Characterizing Interoceptive Differences in Autism: A Systematic Review and Meta-analysis of Case-control Studies.

Interoception, the body's perception of its own internal states, is thought to be altered in autism, though results of empirical studies have been inconsistent. The current study systematically reviewed and meta-analyzed the extant literature comparing interoceptive outcomes between autistic (AUT) and neurotypical (NT) individuals, determining which domains of interoception demonstrate robust between-group differences. A three-level Bayesian meta-analysis compared heartbeat counting performance, heartbeat discrimination performance, heartbeat counting confidence ratings, and self-reported interoceptive attention between AUT and NT groups (15 studies; n AUT  = 467, n NT  = 478). Autistic participants showed significantly reduced heartbeat counting performance [g = - 0.333, CrI 95% (- 0.535, - 0.138)] and higher confidence in their heartbeat counting abilities [g = 0.430, CrI 95% (0.123, 0.750)], but groups were equivalent on other meta-analyzed outcomes. Implications for future interoception research in autism are discussed.