Like an oddly quaint sci-fi story, scientists have managed to encode "false" memories and parts of a song into the brain of a tiny bird.
Researchers at the University of Texas Southwestern taught a zebra finch new information using optogenetics, a technique that uses light to control living neurons that have been genetically modified to be light-sensitive. This information was then used to create a behavior response in the form of a chirpy song.
Zebra finches, a small songbird native to Central Australia renowned for their musical chirps, typically learn songs by listening and mimicking as their father sings. Previous research from the same team has shown that this process is linked to a network of neurons firing between the HVC, a brain area known to be tightly linked to learning from auditory experience, and the NIf, a region linked to forming syllable-specific memories.
Reporting in the journal Science, the researchers found that artificially activating the neurons in the HVC-NIf network could simulate a similar effect of experiencing and learning. Optogenetic techniques were used to manipulate neuron activity between the NIf and HVC brain regions, thereby encoding memories into a bird that had not experienced “tutoring” from its father. These false memories were then used to learn "syllables" of the species' song.
"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," Dr Todd Roberts, a neuroscientist with UT Southwestern's O'Donnell Brain Institute, said in a statement. "The findings enabled us to implant these memories into the birds and guide the learning of their song."
However, the birds were not able to learn the whole song because these two brain regions only deal with certain parts of the song-learning process in birds. The method was only able to teach them the “syllables” of their song, with shorter bursts of light exposure to the neurons resulting in a shorter note and vice versa.
“If we figure out those other pathways, we could hypothetically teach a bird to sing its song without any interaction from its father,” Dr Roberts said. “But we’re a long way from being able to do that.”
As for implanting songs into human brains, that is a long way off. Dr Roberts explained that the human brain and the networks associated with speech are “immensely complicated” compared to those found in a songbird.
Nevertheless, this field of optogenetics could hold some real applications for humans very shortly. For example, the researchers argue their work could be used to deepen our understanding of the neural processes and genes linked to human speech disorders. It could also answer questions about why some genes related to speech are disrupted in people with autism or other neurodevelopmental conditions.