Differences between autistic and non-autistic individuals in audiovisual speech integration: A systematic review and meta-analysis.

This research review looked at how autistic people process speech that they both hear and see (like watching someone's lips while they talk). Across 18 studies with 952 participants, autistic individuals had more difficulty combining what they heard and saw compared to non-autistic people. This difference might affect communication and social skills. The effect seemed stronger in children than adults, but more research with consistent methods is needed.

This systematic review and meta-analysis examined audiovisual speech integration differences between autistic and non-autistic individuals across 18 studies (N=952). Results showed autistic individuals demonstrate significantly impaired audiovisual speech integration compared to non-autistic peers (effect size g=0.69, p<0.001). The impairment was consistent across different ages, sample sizes, study quality levels, and research paradigms. Subgroup analysis suggested larger differences may exist in children compared to adults.

The authors note this integration difficulty may have cascading effects on communication and social behavior, but acknowledge substantial heterogeneity in findings due to small samples and methodological inconsistencies.

Audiovisual speech integration difficulties may contribute to communication and social challenges in autism. Assessment of multisensory processing could inform intervention planning. Findings suggest potential for targeted interventions, particularly in childhood, though more standardized research is needed.

Small sample sizes and inconsistent study designs created substantial heterogeneity in findings. The influence of underlying unisensory and attentional factors remains unclear, limiting understanding of mechanisms.

Research has indicated unique challenges in audiovisual integration of speech among autistic individuals, although methodological differences have led to divergent findings. We conducted a systematic literature search to identify studies that measured audiovisual speech integration among both autistic and non-autistic individuals. Across the 18 identified studies (combined N = 952), autistic individuals showed impaired audiovisual integration compared to their non-autistic peers (g = 0.69, 95 % CI [0.53, 0.85], p <.001). This difference was not found to be influenced by participants' mean ages, studies' sample sizes, risk-of-bias scores, or paradigms employed.

However, a subgroup analysis suggested that child studies may show larger between-group differences than adult ones. The prevailing pattern of impaired audiovisual speech integration in autism may have cascading effects on communicative and social behavior. However, small samples and inconsistency in designs/analyses translated into considerable heterogeneity in findings and opacity regarding the influence of underlying unisensory and attentional factors. We recommend three key directions for future research: larger samples, more research with adults, and standardization of methodology and analytical approaches.