Artificial networks learn to smell like the brain

Using machine learning, a computer model can teach itself to smell in just a few minutes. When it does, researchers have found, it builds a neural network that closely mimics the olfactory circuits that animal brains use to process odors. Animals from fruit flies to humans all use essentially the same strategy to process olfactory information in the brain. But neuroscientists who trained an artificial neural network to take on a simple odor classification task were surprised to see it replicate biology's strategy so faithfully. "The algorithm we use has no resemblance to the actual process of evolution," says Guangyu Robert Yang, an associate investigator at MIT's McGovern Institute for Brain Research, who led the work as a postdoc at Columbia University. The similarities between the artificial and biological systems suggest that the brain's olfactory network is optimally suited to its task.