Vibrotactile Detection, Sensory Adaptation and Temporal Discrimination in Children with Autism Spectrum Disorder: A Systematic Review and Meta-Analysis of Psychophysical and Behavioral Outcomes

Autism Spectrum Disorder (ASD) is a neurodevelopmental condition characterized by differences in social communication, behavior, and sensory processing. Sensory processing differences, particularly in tactile and vibrotactile perception, are frequently reported among children with ASD and may influence their interaction with the environment, behavioral responses, adaptive functioning, and participation in everyday activities. Although sensory abnormalities are widely recognized in autism, the underlying psychophysical mechanisms and behavioral manifestations of vibrotactile processing remain incompletely understood, with considerable variability across studies. This systematic review and meta-analysis aims to comprehensively synthesize the available evidence on vibrotactile detection, sensory adaptation, and temporal discrimination in children with Autism Spectrum Disorder. Specifically, the review will investigate differences in vibrotactile detection thresholds, sensitivity to tactile stimuli, sensory adaptation and habituation, temporal resolution, temporal discrimination thresholds, and related psychophysical and behavioral outcomes between children with ASD and typically developing children or other relevant comparison groups. A systematic search will be conducted across relevant electronic databases to identify eligible empirical studies evaluating vibrotactile and related somatosensory processing outcomes in children with ASD. Studies will be selected according to predefined eligibility criteria, and relevant information regarding study characteristics, participant demographics, sensory assessment paradigms, stimulus parameters, measurement procedures, and outcome measures will be extracted. Methodological quality and risk of bias will be assessed using appropriate tools based on the study designs of the included literature. Where sufficient methodological and statistical homogeneity exists, quantitative synthesis will be performed using appropriate meta-analytic methods. Effect sizes will be calculated to estimate the magnitude and direction of differences in psychophysical and behavioral outcomes between children with ASD and comparison groups. Statistical heterogeneity will be examined, and subgroup analyses, sensitivity analyses, and meta-regression will be considered where feasible to explore potential sources of variability, including age, stimulus frequency, testing methodology, and characteristics of the study population. Where quantitative pooling is not appropriate, findings will be synthesized narratively and systematically. The expected outcomes of this review include a comprehensive characterization of vibrotactile detection, sensory adaptation, and temporal discrimination in children with ASD; identification of consistent patterns and inconsistencies in existing evidence; and clarification of methodological limitations and gaps in current psychophysical research. The findings may contribute to a better understanding of the sensory processing mechanisms associated with autism and inform the development of future research investigating sensory assessment, individualized sensory interventions, and evidence-based rehabilitation approaches. Ultimately, this review seeks to establish a consolidated evidence base for understanding vibrotactile and temporal somatosensory processing in children with ASD, with potential implications for clinical assessment, rehabilitation research, and the development of targeted interventions addressing sensory processing differences.