Preferred Tempo and Low-Audio-Frequency Bias Emerge From Simulated Sub-cortical Processing of Sounds With a Musical Beat

Nathaniel J. Zuk, Laurel H. Carney, Edmund C. Lalor
2018 Frontiers in Neuroscience  
Prior research has shown that musical beats are salient at the level of the cortex in humans. Yet below the cortex there is considerable sub-cortical processing that could influence beat perception. Some biases, such as a tempo preference and an audio frequency bias for beat timing, could result from sub-cortical processing. Here, we used models of the auditory-nerve and midbrain-level amplitude modulation filtering to simulate sub-cortical neural activity to various beat-inducing stimuli, and
more » ... e used the simulated activity to determine the tempo or beat frequency of the music. First, irrespective of the stimulus being presented, the preferred tempo was around 100 beats per minute, which is within the range of tempi where tempo discrimination and tapping accuracy are optimal. Second, sub-cortical processing predicted a stronger influence of lower audio frequencies on beat perception. However, the tempo identification algorithm that was optimized for simple stimuli often failed for recordings of music. For music, the most highly synchronized model activity occurred at a multiple of the beat frequency. Using bottom-up processes alone is insufficient to produce beat-locked activity. Instead, a learned and possibly top-down mechanism that scales the synchronization frequency to derive the beat frequency greatly improves the performance of tempo identification. ACKNOWLEDGMENTS We would like to thank Jacob Berman for his help interpreting the results for the Ballroom dataset. We would also like to thank Andrew Anderson for his comments on the manuscript. All computations were performed on the BlueHive computation cluster at the University of Rochester.
doi:10.3389/fnins.2018.00349 pmid:29896080 pmcid:PMC5987030 fatcat:edswueki7bdstbrzgav5gx2gze