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Brain Image Gallery

It's possible for your brain to keep secrets from you if you injure it. See more pictures of the brain.

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We've all seen it depicted in a sitcom or in a Lifetime movie -- a leading character suffers a bad fall or someone whacks him or her on the head and boom -- the character suddenly doesn't know his or her own name and can't recognize loved ones standing inches away. Television shows that include this kind of memory loss are incorporating a condition called amnesia into their plot. Sometimes amnesia wipes out everything from a person's past, and other times just bits and pieces are missing.

It turns out there are several types of amnesia, and they can be caused by such things as disease, psychological trauma, and yes, even physical trauma such as a severe blow to the head. In most cases, amnesia is a temporary condition and is very brief, lasting from a few seconds to a few hours. However, the duration can be longer depending on the severity of the disease or trauma, possibly lasting for a few weeks or even months. The two types of amnesia you hear about most often are:

  • Retrograde amnesia
  • Anterograde amnesia

Retrograde amnesia is basically a condition in which someone can't recall stored memories, like their mom's maiden name or what happened last Christmas, but they may recall the knock-knock joke their little brother told them a few seconds ago. This is the kind of amnesia you see a lot on soap operas. A married couple is on their honeymoon cruise and somehow the bride falls overboard. After she's rescued, she has no memory of her life before the accident. She doesn't remember her husband or even that she's married, but she does remember the handsome crewmember that plucked her from the ocean. Although you see this a lot on television, it doesn't happen that often in real life.

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