[1] Univ Salamanca, Fac Psychol, Methodol Psychobiol & Basic Psychol Dept, E-37008 Salamanca, Spain
[2] Univ Hosp Salamanca, Neurol Sect, Salamanca, Spain
[3] Univ Salamanca, Dept Stat, E-37008 Salamanca, Spain
[4] Rio Ortega Hosp, Neurol Sect, Valladolid, Spain