Open monitoring meditation contrasts with focused attention practice: instead of concentrating on a single object, the meditator sits in a state of open, receptive awareness — noticing whatever arises in consciousness (sounds, sensations, thoughts, emotions) without selecting any of it as a focal point. Sometimes called 'choiceless awareness' or 'open presence,' this practice is associated with non-reactive monitoring of experience and is considered a more advanced practice that typically develops after focused attention has been stabilized. EEG studies show that open monitoring produces high levels of theta waves, associated with relaxed alertness and creative insight.

Reference:

Wikipedia: Mindfulness

https://en.wikipedia.org/wiki/Mindfulness