Sam Ling

Boston University

Attention alters orientation processing in the human LGN

 

The lateral geniculate nucleus (LGN) is the first brain area to receive projections from the retina, yet its functional role in shaping visual perception remains something of a mystery. Ever since the pioneering work of Hubel & Wiesel, the standard models for vision have treated the LGN primarily as a passive ‘relay station’, simply forwarding information to the visual cortex. In this talk, I will present results demonstrating that, contrary to the standard models, the human LGN plays a very active role in vision, filtering incoming information in ways that were previously believed to arise in visual cortex. Our results reveal three fundamental properties of the human LGN. First, we discovered a cornerstone selective process within the human LGN that has, for decades, been believed to only emerge in cortex: orientation selectivity. We then show that these subcortical orientation representations elicit competitive interactions between each other—a neural computation previously only believed to transpire in the cortex. Finally, we show that the nature of these subcortical orientation representations depend on attentional feedback. Taken together, these results suggest that the LGN serves as a perceptual gateway, filtering sensory information before it even reaches cortex. These findings have the potential to alter how we model even the basic selective properties in the visual system, as well as how we understand attentional feedback.