Sometimes the voices in our heads say the darndest (and meanest!) things. But anyone can learn to silence even the most relentless inner critic.

Text by Whitney Joiner.

While making my bed one morning last fall, I was contemplating the day's schedule when a hostile voice interrupted my mental to-do list. "You'll never find love," it said, apropos of nothing I'd consciously been thinking about.

As cruel as my inner heckler was, I knew exactly where she got her material. Just a month earlier, I'd experienced a major heartbreak. Against my better judgment, I'd fallen in love with my closest male friend, with whom I'd shared countless long-distance road trips, weekend hikes, and hours-long weekly phone calls over the years. When I revealed my deepening feelings, he made it clear that he didn't share them. The intensity and depth of my hurt shocked me.

And yet, I'd begun to recover, in part by listing all of the reasons why we wouldn't have worked out anyway, and in part from finding comfort in the inevitable truth that someday I'd meet someone else. But on that morning, as I pulled the comforter up over the sheets, all constructive and optimistic reasoning about my future romantic odds was drowned out by that persistent voice of doom: "You'll always get rejected. You'll always be alone."

After a brief crying jag, I sat in stunned silence on the freshly made bed, feeling betrayed by my own capricious mind: Did I really believe that eternal romantic abandonment was my fate? No. At other times, I'd been quite lucky at love. So how to explain the cruel hijacking of my own thoughts?

Gone to the Dark Side

Science has some clues. As with most brain functions, the tendency of the mind to wander most likely had an evolutionary purpose, says neuropsychologist Rick Hanson, Ph.D., author of "Buddha's Brain: The Practical Neuroscience of Happiness, Love and Wisdom." In early times, our ancestors led a moment-to-moment existence, hunting down sustenance and avoiding predators. "So a little bit of mind-wandering was adaptive," Hanson says. "It led the brain to see new things, think new thoughts, imagine new problems, and figure out how to deal with something similar in the future." Today, our psyches meander for similar reasons -- and often to dark places. To aid our survival, our brains "evolved a tendency to scan for things to worry about," Hanson explains. "We have hair-trigger systems that evolved to help us run from lions but now activate when we're stuck in traffic or our boss gives us a look or there's a frown across the dinner table."

When the brain perceives a threat or has a negative experience, it initiates a reaction that is stored immediately in memory. In contrast, "positive experiences, unless they are repeated or intense, tend to flow through the mind like water through a sieve," he says. "In a day, 20 things could happen, and only one is negative. What are you mulling over as you fall asleep? It's most likely the one negative thing. The brain is like Velcro for negative experiences and Teflon for positive ones."

Unsurprisingly, your mind's slant toward pessimism has a partner in crime: our wired, fast-paced culture. Constant bombardment of stimuli (anxiety-producing texts and IMs, those jarring email notifications), not to mention the saturation of often disturbing 24-hour news headlines, besieges us and reinforces our inherent negativity bias. "We live in an era where we're generally under continual low-grade stress," Hanson says. "That puts our overall nervous systems and stress response systems on alert."

Don't Believe the Hype

For most, those stockpiles of destructive thoughts tend to tumble into our consciousness when we daydream, perhaps in the momentary reliving of a painful conversation or an embarrassing moment -- or while fending off a brutal internal nag. (No wonder Harvard University researchers found that people whose minds wandered during daily activities were less happy than those who stayed focused.) What's important to know is that these thoughts are just that: thoughts, not truths. "I call them deceptive brain messages," says Rebecca Gladding, M.D., coauthor of "You Are Not Your Brain: The 4-Step Solution for Changing Bad Habits, Ending Unhealthy Thinking, and Taking Control of Your Life." "They bubble up from your brain, but they often do not represent who you are or reflect your true self. They are not factual statements about you, nor are they things you must do, or want to do, in life."

And yet, too often, we wanderers accept these brain blips as facts. "When people see their initial thought as reality, there's nowhere to go other than down that negative spiral," Gladding says. "Your sense of self gets fused with these messages."

