Investigating Hemodynamic Patterns During Beat Processing in Cochlear Implant Users: Insights from a Finger Tapping Study.

Introduction: Individuals with cochlear implants often struggle with melody and timbre perception in music, leading to diminished music appreciation. While they demonstrate proficiency in recognizing beat and rhythm, it remains unclear whether beat information is processed similarly in their brains compared to those with normal hearing.

Methods: In this study, adapted from Rahimpour et al. (2020), both cochlear implant users and normal hearing listeners engaged in finger tapping tasks that synchronized or syncopated with isochronous beats. Participants were asked to align their taps with an auditory metronome (pacing) and then maintain tapping pace after the metronome attenuation (continuation). Hemodynamic responses were recorded using functional near-infrared spectroscopy (fNIRS) during tapping.

Results: Results revealed comparable performance between cochlear implant users and normal hearing listeners in the finger tapping task, with both groups finding the syncopated continuation task particularly challenging for maintaining consistent tapping. Despite similar tapping performance, cochlear implant users exhibited more widespread hemodynamic activation than normal hearing listeners in temporal, frontal, motor, and parietal regions.

Discussion: Cochlear implant users engage auditory-motor networks during beat processing akin to normal hearing listeners; however, factors such as neural adaptation post-cochlear implantation and heightened listening effort may contribute to the observed widespread activation.