It might seem a little silly to use a Grammy award-winning Tina Turner song from the 1980's as a reference to meditation, but Tina actually has been a devoted meditator for decades! Other famous meditators include Phil Jackson, David Lynch, Al Gore, and (of course!) the Dalai Lama. Meditation has been around for thousands of years, and recent research has revealed its profound effects in promoting health, recovery from illness, and creating substantive changes in the brain.

However, the instructions on how to meditate can be very confusing. Think of nothing. Imagine that you're one with the cosmos. Just breathe. Clear your mind.

Rather than stay mired in confusion, here is a brief primer on the four different kinds of meditation. Yes, there's just four.

1. Concentration-based meditation invites you to focus on a single word, phrase, image, or sound, and then asks you to repeat it mentally. Thus, you might think to yourself, "Relax, relax, relax, relax..." Some people use a mantra or prayer as a focus of concentration, too. This kind of meditation is also associated with Herbert Benson's work made famous in the book, The Relaxation Response.
2. Mindfulness meditation asks to to focus on some sensory aspect of your immediate experience. You might focus on your breathing or the sensations in your body, for example. You're not introducing something new to your experience, but rather simply noticing the way it is.
3. Visual imagery involves imaging a relaxing scene or experience. Typically, such meditations suggest a walk on the beach or through a peaceful forest.
4. Insight meditation involves the purposeful consideration of a question or induction of a specific state of being, like compassion. Loving-kindness meditations and Zen koans (e.g., "What is the sound of one hand clapping?") fall into this category.

Meditation practices differ simply based on where you put the focus of your attention.