Background and purpose: Various studies show that emotion affects time perception. On the other hand, clinical reports indicate that individuals with autism have more difficulties in time processing. Present study aimed to compare the effects of emotional events (happy, sad, and neutral) on time perception in children with and without autism.

 Method: Present research was a retrospective study. 13 high functioning children with autism, aged 5 to, were selected using convenience sampling method among the clients of autism centers of Tabriz. In addition, 13 children without autism were selected using convenience sampling method. Two groups were matched in terms of age and sex. Autism range inventory (Ehlerz & Gillberg, 1993) was used for screening the high-functioning autistic children. Then, time reproduction task (in both 2000 and 7000 ms) was performed in both groups. Data was analyzed using multivariate analysis of variance.

Results: Results showed that children with autism had lower time reproduction rate in both durations comparing to normal group (P=0/001).

Conclusion: The observed underestimation in this research is consistent with models of attention, which indicate that attention impairment is one of the primary deficits in autistic children that can lead to distraction and underestimation.