Abstract
Presentation Description :
The two main pathways carrying visual signals from the eye to the cerebral cortices are called parvocellular and magnocellular, after the layers of the dorsal lateral geniculate nucleus through which they pass. Receptive fields of parvocellular and magnocellular cells conform nicely to textbook descriptions of centre-surround spatially opponent, on- or off-centre types. In my presentation I will summarise the diverse properties of receptive fields that are encountered in the evolutionary primitive intercalated / koniocellular layers of the geniculate. I will show that many koniocellular receptive fields are like those of parvocellular and magnocellar cells, but others show diverse properties including orientation selectivity, on/off nonlinear properties, and binocular responses normally associated with cortical receptive fields. Our speculation is that the koniocellular layers contribute to primordial visual pathways serving adaptive responses to visual threats and opportunities (approach/avoidance behaviours).
This is an abstract that was submitted for the 2018 ARVO Annual Meeting, held in Honolulu, Hawaii, April 29 - May 3, 2018.