We tested the effects of an intensive tact instruction procedure on numbers of tacts emitted in non-instructional settings (NIS) using a multiple probe design across 3participants (3and 4-year old boys with autism). The dependent variable was tacts emitted in NIS before/after the mastery of sets of 5 different stimuli. The non-instructional settings included the toy area of the classroom, lunchtime, and the school hallway during transition. All probe sessions were conducted daily for a cumulative 15 minutes, 5 minutes in each NIS. Intensive instruction involved increasing the tact instructions to 100-tact learn units above the daily learn units students were receiving daily. The intervention increased vocal verbal operants (tacts and mands) emitted by the target students in NIS.

We used a delayed non-concurrent pre- and post-intervention probe design to test the effects of a voice conditioning protocol (VCP) with 3 preschoolers with autism on (a) rate of acquisition of listener curricular objectives, (b) observing voices and the presence of adults across 3 settings, (c) selecting to listen to adults tell stories in free play setting, and (d) the occurrence of stereotypy in the story setting. The VCP conditioned voices as reinforcers for listening to recordings of voices via stimulus-stimulus pairing, which resulted in the children listening to audio recordings of voices in 90% of intervals in 5-min concurrent-operant preference tests. After voices became conditioned reinforcers, all 3 children's learning accelerated; 2 children's observing responses increased in the 3 settings; and 2 children selected to listen to stories and also showed decreased stereotypy in the story setting. The data suggest that conditioned reinforcement for observing responses may be a verbal behavior developmental cusp that acts to accelerate learning that involves listening, and that the cusp may be induced using the VCP.

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Autism spectrum disorder (ASD) is a neurodevelopmental disorder characterized by major social, communication and behavioural challenges. The cause of ASD is still unclear and it is assumed that environmental, genetic and epigenetic factors influence the risk of ASD occurrence. MicroRNAs (miRNAs) are short 21-25 nucleotide long RNA molecules which post-transcriptionally regulate gene expression. MiRNAs play an important role in central nervous system development; therefore, dysregulation of miRNAs is connected to changes in behaviour and cognition observed in many disorders including ASD. Based on previously published work, on diagnosing ASD using miRNAs, we hypothesized that miRNAs can be used as biomarkers in children with suspected developmental disorders (DD) including ASD within Bosnian-Herzegovinian (B&H) population. 14 selected miRNAs were tested on saliva of children with suspected developmental disorders including ASD. The method of choice was qRT-PCR as a relatively cheap method available in most diagnostic laboratories in low to mid-income countries (LMIC). Out of 14 analysed miRNAs, 6 were differentially expressed between typically developing children and children with some type of developmental disorder including autism spectrum disorder. Using the most optimal logistic regression, we were able to distinguish between ASD and typically developing (TD) children. We have found 5 miRNAs as potential biomarkers. From those, 3 were differentially expressed within the ASD cohort. All 5 miRNAs had shown good chi-square statistics within the logistic regression performed on all 14 analysed miRNAs. The accuracy of 5-miRNAs model training set was 90.2%, while the validation set had a 90% accuracy. This study has shown that miRNAs may be considered as biomarkers for ASD detection and may be used to identify children with ASD along with standard developmental screening tests. By combining these methods we may be able to reach a reliable and accessible diagnostic model for children with ASD in LMIC such as B&H.

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