Using isochrony, but not meter, to discriminate rhythmic sequences in rats (Rattus norvegicus).

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).