Standardization of RAN-RAS test in Latvian population of 5–18-year-old school students

Rapid automatized naming (RAN) and Rapid alternating stimulus (RAS) test is highly prognostic in assessing potential risks of literacy difficulties and poor phonological skills, even before formal acquisition of reading. Therefore, the test has been established as a gold standard assessment worldwide. This study aimed to standardize RAN-RAS test in Latvian population of 5-18-year-old school students. RAN-RAS test results are measured as a subtest stimulus naming time and analyzed according to age. 695 students (ages 5.0-18.11) from general population with Latvian as native language were enrolled. Assessment was done with RAN-RAS Latvian version (Riemere, Savicka, Kuļičenko, Vabale, Vētra, 2015-2018). Standard naming time was described in seconds as M±SD and analyzed in preschool (5-6 y.o.), younger school (7-12 y.o.), middle school (13-15 y.o.) and young adult (16-18 y.o.) stages. All subtests illustrate a tendency for naming time to decrease with age, as developmental processes occur. Subtest Colors takes 92±31 seconds to name in preschool and 35±5 seconds at middle school. Naming subtest Letters takes 92±45 seconds at preschool, which is the beginning of formal acquisition of letters. Naming time reaches 22±4 seconds at younger school age (12 years), when letters have been automatized visually and phonologically throughout learning process, which explains why naming time stays approximately the same for adults. RAS 2 stimuli subtest naming at 7 years of age took 40±10 seconds, 24±4 seconds for 13-year-olds and 21±3 seconds at age 18. Both RAS subtests show gradual decrease in naming times throughout younger and middle school years until young adult stage, when verbal working memory undergoes expansion in functional capacity. Highest correlation with age was observed for subtest Letters and Numbers. Findings showed that RAN-RAS Latvian version has been standardized for use in speech therapist practice and it can differentiate between participants of different ages appropriately.