Rapid Brain Responses to Familiar vs. Unfamiliar Music - an EEG and Pupillometry study

Human listeners exhibit marked sensitivity to familiar music - perhaps most readily revealed by popular \"name that tune\" games, in which listeners often succeed in recognizing a familiar song based on extremely brief presentation. In this work we used electro-encephalography (EEG) and pupillometry to reveal the temporal signatures of the brain processes that allow differentiation between familiar and unfamiliar music. Participants (N=10) passively listened to snippets (750 ms) of familiar and, acoustically matched, unfamiliar songs, presented in random order. A group of control participants (N=12), which were unfamiliar with all of the songs, was also used. In the main group we reveal a rapid differentiation between snippets from familiar and unfamiliar songs: Pupil responses showed greater dilation rate to familiar music from 100-300 ms post stimulus onset. Brain responses measured with EEG showed a differentiation between familiar and unfamiliar music from 350 ms post onset but, notably, in the opposite direction to that seen with pupillometry: Unfamiliar snippets were associated with greater responses than familiar snippets. Possible underlying mechanisms are discussed.