[Superior colliculus as a subcortical center for visual selection]

Our visual system has limited resources, which need to be allocated in priority to the most relevant elements of the environment. The brain centers of this allocation mechanism, called visual attention, have been studied primarily in cortex. In this review, we describe the role of the superior colliculus, a structure of the brainstem, in attention control. This nucleus exerts its influence on visual selection independently of cortical attentional mechanisms. The exact nature of the subcortical circuits involved remains unknown but it can be hypothesized that the loop connecting the superior colliculus to the basal ganglia are a central actor of this subcortical selection process.