Common marmosets (Callithrix jacchus) cannot recognize global configurations of sound patterns but can recognize adjacent relations of sounds

摘要

Processing the temporal configuration of discrete sounds to extract a regular pattern is fundamental to humans' faculties of perceiving words and musical phrases. To investigate such auditory pattern perception in monkeys, I trained two common marmosets to discriminate between AB-AB and AA-BB patterns under two training paradigms. One was an absolute discrimination task, in which the discrimination between these stimuli without reference cues was required. The other was a relative discrimination task, in which the detection of a change from one stimulus to the other was required. The marmosets failed in the absolute discrimination task but achieved the relative discrimination task. Failure in the absolute task indicated that the marmosets were unable to form a representation of the global sound patterns in their long-term memory stores. In contrast, success in the relative task indicated that the marmosets had short-term memory of ongoing sounds that enabled an online monitoring to detect deviations between incoming sounds and the anticipated upcoming sounds. Thus, the current findings imply that marmosets can at least perceive adjacent tone relations in an auditory stream regardless of the temporal configuration of the global sound patterns.