Seeing and acting at the same time: challenges for brain (and) research.

Traditionally, studies of the visual system of nonhuman primates have investigated neurons while the animal fixates a target in a static environment. Clearly, this is not what our everyday life is like; neither the environment nor we are stationary while we act in our world. On the contrary, we constantly move our eyes or limbs. Here we review a number of recent studies describing the brain in a more realistic mode of operation.