The control of low-level information flow in the visual system.

Visual information processing needs to be error free and efficient. Our visual system tries to achieve the first goal by accommodating a wide variety of visual algorithms for the extraction of the relevant features in the scene, while at the same time the second goal is addressed by controlling the amount of visual information flow in the network employing selective attention. Attentional or pre-attentional mechanisms are found throughout many visual areas and these processes may start as early as in the visual thalamus (lateral geniculate nucleus, LGN). In this review we pay particular attention to experimental and theoretical findings which indicate that even low-level structures, such as LGN and V1, can play a major role in the flow-control of visual information.