Fine-grained Implicit Memory for Key and Tempo

Abstract

Listeners remember the pitch level (key) and tempo of musical recordings they have heard multiple times. They also have long-term implicit memory for the key and tempo of novel melodies heard for the first time in the laboratory. In previous research, however, the stimulus melodies were simple and repetitive and the changes in key or tempo were large. Here, we tested the limits of implicit memory for the key and tempo of more complex stimulus melodies. Musically trained and untrained listeners heard 12 novel melodies during an exposure phase and 24 (12 old, 12 new) during a subsequent test (recognition) phase. From exposure to test, half of the melodies were transposed up or down (changed in key) (Experiment 1), or sped up or slowed down (Experiment 2), but to varying degrees. Musically trained listeners displayed enhanced recognition, but transposing or changing the tempo of the melodies reduced performance similarly for all listeners. The effect of the key change did not wane as the transposition was reduced from 6 semitones to 1, but recognition in general was worse as the pitch range of the stimulus melodies increased. The magnitude of the tempo change had a very small effect on response patterns, but Bayesian analyses indicated that the observed data were more likely without considering magnitude. The results suggest that musically trained and untrained listeners have implicit memory for key and tempo that is remarkably fine-grained, even for melodies that are heard for the first time in the laboratory, such that small changes in either feature make a melody less recognizable.