 The broad objective of this study is to determine the relationship between variations in genes related to dopamine DA neurotransmission in areas of the brain associated with motor leaning e.g. DRD1, DRD2, DRD3, COMT, DAT andor to activity-dependent brain plasticity e.g. BDNF and differences in motor learning rates and cognitive processing abilities in persons with and without cerebral palsy CP. We hypothesize that individual genetic differences will be related to the ability to learn new motor and cognitive skills and may thus provide a potential explanation for the often reported response variability to rehabilitative therapies seen in CP. We will also explore whether motor and cognitive learning abilities are correlated within individuals which could suggest similar underlying neural mechanisms. Finally we would like to evaluate the effect of rewards on procedural learning in CP, to preliminarily assess how behavioral manipulations of the DA system may affect learning across individuals. 