human brains use bang-bang control to control our body movement. all muscles are either on or off, with many individually actuateable groups of fibers per major muscle group. if youve ever lifted weights and started to shake on a hard lift, thats your body switching rapidly between different muscle fibers trying to complete the lift. body feedback takes more than 100 ms, which is way too long to do active feedback control on a lot of the really fast actions we do with our bodies, so for those our brain just does it open loop. it generates a sequence based on your intent and past training and just lets it rip, but we for sure can modify the sequence midway.
this is part of why humanoid robots look so uncanny when they move, they do continuous control which is fundamentally different from how we move our bodies. our brains have special pathways that process others body movements and what those robots do doesnt line up with how we know our bodies move so it looks wrong.
Along these lines: a major league baseball batter must predict where the ball will be before it leaves the pitcher’s hand. There is literally not enough time for the neural signal to get from the eyes to the brain, be processed and then an impulse sent to the arm muscles to swing the bat in the time it takes for the ball to travel to home plate at 95mph.
human brains use bang-bang control to control our body movement. all muscles are either on or off, with many individually actuateable groups of fibers per major muscle group. if youve ever lifted weights and started to shake on a hard lift, thats your body switching rapidly between different muscle fibers trying to complete the lift. body feedback takes more than 100 ms, which is way too long to do active feedback control on a lot of the really fast actions we do with our bodies, so for those our brain just does it open loop. it generates a sequence based on your intent and past training and just lets it rip, but we for sure can modify the sequence midway.
this is part of why humanoid robots look so uncanny when they move, they do continuous control which is fundamentally different from how we move our bodies. our brains have special pathways that process others body movements and what those robots do doesnt line up with how we know our bodies move so it looks wrong.
Along these lines: a major league baseball batter must predict where the ball will be before it leaves the pitcher’s hand. There is literally not enough time for the neural signal to get from the eyes to the brain, be processed and then an impulse sent to the arm muscles to swing the bat in the time it takes for the ball to travel to home plate at 95mph.
We should pass a funny law that requires all humanoid robots to grunt as they move.
Muscles can be either voluntary (choosing to lift a chair) or involuntary (a beating heart) as well.