Guided imagery is a gentle but powerful technique that focuses and directs the imagination. It can be just as simple as an athlete's 10-second trance, just before leaping off the diving board, imagining how a perfect dive feels when slicing through the water. It can be as complex as imagining the busy, focused buzz of thousands of loyal immune cells, scooting out of the thymus gland on a search and destroy mission to wipe out unsuspecting cancer cells.

Although it has been called "visualization" and "mental imagery", these terms are misleading. Guided imagery involves far more than just the visual sense – and this is a good thing, given the fact that only about 55% of the population is strongly wired visually. Instead, imagery involves all of the senses, and almost anyone can do this. Neither is it strictly a "mental" activity – it involves the whole body, the emotions and all the senses, and it is precisely this body-based focus that makes for its powerful impact.

Over the past 25 years, the effectiveness of guided imagery has been increasingly established by research findings that demonstrate its positive impact on health, creativity and performance. We now know that in many instances even 10 minutes of imagery can reduce blood pressure, lower cholesterol and glucose levels in the blood, and heighten short- term immune cell activity. It can considerably reduce blood loss during surgery and morphine use after it. It lessens headaches and pain. It can increase skill at skiing, skating, tennis, writing, acting and singing; it accelerates weight loss and reduces anxiety; and it has been shown, again and again, to reduce the aversive effects of chemotherapy, especially nausea, depression and fatigue. Because it is a right-brained activity, engaging in it will often be accompanied by other functions that reside in that vicinity: emotion, laughter, sensitivity to music, openness to spirituality, intuition, abstract thinking and empathy. And because it mobilizes unconscious processes to assist with conscious goals, it can bring to bear much more of a person's strength and motivation to accomplish a desired end. As subtle and gentle as this technique is, it can be very powerful, and more and more so over time.

One of the most appealing and forgiving features about imagery is that almost anyone can use it. Imagery skips across the barriers of education, class, race, gender and age – a truly equal opportunity intervention. People can invent their own imagery, or they can listen to imagery that's been created for them. Either way, their own imaginations will sooner or later take over, because, even when listening to imagery that's been created in advance, the mind will automatically edit, skip, change or substitute what's being offered for what is needed. So even a tape, CD or written script will become a kind of internal launching pad for the genius of each person's unique imagination.

Guided imagery works because of 3 very simple, common sense principles.

First Principle: The Mind-Body Connection

The body interprets images created in the mind as actual, real events and thus believes the image to be reality. The mind doesn't quite get the difference. That's why, when we read a recipe, we start to salivate. The mind is constructing images of the food -- how it looks, tastes and smells; it might even be evoking the sounds of the food cooking or the feel of its texture as it's being chewed. In the meantime, the body is perceiving "dinner is served", and is responding by generating saliva and appetite.

The mind cues the body particularly well if the images evoke sensory memory and fantasy – sights, sounds, smells, feel and taste – and when there is a strong emotional element involved. So, for instance, a strongly evocative image might be remembering the time you were skiing down an ungroomed trail where you feel the adrenalin rush, hear the swish of the snow flying about, and feel on top of the world. These sensory images are the true language of the body, the only language it understands, immediately and without doubt.

Research in the field of psychoneuroimmunology shows that the body directly responds to a created image indicating that there is a physiological pathway mediating the mind-body connection. As an example, a cancer patient imagining an army infantry unit (symbolizing natural killer cells of the immune system) infiltrating and destroying the enemy camp (a tumor mass) will produce actual and immediate physiological mobilization of the immune system. Similarly, athletes who visualize their abdominal muscles tightening up actually produce a measurable muscular contraction in the abdomen.

Second Principle: The Altered State

In the altered state, we're capable of more rapid and intense healing, growth, learning and performance. We are even more intuitive and creative. In this ordinary but profound mind-state, our brainwave activity and our biochemistry shift. Our moods and cognition change. We can do things we couldn't in a normal, waking state – lift a tree that has fallen on a child; write an extraordinarily delicious poem; replace our terror of a surgical procedure with a calming sense of safety and optimism; abate a life-threatening histamine response to a bee sting.

We wander in and out of altered states all through the day, as a matter of course. Sometimes it's not a conscious choice, and we drive past our exit on the highway. At best, the altered state is a state of relaxed focus, a kind of calm but energized alertness, and a highly functional form of focused daydreaming. Attention is concentrated on one thing or on a very narrow range of things.

As this happens, we find we have a heightened sensitivity to the object of our attention, and a decreased awareness of other things going on around us, things we would ordinarily notice. We are so engrossed, we lose track of time or don't hear people talking to us. Or we are so focused on our tennis, we don't realize we were playing on a twisted ankle, and the pain isn't fully perceived until the game is over.

