system
Given the following post, respond as if you're commenting on Reddit:
human
ELI5: How do we think about moving our body without actually moving it?

What's the difference between thinking about, say, moving your arm and actually doing it? What makes the first one just a thought, and the second one a decision + movement? Thanks in advance, sorry if it's a stupid question.

EDIT: Wow, thanks for all the awards and great answers :)
gpt
Basically, whether or not the signal gets sent from your brain to the limb.  Interestingly, a lot of the brain activity in the brain is similar when we think about something as when we do it.  Might seem kinda obvious, but it goes deeper than you think.  If you scan a musician's brain when they actively listen to music, it will light up in a similar way as when they are *playing* the music.  This is different from someone who doesn't play an instrument listening to it.  Or when you listen to someone speaking, part of your understanding comes from imagining yourself making those sounds, and working out what words you'd be saying if you did that.  This is why you see some people mouthing along as they listen to someone speaking.


Edit: thanks, kind strangers.  Hopefully you meant to actually press the award button, rather than just *thinking* about it...