Function of language skills in preschooler's problem-solving performance: The role of self-directed speech

Although there is evidence that language skills and executive functions (EF) are highly intercorrelated, so far underlying mechanisms are not clear. Using the Tower of London task as a measure of complex EF performance, the present study examined self-directed speech as one possible mechanism underlying these associations by using three approaches: analyzing quantity and quality of self-directed speech, articulatory suppression, and triggering self-directed speech. Participants were N = 73 preschool children from Germany. Results confirm the relation between language skills and EF albeit it cannot be explained by self-directed speech. While quantity and quality of self-directed speech was related to language skills, the use of self-directed speech with planning function was positively related to performance. Findings suggest that the use of self-directed speech with planning function might be an important factor in explaining cognitive advantages. Moreover, results indicated that self-directed speech is helpful in children with lower non-verbal IQ.