Replication of population-level differences in auditory-motor synchronization ability in a Norwegian-speaking population.

The Speech-to-Speech Synchronization test is a powerful tool in assessing individuals' auditory-motor synchronization ability, namely the ability to synchronize one's own utterances to the rhythm of an external speech signal. Recent studies using the test have revealed that participants fall into two distinct groups-high synchronizers and low synchronizers-with significant differences in their neural (structural and functional) underpinnings and outcomes on several behavioral tasks. Therefore, it is critical to assess the universality of the population-level distribution (indicating two groups rather than a normal distribution) across populations of speakers. Here we demonstrate that the previous results replicate with a Norwegian-speaking population, indicating that the test is generalizable beyond previously tested populations of native English- and German-speakers.