The altered state is the power cell of guided imagery. When we consciously apply it, we have an awesome ally, an exceptional source of internal strength and skill.

Third Principle: Locus of Control

When we have a sense of being in control, that, in and of itself, can help us to feel better and do better.

Feeling in control is associated with higher optimism, self-esteem, and ability to tolerate pain, ambiguity and stress. Decades of research in ego psychology informs us that we feel better about ourselves and perform better when we have a sense of mastery over the environment. Conversely, a sense of helplessness lowers self-esteem, our ability to cope and our optimism about the future.

Because guided imagery is an entirely internally driven activity, and the user can decide when, where, how and if it is applied, it has the salutary effect of helping us feel we have some control. This effect is particularly important when people are faced with a medical diagnosis in which they are informed that their only hope is relying on medical treatment. Their traditional coping strategies are now deemed ineffective and this newfound powerlessness can wreak havoc on the disease process. Having a tool that allows participants to have a sense that they are making a difference in their recovery is truly vital.

So, when you put all this together, you have a technique that generates an altered state, in which the mind is directed toward multi-sensory images that the body perceives as real. This is done exactly when, where and how the user wishes. And that's why it's so effective.

There are many kinds of effective healing imagery, and, we are all different, we respond differently to different types. Here are ten common categories of guided imagery:

Feeling State Imagery

This is simple imagery that changes mood, such as seeing yourself in your favorite place, or recalling a happy, peaceful time. Any imagery that can genuinely elicit feelings of love, care, safety and gratitude, will crowd out feelings of fear, anxiety, resentment and anger. All of this qualifies as feeling state imagery.

End State Imagery

This is imagery that uses for its content any desired outcome or goal, in all it's realistic particulars. So imagining a strong, cancer-free body; a perfectly played, confident, relaxed, focused game of tennis; or the perfect job interview, would all be end state imagery, sometimes called "mental rehearsal" in hypnosis.

Energetic Imagery

This is imagery, taken from Ayurvedic and Chinese medicine, as well as quantum physics that use the notion of plentiful, coherent, free-flowing, unblocked energy as the underlying dynamic of good health. Illness, in this paradigm, would be seen as stuck energy, or energy that is withheld from the general flow. A healthy image can be imagined as moving particles in a direct way or an internal feeling of motion.

Cellular Imagery

This imagery focuses on the healthy interaction of the cells, and requires accurate technical knowledge, so it isn't for everyone. For cancer, it would be imagining the natural killer immune cells being more aggressive and selecting specific cancer cells for elimination, or actually imagining the chemotherapy agent penetrating the blood system and specifically targeting cancer cells leaving the healthy body cells untouched.

Physiological Imagery

This is imagery that focuses on larger healing processes in the body, such as sensing the widening, softening and clearing of the arteries for heart disease; imagining the feel of tumours shrinking in the body with cancer; and seeing the opening of swollen, constricted passageways in the lungs for asthma. This too requires accurate knowledge of how the body naturally operates to heal each condition.

Metaphoric Imagery

This is imagery that works with symbols instead of concrete reality, such as seeing a flower opening its petals as a metaphor for enhanced creativity blossoming again; or seeing a tumour as an enemy encampment, being slaughtered by a powerful supply of tanks, missiles and guns.

Psychological Imagery

This is imagery that specifically addresses a person's psychological issues by providing corrective emotional content. So, for instance, it might consist of imagining being surrounded by loving friends and allies to alter the sense of isolation and despair; or seeing oneself through kind and loving eyes, for someone who is relentlessly self-attacking; or perceiving the presence a beloved, recently lost parent to alleviate grief.

Inner Resources Imagery

This active imagery process explores the inner psychological resources of the individual. The goal is to connect with an intuitive inner voice for guidance, or a part of the inner psyche that is wounded and needs healing. Examples include the inner guide, inner healer, inner child, inner parent. Balancing one’s emotions, providing answers to difficult questions and repatterning past traumas can be achieved via this modality.

Spiritual Imagery

This imagery evokes the wider perspective and peaceful or transcendent feelings provided by mystical states of consciousness and prayer. This might involve sensing assistance from angels, guides, power animals, God, or specific religious figures and icons; or imagery that fosters a sense of oneness and connection with all things; or any imagery that deeply opens the heart.

