When you get up in the morning and just before sleep, you are naturally in this state. When you close your eyes your brain automatically starts producing more alpha waves. Many studies monitoring the EEG activity of experienced meditators have revealed strong increases in alpha activity.
Bottom-up processing happens when someone tries to understand language by looking at individual meanings or grammatical characteristics of the most basic units of the text, (e.g. sounds for a listening or words for a reading), and moves from these to trying to understand the whole text.
In the classroom. Learners can be encouraged to use both bottom-up and top-down strategies to help them understand a text. For example in a reading comprehension learners use their knowledge of the genre to predict what will be in the text (top-down), and their understanding of affixation to guess meaning (bottom-up).