the AVS is involved in recognizing auditory objects. At the level of the primary auditory cortex, recordings from monkeys showed higher percentage of neurons selective for learned melodic sequences in area R than area A1, and a study in humans demonstrated more selectivity for heard syllables in the anterior Heschl's gyrus (area hR) than posterior Heschl's gyrus (area hA1). In downstream associative auditory fields, studies from both monkeys and humans reported that the border between the anterior and posterior auditory fields (Figure 1-area PC in the monkey and mSTG in the human) processes pitch attributes that are necessary for the recognition of auditory objects. The anterior auditory fields of monkeys were also demonstrated with selectivity for con-specific vocalizations with intra-cortical recordings. and functional imaging One fMRI monkey study further demonstrated a role of the aSTG in the recognition of individual voices. The role of the human mSTG-aSTG in sound recognition was demonstrated via functional imaging studies that correlated activity in this region with isolation of auditory objects from background noise, and with the recognition of spoken words, voices, melodies, environmental sounds, and non-speech communicative sounds. A meta-analysis of fMRI studies further demonstrated functional dissociation between the left mSTG and aSTG, with the former processing short speech units (phonemes) and the latter processing longer units (e.g., words, environmental sounds). A study that recorded neural activity directly from the left pSTG and aSTG reported that the aSTG, but not pSTG, was more active when the patient listened to speech in her native language than unfamiliar foreign language. Consistently, electro stimulation to the aSTG of this patient resulted in impaired speech perception (see also for similar results). Intra-cortical recordings from the right and left aSTG further demonstrated that speech is processed laterally to music. An fMRI study of a patient with impaired sound recognition (auditory agnosia) due to brainstem damage was also shown with reduced activation in areas hR and aSTG of both hemispheres when hearing spoken words and environmental sounds. Recordings from the anterior auditory cortex of monkeys while maintaining learned sounds in working memory, and the debilitating effect of induced lesions to this region on working memory recall, further implicate the AVS in maintaining the perceived auditory objects in working memory. In humans, area mSTG-aSTG was also reported active during rehearsal of heard syllables with MEG. and fMRI The latter study further demonstrated that working memory in the AVS is for