Visual Priming in Children with Autism Spectrum Disorders

The study aimed at the analyzing of the temporal dynamics of visual priming in children with autism spectrum disorder (ASD). The study involved 20 children with typical development (5 girls and 15 boys, age 6.4 +/- 0.4 years), 20 children with mild form of ASD (all boys, age 6.7 +/- 0.3 years), 20 children with medium form of ASD (18 boys and 2 girls, age 6.6 +/- 0.4 years), 20 children with hard ASD (17 boys and 3 girls, age 6.8 +/- 0.2 years). The priming paradigm was used as a research model. Targets were in the form of gratings of horizontal and vertical lines with a repetition rate of 10 cycles per degree. A prime in the form of a vertical grating with a repetition rate of 2 cycles per degree was presented ahead of the target stimulus by 50-600 ms. In the course of the study, it was found that, in contrast to the typical development, in all children with ASD, the effect of prime is absent at interstimulus intervals (ISI) of 50 divided by 150 ms. The response time decreases to congruent and incongruent targets with ISI 200-600 ms with light and medium ASD and with ISI 200-300 ms with hard ASD. The results indicate that changes in the mechanisms of interaction between the prime and targets and the switching of attention between them are manifested in different time intervals after the prime, depending on the severity of ASD.