Sensory Reactivity in Autism: Integrating Behavioural, Affective, Physiological, and Neural Dimensions

The goal of this paper is to synthesise recent research on sensory reactivity differences in autism across the lifespan, using He et al.'s sensory taxonomy as an organising framework. The review aims to address how behavioural, affective, perceptual, physiological, and neural levels of processing contribute to sensory reactivity differences, and how these differences relate to broader outcomes such as mental health, adaptive functioning, and quality of life.

Across behavioural studies, autistic youth show elevated and variable sensory responsivity, with hypersensitivity predicting internalising symptoms and sensory seeking linked to externalising behaviours. Affective reactivity is consistently elevated across cultures, associated with anxiety and caregiver stress, and sensory seeking may function as a coping mechanism. Psychophysical research reveals domain‑specific perceptual differences-such as reduced tactile adaptation, altered motion noise exclusion, and enhanced pitch discrimination-rather than overarching hyper‑ or hyposensitivity. These perceptual findings often show limited correspondence with questionnaire‑based measures. Physiologically, autonomic dysregulation is implicated, or pharmacological approaches show emerging promise. Neuroimaging evidence highlights excitation-inhibition imbalance and altered connectivity, including dissociations between exogenous and endogenous networks in sensory‑reactive autistic children. Across multiple levels of processing, sensory reactivity differences in autism are robust, heterogeneous, and meaningfully linked to mental health and daily functioning. Key conclusions include: • Sensory hyperreactivity predicts internalising challenges, while sensory seeking may reflect regulatory strategies. • Perceptual differences are domain‑specific • Physiological and neural evidence converges on autonomic dysregulation and differences in connectivity patterns.