Striate cortex of monkey and cat: contrast response function.

Albrecht, Duane G.; Hamilton, David B.

doi:10.1152/jn.1982.48.1.217

Cited by 888 publications

(855 citation statements)

References 6 publications

Supporting

Mentioning

780

Contrasting

Order By: Relevance

“…How can this be reconciled with previous literature in carnivores and primates implying that spatial frequency tuning in individual neurons is contrast-invariant 29 ? The explanation for the discrepancy lies in the fact that the mouse population tuning curve (Fig.…”

Section: Normalization Model Reliably Matches Experimental Datamentioning

confidence: 65%

“…For this reason, we employed Heeger's normalization model 28 , the standard phenomenological model of V1 responses. It was introduced to describe non-linear response phenomena in V1, such as response suppression by a superimposed additional stimulus and, especially relevant in our context, contrast saturation 29 . We used the model to describe how contrast affects the spatial frequency tuning curve (and vice versa) and 7 test whether these predictions would explain our experimental data.…”

Section: Normalization Explains Interplay Of Contrast and Acuitymentioning

confidence: 99%

“…This leads to the normalized population response given by: reduces to a Naka-Rushton function describing neuronal contrast tuning 29 . The population response P(c, f) obeys the…”

Section: Derivation Of Model Predictionsmentioning

confidence: 99%

See 2 more Smart Citations

Contrast gain control and cortical TrkB signaling shape visual acuity

Heimel¹,

Saiepour²,

Chakravarthy³

et al. 2010

Nat Neurosci

View full text Add to dashboard Cite

2The limits of visual acuity and contrast sensitivity are set by the eye, but what we perceive is determined by the visual cortex 1 . In healthy, mature people and animals, the visual acuities of the retina and the cortex are well-matched 2 , but this match is neither automatic nor unbreakable. Differences between cortical and retinal acuity are most apparent during development, when cortical acuity continues to rise after retinal development is completed 3 , and during aging, when behavioral acuity falls even without obvious changes in the eye or the thalamus 4 . Differences also occur as a result of cortical injury or erroneous development. This is the case with amblyopia, the most prevalent (2-4%) visual impairment in young people. Amblyopia is a reduced psychophysical acuity in one or both eyes. It is believed to be caused by deficient processing in the visual cortex 5 , but the mechanisms underlying the dissociations of retinal and cortical acuity in amblyopia and in the healthy aging and developing brain are unclear. Interestingly, there is a good match between changes in the cortical expression level of brain-derived neurotrophic factor (BDNF) and changes in visual acuity.During development, acuity and BDNF levels rise 6 , while both slowly decrease with age 4,7 . This relationship between BDNF and acuity also holds for experimentally induced amblyopia. BDNF mRNA and protein levels 8,9 and acuity 10 in the primary visual cortex (V1) responding to a monocularly deprived eye are all below normal. In amblyopic rats receiving environmental enrichment 11 or antidepressant treatment 12 , increased BDNF expression in the cortex was seen in parallel to the restoration of visual acuity. Moreover, transgenic mice overexpressing BDNF in the forebrain show a faster rise of cortical acuity 6 even when reared in darkness 13 . Although there is a wealth of data on the involvement of BDNF and its main receptor TrkB in neuronal development 14 , synaptic efficacy 15 , -morphology 16 and -plasticity 17,18 , it has remained unknown how BDNF promotes visual acuity at the coding level and whether BDNF signaling plays a role in acuity in the mature cortex. For these reasons we studied visual acuity in adult transgenic mice where, after normal development is completed, cortical TrkB/BDNF signaling is impaired. We found a loss of acuity, caused by a reduction in apparent contrast. Using a combination of experiments and modeling, we show the involvement of cortical gain control in the selective loss of responses to visual stimuli with high spatial frequencies and the maintenance of responses to low spatial frequencies. RESULTS Genetic inhibition of TrkB signaling in the adult cortexTo investigate the role of TrkB signaling in cortical acuity in the mature animal we overexpressed a dominant negative TrkB.T1-EGFP fusion protein 19 in a large proportion of pyramidal cells after the maturation of cortical acuity. This was achieved by crossing mice carrying a Cre-dependent TrkB.T1-EGFP-transgene under the control of the Thy-1 promoter ...

