How (Well) Do You Remember?
Have you ever forgotten where you left your car keys, misplaced your eyeglasses, or forgotten a dental appointment? Of course you have, it is 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. If you think about the millions of things each day that you do remember, you will 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:
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 is 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 it. 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 is because the brain seems to store and retrieve things by their associations.
What would happen if your hippocampus stopped functioning for some reason? You would 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 would not 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 Alzheimer's disease 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 are thinking about other things when other people are speaking. Or we are so distracted by everyday life that we are not able to focus on the details. By forcing yourself to pay attention to something, you will be much more likely to remember it.
What about supplements? You have 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). Evidence 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 is much more to be discovered. "Space is not the last frontier," it has been said. "It's the space between our ears that's the last frontier." Meanwhile, rest assured that when you misplace your keys, it is not necessarily a sign that your memory is failing; you may have been distracted and failed to pay attention when you put them down.
National Institute of Mental Health
National Institute of Neurological Disorders and Stroke
Canadian Mental Health Association
Canadian Psychiatric Association
Brain Basics. National Institute of Mental Health website. Available at: http://www.nimh.ni.... Accessed December 19, 2012.
Brain facts and figures page. University of Washington website. Available at: http://faculty.washington.edu/chudler/facts.html . Accessed December 19, 2012.
Mareib, E. Neural Integration. Human Anatomy and Physiology.2nd ed. Redwood City, CA: The Benjamin/Cummings Publishing Company;1992:476-495.
Mild Cognitive Impairment. EBSCO DynaMed website. Available at: http://www.ebscohost.com/dynamed/what. Updated November 27, 2012. Accessed December 19, 2012.
Last reviewed December 2012 by Brian Randall, MD