Cortical contribution related to top-down regulation in tone perception.

The top-down regulation of prior content facilitates the efficiency of following speech perception through the theta-band synchronization between higher-level cognitive regions and lower-level phonetic processing areas. However, how this regulation affects tone processing and its corresponding functional pathway remains unknown. In this study, we conducted three different auditory oddball paradigms which differed in prior constraints among Mandarin Chinese speakers. We calculated the amplitude of P3 differences caused by tone variations to evaluate the efficiency of tone processing within each paradigm. Theta-band functional connectivity (FC) related to lower-level phonetic processing areas was also analyzed at the source level to identify the specific top-down regulation loop. Our results showed that top-down regulation effects modulated responses to upcoming tonal processing reflected by smaller P3 amplitude differences with the occurrence of semantic priming. Results of FC analysis revealed different corresponding cortical contributions depending on priming content. Semantic-driven top-down regulation enhances FC between the the left caudal middle frontal gyrus and lower-level phonetic processing area. Moreover, when the prior constraint is semantically violated, enhanced FC between the left pars triangularis and the left supramarginal gyrus with lower-level phonetic processing regions were seen. Our study provides neurophysiological insights into the effects of top-down regulation on tone perception.

Supplementary information: The online version contains supplementary material available at 10.1007/s11571-025-10314-1.