The Representation of Time Windows in Primate Auditory Cortex

Whether human and nonhuman primates process the temporal dimension of sound similarly remains an open question. We examined the brain basis for the processing of acoustic time windows in rhesus macaques using stimuli simulating the spectrotemporal complexity of vocalizations. We conducted functional magnetic resonance imaging in awake macaques to identify the functional anatomy of response patterns to different time windows. We then contrasted it against the responses to identical stimuli used previously in humans. Despite a similar overall pattern, ranging from the processing of shorter time windows in core areas to longer time windows in lateral belt and parabelt areas, monkeys exhibited lower sensitivity to longer time windows than humans. This difference in neuronal sensitivity might be explained by a specialization of the human brain for processing longer time windows in speech.