Open Access

Sławomir Jabłoński

• From the perspective of Lev S. Vygotsky's theory, literacy develops as a tool for executing the task of communicating with the use of script and this, in consequence, results in the development of a new higher mental function – written speech (WS). Both components of this function improve in parallel with acquisition of reading and writing: the impressive component (comprehending the meaning of a written text) and the expressive component (conveying meaning in a written form). These components reflect two directions of one process of communication and are like 'two sides of the same coin'. Reading and writing demand not only written speech activity but also activity of other mental functions, especially those necessary for planning and controlling behavior which are known as executive functions (EF). Little is found about how EF and two components of WS interact between the age of 3 and 11 when they develop quickly. The main research hypotheses are that (1) the relative dominance of the impressive and the expressive component of written speech is different across age groups and that (2) the level of EF development is connected to patterns of dominance between the impressive and the expressive component of WS. A database from a previous cross-sectional study of 1103 healthy, Polish speaking children between the age of 3 and 11 was used for exploratory analysis of the EF-WS relationship. The subjects were examined with the use of the Literacy Assessment Battery, designed for assessing the development of WS. Also, the paradigm of dimensional change card sort was applied for the measurement of two EF: inhibitory control and cognitive flexibility. The conducted analyses of the results confirmed both research hypotheses. Differences in the relative dominance of either the impressive or the expressive component of WS suggest that advances in the reading ability and in the writing ability cannot have the same dynamics. In turn, the level of EF development seems to predict the relation between both WS components most strongly in the age periods where the most dynamic progress in inhibitory control or cognitive flexibility takes place. Further longitudinal studies with a wider range of EF measures, which would give an opportunity to explore causal relations between EF and WS, could be promising, especially in view of identification of literacy development factors.