Neuronal basis of perceptual learning in striate cortex

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.

Can Emotional Competence Be Taught in Higher Education? A Randomized Experimental Study of an Emotional Intelligence Training Program Using a Multimethodological Approach

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Carbon Nano‐Onions Made Directly from CO2 by Molten Electrolysis for Greenhouse Gas Mitigation

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“…[28] Multiwalled carbon nanotubes (CNTs) comprised of concentric cylinders of graphene sheet have been studied in greater detail than their analogous CNO concentric spheroid counterparts CNOs. In 2015 we introduced a chemistry to synthesize CNTs at high yield by electrolysis of CO 2 , [1,[29][30][31][32][33][35][36][37][38][39] rather than their conventional CVD synthesis from organometallics. We have demonstrated [31] and quantified [39] the affinity for molten lithium carbonates to absorb both atmospheric and flue gas levels of CO 2 , and have previously utilized 13 C isotope CO 2 to track and demonstrate in molten lithium carbonate that CO 2 originating from the gas phase serves as the renewable carbon building blocks in the observed CNT product and the net reaction is in accord with [31] ( ) (…”

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