Accept no imitations, unless you’re learning to speak
Birdsong learning was admittedly my favorite area of neuroscience as a young scientist, not only because of the auditory aesthetic of chirping canaries, but also because the way juvenile songbirds learn to sing is intriguingly similar to how humans learn to speak. Thus I’m moved to give special notice to a paper in PLoS Biology by Sebastian Haesler, Constance Sharff and colleagues. This new study confirms in genetic detail the parallels between singing birds and human language.
A genetically determined speech abnormality has been linked to a transcription factor FoxP2, and this gene’s function is believed to be important in the basal ganglia of the brain. FOXP2 is also expressed in the basal ganglia of canaries and zebrafinches at a time when these birds learn their songs, providing an intriguing suggestion of its importance for song learning as well. Now, Haesler et al. accomplished the technical feat of knocking down FoxP2 (using RNAi) in the basal ganglia before zebrafinches start to imitate songs from adult tutors. With FoxP2 experimentally altered, these birds experienced a host of problems imitating their tutors, including high variability in the acoustic structure of the song and duration of the syllables. This is akin to developmental verbal dyspraxia seen in children that have inherited a version of FoxP2 with a chromosomal translocation.
The importance of understanding language difficulties is not lost on me, especially now that I have a bubbly, babbly 10-month-old son who already echoes my words (he clearly said “chicken” last night during dinner). Although the translational benefit is yet unclear, this new experimental insight only reinforces what the field has inferred based on behavior: that hopefully what we learn from our feathered friends really will teach us something profound about human language as well.