title: The effect of viewing graspable objects and actions in Parkinson's disease.
abstract: Viewing action-relevant stimuli such as a graspable object or another person moving can affect the observer's own motor system. Evidence exists that external stimuli may facilitate or hinder movement in Parkinson's disease, so we investigated whether action-relevant stimuli would exert a stronger influence. We measured the effect of action-relevant stimuli (graspable door handles and finger movements) on reaction times compared with baseline stimuli (bars and object movements). Parkinson's patients were influenced by the location of the baseline stimuli, but unlike healthy controls, action-relevant stimuli did not exert a stronger influence. This suggests that external cues exert their influence in Parkinson's disease through lower-level visual processes and the influence of action-relevant stimuli on the motor system is disrupted.
authors.affiliation: School of Psychological Sciences, University of Manchester, Manchester, and Greater Manchester Neurosciences Unit, Hope Hospital, Salford, UK. ellen@poliakoff.org.uk
authors.forename: Ellen
authors.initials: E
authors.lastname: Poliakoff
authors.forename: Adam
authors.initials: A
authors.lastname: Galpin
authors.forename: Jeremy
authors.initials: J
authors.lastname: Dick
authors.forename: Peter
authors.initials: P
authors.lastname: Moore
authors.forename: Steven P
authors.initials: SP
authors.lastname: Tipper
mesh_terms: D000368:Aged; D005260:Female; D018737:Hand Strength / Q000502:physiology*; D006801:Humans; D008297:Male; D008875:Middle Aged; D009068:Movement / Q000502:physiology*; D010300:Parkinson Disease / Q000503:physiopathology*; D010775:Photic Stimulation; D011597:Psychomotor Performance / Q000502:physiology*; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values