Because difficulty is not the same for everyone: the impact of complexity in working memory is associated with cannabinoid 1 receptor genetic variation in young adults. - Ruiz-Contreras, Alejandra E.; Román-López, Talía V.; Caballero-Sánchez, Ulises; Rosas-Escobar, Cintia B.; Ortega-Mora, E. Ivett; Barrera-Tlapa, Miguel A.; Romero-Hidalgo, Sandra; Carrillo-Sánchez, Karol; Hernández-Morales, Salvador; Vadillo-Ortega, Felipe; González-Barrios, Juan Antonio; Méndez-Díaz, Mónica; et al. (Memory, 2017)