Is a minecraft LAN-world accesible from another account?

So i play some minecraft with my brother and he would load his world and then set it open to the LAN-network so i could join him and we could play together, but he's only home in the weekends and sometimes i would like to play in the week, so i already tried to import his map folder into my minecraft folder, and everything goes fine and if he wants to play in the weekends, i would just give him my world folder and he would paste it, but when i open minecraft, i spawn as his account, with all the items and exp and on the place he logged out. So now i would like to know if it's possible to play on his world without spawning as his account, but as mine.