Transformational Fantasy

This imagery is where the person engages in a personal dialogue with a specific body part, process or entity residing within the person. This allows for the person to pay heed to the natural intelligence that each cell or system possesses. As a result it gives the person a sense of understanding why and a sense of power to transform from the inside out the disease process. This process may involve ‘becoming’ the cancer and interacting with this part and discovering why, when and what its function is. Transformational imagery is quite powerful, and due to the complexity of its often-unexpected process, it is best reserved for advanced users or with an experienced therapist.

What are some really good conditions for making my imagery as effective as possible?

Being relaxed; using all of your senses, especially your kinaesthetic or feeling sense; continued practice; going to the same place with the same music or props each time; using touch as a conditioning cue (such as putting your hands over your belly each time, and breathing deeply); not trying too hard or being too exacting about how you do this. Practicing with a group of people also helps.

Is imagery the same as self-hypnosis?

Yes, in a sense it is, but hypnosis is really a broader category that includes verbal suggestion and thoughts without images along with guided imagery. For instance, telling yourself in the altered state that you'll be calm and confident qualifies as self-hypnosis. Seeing yourself that way, in sights, sounds or feelings is imagery. Although hypnosis also uses images, it isn't limited to them.

How is imagery different from meditation?

Meditation is also a broader category. Imagery is a form of meditation. Meditation is any kind of deliberate focus, usually on just one thing or a very narrow band of things. This often clears the mind, slows it down and calms and strengthens the meditator. Furthermore, in meditation the goal is simply toi become aware of whatever is whereas the goal of imagery is to manipulate a consciously created image to attain a pre-specified goal. For most westerners, imagery is easier to work with, more absorbing and appealing than the more rigorous mindfulness meditation.

How often should I practice my imagery?

Everyone's needs are different, but you might want to start out a couple of times a day for about 15 minutes each time for 3 or 4 weeks. First thing in the morning and just before falling asleep at night are usually convenient and especially potent times for imagery.

Do I have to believe it will work for it to work?

No. You just have to give it a try, putting your analytic mind on hold, and preferably try it more than just once. Skill improves with practice. But a lot of sceptics end up doing quite well with imagery.

Is this an ability some are born with and others aren't?

No. Everyone can do this, although it does seem to come more easily to some than to others. But anyone can improve with practice.

How do kids do with guided imagery?

Kids are naturals at this, responding to it easily and intensely, because they haven't had time to be acculturated away from this natural, inborn ability. Adolescents are excellent candidates for guided imagery, probably due, at least in part, to all those volatile hormones coursing through their veins.

© Naparstek, B. 2000 http://www.healthjourneys.com

© Naparstek, B. Staying Well with Guided Imagery, Warner Books, 1994

Lusk, J.T., 30 Scripts for relaxation, imagery and self-healing. Whole Person Associates, 1992

Rossman, M. Fighting Cancer from Within. Henry Holt & Company, 2003

Achterberg, J. Imagery in Healing: Shamanism and Modern Medicine New Science Library 1985.

Rossman, M. Guided Imagery for Self-Healing H.J. Kramer, 2000.

Brigham, D.D., Imagery for Getting Well: Clinical Applications of Behavioral Medicine, W.W. Norton

You do not have to be a "believer" in order for imagery to help.

Positive expectancy helps, but even a sceptical willingness to give it a try can be quite sufficient.

Touch may be the most powerful accompaniment to imagery you can employ, both to help with relaxation and to increase the kinaesthetic power of the images

Imagery combined with therapeutic massage, energy work, or other kinaesthetic modalities is very potent, and more than the sum of its parts.

Using the same posture cues, gestures or hand-positioning with each imaging session creates an "anchor" that conditions you to respond immediately to the posture.

You can then adopt the posture in a meeting, or while waiting in traffic, or while resting, and your body will respond the way it did during the imagery. Be sure that when you rehearse the imagery, you use this anchoring technique with the identical image and gesture at all times.

If you aren't used to being both relaxed and awake at the same time, you will routinely fall asleep during an imagery session, especially if you're listening to a tape.

If you want to stay awake, you might try sitting up, standing, walking or listening with your eyes half-open. Even asleep, though, you'll benefit from repeated listening, as demonstrated in test results with sleeping diabetics and unconscious surgery patients.

Don't worry if you keep "spacing out" or losing track of a guided imagery narrative.

This is not an indicator that you're listening wrong. On the contrary, a wandering mind is normal.

You may tear up, get a runny nose, cough, yawn, feel heaviness in your limbs, get tingling along the top of their scalp or in your hands and feet, or experience minor, involuntary muscle-movements.

These are entirely normal responses.

Other indicators of a strong response to imagery are unusual stillness, emotional releases, and/or a sense of clearing or lightness.

Typically an imaging exercise, regardless of what it's for, will clear a headache, relieve stress, lift mood and reduce pain.