Dr Dagmara Dimitriou and Professor Annette Karmiloff-Smith presented at the 24th Biennial Meeting of

Here is the abstract from their invited symposia: Infants spend three-quarters of their time sleeping, children about half of their time, and adults about one-third. Adolescence is a period of development during which sleep patterns often change quite radically. So, why do we spend so much time sleeping? Is it merely for the body and brain to take a rest? Recent findings confirm that, far from taking a rest, parts of the brain are more active during sleep than during wakefulness, consolidating memories of events that happened during the day. Indeed, sleep plays a crucial role both in brain development and in learning, memory and daytime functioning. Optimal quality and quantity of sleep yields more effective learning in terms of knowledge acquisition, executive function and memory consolidation (Gomez et al., 2006; Wilhelm, Prehn-Kristensen & Born, 2012). In contrast, poor sleep quality, particularly sleep fragmentation, is a strong predictor of lower academic performance (Frediksen, Rhodes, Reddy & Way, 2004), reduced attentional capacities (e.g., Ashworth, Hill, Karmiloff-Smith & Dimitriou, 2014), poor executive function (Archbold, Giordani, Ruzicka & Chervin, 2004; Edgin et al., 2015) and challenging behaviours (Lewin, Rosen, England & Dahl, 2002). The role of sleep in neural development is also being increasingly recognized (Huber & Born, 2014; Walker, 2006). Using human and animal models of sleep, scientists are currently unraveling the complexities of circadian rhythms and of the role of sleep cycle in promoting healthy neural, cognitive, socio-emotional and physical development (Foster, 2004; Kreitzman & Foster, 2010). This symposium examines the biology of circadian rhythms and sleep, as well as the implications for both typical and atypical development.