P1-28: Supranormal Orientation Selectivity of Visual Neurons in Orientation-Restricted Animals

Abstract

Altered sensory experience in early life often leads to remarkable adaptations in humans and animals. Consistent with this, previous studies have reported that restricting visual inputs in young animals can make drastic long-lasting changes in the early sensory areas of their brains. Typically, the majority of sensory neurons are allocated to stimulus features to which the animals were exposed. However, if that is the only change, it will make the sensory encoding highly redundant with many neurons signaling the same features. Are there additional changes, heretofore unnoticed, to functional properties of single neurons in such adaptation processes? Here we show that stimulus selectivities like the sharpness of tuning of single neurons in the primary visual cortex are modified to match a particular environment that has a restricted range of orientations. Specifically, we found in orientation-restricted animals that neurons tuned to an experienced orientation show sharper orientation tuning than neurons in normal animals, whereas the opposite was true for neurons tuned to non-experienced orientations. The sharpened tuning appears to be due to elongated receptive fields. Additionally, quality of signals such as the signal-to-noise ratio can be improved by averaging the activities of a population of neurons unless the same noise source is shared. Correlation of noise shared across neurons in the orientation-restricted animals was comparable to that in normal animals, confirming the potential for such improvements. Our results demonstrate that restricted sensory experiences can sculpt the supranormal functions of neurons tailored for a particular environment.