The influence of natural contour and face size on the spatial frequency tuning for identifying upright and inverted faces

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.

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Spatial-frequency and orientation tuning in psychophysical end-stopping

Visual Neuroscience ◽

10.1017/s0952523898154019 ◽

1998 ◽

Vol 15 (4) ◽

pp. 585-595 ◽

Cited By ~ 10

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.

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Functional organization of spatial frequency tuning in macaque V1 revealed with two-photon calcium imaging

Progress in Neurobiology ◽

10.1016/j.pneurobio.2021.102120 ◽

2021 ◽

pp. 102120

Author(s):

Shu-Chen Guan ◽

Nian-Sheng Ju ◽

Louis Tao ◽

Shi-Ming Tang ◽

Cong Yu

Keyword(s):

Spatial Frequency ◽

Calcium Imaging ◽

Functional Organization ◽

Frequency Tuning ◽

Two Photon ◽

Spatial Frequency Tuning

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

Journal of Neurophysiology ◽

10.1152/jn.00847.2004 ◽

2005 ◽

Vol 93 (6) ◽

pp. 3537-3547 ◽

Cited By ~ 20

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.

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