Predictions about prosody facilitate lexical access: Evidence from P50/ N100 and MMN components

Research into the neural foundation of perception asserts a model where top-down predictions modulate the bottom-up processing of sensory input. Despite becoming increasingly influential in cognitive neuroscience, the precise account of this predictive coding framework remains debated. In this study, we aim to contribute to this debate by investigating how predictions about prosody facilitate speech perception, and to shed light especially on lexical access influenced by simultaneous predictions in different domains, inter alia, prosodic and semantic. Using a passive auditory oddball paradigm, we examined neural responses to prosodic changes, leading to a semantic change as in Dutch nouns canon [' kaMODIFIER LETTER TRIANGULAR COLONnon] 'canon' vs kanon [kaMODIFIER LETTER TRIANGULAR COLON ' non] 'cannon', and used acoustically identical pseudowords as controls. Results from twenty-eight native speakers of Dutch (age range 18-32 years) indicated an enhanced P50/N100 complex to prosodic change in pseudowords as well as an MMN response to both words and pseudowords. The enhanced P50/N100 response to pseudowords is claimed to indicate that all relevant auditory information is still processed by the brain, whereas the reduced response to words might reflect the suppression of information that has already been encoded. The MMN response to pseudowords and words, on the other hand, is best justified by the unification of previously established prosodic representations with sensory and semantic input respectively. This pattern of results is in line with the predictive coding framework acting on multiple levels and is of crucial importance to indicate that predictions about linguistic prosodic information are utilized by the brain as early as 50 ms.

Automated summary

Research on the neural foundation of perception suggests that top-down predictions play a crucial role in modulating the processing of sensory input. This study investigates how predictions about prosody facilitate speech perception and sheds light on the influence of simultaneous predictions in different domains, such as prosody and semantics, on lexical access. The results show enhanced neural responses to prosodic changes in pseudowords, indicating that the brain still processes all relevant auditory information. On the other hand, the reduced response to words suggests the suppression of information that has already been encoded. The MMN response to pseudowords and words is explained by the integration of prosodic representations with sensory and semantic input. These findings support the predictive coding framework acting on multiple levels and highlight the early utilization of predictions about linguistic prosodic information by the brain within 50 ms.