Emotional valence is represented in right posterior superior temporal sulcus and medial prefrontal cortex. The posterior intermediate sulcus separates the fasciculus gracilis from the fasciculus cuneatus. The middle and inferior frontal gyri are divided by the inferior frontal sulcus. It corresponds to the angular gyrus surrounding the caudal tip of the superior temporal sulcus. The superior and middle frontal gyri are divided by the superior frontal sulcus. The most medial part of the medulla is the posterior median sulcus. The superior pontine sulcus separates the pons from the midbrain. The human primary motor cortex is located on the anterior wall of the central sulcus. It usually occurs in the mandibular labial sulcus. Also absent was part of a bordering region called the lateral sulcus (Sylvian fissure). The anterolateral sulcus is lateral to the pyramids. Ventrally the primary motor cortex is bordered by the insular cortex in the lateral sulcus. It follows the anterior interventricular sulcus around the pulmonary trunk. An anterior relieving incision is made extending down into the sulcus. They concluded that the N170 arose from the posterior superior temporal sulcus.