Formation and lateralization of internal representations underlying motor commands during precision grip.
The capability to store and retrieve weight-related information from a lift to scale the force output during a subsequent lift was examined in 10 healthy adults and 50 children (age 2-10 years), as well as a 22-year-old patient with corpus callosum agenesis. Subjects lifted a test object between the thumb and index finger while the isometric fingertip forces were measured. The results suggest that both healthy children and adults can transfer weight-related information between the right and left hand, although a lateralization was found. Also, the storage and retrieval of weight-related information appears to be a dynamic process dependent on both previous sensory information and knowledge of future movements. Late maturation of interhemispheric connections and asymmetric loss of some information during the transfer between hemispheres suggest a lateralization of the internal representation. The patient with a corpus callosum agenesis supported this hypothesis.
Gordon
A M
AM
Nobel Institute for Neurophysiology, Karolinska Institute, Stockholm, Sweden.
Forssberg
H
H
Iwasaki
N
N
D000293:Adolescent; D000328:Adult; D000367:Age Factors; D061085:Agenesis of Corpus Callosum; D001288:Attention / Q000502:physiology; D002648:Child; D002675:Child, Preschool; D003337:Corpus Callosum / Q000503:physiopathology; D004292:Dominance, Cerebral / Q000502:physiology*; D005260:Female; D007839:Functional Laterality / Q000502:physiology*; D006801:Humans; D007092:Imagination / Q000502:physiology*; D007537:Isometric Contraction / Q000502:physiology*; D007699:Kinesthesis / Q000502:physiology*; D008297:Male; D012016:Reference Values; D012691:Serial Learning / Q000502:physiology; D014892:Weight Perception / Q000502:physiology; D016474:Weight-Bearing / Q000502:physiology