Delta waves are characteristic of sleep. There was little delta during the relaxing and meditative tasks, confirming that non-directive meditation is different from sleep.

Beta waves occur when the brain is working on goal-oriented tasks, such as planning a date or reflecting actively over a particular issue. EEG showed few beta waves during meditation and resting.
"These findings indicate that you step away from problem solving both when relaxing and during meditation," says Ellingsen.