Our brain is a very complicated machine. What we know for sure is that we don't know everything about it and about its functionality.
Trying to look at the specific story - a movement is just a serious of still pictures as we all know. Now, if for some reason, this uncles brain can only "read" the pictures muc slower than a a regular person (let's assume the uncle's brain can only read the pictures every 5 seconds), then yes - the world this uncle see is still with no movements.
Could be jsut a crazy story, but if it made me think about it, then it's a good one...