Personal reality warp

The personal reality warp was a device which transported its user to an empty parallel dimension, and populated it with a reality based on their thoughts. The Sixth Doctor had one he'd been tinkering with in his TARDIS. Peri Brown accidentally activated it and ended up in a world based on a combination of Alice in Wonderland (which she had just been reading) and vegetables (which she had just been eating). (COMIC: Salad Daze)