The HAS-BME Research Group in Cognitive Science investigates the relationship between sleep and learning with OTKA and NIMH support. Building upon earlier work, the research group is looking at perceptual and motor skill learning in people living with genetically based developmental disorders and in typically developing people. As they have shown before, cortical mechanisms defining fine perceptual discrimination and motor skill learning take a long time, even decades in humans to become fully mature. The human cortex is extremely sensitive to environmental stimulation and epigenetic influences during this long plastic period. It is important to define all the factors promoting and delaying development because these will help to encourage healthy development (education), and to correct atypical developmental directions (medication). People with developmental disorders and mental retardation pose a difficult burden on society, cannot lead an independent life, and long-term care of these patients and their families has to be provided. Our research offers help in two ways: (1) early diagnosis and the possibility of effective early therapy, (2) improvement of severe problems by defining epigenetic (e.g., sleep patterns) and behavioral components of the disorder that can be improved by different medical treatments. Quality of life in these populations might improve due to the treatments, and they might become independent and self-supporting citizens. In a modern, generally sleep-deprived society, there are consequences of this research with respect to the typically developing population as well.