Written lexical decision
As an in-game reading task, we implemented a written lexical decision assessment at T2 where children saw a word or pseudoword on screen and had to either accept it as a real word or reject it as a pseudoword by clicking on a green checkbox or a red cross. This task contained 16 words and 16 pseudowords and was split into two levels of 16 items, each with a 3-min time limit. For data analyses, we used single-trial measures in which we considered accuracy and response times for each word and pseudoword. Like the reading fluency task, monosyllabic words with two to four characters (mean and median length 3.1 and three letters respectively) and a frequency range of four to 24,266 per million (mean and median frequencies of 2,546 and 124 per million, respectively) were used. The pseudowords were created based on those 16 words using the psycholinguistic pseudoword generating software Wuggy (