Hemispheric differences in the control of limb dynamics: a link between arm performance asymmetries and arm selection...

Area of Science:

• Neuroscience
• Human motor control
• Cognitive science

Background:

• Handedness is debated as either a preference or sensorimotor asymmetry.
• Neural lateralization models propose distinct hemispheric control processes.
• Interlimb sensorimotor performance asymmetries are observable outcomes of these processes.

Purpose of the Study:

• To investigate if arm selection is influenced by interlimb performance asymmetries.
• To examine the relationship between sensorimotor asymmetries and task-dependent arm choice.
• To test the hypothesis that arm preference results from an interaction between performance asymmetries and task demands.

Main Methods:

• Right-handed subjects performed choice and nonchoice reaches to radial targets.
• Targets were arranged to minimize hemispace biases for midline choices.
• Hand paths and inverse dynamics were analyzed to assess performance and coordination strategies.

Main Results:

• Midline targets, equidistant from both hands, were reached more often with the dominant arm.
• Dominant arm reaches were straighter and more accurate.
• The dominant arm exhibited a more proficient strategy, better exploiting intersegmental dynamics.

Conclusions:

• Sensorimotor asymmetries in dynamic coordination may determine limb choice.
• Findings support models where action selection depends on performance capabilities.
• Results have implications for understanding handedness and neural lateralization.