Speech Science Forum -- Kathleen Schneider

Auditory-motor synchronization involves the coupling of neural oscillatory activity in the brain’s auditory and motor cortices with external auditory rhythms. It has been suggested that this synchronization supports speech perception by transmitting the quasi-rhythmic envelope structure of the speech signal. Synchronization thereby plays a role in signalling speaking rate and conveying linguistic stress and prosody. In neurotypical individuals, speech-specific synchronization follows a bimodal distribution of high and low synchronizers, with high synchronizers exhibiting stronger auditory-motor coupling and enhanced degrees of synchrony. However, synchronization varies depending on task demands, input signals, motor output, an individual differences in auditory, prosodic, and musical abilities. In individuals with aphasia, deficits in associated functions contribute to impaired speech perception and manifest as greater variability in auditory-motor synchronization to non-speech rhythms. In contrast, speech-specific synchronization in aphasia has not been systematically studied, and the interplay between auditory comprehension, aphasia severity, speech fluency, and speech-motor skills for synchronization remains unexplored. To assess auditory-motor synchronization in individuals with aphasia (n = 16) as compared to neurotypical controls (n = 32), we employed two behavioural paradigms. Tapping tasks measured synchronization to metronome and musical rhythms, while a speech-to-speech synchronization task assessed speech-specific auditory-motor coupling by requiring participants to whisper in phase with a syllable train. Using linked linear mixed models, we analysed both tasks in relation to individual differences in auditory, prosodic, and musical abilities, examining both within- and between-group variability. In this talk, I will present preliminary findings on synchronization variability and discuss the feasibility and limitations of measuring speech-specific synchronization in aphasia. These insights contribute to an ongoing pilot project as part of an external lab visit at Patti Adank’s lab at UCL.

Zoom link: https://ucl.zoom.us/j/92052680901