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Neuronal basis of perceptual learning in striate cortex.

Ren Z, Zhou J, Yao Z, Wang Z, Yuan N, Xu G, Wang X, Zhang B, Hess RF, Zhou Y - Sci Rep (2016)

Bottom Line: It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect).Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally.These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR.

View Article: PubMed Central - PubMed

Affiliation: CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, P.R. China.

ABSTRACT
It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect). However, the underlying neural mechanisms of this high spatial frequency training improvement remain to be elucidated. In the present study, we examined four properties of neurons in primary visual cortex (area 17) of adult cats that exhibited significantly improved acuity after contrast sensitivity training with a high spatial frequency grating and those of untrained control cats. We found no difference in neuronal contrast sensitivity or tuning width (Width) between the trained and untrained cats. However, the trained cats showed a displacement of the cells' optimal spatial frequency (OSF) to higher spatial frequencies as well as a larger neuronal signal-to-noise ratio (SNR). Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally. These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR.

No MeSH data available.


Training effect on striate neurons.Blue and red colored plots represent control and trained cats, respectively. LSF, MSF and HSF indicate neurons with low spatial frequency (<0.45 c/d), medium spatial frequency (0.45–0.85 c/d) and high spatial frequency (>0.85 c/d), respectively. (a) There was no significant difference between the threshold contrast sensitivity (TC) of striate neurons from control and trained cats. (b) There was significant difference between the OSF distribution for striate neurons from control and trained cats. The arrows indicated the mean of OSF values (0.55 ± 0.02 c/d for control cats, and 0.70 ± 0.03 c/d for trained cats) (mean ± SE). (c) Neither significant training effect nor interactions between training and SF were found in Width between trained and control cats. Error bars indicate SEM. (d) Significant difference was showed in SNR between control and trained cats (Two way ANOVA, F (1,367) = 9.904, p = 0.002). ‘*’indicates p < 0.05.
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f3: Training effect on striate neurons.Blue and red colored plots represent control and trained cats, respectively. LSF, MSF and HSF indicate neurons with low spatial frequency (<0.45 c/d), medium spatial frequency (0.45–0.85 c/d) and high spatial frequency (>0.85 c/d), respectively. (a) There was no significant difference between the threshold contrast sensitivity (TC) of striate neurons from control and trained cats. (b) There was significant difference between the OSF distribution for striate neurons from control and trained cats. The arrows indicated the mean of OSF values (0.55 ± 0.02 c/d for control cats, and 0.70 ± 0.03 c/d for trained cats) (mean ± SE). (c) Neither significant training effect nor interactions between training and SF were found in Width between trained and control cats. Error bars indicate SEM. (d) Significant difference was showed in SNR between control and trained cats (Two way ANOVA, F (1,367) = 9.904, p = 0.002). ‘*’indicates p < 0.05.

Mentions: In Fig. 3a, neurons’ contrast sensitivities are plotted as a function of spatial frequency for the two groups. Neurons were clustered into seven groups based on their optimum spatial frequency. Contrast sensitivity of individual neurons was defined as the inverse of each neuron’s threshold contrast sensitivity, which was obtained by receiver operating characteristic (ROC) analysis15 (See Supplemental method). Surprisingly, we did not find any significant differences of threshold contrast sensitivity between the trained and untrained groups (F (1,359) = 0.011, p = 0.917, Fig. 3a). Furthermore, we found no significant interaction between training and stimulus spatial frequency for neuronal threshold contrast sensitivity (F (6,359) = 1.601, p = 0.146), which means that the shape of the contrast sensitivity function was invariant between the two groups. These results suggest that the improved visual acuity we observed is not likely to be accounted for by a change in neuronal contrast sensitivity of individual striate neurons.


Neuronal basis of perceptual learning in striate cortex.

