title: Sequence learning in Parkinson's disease: Focusing on action dynamics and the role of dopaminergic medication.
abstract: Previous studies on movement sequence learning in Parkinson's disease (PD) have produced mixed results. A possible explanation for the inconsistent findings is that some studies have taken dopaminergic medication into account while others have not. Additionally, in previous studies the response modalities did not allow for an investigation of the action dynamics of sequential movements as they unfold over time. In the current study we investigated sequence learning in PD by specifically considering the role of medication status in a sequence learning task where mouse movements were performed. The focus on mouse movements allowed us to examine the action dynamics of sequential movement in terms of initiation time, movement time, movement accuracy, and velocity. PD patients performed the sequence learning task once on their regular medication, and once after overnight withdrawal from their medication. Results showed that sequence learning as reflected in initiation times was impaired when PD patients performed the task ON medication compared to OFF medication. In contrast, sequence learning as reflected in the accuracy of movement trajectories was enhanced when performing the task ON compared to OFF medication. Our findings suggest that while medication enhances execution processes of movement sequence learning, it may at the same time impair planning processes that precede actual execution. Overall, the current study extends earlier findings on movement sequence learning in PD by differentiating between various components of performance, and further refines previous dopamine overdose effects in sequence learning.
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium; School of Kinesiology, University of Michigan, 401 Washtenaw Avenue, Ann Arbor, MI 48109-2214, USA. Electronic address: marit.ruitenberg@ugent.be.
authors.forename: Marit F L
authors.initials: MFL
authors.lastname: Ruitenberg
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium.
authors.forename: Wout
authors.initials: W
authors.lastname: Duthoo
authors.affiliation: Department of Neurology, Ghent University Hospital, De Pintelaan 185, 9000 Ghent, Belgium.
authors.forename: Patrick
authors.initials: P
authors.lastname: Santens
authors.affiliation: School of Kinesiology, University of Michigan, 401 Washtenaw Avenue, Ann Arbor, MI 48109-2214, USA.
authors.forename: Rachael D
authors.initials: RD
authors.lastname: Seidler
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium.
authors.forename: Wim
authors.initials: W
authors.lastname: Notebaert
authors.affiliation: Department of Experimental Psychology, Ghent University, Henri Dunantlaan 2, 9000 Ghent, Belgium.
authors.forename: Elger L
authors.initials: EL
authors.lastname: Abrahamse
mesh_terms: D000368:Aged; D000977:Antiparasitic Agents / Q000627:therapeutic use*; D001696:Biomechanical Phenomena; D015259:Dopamine Agents / Q000627:therapeutic use*; D005260:Female; D006225:Hand / Q000503:physiopathology; D006801:Humans; D007858:Learning / Q000187:drug effects* / Q000502:physiology; D008297:Male; D008875:Middle Aged; D009048:Motor Skills / Q000187:drug effects* / Q000502:physiology; D009483:Neuropsychological Tests; D010300:Parkinson Disease / Q000188:drug therapy* / Q000503:physiopathology / Q000523:psychology
chemical_list: D000977:Antiparasitic Agents; D015259:Dopamine Agents
keywords: Dopamine; Mouse tracking; Movement sequence learning; Parkinson's disease