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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 not only increased contrast sensitivity at the trained SF, but also improved the cat’s visual acuity.(a) Learning curves of the four trained cats. Each color represents one cat. (b,c) Post- versus pre-training visual acuity for trained eyes and untrained eyes in trained cats, respectively. Each dot represents one eye. The points are above the dashed line (slope = 1), indicating both the visual acuity for trained and untrained eyes in trained cats improved after training.
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f2: Training not only increased contrast sensitivity at the trained SF, but also improved the cat’s visual acuity.(a) Learning curves of the four trained cats. Each color represents one cat. (b,c) Post- versus pre-training visual acuity for trained eyes and untrained eyes in trained cats, respectively. Each dot represents one eye. The points are above the dashed line (slope = 1), indicating both the visual acuity for trained and untrained eyes in trained cats improved after training.

Mentions: After these initial baseline measurements, cats were trained monocularly at 1.0 c/d using the same task as the conditioning stage for about forty days. A staircase procedure was used to track the threshold contrast of the grating for each cat over the entire training course. As expected, contrast sensitivity at the trained spatial frequency systematically increased for all the cats, by 15.34 ± 6.45 dB (Mean ± SD) on average (Fig. 2a). Training also increased the grating acuity of trained eyes from 1.08 ± 0.16 c/d to 1.46 ± 0.21 c/d (Mean ± SD; Paired t test, t (3) = 3.453, p = 0.040, Fig. 2b), and that of untrained eyes from 1.15 ± 0.17 c/d to 1.34 ± 0.17 c/d (Mean ± SD; Paired t test, t (3) = 3.326, p = 0.044, Fig. 2c). Moreover, the increase of visual acuity was not significantly different between eyes (Two way ANOVA, F (1, 12) = 0.987, p = 0.34).


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 not only increased contrast sensitivity at the trained SF, but also improved the cat’s visual acuity.(a) Learning curves of the four trained cats. Each color represents one cat. (b,c) Post- versus pre-training visual acuity for trained eyes and untrained eyes in trained cats, respectively. Each dot represents one eye. The points are above the dashed line (slope = 1), indicating both the visual acuity for trained and untrained eyes in trained cats improved after training.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC4837366&req=5

f2: Training not only increased contrast sensitivity at the trained SF, but also improved the cat’s visual acuity.(a) Learning curves of the four trained cats. Each color represents one cat. (b,c) Post- versus pre-training visual acuity for trained eyes and untrained eyes in trained cats, respectively. Each dot represents one eye. The points are above the dashed line (slope = 1), indicating both the visual acuity for trained and untrained eyes in trained cats improved after training.
Mentions: After these initial baseline measurements, cats were trained monocularly at 1.0 c/d using the same task as the conditioning stage for about forty days. A staircase procedure was used to track the threshold contrast of the grating for each cat over the entire training course. As expected, contrast sensitivity at the trained spatial frequency systematically increased for all the cats, by 15.34 ± 6.45 dB (Mean ± SD) on average (Fig. 2a). Training also increased the grating acuity of trained eyes from 1.08 ± 0.16 c/d to 1.46 ± 0.21 c/d (Mean ± SD; Paired t test, t (3) = 3.453, p = 0.040, Fig. 2b), and that of untrained eyes from 1.15 ± 0.17 c/d to 1.34 ± 0.17 c/d (Mean ± SD; Paired t test, t (3) = 3.326, p = 0.044, Fig. 2c). Moreover, the increase of visual acuity was not significantly different between eyes (Two way ANOVA, F (1, 12) = 0.987, p = 0.34).

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.