caa a22 4500 445352388 CHVBK 20180317142848.0 cr unu---uuuuu 170323e20110901xx s 000 0 eng 10.1007/s00221-011-2793-x doi (NATIONALLICENCE)springer-10.1007/s00221-011-2793-x Levodopa medication does not influence motor inhibition or conflict resolution in a conditional stop-signal task in Parkinson's disease [Elektronische Daten] [Ignacio Obeso, Leonora Wilkinson, Marjan Jahanshahi] Evidence from animal, clinical, and imaging studies suggests that the basal ganglia and their frontal connections mediate motor inhibition, but the role of dopamine remains unclear. The aim of our study was to investigate, for the first time, whether levodopa medication influences motor inhibition and conflict resolution on the conditional stop-signal reaction time task in patients with Parkinson's disease (PD) tested on or off their medication. Sixteen PD patients and 17 healthy controls performed the conditional stop-signal reaction time (SSRT) task, which requires inhibition of responses when a stop signal is presented on "critical” trials. Additionally, on "non-critical” trials, participants are instructed to ignore the stop signal and respond, thus generating conflict between motor inhibition and initiation; and conflict-induced slowing (CIS) on these "non-critical” trials. Levodopa medication did not significantly influence response initiation, inhibition (SSRT) or the measure of conflict resolution (CIS). Compared to healthy controls, PD patients showed significantly worse response initiation and inhibition both on and off their levodopa medication. Our results suggest that motor inhibition or conflict-induced slowing on the conditional stop-signal RT task are not altered by dopamine replacement in PD. This conclusion is consistent with evidence from animal studies and clinical pharmacological investigations suggesting a role for noradrenaline in motor inhibition and impulsivity. Springer-Verlag, 2011 Parkinson's disease nationallicence Fronto-striatal circuits nationallicence Levodopa nationallicence Dopamine nationallicence Inhibition nationallicence Conditional stop-signal task nationallicence Obeso Ignacio Cognitive-Motor Neuroscience Group, Sobell Department of Motor Neuroscience and Movement Disorders, UCL, Institute of Neurology and The National Hospital for Neurology and Neurosurgery, 33 Queen Square, WC1N 3BG, London, UK aut Wilkinson Leonora Cognitive-Motor Neuroscience Group, Sobell Department of Motor Neuroscience and Movement Disorders, UCL, Institute of Neurology and The National Hospital for Neurology and Neurosurgery, 33 Queen Square, WC1N 3BG, London, UK aut Jahanshahi Marjan Cognitive-Motor Neuroscience Group, Sobell Department of Motor Neuroscience and Movement Disorders, UCL, Institute of Neurology and The National Hospital for Neurology and Neurosurgery, 33 Queen Square, WC1N 3BG, London, UK aut Experimental Brain Research Springer-Verlag 213/4(2011-09-01), 435-445 0014-4819 213:4<435 2011 213 221 https://doi.org/10.1007/s00221-011-2793-x text/html Onlinezugriff via DOI 1 research-article jats NATIONALLICENCE 856 40 https://doi.org/10.1007/s00221-011-2793-x text/html Onlinezugriff via DOI NATIONALLICENCE 700 1- Obeso Ignacio Cognitive-Motor Neuroscience Group, Sobell Department of Motor Neuroscience and Movement Disorders, UCL, Institute of Neurology and The National Hospital for Neurology and Neurosurgery, 33 Queen Square, WC1N 3BG, London, UK aut NATIONALLICENCE 700 1- Wilkinson Leonora Cognitive-Motor Neuroscience Group, Sobell Department of Motor Neuroscience and Movement Disorders, UCL, Institute of Neurology and The National Hospital for Neurology and Neurosurgery, 33 Queen Square, WC1N 3BG, London, UK aut NATIONALLICENCE 700 1- Jahanshahi Marjan Cognitive-Motor Neuroscience Group, Sobell Department of Motor Neuroscience and Movement Disorders, UCL, Institute of Neurology and The National Hospital for Neurology and Neurosurgery, 33 Queen Square, WC1N 3BG, London, UK aut NATIONALLICENCE 773 0- Experimental Brain Research Springer-Verlag 213/4(2011-09-01), 435-445 0014-4819 213:4<435 2011 213 221 Metadata rights reserved Springer special CC-BY-NC licence nationallicence BK010053 XK010053 XK010000 NATIONALLICENCE NATIONALLICENCE NL-springer