Repetitive Stimulation Enhances V1 Encoding Efficiency

Abstract

Repeated stimulus presentations reduce neuronal responses across many brain areas (repetition suppression) while improving performance in associated tasks (repetition priming). The neuronal mechanisms that enhance performance in the face of reduced brain activity are unknown. Here we demonstrate that stimulus repetition increases encoding efficiency among cortical neurons, which enhances stimulus representations despite reduced spiking activity. Using a repetition priming-evoking stimulus sequence, we recorded laminar responses in monkey primary visual cortex (V1). We found that repetition suppression is most pronounced outside the V1 layers that receive retinogeniculate input and is robust to alternating stimuli between the two eyes, suggesting that repetition suppression is of cortical origin. This V1 spiking suppression is accompanied by sharpened neural tuning as well as increased neuronal synchrony, however not by decreased response latency. These results suggest that repetition priming and repetition suppression arise from modulated cortical neuronal processing that enhances encoding efficiency as stimuli repeat.