Ferran Mayayo

Musical meter emerges from the hierarchical organization of beats, which is influenced by both external acoustic cues and internally driven processes. This study examines neural and behavioral responses to auditory sequences when two simultaneous grouping patterns, melodic repetition and intensity accents, are candidates to establish a ternary or quaternary metrical representation. We also investigated how tonal coherence and tempo affect these metrical representations. To do so, we recorded finger tapping responses and electroencephalograms (EEG) from musically-naïve participants while they listened to musical sequences. The frequency-tagging analyses of the EEG indicated that melodic repetition, compared to intensity accents, enhances neural synchronization to metrical groupings. In contrast, disrupting tonal coherence with microtonal intervals reduces neural responses to both grouping patterns. No neural synchronization to any of these patterns was observed during a grouping-continuation imagery task. Behavioral data from the tapping task revealed a strong preference for quaternary over ternary groupings. These findings provide evidence that a repeating melodic pattern can establish neural responses to its periodicity, which likely scaffolds a metrical representation of the rhythmic sequences in the brain through complex interactions between bottom-up and top-down mechanisms in the formation of musical meter.

Humans are capable of recognizing the temporal organization of a rhythm by perceiving its metrical structure even when it is evoked only by temporal alterations. There is also plenty of data suggesting that several animal species can track different rhythmic cues. However, there is no clear evidence that nonhuman animals can extract metrical information from an auditory rhythm. To explore this issue, we familiarized rats (Rattus norvegicus) to auditory rhythmic sequences. We then tested them with novel sequences that presented temporal variations at the metrical, grouping, or tone duration level. We observed that the animals responded differently to the familiar versus the novel sequences, suggesting that temporal alterations are sufficient for the animals to discriminate between auditory rhythmic sequences. Likewise, the use of temporal accents could be relevant to provide metrical information, although it is still an open issue the extent to which the animals are able to induce meter from rhythmic sequences. (PsycInfo Database Record (c) 2025 APA, all rights reserved).

Meter induction is a key process for rhythm perception. However, while some nonhuman animals readily detect temporal regularities and perceive beats in auditory sequences, there is no consistent evidence that they extract metrical structures. In the present experiment, we familiarized rats (Rattus norvegicus) to auditory rhythmic sequences that evoked a duple or a triple meter. We then tested their recognition of these familiar sequences when pitted against novel sequences that evoked no meter (isotonic), evoked a different meter (either duple or triple), or were nonmetrical (nonisochronous). The animals only discriminated isochronous from nonisochronous sequences. However, we found no evidence for meter induction, as the animals did not discriminate familiar from isotonic sequences or from sequences with a different meter. The findings suggest that, under a familiarization paradigm, the natural tendency of the animals is to focus on temporal rather than melodic changes to recognize rhythmic sequences. (PsycInfo Database Record (c) 2024 APA, all rights reserved).

Octave equivalence describes the perception that two notes separated by a doubling in frequency have a similar quality. In humans, octave equivalence is important to both music and language learning and is found cross-culturally. Cross-species studies comparing human and non-human animals can help illuminate the necessary pre-conditions to developing octave equivalence. Here, we tested whether rats ( Rattus norvegicus ) perceive octave equivalence using a standardized cross-species paradigm. This allowed us to disentangle concurring hypotheses regarding the evolutionary roots of this phenomenon. One hypothesis is that octave equivalence is directly connected to vocal learning, but this hypothesis is only partially supported by data. According to another hypothesis, the harmonic structure of mammalian vocalizations may be more important. If rats perceive octave equivalence, this would support the importance of vocal harmonic structure. If rats do not perceive octave equivalence, this would suggest that octave equivalence evolved independently in several mammalian clades due to a more complex interplay of different factors such as—but not exclusively—the ability to vocally learn. Evidence from our study suggests that rats do perceive octave equivalence, thereby suggesting that the harmonic vocal structure found in mammals may be a key pre-requisite for octave equivalence. Stage 1 approved protocol: the study reported here was originally accepted as a Registered Report and the study design was approved in Stage 1. We hereby confirm that the completed experiment(s) have been executed and analysed in the manner originally approved with any unforeseen changes in those approved methods and analyses clearly noted. The approved Stage 1 protocol can be found at: https://osf.io/gvf7c/?view_only=76dc1840f31c4f9ab59eb93cbadb98b7 .