アイテム詳細

要旨

The human voice not only transmits spoken language, but itself carries considerable meaning. Reflecting this importance, imaging studies have identified a region in the auditory cortex of the human brain that is sensitive to the human voice. For animals that cannot expand their vocal repertoire linguistically, the correct interpretation of the vocalizations of their conspecifics is of even greater importance for survival and social interactions. However, it is uncertain whether other primates share homologous voice regions or whether the human voice area is tightly linked to human language and thus unique. Here, we used high-resolution functional imaging (fMRI) of macaque monkeys to compare the strength of the activity response to conspecific vocalizations with that elicited by other sound categories, including the vocalizations of heterospecifics. We found several brain regions demonstrating a strong preference for conspecific vocalizations and identified a candidate ‘voice’ area located in the higher proc
essing stages of auditory cortex, in the anterior portions of the superior-temporal plane (STP). In contrast, the corresponding well-known human voice area resides below the STP, highlighting the possibility of an evolutionary expansion and differentiation of the human auditory cortex away from the STP. The presence of a voice region in nonhuman primates supports the notion that such specialized areas do not depend on linguistic capabilities. In all cases, our findings suggest that the auditory cortex of other vocal animals possess regions that are specialized for processing the ‘voice‘ of conspecifics.