Ren Z, Zhou J, Yao Z, Wang Z, Yuan N, Xu G, Wang X, Zhang B, Hess RF, Zhou Y - Sci Rep (2016)

Training effect on striate neurons.Blue and red colored plots represent control and trained cats, respectively. LSF, MSF and HSF indicate neurons with low spatial frequency (<0.45 c/d), medium spatial frequency (0.45–0.85 c/d) and high spatial frequency (>0.85 c/d), respectively. (a) There was no significant difference between the threshold contrast sensitivity (TC) of striate neurons from control and trained cats. (b) There was significant difference between the OSF distribution for striate neurons from control and trained cats. The arrows indicated the mean of OSF values (0.55 ± 0.02 c/d for control cats, and 0.70 ± 0.03 c/d for trained cats) (mean ± SE). (c) Neither significant training effect nor interactions between training and SF were found in Width between trained and control cats. Error bars indicate SEM. (d) Significant difference was showed in SNR between control and trained cats (Two way ANOVA, F (1,367) = 9.904, p = 0.002). ‘*’indicates p < 0.05.
© Copyright Policy - open-access
Related In: Results  -  Collection

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getmorefigures.php?uid=PMC4837366&req=5

f3: Training effect on striate neurons.Blue and red colored plots represent control and trained cats, respectively. LSF, MSF and HSF indicate neurons with low spatial frequency (<0.45 c/d), medium spatial frequency (0.45–0.85 c/d) and high spatial frequency (>0.85 c/d), respectively. (a) There was no significant difference between the threshold contrast sensitivity (TC) of striate neurons from control and trained cats. (b) There was significant difference between the OSF distribution for striate neurons from control and trained cats. The arrows indicated the mean of OSF values (0.55 ± 0.02 c/d for control cats, and 0.70 ± 0.03 c/d for trained cats) (mean ± SE). (c) Neither significant training effect nor interactions between training and SF were found in Width between trained and control cats. Error bars indicate SEM. (d) Significant difference was showed in SNR between control and trained cats (Two way ANOVA, F (1,367) = 9.904, p = 0.002). ‘*’indicates p < 0.05.
Mentions: In Fig. 3a, neurons’ contrast sensitivities are plotted as a function of spatial frequency for the two groups. Neurons were clustered into seven groups based on their optimum spatial frequency. Contrast sensitivity of individual neurons was defined as the inverse of each neuron’s threshold contrast sensitivity, which was obtained by receiver operating characteristic (ROC) analysis15 (See Supplemental method). Surprisingly, we did not find any significant differences of threshold contrast sensitivity between the trained and untrained groups (F (1,359) = 0.011, p = 0.917, Fig. 3a). Furthermore, we found no significant interaction between training and stimulus spatial frequency for neuronal threshold contrast sensitivity (F (6,359) = 1.601, p = 0.146), which means that the shape of the contrast sensitivity function was invariant between the two groups. These results suggest that the improved visual acuity we observed is not likely to be accounted for by a change in neuronal contrast sensitivity of individual striate neurons.

Bottom Line: It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect).Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally.These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR.

View Article: PubMed Central - PubMed

Affiliation: CAS Key Laboratory of Brain Function and Disease, and School of Life Sciences, University of Science and Technology of China, Hefei, Anhui, P.R. China.

ABSTRACT
It is well known that, in humans, contrast sensitivity training at high spatial frequency (SF) not only leads to contrast sensitivity improvement, but also results in an improvement in visual acuity as assessed with gratings (direct effect) or letters (transfer effect). However, the underlying neural mechanisms of this high spatial frequency training improvement remain to be elucidated. In the present study, we examined four properties of neurons in primary visual cortex (area 17) of adult cats that exhibited significantly improved acuity after contrast sensitivity training with a high spatial frequency grating and those of untrained control cats. We found no difference in neuronal contrast sensitivity or tuning width (Width) between the trained and untrained cats. However, the trained cats showed a displacement of the cells' optimal spatial frequency (OSF) to higher spatial frequencies as well as a larger neuronal signal-to-noise ratio (SNR). Furthermore, both the neuronal differences in OSF and SNR were significantly correlated with the improvement of acuity measured behaviorally. These results suggest that striate neurons might mediate the perceptual learning-induced improvement for high spatial frequency stimuli by an alteration in their spatial frequency representation and by an increased SNR.

No MeSH data available.