Interactivity between high and low level systems play a key role in visual cognition

Most studies examining the visual system in humans focus on the functional contribution of cortical networks, neglecting the possible involvement of subcortical structures in those processes. This apparent benign neglect may be a consequence of the fact that it is very difficult to study subcortical brain functioning in humans. In this talk, I will present evidence for the involvement of subcortical, rudimentary, mechanisms in what is usually considered cortical processess. Examples from a host of different cognitive domains will be offered, including attentional orienting, eye movement control and global-local processing. The studies utilize a multiplicity of methods including phylogenetic models, human patients, pupillomtery, imaging and behavioral studies to demonstrate the ubiquitous involvement of lower-order structures in seemingly complex cortical tasks.