GYRUS By N., Pam M.S. - May 11, 2013 the term that is used to describe a ridged or raised portion of a convoluted brain surface. Compare sulcus. GYRUS: "Gyrus describes a ridged or raised portion of a convoluted brain surface. " Related Psychology Terms PRECUNEUS RHINAL FISSURE CALCARINE FISSURE FISSURE CALLOSAL SULCUS LINGUAL GYRUS CALCARINE AREA POSTCENTRAL GYRUS PRECENTRAL GYRUS UNCUS Cite this page: N., Pam M.S., "GYRUS," in PsychologyDictionary.org, May 11, 2013, https://psychologydictionary.org/gyrus/ (accessed February 25, 2020).