The effect of tiredness on attention, word-learning, and their respective brain regions in infancy.

A lack of sleep is harmful to our cognition, mental health, and our brains. Sleep is particularly important in infancy because of the need for continuous consolidation of new information. Thus, similar to adults, a lack of sleep has been shown to be detrimental to cognitive and neural development, particularly for those with neurodevelopmental disorders (NDDs). Despite this, the specific effects of poor sleep (tiredness) on aspects of infant cognition have not yet been determined. This project fills this crucial gap by exploring the effect of tiredness on attention and word-learning, two crucial cognitive skills affected by sleep. A novel neuroimaging method, functional near-infrared spectroscopy (fNIRS), will be used to record brain activation in the frontal and parietal cortices, key brain regions for attention and word-learning. Three studies will be conducted. The first will relate tiredness (via a questionnaire) to attention (via fNIRS and a wordless picture-book task), in 52 10 month-olds. The second will relate tiredness to attention and word-learning (also using fNIRS) in 52 16-24-month-olds. Lastly, parent sleep and mental health will be explored as predictors of infant tiredness. These studies, together, have the potential to make a significant impact. They will uncover novel findings about tiredness and bring a new perspective about the role of sleep in development. The study will bring new knowledge to those researching effective interventions for NDDs, highlighting the importance of sleep and tiredness across development.