Friedreich ataxia (FRDA) is the most common of the genetically inherited ataxias. We recently demonstrated that people with FRDA have impairment in motor planning – most likely because of pathology affecting the cerebral cortex and/or cerebello-cortical projections. We used the Simon interference task to examine how effective 13 individuals with FRDA were at inhibiting inappropriate automatic responses associated with stimulus–response incompatibility in comparison with control participants.

Impaired inhibition of prepotent motor tendencies in Friedreich ataxia demonstrated by the Simon interference task