Limits...
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.


Effects of training on neuronal properties between neurons with different orientations.(a–d) represent distributions of contrast sensitivity, OSF, Width and SNR of neurons with preferred orientation near (±20°) (NN, gray background) and away (NA, white background) from the trained orientations for control (blue) and trained (red) cats. The learning effect was not specific to the trained orientation.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
getmorefigures.php?uid=PMC4837366&req=5

f4: Effects of training on neuronal properties between neurons with different orientations.(a–d) represent distributions of contrast sensitivity, OSF, Width and SNR of neurons with preferred orientation near (±20°) (NN, gray background) and away (NA, white background) from the trained orientations for control (blue) and trained (red) cats. The learning effect was not specific to the trained orientation.

Mentions: So far we have demonstrated that the optimum spatial frequency and SNR of striate neurons were increased in trained cats, one critical question is whether these differences we observed were limited to neurons whose orientation preference corresponded to that of the target orientation. In the analysis to date we have assumed that orientation is unimportant because neuronal properties have been averaged across neurons with different oriental preferences. To examine this, we divided the neurons into two groups: neurons with optimal orientation near (±20°, NN) the target orientation and those away from the target orientations (NA). Interestingly, we did not find any significant difference in post-training neuronal properties between NN and NA in the trained cats: Threshold contrast sensitivity (t (188) = 0.808, p = 0.420), optimum spatial frequency (t (188) = 1.49, p = 0.138), tuning bandwidth (t (188) = 0.679, p = 0.498) and SNR (t (188) = 1.063, p = 0.289). The two-way ANOVA analysis also showed that there were no significant interaction between training and orientation on threshold contrast sensitivity (F (1,369) = 0.894, p = 0.345), optimum spatial frequency (F (1,369) = 2.872, p = 0.091), tuning bandwidth (F (1,369) = 1.153, p = 0.284) and SNR (F (1,369) = 0.281, p = 0.596) for the comparison of trained and untrained cats (Fig. 4). These results indicated that the neuronal differences in the training group were not orientation specific.


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)

Effects of training on neuronal properties between neurons with different orientations.(a–d) represent distributions of contrast sensitivity, OSF, Width and SNR of neurons with preferred orientation near (±20°) (NN, gray background) and away (NA, white background) from the trained orientations for control (blue) and trained (red) cats. The learning effect was not specific to the trained orientation.
© Copyright Policy - open-access
Related In: Results  -  Collection

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

f4: Effects of training on neuronal properties between neurons with different orientations.(a–d) represent distributions of contrast sensitivity, OSF, Width and SNR of neurons with preferred orientation near (±20°) (NN, gray background) and away (NA, white background) from the trained orientations for control (blue) and trained (red) cats. The learning effect was not specific to the trained orientation.
Mentions: So far we have demonstrated that the optimum spatial frequency and SNR of striate neurons were increased in trained cats, one critical question is whether these differences we observed were limited to neurons whose orientation preference corresponded to that of the target orientation. In the analysis to date we have assumed that orientation is unimportant because neuronal properties have been averaged across neurons with different oriental preferences. To examine this, we divided the neurons into two groups: neurons with optimal orientation near (±20°, NN) the target orientation and those away from the target orientations (NA). Interestingly, we did not find any significant difference in post-training neuronal properties between NN and NA in the trained cats: Threshold contrast sensitivity (t (188) = 0.808, p = 0.420), optimum spatial frequency (t (188) = 1.49, p = 0.138), tuning bandwidth (t (188) = 0.679, p = 0.498) and SNR (t (188) = 1.063, p = 0.289). The two-way ANOVA analysis also showed that there were no significant interaction between training and orientation on threshold contrast sensitivity (F (1,369) = 0.894, p = 0.345), optimum spatial frequency (F (1,369) = 2.872, p = 0.091), tuning bandwidth (F (1,369) = 1.153, p = 0.284) and SNR (F (1,369) = 0.281, p = 0.596) for the comparison of trained and untrained cats (Fig. 4). These results indicated that the neuronal differences in the training group were not orientation specific.

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.