Have you ever forgotten where you left your car keys, misplaced your eyeglasses, or forgotten a dental appointment? Of course you have, it's only human.
Are such lapses signs of an inferior memory? Definitely not. In fact, many people mistakenly believe that their memory is "bad" or on its way to becoming lost. It's usually not. And if you think about the millions of things each day that you do remember, you'll realize that your memory is really quite astounding.
For example, consider the routine act of meeting a friend for dinner. At minimum, you have to remember:
Your friend's name and face
The history of your relationship
The concept of time
The actual time of your dinner date
Which restaurant you'll be eating at
Directions for getting there
How to drive your car (or walk or flag a taxi)
How to read the menu
What the different dishes taste like and whether you like them
To bring money or a credit card, and a bevy of other details
Is It All in Your Head?
All of this information, along with the capacity to store, recall, and analyze it, is a mere fraction of what's stored in the roughly three pounds of tissue that constitute your brain.
The basic building block of the brain is the nerve cell, or neuron. The cortex, or outer layer, of your brain contains approximately 10-20 billion neurons. Neurons connect with each other via electrical impulses, which trigger the release of chemicals called neurotransmitters. These neurotransmitters are released and taken up at contact points called synapses. Each sound, image, feeling, taste, smell or event we perceive activates a unique subset of these synapses. Each time the memory is recalled, that same pattern is reactivated, making the connections stronger and more indelible. Thus, the memories you recall most often become the most ingrained. To make something easier to recall, you can practice remembering it—a study technique used by many students.
Is It Temporary or Permanent?
Neurologists talk about three different kinds of memory: immediate, short-term and long-term memory. Immediate memory is how much information someone can keep in mind without memorizing, such as a phone number. Information in short-term memory lasts minutes or hours and then is gone, unless that information is moved to long-term memory. An example of working memory is remembering three unrelated items at five minutes.
The decision to move something into short-term memory is handled by a structure in the brain called the hippocampus. The hippocampus appears to be involved with conscious recollection. Information that has emotional significance to you, such as your child's birth date, is more likely to be passed onto long-term memory. Details that are related to information already stored in your memory, such as a sign announcing an early bird special at your favorite restaurant, usually make the cut as well. That's because the brain seems to store and retrieve things by their associations.
What would happen if your hippocampus stopped functioning for some reason? You'd still be able to carry on an intelligent conversation with a new acquaintance. But if the person you were chatting with left the room and came back five minutes later, you wouldn't remember ever having met her, let alone having spoken with her just minutes before.
You may wonder if your memory will inevitably weaken as you age. Although some people in their 80s have sharper memories than their children, experts agree that the ability to form and recall memories does change somewhat with age. The good news is that barring
or some other condition that affects brain function, the change in your memory abilities is likely to be small. As we age, we continue to form new memories, but the memories tend to include less detail. For example, you might remember that you saw a friend one morning, but perhaps not recall what he was wearing.
What About Memory Enhancers?
You can improve your ability to recall information by doing one, simple thing: pay attention. Often we're thinking about other things when other people are speaking. Or we're so distracted by everyday life that we're not able to focus on the details. By forcing yourself to pay attention to something, you'll be much more likely to remember it.
What about supplements? You've probably seen them advertised in magazines or heard about them from friends: pills that claim to improve memory. The most widely available of these are ginkgo biloba (an herb), vitamin E (an antioxidant), and DHEA (a hormone). Although all of the evidence isn't in yet, it is currently inconclusive whether these supplements boost memory function in healthy adults. Since each of these substances may be associated with some risk, it is important to talk to your doctor before taking any herbs or supplements.
As much as scientists have learned about memory, there's much more to be discovered. "Space is not the last frontier," it's been said. "It's the space between our ears that's the last frontier." Meanwhile, rest assured that when you misplace your keys, it's not necessarily a sign that your memory is failing; you may have been distracted and failed to pay attention when you put them down.
Brain facts and figures page. University of Washington website. Available at: http://faculty.washington.edu/chudler/facts.html. Accessed January 8, 2009.
Kirshner HS. Approaches to intellectual and memory impairments. In: Bradley WG, Daroff RB, Fenichel GM, Jankovic J, eds. Neurology in Clinical Practice. 5th ed. Philadelphia, PA: Butterworth Heniemann Elsevier; 2008:59-68.
Kritchevsky M, Marchand ER, Hillyard SA, Manley LD. Clinical correlation: frontal system dysfunction and disorders of memory. In: Kirtchevsky M, Marchand ER, Hillyard SA, Manley LD. Basic Neurology Lecture Notes. San Diego, CA; 2000:389-391.
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