A spiking thalamus model for form and motion processing of images

The thalamus, far from being a simple relay, supports several functions including attention and awareness. Recent spiking models of the thalamus tend to focus on abstract thalamocortical features such as rhythms and synchrony. Here a new spiking retino-thalamic model is presented that reproduces several aspects in visual processing including distinct form and motion processing pathways. Using test and natural image sequences, differences between parvocellular and magnocellular relay neurons are studied. In line with several experimental results, parvocellular neurons are found to be more sensitive to changes in color (necessary for form processing) than temporal frequency (necessary for motion processing) and conversely for magnocellular neurons. This model can in turn be used as input into subsequent cortical models or as a tool to aid in experimentation. Future extensions could include modeling brainstem or cortical influence on thalamic processing, as well as the control of virtual agents.