Auditory sequence perception in common marmosets (Callithrix jacchus)

Abstract

One of the essential linguistic and musical faculties of humans is the ability to recognize the structure of sound configurations and to extract words and melodies from continuous sound sequences. However, monkeys’ ability to process the temporal structure of sounds is controversial. Here, to investigate whether monkeys can analyze the temporal structure of auditory patterns, two common marmosets were trained to discriminate auditory patterns in three experiments. In Experiment 1, the marmosets were able to discriminate trains of either 0.5- or 2-kHz tones repeated in either 50- or 200-ms intervals. However, the marmosets were not able to discriminate ABAB from AABB patterns consisting of A (0.5-kHz/50-ms pulse) and B (2-kHz/200-ms pulse) elements in Experiment 2, and A (0.5-kHz/50-ms pulse) and B (0.5-kHz/200-ms pulse) [or A (0.5-kHz/200-ms pulse) and B (2-kHz/200-ms pulse)] in Experiment 3. Consequently, the results indicated that the marmosets could not perceive tonal structures in terms of the temporal configuration of discrete sounds, whereas they could recognize the acoustic features of the stimuli. The present findings were supported by cognitive and brain studies that indicated a limited ability to process sound sequences. However, more studies are needed to confirm the ability of auditory sequence perception in common marmosets.