Neurophysiological alterations during sensory processing in autism - a meta-analysis.

This study looked at how autistic brains process sensory information differently. Researchers combined data from 145 studies with over 7,000 people. They found that autistic people's brains take slightly longer to respond to sights, sounds, and other sensory input. This delay was especially noticeable in people with language difficulties and in teenagers/adults. These brain timing differences might help explain why autistic people experience sensory and social challenges differently.

This large meta-analysis examined neurophysiological differences in sensory processing between autistic and non-autistic individuals across 145 studies involving over 7,000 participants. Using brain imaging techniques (EEG/MEG), researchers found that autistic individuals showed significantly delayed timing in early brain responses to sensory information, particularly in P/M50, P/M100, N170, and P/M200 components. The P/M50 delay was most pronounced in individuals with language impairments, while N170 delays were most notable in autistic adolescents and adults. No significant differences in response amplitudes were found.

These timing delays may relate to sensory filtering challenges and altered social perception in autism, though substantial variability between studies limits immediate clinical applications.

Delayed neurophysiological responses may serve as potential biomarkers for autism, particularly P/M50 and N170 components. However, substantial heterogeneity and modest effect sizes currently limit clinical application. Findings support neurophysiological basis for sensory processing differences in autism and highlight need for individualized approaches to sensory interventions.

Substantial heterogeneity between studies limits interpretation. Modest effect sizes reduce clinical applicability. The study notes that variability between individual studies was high, which affects the reliability of findings for practical use.

While sensory processing alterations in autism are well-documented, the neurophysiological correlates remain unclear. This meta-analysis examined differences in early event-related potentials (ERP) and event-related fields (ERF) between autistic and non-autistic individuals using electroencephalography and magnetoencephalography to identify neurophysiological alterations that may underlie variations in sensory perception, communication, and social interaction in autism. Following PRISMA guidelines, a database search was conducted for peer-reviewed studies published from January 1980 onwards. Random-effects meta-analyses were performed using the metafor package in R.

Standardised mean-group differences in early ERP/ERF latencies and amplitudes were analysed with moderator analyses exploring demographic and methodological factors, including neurophysiological technique, sensory modality, age group, sex, and language impairment. 145 studies (3778 autistic, 3484 non-autistic participants) were included. Autistic individuals exhibited significantly longer latencies in P/M50 (SMD = 0.44; SE = 0.21; 95% CI 0.03-0.86; p = 0.04), P/M100 (SMD = 0.18; SE = 0.08; 95% CI 0.01-0.36; p = 0.03), N170 (SMD = 0.33; SE = 0.12; 95% CI 0.10-0.56; p = 0.01), and P/M200 (SMD = 0.30; SE = 0.09; 95% CI 0.12-0.48; p = 0.00) components. P/M50 showed the greatest latency alteration, with an effect-size nearing medium, especially in individuals with language impairment (Q(2) = 7.70, p = 0.02), followed by N170 most notable in autistic adolescents and adults (Q(3) = 12.30, p = 0.01). No significant amplitude alterations were found, and substantial heterogeneity was observed.

Neurophysiological characteristics of sensory processing in autism implicate multiple mechanisms and stages given prolonged P/M50- and N170-latency (associated with sensory filtering challenges and social perception alterations, respectively). These component timings show potential as biomarkers, though heterogeneity and modest effect-sizes limit clinical application, highlighting the need for further research.