Even if you don’t have rhythm, your pupils do. In a new study, neuroscientists played drumming patterns from Western music, including beats typical in pop and rock, while asking volunteers to focus on computer screens for an unrelated fast-paced task that involved pressing the space bar as quickly as possible in response to a signal on the screen. Unbeknownst to the participants, the music omitted strong and weak beats at random times. (You can listen below for an example of a music clip they used. If you listen carefully, you can hear bass and hi-hat beats omitted throughout.) Eye scanners tracked the dilations of the subjects’ pupils as the music played. Their pupils enlarged when the rhythms dropped certain beats, even though the participants weren’t paying attention to the music. The biggest dilations matched the omissions of the beats in the most prominent locations in the music, usually the important first beat in a repeated set of notes. The results suggest that we may have an automatic sense of “hierarchical meter”—a pattern of strong and weak beats—that governs our expectations of music, the researchers write in the February 2017 issue of Brain and Cognition. Perhaps, the authors say, our eyes reveal clues into the importance that music and rhythm plays in our lives.