Processing vocal signals for recognition during antiphonal calling in tamarins

The ability to recognize a conspecific signal is essential to communication. In addition to recognizing the type of call, receivers extract a range of information from the signal about the producer, including identity, sex and dialect. Despite the apparent ease with which this is accomplished, few available data address the computational processes underlying recognition. While it is possible that recognition of the signal and its information content occur in a single stage of processing, different components of the signal may be processed separately. Here we present a series of experiments designed to examine this issue in the cottontop tamarin, Saguinus oedipus. Using the tamarins' natural vocal response to hearing their species-specific combination long call (CLC), antiphonal calling, we presented tamarins with manipulated and unmanipulated CLCs and measured both the number of antiphonal responses and the latency to produce an antiphonal call. Results indicated that recognition of the call type and recognition of the caller occur in separate computational stages of signal processing. These data provide insights into how sensory information is organized by a call recognition system.