The mnemonic chambers were special devices located throughout the Great Clock that could be used to look inside the user's subconscious mind. In other words, you literally walk right into the dream world.
During his captivity within the Clock, Clank was suspended in a chamber for over a year while Nefarious tried to hack into his mind to find a way inside the Orvus Chamber. His attempts failed and Clank was able to escape after a power failure.
After Clank's escape and subsequent acceptance of his position of Senior Caretaker of the Clock, he used mnemonic chambers to access his subconscious mind and communicate with a digital simulation of his creator, Orvus. During these encounters, Clank learned more about the Clock and mastered new abilities that allowed him to perform his duties as Senior Caretaker.
During one trip in mnemonic station Iota, Clank encountered The Plumber who claimed he had taken a wrong turn and ended up in Clank's subconscious by accident. After giving Clank a cryptic clue about not risking more than six minutes, Clank was thrown down a pipe and back into reality. The incident prompted Sigmund to question whether the chamber was working as he noted strange neural activity during the encounter.
- The word mnemonic is used to describe things which aid memory, such as short poems and visual stimulus. Mnemonics rely on associations between easy to remember things which can be related back to the thing that needs to be remembered.