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Tuesday, March 24, 2015 - 3:00pm

IRCS Conference Room

Sandra R. Waxman
Professor of Psychology
Northwestern University

Listening to the call of the wild: Human infants' responses to vocalizations of other species

Language is a signature of our species. To acquire a language, infants must identify which signals are part of their language and discover how these are linked to the objects and events they encounter. For infants as young as 3 months of age, listening to human vocalizations promotes the formation of object categories, a fundamental cognitive capacity (Ferry Hespos & Waxman, 2010). Moreover, this precocious link is not unique to human vocalizations: For human infants at 3 and 4 months, non-human primate vocalizations (Madagascar, blue-eyed lemur: Eulemur macaco flavifrons) also promote object categorization, mirroring precisely the advantages conferred by human vocalizations, but by 6 months, non-human primate vocalizations no longer exert this advantageous effect (Ferry, et al., 2013). This suggests that the link between human vocalizations and cognition emerges from a broader template that initially encompasses vocalizations of human and non-human primates (but not backward speech), and that is rapidly tuned specifically to human vocalizations. In today's talk, I'll present new evidence aimed at identifying (a) the boundary conditions on the range of naturally-produced vocalizations that initially facilitate object categorization (zebra finch: Taeniopygia guttata) and (b) the guiding force of exposure as infants home in on which signals they will continue to link to cognition and which they will 'tune out.'