Visual Benefit in Lexical Tone Perception in Mandarin: An Event-related Potential Study

Congruent visual information enhances auditory speech perception. This visual benefit has been widely observed in perception of consonants and vowels, and linked to reduced amplitudes and latencies of auditory N1 and P2 event-related potential (ERP) components when visual information was present. However, it remains unclear whether lexical tone perception in Mandarin also shows this visual benefit. This question is theoretically important given the low visual saliency of lexical tones. The current study compared the N1/P2 reduction in Mandarin lexical tones and consonants perception with a discrimination task. Result showed amplitude reductions in N1/P2 and a latency reduction in N1 for audiovisual lexical tone perception. These findings suggest that lexical tone perception was also helped by visual information as found in consonants. Furthermore, this visual benefit in N1 for lexical tone perception was delayed relative to consonants.