Purves chapter 12: central visual pathway: overview. Retinogeniculostriate pathway/ primary visual pathway: conveys info essential for seeing: pretectum: second major target ; collection of neurons that lies b/w thalamus and midbrain. Project into edinger-westphal nucleus (small group of nerve cells close to nucleus of oculomotor nerve in midbrain) Light increases activity of pretectal neurons --> stimulate eginder-westphal neurons -- > constrict pupil: both eyes will have a response even if only one pupil is being stimulated with light, suprachiasmatic nucleus: in hypothalamus; Temporal more extensive: superior v inferior divisions; horizontal line. Images of objects in visual field inverted in retinal surface. Objects in temporal part of visual field are seen by nasal; superior by inferior: binocular field: 2 symmetrical visual hemifields (l and r) L binocular hemifield == nasal of r eye and temporal of l eye. R binocular hemifield == nasal of l eye and temporal of r eye: visual hemifield.