Mismatch negativity to different deviant changes in autism spectrum disorders: A meta-analysis

Objective: Mismatch negativity (MMN) has been continuously used to evaluate the functional integrity of central auditory processing. However, it still remains inconclusive whether patients with autism spectrum disorder (ASD) demonstrate reduced MMN responses in all deviant types. Methods: To reconcile the previous controversial findings, we performed a meta-analysis of peer-reviewed MMN articles concerning ASD. The potential moderators regarding different deviant types, diagnosis, and age on the effect sizes (Hedges’ g) were also assessed. Results: Compared to the controls, ASD patients showed reduced MMN amplitudes (g = −0.37, p = 0.001) and prolonged latencies (g = −0.33, p = 0.041) in response to speech-sound deviants. Children/adolescents with ASD manifested reduced MMN amplitudes in response to tone-duration deviants (g = −0.46, p = 0.014). Furthermore, the results showed significantly shortened MMN latencies to tone-frequency deviants in patients with autism (g = 0.29, p = 0.038) and, in contrast, prolonged MMN latencies (g = −0.74, p = 0.001) in patients with Asperger syndrome. Conclusion: MMN deficits are robust in ASD patients, suggesting an altered central ability in auditory discrimination. Significance: MMN alterations were displayed in different profiles with respect to frequency, duration and phoneme changes.