequency. These results suggest that spatial-frequency elevation occurs later in the visual system than adaptation or that these two processes are independent of one another, at least under the conditions of these experiments.

Effects of rearing kittens with convergent strabismus on development of receptive-field properties in striate cortex neurons

1983 ◽  
Vol 50 (1) ◽  
pp. 265-286 ◽  
Author(s):  
Y. M. Chino ◽  
M. S. Shansky ◽  
W. L. Jankowski ◽  
F. A. Banser
Keyword(s):  
Receptive Field ◽  
Spatial Frequency ◽  
Striate Cortex ◽  
Frequency Tuning ◽  
Tuning Curves ◽  
Spatial Frequency Tuning ◽  
Receptive Field Properties ◽  
Convergent Strabismus ◽  
Striate Neurons ◽  
Contrast Thresholds

Convergent strabismus was induced surgically in seven kittens at 3 wk of age. Recordings were made in 131 cells in the striate cortex of these strabismic kittens after maturation, and the results were compared to the data obtained from 140 striate neurons in normally reared cats. All our samples had receptive fields (RFs) within 5 degrees of the area centralis. The spatial and temporal response properties were quantitatively analyzed by using drifting sinusoidal gratings of various contrasts as well as spatial and temporal frequencies. In contrast to other reports, the receptive-field properties of the striate neurons exclusively driven or dominated by the deviating eye were quite abnormal. The spatial frequency tuning curves in strabismic cats were different from those obtained from normals in that the optimal spatial frequencies and spatial resolutions were shifted to lower values and the bandwidths were significantly broader. The contrast-response functions show that contrast thresholds, measured at the optimal spatial frequency, were significantly higher and the slope of the functions much flatter in strabismic animals. Moreover, receptive-field sizes were much larger and the sharpness of orientation tuning was reduced in strabismic cats. Direction selectivity, however, was normal in those animals. The temporal frequency tuning curves were also abnormal, particularly in that temporal resolution was considerably reduced in strabismic cats compared with normally reared cats. In addition, many cells in strabismic animals exhibited much longer latencies to visual and optic chiasm (OX) stimulations. All these effects, to our great surprise, were also observed in the striate units controlled by the nondeviating eye, although the magnitude of the alteration depends on the receptive-field property. The abnormalities found in spatial frequency tuning, contrast thresholds, and RF sizes were as severe as those revealed in the deviating eye. On the other hand, the effects on other RF properties were minimal or less severe. These physiological findings correspond very well with results from behavioral measurements of spatial contrast sensitivity in the same cats reported elsewhere. It is concluded from these results that the nondeviating eye in convergent strabismic animals, and perhaps humans, should not always be presumed "normal."

Role of intrathalamic inhibition on the spatial frequency tuning of neurons in the lateral geniculate nucleus of the cat

2009 ◽  
Vol 65 ◽  
pp. S106
Author(s):  
Akihiro Kimura ◽  
Satoshi Shimegi ◽  
Shin-ichiro Hara ◽  
Masahiro Okamoto ◽  
Hiromichi Sato
Keyword(s):  
Spatial Frequency ◽  
Lateral Geniculate Nucleus ◽  
Frequency Tuning ◽  
Spatial Frequency Tuning ◽  
Lateral Geniculate

Adaptation in single units in visual cortex: The tuning of aftereffects in the spatial domain

1989 ◽  
Vol 2 (6) ◽  
pp. 593-607 ◽  
Author(s):  
A. B. Saul ◽  
M. S. Cynader
Keyword(s):  
Spatial Frequency ◽  
Cortical Neurons ◽  
Frequency Tuning ◽  
Cortical Cell ◽  
Selective Adaptation ◽  
Single Units ◽  
Spatial Frequency Tuning ◽  
Sinusoidal Gratings ◽  
A Cell ◽  
Drift Direction

AbstractCat striate cortical neurons were investigated using a new method of studying adaptation aftereffects. Stimuli were sinusoidal gratings of variable contrast, spatial frequency, and drift direction and rate. A series of alternating adapting and test trials was presented while recording from single units. Control trials were completely integrated with the adapted trials in these experiments.Every cortical cell tested showed selective adaptation aftereffects. Adapting at suprathreshold contrasts invariably reduced contrast sensitivity. Significant aftereffects could be observed even when adapting at low contrasts.The spatial-frequency tuning of aftereffects varied from cell to cell. Adapting at a given spatial frequency generally resulted in a broad response reduction at test frequencies above and below the adapting frequency. Many cells lost responses predominantly at frequencies lower than the adapting frequency.The tuning of aftereffects varied with the adapting frequency. In particular, the strongest aftereffects occurred near the adapting frequency. Adapting at frequencies just above the optimum for a cell often altered the spatial-frequency tuning by shifting the peak toward lower frequencies. The fact that the tuning of aftereffects did not simply match the tuning of the cell, but depended on the adapting stimulus, implies that extrinsic mechanisms are involved in adaptation effects.

Spatial-frequency and orientation tuning in psychophysical end-stopping

1998 ◽  
Vol 15 (4) ◽  
pp. 585-595 ◽  
Author(s):  
CONG YU ◽  
DENNIS M. LEVI
Keyword(s):  
Spatial Frequency ◽  
Frequency Tuning ◽  
Spatial Filter ◽  
Orientation Tuning ◽  
Maximal Strength ◽  
Facilitation Effect ◽  
Spatial Filters ◽  
Spatial Frequency Tuning ◽  
Spatial Frequencies ◽  
Wide Range

A psychophysical analog to cortical receptive-field end-stopping has been demonstrated previously in spatial filters tuned to a wide range of spatial frequencies (Yu & Levi, 1997a). The current study investigated tuning characteristics in psychophysical spatial filter end-stopping. When a D6 (the sixth derivative of a Gaussian) target is masked by a center mask (placed in the putative spatial filter center), two end-zone masks (placed in the filter end-zones) reduce thresholds. This “end-stopping” effect (the reduction of masking induced by end-zone masks) was measured at various spatial frequencies and orientations of end-zone masks. End-stopping reached its maximal strength when the spatial frequency and/or orientation of the end-zone masks matched the spatial frequency and/or orientation of the target and center mask, showing spatial-frequency tuning and orientation tuning. The bandwidths of spatial-frequency and orientation tuning functions decreased with increasing target spatial frequency. At larger orientation differences, however, end-zone masks induced a secondary facilitation effect, which was maximal when the spatial frequency of end-zone masks equated the target spatial frequency. This facilitation effect might be related to certain types of contour and texture perception, such as perceptual pop-out.

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.

scholarly journals Dynamics of spatial frequency tuning of macaque LGN

2010 ◽  
Vol 2 (7) ◽  
pp. 219-219
Author(s):  
C. Bredfeldt ◽  
D. Ringach
Keyword(s):  
Spatial Frequency ◽  
Frequency Tuning ◽  
Spatial Frequency Tuning

scholarly journals The impact of face size and natural contour on spatial frequency tuning: still no difference between upright and inverted faces!

2015 ◽  
Vol 15 (12) ◽  
pp. 160
Author(s):  
Jessica Royer ◽  
Verena Willenbockel ◽  
Caroline Blais ◽  
Frédéric Gosselin ◽  
Sandra Lafortune ◽  
...  
Keyword(s):  
Spatial Frequency ◽  
Frequency Tuning ◽  
Spatial Frequency Tuning ◽  
The Impact ◽  
Face Size
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