Neural and Physiological Habituation in Autism: A Systematic Review

Habituation is a fundamental form of learning that enables organisms to filter out irrelevant environmental stimuli and focus on significant information. Autistic individuals frequently exhibit altered sensory processing, which may be partially explained by disruptions in habituation mechanisms. We carried out a systematic review – following PRISMA guidelines – to critically evaluate the current literature on neural and physiological habituation in autism. We included studies exploring differences in neural and/or physiological habituation between autistic individuals or those with a family history of autism and controls (either neurotypical or with other diagnoses), or investigating associations between autistic traits and habituation. Twenty-five studies (1691 participants, 818 with a diagnosis or family history of autism, 652 non-autistic controls, 221 with other diagnoses) met inclusion criteria. Across studies, we observed a general pattern of reduced habituation in autistic individuals or those with a family history of autism in response to a range of repeated auditory, visual, and somatosensory stimuli. However, we also highlight the heterogeneity of habituation findings in autism across different experimental methodologies, sensory modalities, and brain regions. We discuss the findings in relation to the development of targeted interventions that address sensory processing challenges in autism.