RT Journal Article
SR Electronic
T1 Learning orthogonalizes visual cortical population codes
JF bioRxiv
FD Cold Spring Harbor Laboratory
SP 2021.05.23.445338
DO 10.1101/2021.05.23.445338
A1 Failor, Samuel W.
A1 Carandini, Matteo
A1 Harris, Kenneth D.
YR 2021
UL http://biorxiv.org/content/early/2021/05/23/2021.05.23.445338.abstract
AB The response of a neuronal population to a stimulus can be summarized by a vector in a high-dimensional space. Learning theory suggests that the brain should be most able to produce distinct behavioral responses to two stimuli when the rate vectors they evoke are close to orthogonal. To investigate how learning modifies population codes, we measured the orientation tuning of 4,000-neuron populations in visual cortex before and after training on a visual discrimination task. Learning suppressed responses to the task-informative stimuli, most strongly amongst weakly-tuned neurons. This suppression reflected a simple change at the population level: sparsening of population responses to relevant stimuli, resulting in orthogonalization of their rate vectors. A model of F-I curve modulation, requiring no synaptic plasticity, quantitatively predicted the learning effect.Competing Interest StatementThe authors have declared no competing interest.