Abstract

B. J. White, D. J. Berg, J. Y. Kan, R. A. Marino, L. Itti, D. P. Munoz, Superior colliculus neurons encode a visual saliency map during free viewing of natural dynamic video, Nature Communications, Vol. 8, No. 14263, pp. 1-9, Jan 2017. [2015 impact factor: 11.329] (Cited by 148)

Abstract: Models of visual attention postulate the existence of a saliency map whose function is to guide attention and gaze to the most conspicuous regions in a visual scene. Although cortical representations of saliency have been reported, there is mounting evidence for a subcortical saliency mechanism, which pre-dates the evolution of neocortex. Here, we conduct a strong test of the saliency hypothesis by comparing the output of a well-established computational saliency model with the activation of neurons in the primate superior colliculus (SC), a midbrain structure associated with attention and gaze, while monkeys watched video of natural scenes. We find that the activity of SC superficial visual-layer neurons (SCs), specifically, is well-predicted by the model. This saliency representation is unlikely to be inherited from fronto-parietal cortices, which do not project to SCs, but may be computed in SCs and relayed to other areas via tectothalamic pathways.

Themes: Model of Bottom-Up Saliency-Based Visual Attention, Computational Modeling, Monkey Electrophysiology