The
pretectal area, or
pretectum, is a
midbrain structure composed of seven nuclei and comprises part of the subcortical visual system. Through reciprocal bilateral projections from the
retina, it is involved primarily in mediating behavioral responses to acute changes in ambient light such as the
pupillary light reflex, the
optokinetic reflex, and temporary changes to the
circadian rhythm. In addition to the pretectum's role in the visual system, the anterior pretectal nucleus has been found to mediate
somatosensory and
nociceptive information.