Left hemispheric specialization for learned, skilled, and purposeful action.
Three-dimensional motion analyses were performed on trajectories of repetitive "slicing" gestures by 4 participants with left-hemisphere lesions and limb apraxia, 6 participants with right-hemisphere lesions, and 7 neurologically intact participants. Left hemispheric lesioned participants with apraxia, but not right hemispheric lesioned participants showed impaired coupling of spatial and temporal aspects of wrist trajectories and deficits in interjoint coordination. Both groups of brain-lesioned participants differed from control participants in the 3-D plane of the wrist motion. The deficits of some right hemispheric lesioned participants in controlling the plane of wrist motion may be a consequence of left hemispatial neglect with rightward deviations. In contrast, the deficits of apraxic participants in controlling wrist trajectories and coordinating joint motions seem to reflect a deficit in these participants for the movement plan.
Poizner
H
H
Center for Molecular and Behavioral Neuroscience, Rutgers University, Newark, New Jersey 07102, USA. poizner@signer.rutgers.edu
Merians
A S
AS
Clark
M A
MA
Macauley
B
B
Rothi
L J
LJ
Heilman
K M
KM
D000368:Aged; D001072:Apraxias / Q000209:etiology / Q000473:pathology / Q000503:physiopathology*; D001132:Arm / Q000503:physiopathology*; D001925:Brain Damage, Chronic / Q000503:physiopathology*; D016022:Case-Control Studies; D002540:Cerebral Cortex / Q000473:pathology / Q000503:physiopathology*; D002544:Cerebral Infarction / Q000150:complications / Q000503:physiopathology*; D004292:Dominance, Cerebral / Q000502:physiology; D004550:Elbow / Q000503:physiopathology; D005625:Frontal Lobe / Q000473:pathology / Q000503:physiopathology; D006801:Humans; D007091:Image Processing, Computer-Assisted; D007206:Individuality; D008875:Middle Aged; D009048:Motor Skills / Q000502:physiology*; D009949:Orientation / Q000502:physiology; D010296:Parietal Lobe / Q000473:pathology / Q000503:physiopathology; D012782:Shoulder / Q000503:physiopathology; D013028:Space Perception / Q000502:physiology; D018709:Statistics, Nonparametric; D013997:Time Factors; D013996:Time and Motion Studies; D014953:Wrist / Q000503:physiopathology