The impact of deep brain stimulation on executive function in Parkinson's disease. - Jahanshahi,M.; Ardouin,C.; Brown,R.; Rothwell,J.; Obeso,J.; Albanese,A.; Rodriguez-Oroz,M.; Moro,E.; Benabid,A.; Pollak,P.; Limousin-Dowsey,P. (Brain, 2000)