Involvement of the AATn polymorphism of the CNR1 gene in the efficiency of procedural learning in humans

► Genotypic frequencies of the AAT polymorphism of CNR1 in a healthy sample. ► The two AATn genotypes of CNR1 differ with respect to their efficiency in procedural learning. ► This effect is not caused by a motor difference between genotypes. ► This effect is related to procedural learning, not to recognition memory.