Worse, buying into this process creates chronic discomfort that can make us fling ourselves head-long into unhealthy habits -- smoking, overeating, or obsessively checking email -- for consolation. Eventually, the more fixed these bad habits become, the worse we feel, creating a self-perpetuating cycle. "The brain literally builds structure around what we dwell on," Hanson says. "If your neurons are firing away on negative ruminations, that's gradually stitching negativity into the fabric of your brain."

Tuning Out the Hecklers

As ingrained as mind-wandering is, experts say it's possible to minimize it -- and to calibrate it with constructive messages. "By focusing attention differently," Gladding says, "we can wire healthy responses into the brain instead of unhealthy ones." Think of your attention like a spotlight, Hanson says: "It illuminates whatever it rests upon. But most people don't have good control of it." When we're more attuned to where our mind drifts, we can keep attention where we want it, he says, "and pull it away from things that aren't good for us, like grinding self-criticism."

Gladding suggests four steps to steer away from negative chatter, but she also recommends mindfulness meditation -- "the most direct route to figuring out what's going on inside your head" -- as do many neuroscientists and psychologists. This technique trains your mind to be in the present and view your thoughts as just thoughts, not reality. "Mindfulness teaches us to see the difference between the actual event and the story we're telling about it," says Sharon Salzberg, author of "Real Happiness: The Power of Meditation."

It takes practice but not a huge commitment. Even just five minutes daily of focusing on your in- and out-breaths can loosen the hold of negativity. Over time, you'll notice that instead of automatically believing your thoughts, you're observing them with spaciousness. "Keep practicing," Salzberg says, "and when you get caught in something, you'll think, 'I'm making up this story,' a lot sooner than before."

I've practiced meditation now for nearly a decade, and while it doesn't always prevent corrosive thoughts from derailing me -- like they did during my bed-making that morning -- the attention-focusing skills I've gained do help relax their grip. An oft-quoted Buddhist proverb says, "Pain is inevitable, but suffering is optional." In my case, I know I can't avoid the pain of heartbreak, but I've learned to minimize the suffering that comes from dwelling on it. Years ago, I would have responded to my mind's hurtful ramblings about my romantic disappointment by wildly distracting myself -- with a drink (or many), a pack of cigarettes, or frantic calls to my girlfriends -- and taking it all personally. These days, it's more likely that I can recognize that voice as the false echo of my worst fears, sit for a while with the discomfort of having heard it, and move on, assuaged by the knowledge that my heart -- and mind -- are on the mend.

Shush That Inner Critic

In the 1990s, psychiatrist Jeffrey Schwartz, M.D., discovered that mindfulness can literally rewire the brain. His latest book, "You Are Not Your Brain," with coauthor Rebecca Gladding, M.D., builds on that groundbreaking research, offering a road map for kicking the habit of negative thinking. Consider this four-step process your doom-and-gloom escape hatch.

1. Relabel
To stop hostile self-talk, first you must become aware of it -- and call it what it is. "Say to yourself, 'Oh, I'm ruminating again,'" Gladding says. Also notice any physical sensations accompanying the chatter (perspiration, muscle tension, etc.). Being aware of how the body reacts can help you recognize a destructive thought pattern faster.

2. Reframe
In this step, the goal is to change your perception of your ruminations -- to acknowledge that they're deceptive messages, not honest truths. "Remind yourself: '"This isn't me; it's just my brain.'"

3. Refocus
Now direct your attention to something positive -- the key to fixing automatic responses to your brain's negativity bias. "Make a list of things you find helpful or enjoyable. If you're at work, focus on something more interesting to you for a little bit. Or sit and focus on your breath for a few minutes, as you would in meditation," Gladding says. "Try anything healthy that's going to snap you out of the negative cycle."

4. Revalue
If you follow the previous steps, eventually the process will become a habit. Gladding and Schwartz call this "revaluing" because it allows you to move from a mere cognitive understanding of deceptive brain messaging to knowing as soon as harsh thoughts arise that they have little or no worth. "As you go through this process, you realize how unhelpful these mind messages are," Gladding says, "and that you truly are someone wonderful in spite of what your brain is often trying to tell you."

Whitney Joiner is a freelance writer in Marfa, Texas.