The sifting of visual information in the superior colliculus.

Kyu Hyun Lee,Markus Meister,Alvita Tran,Zeynep Turan

doi:10.7554/elife.50678

Abstract

Much of the early visual system is devoted to sifting the visual scene for the few bits of behaviorally relevant information. In the visual cortex of mammals, a hierarchical system of brain areas leads eventually to the selective encoding of important features, like faces and objects. Here, we report that a similar process occurs in the other major visual pathway, the superior colliculus. We investigate the visual response properties of collicular neurons in the awake mouse with large-scale electrophysiology. Compared to the superficial collicular layers, neuronal responses in the deeper layers become more selective for behaviorally relevant stimuli; more invariant to location of stimuli in the visual field; and more suppressed by repeated occurrence of a stimulus in the same location. The memory of familiar stimuli persists in complete absence of the visual cortex. Models of these neural computations lead to specific predictions for neural circuitry in the superior colliculus.

Highlights

Whereas the human eye takes in about one gigabit of raw visual information every second, we end up using only a few tens of bits to guide our behavior (Pitkow and Meister, 2014)
We report on three kinds of neural computations that separate behaviorally relevant from irrelevant stimuli, and we trace their emergence from the superficial to the deep layers of the superior colliculus (SC): (1) an increasing selectivity for the threat stimulus; (2) an increasing invariance to location of that stimulus; and (3) the suppression of neural responses to a familiar stimulus
To track visual computations in the mouse SC, we recorded from hundreds of neurons simultaneously in all layers of the structure using multi-electrode silicon prongs (Du et al, 2011)

Summary

Introduction

Whereas the human eye takes in about one gigabit of raw visual information every second, we end up using only a few tens of bits to guide our behavior (Pitkow and Meister, 2014). Those bits are carefully selected from the scene, and which specific bits get used depends entirely on the context and goals. How the visual brain sifts the onslaught of visual data for the few behaviorally relevant nuggets has been an enduring mystery Much research in this area has focused on the primate visual system, and the phenomena of invariant object recognition. Empirical evidence regarding the actual biological microcircuits has been difficult to obtain

Methods

Results

Conclusion