The Human Brain

Even if you're very ticklish, you probably are incapable of tickling yourself. Learn why.

One in three people consistently struggle through the autumn and winter months with a type of depression known as seasonal affective disorder (SAD). Here are some tips for dealing with it.

By Harriet Bowyer

Ever find yourself momentarily disoriented in a familiar place or encounter a friend who looks like a stranger? You could be experiencing jamais vu.

By Jennifer Walker-Journey

This new form of sound therapy takes advantage of the fact that a different frequency in each ear yields a third frequency that can allegedly calm you down or improve your focus. Does it really work? Our writer tried it out.

By Alia Hoyt

We see faces in clouds, on buildings — heck, in grilled cheese sandwiches. But why is that? And how is this a help to our survival?

By Dave Roos

Alcoholism can be difficult to spot. Learn the difference between heavy drinking and alcoholism, how alcohol affects the body, what factors may lead to alcoholism and what treatments are available for this addiction.

By Stephanie Watson

Dreams combine verbal, visual and emotional stimuli into mystifying storylines. Should we bother to interpret them? Are they random brain impulses, or do they offer insight into our waking lives?

By Lee Ann Obringer & Yves Jeffcoat

Your co-worker just yawned in a meeting, and now everyone on his side of the table is yawning, too. Learn about what might've caused him to do it in the first place and why you're likely to yawn right along with them.

By Melanie Radzicki McManus

Collective hysteria can spread when a fear exists of exposure to a disease, combined with a contained environment. Learn more about collective hysteria works.

By Jacob Silverman & Austin Henderson

We've all heard of a "sixth sense" and extra-sensory perception. So how many ways can we actually sense the world around us?

By HowStuffWorks.com Contributors

Every animal sleeps -- some more than others -- but why they do it is a mystery to scientists. Is sleep more than just beauty rest? Could skimping on it kill you? And how much do you really need?

By Marshall Brain

Nostalgia, contrary to centuries of common knowledge, appears to be a good thing. A really good thing.

By Julia Layton

You've probably experienced that moment where you're driving, get lost, turn down the radio, and then think, "Why did I just do that?"

By Maria Trimarchi

Pain is subjective — what is excruciating to you might be tolerable to me. Which is why it's so difficult to measure and control.

By Jennifer Sellers

When you see someone yawning, even in a picture, chances are a yawning urge will come over you, too. But is this also true of sneezing, and if so, why?

By Laurie L. Dove

Have you ever met someone with a unique first name, and then all of a sudden you hear the name everywhere you turn? That's the Baader-Meinhof phenomenon at work. How did it get that handle?

By Kate Kershner & Austin Henderson

Are you a person who likes to be social but also values some alone time? You are? How did we guess without knowing you? Welcome to the Barnum effect.

By Kate Kershner

Why does the experience of sleep paralysis often summon explanations of demonic visitations? Visit the place where dreams and reality overlap, and where science and myth attempt to interpret our hallucinations.

By Robert Lamb

Odd as it may seem, many antidepressants like Zoloft having warning labels about increases in suicidal thoughts. Why would that be? And how will you know if your medication is actually working?

By Laurie L. Dove

We often throw around the word "insanity" for acts that seem to have no rational explanation (like a teacher giving an insanely difficult test). Legally speaking, though, it's actually a narrow term that's very difficult to prove in court.

By Chris Opfer

Most of us don't intuitively classify electroshocks as therapeutic, but this 1950s-era treatment has changed a lot since it was first introduced. When and why do mental health experts now turn to it?

By Kate Kershner

You're deep in dreamland when you hear an explosion so loud you wake up. But there's nothing outside or inside your house making the noise. What just happened?

By Sean Russell

You've just touched a hot stove -- and probably felt an immediate sharp pain, then a dull ache. How do we sense pain, and why does it eventually go away?

By Craig Freudenrich, Ph.D.

That man dressed in animal skins and running around Jerusalem trying to baptize people isn't alone. Tourists in Jerusalem sometimes suffer from a strange conviction that they are Biblical figures. Are they mentally ill or is there more to it?

By Katie Lambert

You might think that not being able to feel pain would be a blessing. No tears, no painkillers, no lingering aches. But really, not being able to feel pain is dangerous.

By Katie Lambert