Complex motor function in humans: validating and extending the postulates of Alexandr R. Luria.
OBJECTIVE
We used functional brain imaging to reevaluate Luria's postulates and to elaborate the neural circuitry underlying performance of complex motor tasks.


BACKGROUND
The anatomic organization and physiologic functioning of the normal human motor system have great significance for understanding motor dysfunction and remediation in neurology. Working with victims of penetrating head injuries, noted Russian neuropsychologist Aleksandr R. Luria designed several tests of fine motor control to understand their difficulties with complex voluntary movements. This led to his postulates that such function involves the premotor cortices and their interaction with the parietal lobe.


METHODS
Six healthy young adults performed the hand imitation, fist-scissors-gun, and piano key tasks during blood oxygen level-dependent functional magnetic resonance imaging at 3 T.


RESULTS
All 3 tasks revealed activation of both premotor and parietal cortices. Furthermore, while hand Imitation relied more on the ventral premotor area and right parietal lobe, fist-scissors-gun and piano key relied more on the supplementary motor cortex.


CONCLUSIONS
We postulate that differences in task-dependent activations across these tasks relate to degrees of sequential movement, pacing, and imitation. These results uphold Luria's original hypotheses, and extend that work by providing a further characterization of the motor areas involved in complex motor behaviors.
Bhimani
Ashish A
AA
The University of Chicago, Chicago, IL 60637, USA.
Hlustik
Petr
P
Small
Steven L
SL
Solodkin
Ana
A
D000293:Adolescent; D000328:Adult; D000704:Analysis of Variance; D001931:Brain Mapping; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007100:Imitative Behavior / Q000502:physiology; D008182:Luria-Nebraska Neuropsychological Battery; D008279:Magnetic Resonance Imaging; D008297:Male; D009044:Motor Cortex / Q000502:physiology*; D009048:Motor Skills / Q000502:physiology*; D009434:Neural Pathways / Q000502:physiology; D010296:Parietal Lobe / Q000502:physiology*; D011434:Proprioception / Q000502:physiology; D012016:Reference Values; D018709:Statistics, Nonparametric