The aim of this research project is to examine synaptic plasticity in populations with intellectual disability or autism spectrum disorder using electroencephalography and behavioral measures in order to unveil the neuronal mechanisms underlying learning disabilities. Various populations are the main focus, such as Fragile X Syndrome, Down Syndrome, Tuberous sclerosis complex and SYNGAP1 mutation. Learning mechanisms are the central topic of this research. Three age groups, including participants from 5 to 30 years of age, are tested. Data will be compared to an age- and gender-matched control group in order to find specific biomarkers of learning in populations with neurodevelopmental disorders.