Researchers at the University of Washington School of Medicine have developed a software program that enlists artificial intelligence to decipher the ultrasonic vocalizations made by mice and rats.
The “DeepSqueak” program, described today in a study published by the journal Neuropsychopharmacology, focuses on squeaks and whistles that are well above the range of human hearing.
Software converts the audio signals into visual graphs, or sonograms, and then puts those images through the kinds of machine-vision algorithms that are used for autonomous vehicles.
“DeepSqueak uses biomimetic algorithms that learn to isolate vocalizations by being given labeled examples of vocalizations and noise,” Russell Marx, one of the study’s authors, explained in a news release.
Marx created the program along with fellow UW researcher Kevin Coffey, who specializes in studying the psychological effects of drugs. Marx and Coffey work in Professor John Neumaier’s lab at UW Medicine, which uses rodents to investigate behaviors related to stress and addiction.
The three authors report that DeepSqueak works better than other automated programs or unassisted audio analysis when it comes to reducing false positives and cutting down the time required for analysis.
DeepSqueak is designed to help researchers figure out what rodents are saying during drug experiments, and the work is already yielding insights.
“The animals have a rich repertoire of calls, around 20 kinds,” Coffey said. “With drugs of abuse, you see both positive and negative calls.”
Based on their vocalizations, the rodents seem happiest when they’re anticipating a reward, such as sugar, or are playing with their peers, Coffey said.
When two male mice get together, they make the same calls over and over. And when male mice sense a female mouse nearby, they utter the ultrasonic equivalents of “wolf whistles.” The whistles get more complex when the males can smell but not see the females, which suggests that male mice have distinct songs for different stages of courtship.
But this isn’t just about the mice. Neumaier, a professor of psychiatry and behavioral sciences who is associate director of UW’s Alcohol and Drug Abuse Institute, says the goal is to help human patients get through their withdrawal from alcohol or opioids.
“If scientists can understand better how drugs change brain activity to cause pleasure or unpleasant feelings, we could devise better treatments for addiction,” Neumaier said.