Although changes in brain activity during learning have been extensively examined at the single neuron level, the coding strategies employed by cell populations remain mysterious. We examined neuronal populations in macaque area V4 during a rapid form of perceptual learning that emerges within tens of minutes. Multiple single-units and LFP responses were recorded as monkeys improved their performance in an image discrimination task. We show that the increase in behavioral performance during learning is predicted by a tight coordination of spike timing with local population activity. More spike-LFP theta synchronization is correlated with higher learning performance while high-frequency synchronization is unrelated with changes in performance, but these changes were absent once learning had stabilized and stimuli became familiar or in the absence of learning. These findings reveal a novel mechanism of plasticity in visual cortex by which elevated low-frequency synchronization between individual neurons and local population activity accompanies the improvement in performance during learning.
Animal experimentation: This study was performed in strict accordance with the recommendations in the Guide for the Care and Use of Laboratory Animals of the National Institutes of Health. All of the animals were handled according to approved institutional animal care and use committee (IACUC) protocols (AWC-14-0114) of the Texas Health Science Center at Houston. The protocol was approved by the Committee on the Ethics of Animal Experiments of the Texas Health Science Center at Houston. All surgery was performed under isoflurane anesthesia, and every effort was made to minimize suffering.
- Sacha B Nelson, Brandeis University, United States
© 2015, Wang & Dragoi
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