Wired for sleep: a student prepares to have an electroencephalogram or EEG (image: University of Waikato)
We sleep through about a third of our lives, yet we still don't know why we need that much sleep. Neither is it clear what happens in the brain as we drift off or cycle from quiet slow-wave sleep to rapid-eye-movement (REM) sleep. University of Waikato physicists Moira and Alistair Steyn-Ross, in collaboration with colleague Marcus Wilson, hope to answer some of these open questions by comparing natural sleep with a mathematical model they developed to describe the enforced sleep brought on by anaesthetic drugs.
The anaesthetic-induced changes in brain states from wakefulness to unconsciousness have similarities to general phase transitions in physics, such as water freezing to form ice. The team's goal is to improve our understanding of how the brain cycles through different sleep states and how sleep is linked to memory formation and learning.
