The term accessory insular gyrus (AIG) refers to a small convolution of the insula (INS) identified by dissection in 82% of human hemispheres. One of five gyri of the anterior insula (INSa), it is bounded rostrally by the anterior limiting sulcus. A branch of the same sulcus separates it dorsally from the anterior short gyrus. It is continuous ventrally with the transverse insular gyrus ( Ture-1999 ). It is not found in macaques or rodents ( NeuroNames ).