Churchland lab

Sharon Gobes alongside Sahitya Raja and Pim Chirathivat

In humans, massive changes take place in the brain over the course of language learning in infants. A poster today from Wellesley College, presented by 3 undergraduate students from Sharon Gobes lab, hope to gain insight into this process by studying the brains of juvenile birds around the time they learn their father’s song. In birds, song is known to preferentially activate neurons on the left side of the brain; a leftwards lateralization is likewise seen in humans. The group wondered whether this is an active process: would song natually activate the left hemisphere, even in birds who weren’t exposed to song during development?

Song stimulus (left) and a frequency matched control (right)

To test this, they reared a cohort of birds without exposure to a tutor’s song and measured neural activity in the caudomedial nidopallium, a structure involved in song. In this special cohort, birdsong didn’t have its characteristic effect on the left hemisphere. Instead, both hemispheres responded. Interestingly, a control sound with the same frequency profile activated the birds’ brain in a normal fashion, suggesting that they could process ordinary sounds typically. These results suggest that changes in the brain during vocal learning are driven by exposure to the right stimulus- in this case, the song of a tutor. The take home message? Appropriate developmental environments are necessary, even for innate behaviors.