Evolution of Visual Attention in Primates

Selective attention refers to the ability to voluntarily prioritize information that is chosen from competing inputs and is therefore different from the reflexive orienting to salient events in the environment. While orienting responses are mediated by the midbrain and are present in many species outside the mammalian line including reptiles, amphibians, and birds, the neural machinery needed for selective processing recruits a large-scale thalamocortical network. This network has primarily been studied in nonhuman and human primates and has emphasized the visual domain. We review the principles of attentional modulation in the primate visual system as well as the principles of attentional control exerted by higher-order cortex and the thalamus, emphasizing both commonalities and differences in mechanisms observed in the human and nonhuman primate brain.