Auditory Sensitivity in Autism: A Systematic Review of Mismatch Negativity and Mismatch Field Responses.
Sara Cacciato-Salcedo, Shreya Jaokar, Neil J Ingham and 2 others
PMID 42144892WHAT IT FOUND
Autistic children often showed smaller brain responses to unexpected sounds than non-autistic peers, especially for changes in tone frequency, but other studies found larger responses or none, and adult findings were mostly null.
Timing differences were inconsistent and tracked language and sensory profile more than diagnosis.
Key findings
01Across 55 passive oddball studies, smaller MMN/MMF responses in autistic participants were reported most often in childhood, most consistently for tone frequency contrasts, but some studies found larger responses and others found no difference; adolescent findings were mixed and most adult non-speech findings were null.
02Prolonged mismatch timing appeared only in a subset of studies and was more closely related to within-autism variation such as language ability, auditory sensitivity or intolerance to change than to diagnosis, and a recent meta-analysis found no overall group difference in latency.
03Most studies could not test left-right differences because they recorded at midline electrodes, and among those that could, right-hemisphere weighting was reported more often in autistic participants, most clearly for speech contrasts such as phoneme identity, pitch, emotional prosody and lexical stress.
STILL TO COME
How it was doneWhat they foundWhat it means for SLPs
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What it does not show
The studies differed so much that the authors described their findings rather than combining them, so there is no single number for how big any difference is. Many of the included studies were small, and most were rated only fair quality, with two rated satisfactory. Few studies reported effect sizes or confidence intervals, which limits comparison between them. Most studies recorded from midline electrodes or reported where activity came from without testing left against right, so the laterality findings rest on a minority of studies. Almost no study tested for differences between autistic males and females, and eight studies included only males, so the findings may not apply to autistic females. The evidence is concentrated in childhood (39 of 55 studies), with few adolescent and adult studies, so it cannot describe a lifespan trajectory. Stimuli, deviant sounds, electrode placements and analyses differed widely, so apparent inconsistencies between studies may reflect method rather than biology. The review reports no total participant number, and the authors note that this research is concentrated in high-income countries.
Declared interests
The authors declare no conflicts of interest. The text does not name a funder.
The easy way to misread this
Do not read this as showing that autistic people have a blunted auditory system, or that mismatch responses can be used as a marker of autism. Many included studies found larger responses or no difference at all, the direction depended on the sound used and the age group, and the meta-analysis the authors cite found no overall group difference in timing. Most studies were also too small and too differently designed to be pooled.
Summarised by AI from the full paper, without a clinician reviewing it. Check it against the source before it changes what you do. Read it on PubMed →