Contrast adaptation and contrast gain control

1991 ◽  
Vol 87 (1) ◽  
Author(s):  
L.M. M��tt�nen ◽  
J.J. Koenderink
Keyword(s):  
Gain Control ◽  
Contrast Gain ◽  
Contrast Gain Control ◽  
Contrast Adaptation

Contrast and Temporal Frequency-Related Adaptation in the Pretectal Nucleus of the Optic Tract

2005 ◽  
Vol 94 (1) ◽  
pp. 136-146 ◽  
Author(s):  
M. R. Ibbotson
Keyword(s):  
Visual Cortex ◽  
Optic Tract ◽  
Gain Control ◽  
Response Functions ◽  
High Contrast ◽  
Motion Adaptation ◽  
Contrast Gain ◽  
Contrast Gain Control ◽  
Contrast Adaptation ◽  
Contrast Response

In mammals, many cells in the retino-geniculate-cortical pathway adapt during stimulation with high contrast gratings. In the visual cortex, adaptation to high contrast images reduces sensitivity at low contrasts while only moderately affecting sensitivity at high contrasts, thus generating rightward shifts in the contrast response functions (contrast gain control). Similarly, motion adaptation at particular temporal frequencies (TFs) alters the temporal tuning properties of cortical cells. For the first time in any species, this paper investigates the influence of motion adaptation on both the contrast and TF responses of neurons in the retino-pretectal pathway by recording from direction-selective neurons in the nucleus of the optic tract (NOT) of the marsupial wallaby, Macropus eugenii. This species is of interest because its NOT receives almost all input directly from the retina, with virtually none from the visual cortex (unlike cats and primates). All NOT cells show changes in their contrast response functions after adaptation, many revealing contrast gain control. Contrast adaptation is direction-dependent, preferred directions producing the largest changes. The lack of cortical input suggests that contrast adaptation is generated independently from the cortex in the NOT or retina. Motion adaptation also produces direction-selective effects on the TF tuning of NOT neurons by shifting the location of the optimum TF. Cells that show strong adaptation to contrast also tend to show large changes in TF tuning, suggesting similar intracellular mechanisms. The data are discussed in terms of the generality of contrast adaptation across mammalian species and across unconnected brain regions within the same species.

Contrast gain control in the cat's visual system

1985 ◽  
Vol 54 (3) ◽  
pp. 651-667 ◽  
Author(s):  
I. Ohzawa ◽  
G. Sclar ◽  
R. D. Freeman
Keyword(s):  
Contrast Sensitivity ◽  
Cortical Neurons ◽  
Time Course ◽  
Gain Control ◽  
Local Contrast ◽  
Response Functions ◽  
Contrast Gain ◽  
Contrast Gain Control ◽  
Contrast Adaptation ◽  
Contrast Response

We have examined the idea that the adaptation of cortical neurons to local contrast levels in a visual stimulus is functionally advantageous. Specifically, cortical cells may have large differential contrast sensitivity as a result of adjustments that center a limited response range around a mean level of contrast. To evaluate this notion, we measured contrast-response functions of cells in striate cortex while systematically adapting them to different contrast levels of stimulus gratings. For the majority of cortical neurons tested, the results of this basic experiment show that contrast-response functions shift laterally along a log-contrast axis so that response functions match mean contrast levels in the stimulus. This implies a contrast-dependent change in the gain of the cell's contrast-response relationship. We define this process as contrast gain control. The degree to which this contrast adjustment occurs varies considerably from cell to cell. There are no obvious differences regarding cell type (simple vs. complex) or laminar distribution. Contrast gain control is almost certainly a cortical function, since lateral geniculate cells and fibers exhibit only minimal effects. Tests presented in the accompanying paper (37) provide additional evidence on the cortical origin of the process. In another series of experiments, the effect of contrast adaptation on physiological estimates of contrast sensitivity was evaluated. Sustained adaptation to contrast levels as low as 3% was capable of nearly doubling the thresholds of most of the cells tested. Adaptation may therefore be an important factor in determinations of the contrast sensitivity of cortical neurons. We tested the spatial extent of the mechanisms responsible for these gain-control effects by attempting to adapt cells using both a large grating and a grating patch limited to that portion of a cell's receptive field from which excitatory discharges could be elicited directly (the central discharge region). Adaptation was found to be an exclusive property of the central region. This held even in the case of hypercomplex cells, which received strong influences from surrounding regions of the visual field. Finally, we measured the time course of contrast adaptation. We found the process to be rather slow, with a mean time constant of approximately 6 s. Once again, there was considerable variability in this value from cell to cell.

scholarly journals Virtual Retina: A biological retina model and simulator, with contrast gain control

2008 ◽  
Vol 26 (2) ◽  
pp. 219-249 ◽  
Author(s):  
Adrien Wohrer ◽  
Pierre Kornprobst
Keyword(s):  
Gain Control ◽  
Contrast Gain ◽  
Contrast Gain Control

scholarly journals Depth-dependent contrast gain-control

2010 ◽  
Vol 3 (9) ◽  
pp. 49-49
Author(s):  
R. N Aslin ◽  
R. A Jacobs ◽  
P. W Battaglia
Keyword(s):  
Gain Control ◽  
Contrast Gain ◽  
Contrast Gain Control

Contrast gain control in the cat visual cortex

Nature ◽  
1982 ◽  
Vol 298 (5871) ◽  
pp. 266-268 ◽  
Author(s):  
I. Ohzawa ◽  
G. Sclar ◽  
R. D. Freeman
Keyword(s):  
Visual Cortex ◽  
Gain Control ◽  
Contrast Gain ◽  
Contrast Gain Control ◽  
Cat Visual Cortex

Callosal regulation of contrast gain control machinery in the human visual system

2013 ◽  
Vol 333 ◽  
pp. e608
Author(s):  
T. Bocci ◽  
M. Caleo ◽  
L. Restani ◽  
L. Briscese ◽  
E. Giorli ◽  
...  
Keyword(s):  
Visual System ◽  
Human Visual System ◽  
Gain Control ◽  
Contrast Gain ◽  
Contrast Gain Control

13. Color Contrast Gain Control

Color Vision ◽  
1998 ◽  
pp. 251-266
Keyword(s):  
Gain Control ◽  
Color Contrast ◽  
Contrast Gain ◽  
Contrast Gain Control

Silicon synaptic adaptation mechanisms for homeostasis and contrast gain control

2002 ◽  
Vol 13 (6) ◽  
pp. 1497-1503 ◽  
Author(s):  
Shih-Chii Liu ◽  
B.A. Minch
Keyword(s):  
Gain Control ◽  
Contrast Gain ◽  
Contrast Gain Control ◽  
Adaptation Mechanisms

scholarly journals Model of visual contrast gain control and pattern masking

1997 ◽  
Vol 14 (9) ◽  
pp. 2379 ◽  
Author(s):  
Andrew B. Watson ◽  
Joshua A. Solomon
Keyword(s):  
Gain Control ◽  
Contrast Gain ◽  
Contrast Gain Control ◽  
Visual Contrast ◽  
Pattern Masking
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