Scientists have artificially altered the song of young birds by implanting song memories into their brains with light pulses, in a discovery which may lead to developments in the treatment of humans with speech difficulties.
The research team at the University of Texas Southwestern (UTSW), whose findings were published in the journal Science, chose to use male zebra finches in their experiments because the vocal development of the Australian species is similar to that of humans.
The team used light pulses to activate a circuit of neutrons in the birds’ brains, in a relatively new process called optogenetics. This allowed the young finches to learn parts of song which they were not taught by their parents.
It is hoped the findings will yield clues on where to look in the human brain to improve our understanding of conditions which affect language like autism.
Todd Roberts, a neuroscientist who conducted the research at the UTSW’s O’Donnell Brain Institute, said in a press release: “This is the first time we have confirmed brain regions that encode behavioral-goal memories – those memories that guide us when we want to imitate anything from speech to learning the piano.”
“The findings enabled us to implant these memories into the birds and guide the learning of their song.”
Roberts added that he and his colleagues did not teach the birds all they needed to know. Instead, they encoded memories into the young birds which taught them syllables of song – the longer the light exposure, the longer the note.
Stressing it was just one piece of the larger puzzle, Roberts said: “If we figure out those other pathways, we could hypothetically teach a bird to sing its song without any interaction from its father. But we’re a long way from being able to do that.”
The two regions of the brain which the research focused on were the nucleus interfacialis (NIf) and the high vocal center (HVC), a key area of the brain in songbirds. The scientists found that the encoded memories were formed in the NIf but were then shared elsewhere.
When communication between the NIf and HVC was shut off prior to the finches being tutored, the birds were not able to copy the song.