show abstract

Section: Normalization Model Reliably Matches Experimental Datamentioning

confidence: 65%

Section: Normalization Explains Interplay Of Contrast and Acuitymentioning

confidence: 99%

See 1 more Smart Citation

Contrast gain control and cortical TrkB signaling shape visual acuity

Heimel¹,

Saiepour²,

Chakravarthy³

et al. 2010

Nat Neurosci

View full text Add to dashboard Cite

show abstract

“…Visual inspection of the results suggests that the changes are similar to those expected by an increase in "contrast gain" (see Figure 1). Thus, to further characterize our results, average data for shock-paired and unpaired conditions were independently fit ( Figure 3A, solid and dashed lines) according to the Naka-Rushton contrast response model (Albrecht & Hamilton, 1982;Sclar et al, 1990):…”

Section: Resultsmentioning

confidence: 99%

Affective learning increases sensitivity to graded emotional faces.

Lim¹,

Pessoa²

2008

Emotion

View full text Add to dashboard Cite

How does the affective significance of emotional faces affect perceptual decisions? We manipulated affective significance by pairing 100% fearful faces with aversive electrical stimulation and hypothesized that increasing the significance of a stimulus via its prior history would lead to enhanced processing. After fear conditioning, participants viewed graded emotional faces that ranged from neutral to fearful. Faces were shown either in a color that was previously paired with shock or a color not paired with shock during conditioning. Increases in the frequency of "fearful" responses for faces shown in the shock-paired color were most robust for faces at intermediate intensity levels (40 -60% fearful). Psychometric fits to the data revealed significant increased sensitivity for shock-paired relative to unpaired faces. Thus, despite identical physical features for shock-paired and unpaired stimuli (aside from the color, which was counterbalanced), more frequent (and faster) "fearful" responses were made when participants viewed affectively significant stimuli.

show abstract

“…A few studies have noted supersaturation in the conventional CRF of some cat area 17 neurons (e.g., Albrecht & Hamilton, 1982;Bonds, 1991Bonds, , 1993Peterson & Freeman, 2003). Li and Creutzfeldt (1984) found that the CRF of cat area 17 neurons, measured using drifting bars, exhibited supersaturation in all 104 neurons investigated.…”

mentioning

confidence: 99%

The direction-selective contrast response of area 18 neurons is different for first- and second-order motion

et al. 2005

View full text Add to dashboard Cite

Cortical neurons selective for the direction of motion often exhibit some limited response to motion in their nonpreferred directions. Here we examine the dependence of neuronal direction selectivity on stimulus contrast, both for first-order (luminance-modulated, sine-wave grating) and second-order (contrast-modulated envelope) stimuli. We measured responses from single neurons in area 18 of cat visual cortex to both kinds of moving stimuli over a wide range of contrasts (1.25-80%). Direction-selective contrast response functions (CRFs) were calculated as the preferred-minus-null difference in average firing frequency as a function of contrast. We also applied receiver operating characteristic analysis to our CRF data to obtain neurometric functions characterizing the potential ability of each neuron to discriminate motion direction at each contrast level tested. CRFs for sine-wave gratings were usually monotonic; however, a substantial minority of neurons (35%) exhibited nonmonotonic CRFs (such that the degree of direction selectivity decreased with increasing contrast). The underlying preferred and nonpreferred direction CRFs were diverse, often having different shapes in a given neuron. Neurometric functions for direction discrimination showed a similar degree of heterogeneity, including instances of nonmonotonicity. For contrast-modulated stimuli, however, CRFs for either carrier or envelope contrast were always monotonic. In a given neuron, neurometric thresholds were typically much higher for second-than for first-order stimuli. These results demonstrate that the degree of a cell's direction selectivity depends on the contrast at which it is measured, and therefore is not a characteristic parameter of a neuron. In general, contrast response functions for first-order stimuli were very heterogeneous in shape and sensitivity, while those for second-order stimuli showed less sensitivity and were quite stereotyped in shape.

show abstract

Striate cortex of monkey and cat: contrast response function.

Cited by 888 publications

References 6 publications

Contrast gain control and cortical TrkB signaling shape visual acuity

Contrast gain control and cortical TrkB signaling shape visual acuity

Affective learning increases sensitivity to graded emotional faces.

The direction-selective contrast response of area 18 neurons is different for first- and second-order motion

Contact Info

Product

Resources

About