Abstract:

Sleep problems have a significant impact on the development of preschool children's behavior, cognition, language and health, with language development being of particular concern The current paper is intended to sort out the relationship between preschool children’s sleep problems and language impairment from four perspectives: whether there is a close relationship between sleep problems and language impairment, how sleep problems affect language development, what factors influence the relationship between sleep problems and language impairment, and whether the intervention of sleep problems is effective in improving the language ability of preschool children.
First, is there a close relationship between sleep problems and language impairment in preschool children? By reviewing the existing literature both at home and abroad, it is found that sleep problem is a potential factor affecting language impairment in preschool children. On the one hand, the incidence of sleep problems such as difficulty in falling asleep, lack of sleep and sleep disordered breathing in preschool children with language impairment is higher than that in normal children. On the other hand, longer sleep latency, shorter nighttime sleep and the lower sleep efficiency are closely related to more serious communication impairment, less receptive vocabulary and poorer oral expression ability of preschool children with language impairment.
Secondly, how do sleep problems affect the language development of preschool children? Drawing upon the existing literature, the paper sorted out three hypotheses on the internal mechanism of sleep problems affecting language development: the sleep dependent memory consolidation hypothesis, the alertness hypothesis and the synaptic homeostasis hypothesis. These three hypotheses demonstrate how sleep problems affect language development from the perspectives of cognitive, physiological and neural mechanisms. Although self-justifying rationale is found in each hypothesis, their explanatory power and scope of application are to some extent challenged in practice.
Thirdly, what factors affect the relationship between sleep problems and language disorders in preschool children? Based on the literature review, the paper finds that the relationship between sleep problems and language impairment in preschool children is affected by the severity of sleep problems, family factors, sociocultural factors, and age factors in particular. Finally, is sleep problem intervention effective in improving language impairment in preschool children? Previous studies have shown that behavioral intervention, drug treatment, surgical treatment and play-based intervention help improve the language ability of preschool children. However, it has not been testified why these sleep problem interventions are effective in promoting children's language development.
Therefore, previous intervention studies only serve to explain the close correlation between preschool children's sleep problems and language impairment from another perspective, but fail to determine the causal relationship between them. In short, the previous studies both at home and abroad have explored the relationship between sleep problems and language impairment in preschool children. However, the relationship between preschool children's sleep problems and language impairment has not been determined. Many unsolved problems need to be further explored.
Future research is expected to provide further insight into the internal mechanism underlying the correlation between sleep problems and language impairment, to facilitate the understanding of the relationship between sleep problems and language ability of children of different ages, and to explore effective game intervention methods in the context of inclusive education.

Key words: preschool children, sleep problems, language disorders