Superior colliculus neurons encode a visual saliency map during free viewing of natural dynamic video

Nat Commun. 2017 Jan 24;8:14263. doi: 10.1038/ncomms14263.


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.

Publication types

  • Research Support, Non-U.S. Gov't

MeSH terms

  • Animals
  • Attention / physiology*
  • Computer Simulation
  • Macaca mulatta
  • Male
  • Models, Animal
  • Models, Neurological*
  • Neural Pathways
  • Neurons / physiology*
  • Photic Stimulation / methods
  • Saccades
  • Software
  • Superior Colliculi / cytology
  • Superior Colliculi / physiology*
  • Thalamus / physiology
  • Visual Perception / physiology*