Indeed, a pattern of behaviour similar to that observed in the PD patients in the current investigation was reported previously in studies that used the same paradigm to investigate the modulatory role of the COMT val158met polymorphism, which is known to have a marked effect on frontal-lobe dopamine levels, on attentional set formation in PD (Fallon et al., 2013b, Fallon et al., 2015, Williams-Gray et al., 2008). The gene discussed is COMT; the disease is Parkinson disease.