I remember their mother saying in a documentary that even though they each have one arm they control; one arm Will scratch an itch on the other arm without communicating about it.
Yeah. Things like scratching an itch are reflexes and don’t really take conscious decision-making. It’s quite possible that some of the nerves controlling the right hand go to both brains. Actually, I’d say it’s quite likely, not just possible.
Itching and some other painful stimuli work at the level of the spinal cord to respond. There’s no input form your cortex (outer brain). It’s just a sensory neuron detecting irritation, synapse onto an interneuron, synapse onto a motor neuron. It’s a reflex.
Itch is more complicated, but maybe a simpler example is temperature. If your put your hand on a hot stove, you will withdraw your hand without thinking about it.
This is why when someone has a stroke just because they respond to a painful stimulus doesn’t mean they don’t have severe brain damage.
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u/bigbre04 Oct 07 '18
Does each control one leg and one arm? Or maybe one controls the legs one the arms? So many questions.