PT  - JOURNAL ARTICLE
AU  - Andrey Vyshedskiy
AU  - Megan Catherine DuBois
AU  - Emma Mugford
AU  - Irene Piryatinsky
TI  - Development of the Linguistic Evaluation of Prefrontal Synthesis (LEPS) test for children with language delay
AID  - 10.1101/467183
DP  - 2018 Jan 01
TA  - bioRxiv
PG  - 467183
4099  - http://biorxiv.org/content/early/2018/11/09/467183.short
4100  - http://biorxiv.org/content/early/2018/11/09/467183.full
AB  - Prefrontal Synthesis is the conscious, purposeful process of synthesizing novel mental images from objects stored in memory. The ability to perform Prefrontal Synthesis is essential for understanding flexible syntax, spatial prepositions, and verb tenses. In typical children, the timeline of Prefrontal Synthesis acquisition correlates strongly with vocabulary expansion. On the other hand, children with language delay may learn hundreds of words but never acquire Prefrontal Synthesis. In these individuals, tests assessing vocabulary comprehension may fail to demonstrate the profound deficit in Prefrontal Synthesis. We developed a 10-item Linguistic Evaluation of Prefrontal Synthesis (LEPS) test and used it to assess Prefrontal Synthesis in 20 neurotypical children age 2 to 6 years and in three individuals with intellectual disabilities. All neurotypical children age 4 years and older as well as two atypical individuals received the score of 5 or greater out of the maximum possible score of 10. An individual with low-functioning autism received the score of 2. LEPS is copyright-free and takes approximately 10 minutes. As LEPS does not rely on productive language, it may be an especially useful tool for assessment of nonverbal children.