Poster C65, Wednesday, August 21, 2019, 10:45 am – 12:30 pm, Restaurant Hall
Speech production rate modulates perception only for a subgroup of the population
M. Florencia Assaneo1, Johanna M. Rimmele2, David Poeppel1,2;1Department of Psychology, New York University, 2Max Planck Institute for Empirical Aesthetics, Frankfurt/Main
Recent studies suggest that auditory perception relies on temporal predictions from the motor system to increase its performance (see Rimmele et al. 2018). However, there exists little behavioral evidence for this conjecture in the speech domain. In order to test this prediction, we designed a behavioral protocol capable of testing the influence of rhythmic speech production on speech perception. In line with previous results (Assaneo et al. 2019), we hypothesize that individual differences in the degree of audio-motor coupling could modulate the strength of behavioral effects. Thus, we first measured and subsequently classified participants into two groups according to the strength of their spontaneous audio-motor synchronization (high or low). Next, during the main experiment participants were instructed to produce rhythmic sequences of syllables. Immediately following speech production offset, a syllable was presented, embedded in noise, and participants performed a syllable discrimination task. Using a decoding approach, we assessed whether task performance was modulated by the phase of the syllable presentation with regard to the motor rhythm. The motor rhythm was derived from the oscillation generated by the produced speech envelope. We show that, only for individuals with high audio-motor coupling, performance is modulated by the speech production rhythm; i.e., participants’ perceptual performance is predicted by stimulus occurrence with respect to motor production phase.
Themes: Speech Perception, Multisensory or Sensorimotor Integration
Method: Behavioral