ABOVE: Six emotion-linked facial expressions of mice
JULIA KUHL
If a mouse is in a lot of pain, an experienced handler may see it in the animal’s facial expression—its narrowed eyes and bulging cheeks. But, subtler facial expressions may be more difficult to match to their moods. So researchers developed an unbiased machine learning approach to study hundreds of videos of mice and, as a result, have now catalogued a range of emotion-specific facial expressions. These expressions, the researchers show, can serve as handy readouts for studying the neural basis of emotions.
“It’s a tour de force in terms of techniques,” says neuroscientist Sheena Josselyn of the University of Toronto who was not involved in the research. “Using the techniques . . . they are really beginning to give [emotion] a scientific definition, which I think is really important.”
“The results provide an important advance by adding quantitative analysis of facial ...
