Visual topography of the striate projection zone in the posterior superior temporal sulcus (MT) of the macaque

in the striate projection zone in the posterior portion of the superior temporal sulcus of the macaque (MT) was mapped with mul-tiunit electrodes. The animals were immo-bilized and anesthetized and in each animal 25-35 electrode penetrations were typically made over several recording sessions. 2. MT contains a representation of vir-tually the entire contralateral visual field. The representation of the vertical meridian forms its ventrolateral border and lies near the bottom of the lower bank of the superior temporal sulcus (STS). The representation of the horizontal meridian runs across the floor of STS. The upper field is located ven-tral and anterior and the lower field dorsal and posterior. The medial border lies at the junction of the floor of STS and its upper bank. 3. MT is similar to striate cortex in being a first-order transformation of the visual field. In both areas, receptive-field size and cortical magnification increase with eccen-tricity. MT is much smaller than striate cor-tex and has much larger receptive fields at a given eccentricity and a cruder topog-raphy. 4. The results further support the sug-gestion that MT in the macaque is homol-ogous to visual area MT in New World pri-mates