A critical analysis of Lin et al.'s (2021) failure to observe forward entrainment in pitch discrimination

Abstract

Forward entrainment refers to that part of the entrainment process that outlasts the entraining stimulus. Several studies have demonstrated psychophysical forward entrainment in a pitch-discrimination task. In a recent paper, Lin et al. (2021) challenged these findings by demonstrating that a sequence of 4 entraining pure tones does not affect the ability to determine whether a frequency modulated pulse, presented after termination of the entraining sequence, has swept up or down in frequency. They concluded that rhythmic sequences do not facilitate pitch discrimination. Here, we describe several methodological and stimulus design flaws in Lin et al.'s study that may explain their failure to observe forward entrainment in pitch discrimination.