If a person suffered injury to the right motor cortex that resulted in paralysis of the left arm and later showed some evidence of recovery of function, which of the following would be a likely explanation?
A) Using the right arm more strengthened the left arm.
B) The left motor cortex strengthened its control over the left arm.
C) New neurons grew in place of the damaged ones.
D) The left arm was deafferented.

Question

Quizplus · Accepted Answer

Recovery of function after injury to the motor cortex is often due to the adjacent areas of the cortex taking over the damaged area's function. In this case, it is likely that the left motor cortex strengthened its control over the left arm, resulting in some recovery of function. The other options are less likely explanations. Using the right arm more would not necessarily strengthen the left arm, as the motor pathway for the left arm would still be damaged. New neurons growing in place of the damaged ones is also unlikely, as the adult brain has limited capacity for neurogenesis. Lastly, deafferentation refers to the loss of sensory input to a limb, and would not lead to recovery of motor function.

If a Person Suffered Injury to the Right Motor Cortex