Poorer auditory sensitivity is related to stronger visual enhancement of the human auditory mismatch negativity (MMNm)

Abstract

Multisensory processing facilitates perception of our everyday environment and becomes particularly important when sensory information is degraded or close to the discrimination threshold. Here, we used magnetoencephalography and an audiovisual oddball paradigm to assess the complementary role of visual information in subtle pitch discrimination at the neural level of participants with varying levels of pitch discrimination abilities, i.e., musicians and nonmusicians. The amplitude of the auditory mismatch negativity (MMNm) served as an index of sensitivity. The gain in amplitude resulting from compatible audiovisual information was larger in participants whose MMNm amplitude was smaller in the condition deviating only in the auditory dimension, in accordance with the multisensory principle of inverse effectiveness. These findings show that discrimination of even a sensory-specific feature as pitch is facilitated by multisensory information at a pre-attentive level, and they highlight the importance of considering inter-individual differences in uni-sensory abilities when assessing multisensory processing.