Neural Oscillations and N400 Responses in Familiar Versus Unfamiliar Melodies

Abstract

Music must serve a purpose; it must be a part of something larger than itself, a part of humanity.
Pau Casals

This research project is focused on music cognition, aiming to answer which mechanisms are involved in our brains when we process familiar versus unfamiliar melodies, as well as the responses to in-key violations. In-key violations are considered musical semantic violations within melodies, similar to linguistic semantic violations within sentences. We endeavor to see how neural oscillations are triggered in known versus unknown music, focusing on theta and gamma modulation [1]. Moreover, regarding the in-key violations, this research tries to shed light on the N400 ERP elicited.

Despite extensive focus on the N400 in language, its role in music remains understudied. Linguistic and musical cognition may be supported by shared syntactic processing resources, and ERP interference studies involving concurrent language/music processing show effects when both processing domains are simultaneously perturbed by violations [2]. However, the N400 that occurs with contextual violations within stimuli has been researched decently well within spoken language, but less so with music.
Current knowledge suggests that unexpected notes may elicit a musical analogue of language N400 effects, but only for familiar melodies. Therefore, components of language and music processing may be shared, particularly mechanisms responsible for managing access and retrieval of information from long-term memory [3].

In brain oscillations, the neural responses modulated by familiarization aren't spectrally clear, but it has been observed that responses change with each repetition of a music piece. Distinct patterns of event-related desynchronization (ERD) in gamma and theta oscillations during the familiarization with initially unknown music have been found [1].

This research is part of a larger international project on semantic music memory in Alzheimer's patients. In Vienna, the brain activity of 40 participants is being recorded using EEG while they are exposed to familiar (Austrian songs) versus unfamiliar music (newly composed).

We anticipate N400 responses to memory violations, especially in familiar songs. Theta and gamma oscillations may be related to the memory of music, and uncovering their neural dynamics is key to grasping their roles during familiarization.

Finally, this study can provide insights into music processing mechanisms and the neural basis of memory formation and retrieval in music cognition. It deepens our understanding of cognitive processes in music and language processing, with potential applications in Alzheimer’s disease research.

References

[1] A. Malekmohammadi, S. K. Ehrlich, and G. Cheng, "Modulation of theta and gamma oscillations during familiarization with previously unknown music" Brain research, vol. 1800 p. 148198, February 2023 [Accessed May 3, 2024]

[2] R. A. Miranda, and M. T. Ullman, "Double dissociation between rules and memory in music: an event-related potential study" NeuroImage vol. 38, no. 2, p. 331–345. November 2007 [Accessed May 5, 2024]

[3] N. Calma-Roddin and J. E. Drury. "Music, Language, and The N400: ERP Interference Patterns Across Cognitive Domains" Scientific reports, vol. 10, no. 1, p. 11222. July 2020 [Accessed May 5, 2024]