Think back to the time when your love was new, when you had just fallen in love:

How did you know you were in love? Maybe you couldn't eat, couldn't sleep, couldn't concentrate on work or chores or anything that didn't involve your love object. Maybe you felt like a totally different person, unrecognizable even to yourself. Even those who have long-standing fears of intimacy find deep connections in the initial throes of love--under love's umbrella, emotional intimacy magically becomes as natural as breathing.

And sure enough, your brain--on a very physical, measurable, scientific level--was revealing its own set of marked changes when your love was new. Understanding the truth behind that can help you infuse your long-term relationship with new life, even if the days of heady, brand-new love are long behind you.

What the research says about falling in love

Dr. Helen Fisher and her research team wanted to know what happens to the brain when people fall in love. In a series of clever experiments, she took people who described themselves as head-over-heels in love and did MRI scans of their brains while they looked at pictures of their loved ones. Dr. Fisher also scanned their brains when they looked at pictures of strangers (i.e., people they had no feelings towards).

Guess what happens to your brain when you're in love?

When you are in love, the pleasure centers of your brain go into over-drive. In particular, two brain chemicals (the neurotransmitters dopamine and norepinephrine) are secreted in greater amounts. These chemicals are associated with feelings of happiness, elation, greater focus and goal-directed behavior (physical activity and certain drugs also increase these brain chemicals).

This explains why you feel so wonderful when you fall in love--you're high! (But it's the kind of high that's totally legal and doesn't come with dangerous side effects.)

As love deepens and time passes, the intensity of infatuation wanes and these brain chemicals go back to normal levels. This allows you to become less consumed with your new lover, which is important so you can begin to regain the balance in your life that existed before you fell in love. If your dopamine levels never returned to normal, you'd never get anything done at work or at home, since you'd only be able to think about your partner. Other important areas of your life would suffer.

Let's use this research to deepen intimacy and create a more vibrant relationship:

Intense love, exercise and certain drugs aren't the only ways you can keep the pleasure centers of your brain active (and, in case it isn't obvious, I'm only recommending the first two). Activities that are novel and exciting also naturally increase your dopamine levels.

Here's the important point for your relationship: when you and your partner share novel and exciting experiences, you will both surround your relationship with positive feelings (happiness, excitement, joyfulness). The positive feelings you experience will be associated with your partner (and you will be associated with his/her positive feelings). This will deepen intimacy and keep love and passion alive!

This might explain why couples feel the need to go on vacation to rekindle their relationship fires--they are creating experiences that are mutually exciting and new, and even though they don't realize it, they're stimulating the pleasure centers of their brains. Have you ever felt closer with your partner during and after vacations?

Putting this research to work for your relationship:

Make a commitment to do something novel together

This can be simple and cost nothing, or complicated and expensive (like visiting a far-off destination). It's up to you.

Research findings show that couples who make novel experiences a regular part of their relationship rate their relationships more positively. Apply this important data to your own relationship--try new things together.

Here are some ideas:

~Go to a new restaurant or cook a new meal together.

~Take a class together (some ideas: adult education classes, art, yoga, dance, physical fitness, cooking, foreign language).

~Create something together (a birdhouse, a bench, a floral arrangement, a model of the Titanic).

~Decorate a room together (where you're both involved with every aspect of the project, instead of one partner doing all the legwork while the other partner just nods approval at the color choices).

~Take up a new hobby (photography, woodworking, puzzling or puzzle-making, stamp collecting, skiing).

~Get fit together. Join a gym as a couple. Or walk or hike (taking different routes from time to time).

~Vary your leisure activities. Go to concerts and plays and museums. (And if you've never been to the opera, you can't very well say you don't like it…right?)

~Volunteer for something you're both passionate about. Imagine how good you'll feel if you and your partner benefit from the togetherness of doing something new while bringing aid to someone who really needs it.

…Brainstorm together about other new experiences you'd both like to try--research shows that variety is in fact the spice of life (and of love)!