MEMORY

What is memory?

Simply put, memory is the mental activity of recalling information that you have learned or experienced. That simple definition, though, covers a complex process that involves many different parts of the brain and serves us in disparate ways.
Memory can be short-term or long-term. In short-term memory, your mind stores information for a few seconds or a few minutes: the time it takes you to dial a phone number you just looked up or to compare the prices of several items in a store. Such memory is fragile, and it’s meant to be; your brain would soon read “disk full” if you retained every phone number you called, every dish you ordered in a restaurant, and the subject of every ad you watched on TV. It’s also meant to hold an average of seven items, which is why you can usually remember a new phone number for a few minutes but need your credit card in front of you when you’re buying something online.
Long-term memory involves the information you make an effort (conscious or unconscious) to retain, because it’s personally meaningful to you (for example, data about family and friends), or you need it (such as job procedures or material you’re studying for a test), or it made an emotional impression (a movie that had you riveted, the first time you ever caught a fish, the day your uncle died). Some information that you store in long-term memory requires a conscious effort to recall: personal memories about experiences you’ve had at specific times (episodic memory) and factual data not bound to time or place (semantic memory), which can be everything from the names of the planets to the color of your child’s hair. Another type of long-term memory is procedural memory, which involves skills and routines you perform so often that they don’t require conscious recall.
These areas of the brain are especially important in the formation and retention of memory:

• The hippocampus, a primitive structure deep in the brain, plays the single largest role in processing information as memory.
• The amygdala, an almond-shaped area near the hippocampus, processes emotion and helps imprint memories that involve emotion.
• The cerebral cortex, the outer layer of the brain, stores most long-term memory in different zones, depending on what kind of processing the information involves: language, sensory input, problem-solving, and so forth.

In addition, memory involves communication among the brain’s network of neurons, millions of cells activated by brain chemicals called neurotransmitters.

Stages of Memory Formation and Maintenance
Acquisition	New information enters your brain along pathways between neurons in the appropriate area of the brain. The key to encoding information into your memory is concentration; unless you focus on information intently, it goes “in one ear and out the other.” This is why teachers are always nagging students to pay attention!
Consolidation	If you’ve concentrated well enough to encode new information in your brain, the hippocampus sends a signal to store the information as long-term memory. This happens more easily if it’s related to something you already know, or if it stimulates an emotional response.
Retrieval	When you need to recall information, your brain has to activate the same pattern of nerve cells it used to store it. The more frequently you need the information, the easier it is to retrieve it along healthy nerve cell connections.

How can I improve my memory?

If you think you have a poor memory, you may just have some less-than-effective habits when it comes to taking in and processing information. Barring disease, disorder, or injury, you can improve your ability to learn and retain information.

General Guidelines for Improving Memory
Pay attention.	You can’t remember something if you never learned it, and you can’t learn something — that is, encode it into your brain — if you don’t pay enough attention to it. It takes about eight seconds of intent focus to process a piece of information through your hippocampus and into the appropriate memory center. So no multitasking when you need to concentrate. If you distract easily, try to receive information in a quiet place where you won’t be interrupted.
Tailor information acquisition to your learning style.	Most people are visual learners; they learn best by reading or otherwise seeing what it is they have to know. But some are auditory learners who learn better by listening. They might benefit by recording information they need and listening to it until they remember it.
Involve as many senses as possible.	Even if you’re a visual learner, read out loud what you want to remember. If you can recite it rhythmically, even better. Try to relate information to colors, textures, smells and tastes. The physical act of rewriting information can help imprint it onto your brain.
Relate information to what you already know.	Connect new data to information you already remember, whether it’s new material that builds on previous knowledge or an address of someone who lives on a street where you already know someone.
Organize information.	Write things down in address books and datebooks and on calendars; take notes on more complex material and reorganize the notes into categories later. Use both words and pictures in learning information.
Understand and be able to interpret complex material.	For more complex material, focus on understanding basic ideas rather than memorizing isolated details. Be able to explain it to someone else in your own words.
Rehearse information frequently and “overlearn.”	Review what you’ve learned the same day you learn it, and review it at intervals thereafter. What researchers call “spaced rehearsal” is more effective than “cramming.” If you’re able to “overlearn” information so that recalling it becomes second nature, so much the better.
Be motivated and keep a positive attitude.	Tell yourself that you want to learn what you need to remember and you can learn and remember it. Telling yourself you have a bad memory actually hampers the ability of your brain to remember, while positive mental feedback sets up an expectation of success.

Mnemonic devices

Mnemonics (the initial “m” is silent) are clues of any kind that help us remember something, usually by causing us to associate the information we want to remember with a visual image, a sentence, or a word.

Common types of mnemonic devices include:

• Visual images: a microphone to remember the name “Mike,” a rose for “Rosie.” Use positive, pleasant images, because the brain often blocks out unpleasant ones, and make them vivid, colorful, and three-dimensional — they’ll be easier to remember.
• Sentences in which the first letter of each word is part of or represents the initial of what you want to remember. Millions of musicians, for example, first memorized the lines of the treble staff with the sentence “Every good boy does fine” (or “deserves favor”), representing the notes E, G, B, D, and F. Medical students often learn groups of nerves, bones, and other anatomical features using nonsense sentences.
• Acronyms, which are initials that creates pronounceable words. The spaces between the lines on the treble staff, for example, are F, A, C, and E: FACE.
• Rhymes and alliteration: remember learning “30 days hath September, April, June, and November”? A hefty guy named Robert can be remembered as “Big Bob” and a smiley co-worker as “Perky Pat” (though it might be best to keep such names to yourself).
• Jokes or even off-color associations using facts, figures, and names you need to recall, because funny or peculiar things are easier to remember than mundane images.
• “Chunking” information; that is, arranging a long list in smaller units or categories that are easier to remember. If you can reel off your Social Security number without looking at it, that’s probably because it’s arranged in groups of 3, 2, and 4 digits, not a string of 9.
• “Method of loci”: This is an ancient and effective way of remembering a lot of material, such as a speech. You associate each part of what you have to remember with a landmark in a route you know well, such as your commute to work.

Brain exercise

Memory, like muscular strength, is a “use it or lose it” proposition. The more you work out your brain, the better you’ll be able to process and remember information.

Novelty and sensory stimulation are the foundation of brain exercise. If you break your routine in a challenging way, you’re using brain pathways you weren’t using before. This can involve something as simple as brushing your teeth with your nondominant hand, which activates little-used connections on the nondominant side of your brain. Or try a “neurobic” exercise that forces you to use your faculties in unusual ways, like showering and getting dressed with your eyes closed. Take a course in a subject you don’t know much about, learn a new game of strategy, cook up some recipes in an unfamiliar cuisine. That’s the most effective way to keep your synapses firing.

How can healthy habits help my memory?

Treating your body well can enhance your ability to process and recall information.

Regular exercise	Increases oxygen to your brain. Reduces the risk for disorders that lead to memory loss, such as diabetes and cardiovascular disease. May enhance the effects of helpful brain chemicals and protect brain cells.
Managing stress	Cortisol, the stress hormone, can damage the hippocampus if the stress is unrelieved. Stress makes it difficult to concentrate.
Good sleep habits	Sleep is necessary for memory consolidation. Sleep disorders like insomnia and sleep apnea leave you tired and unable to concentrate during the day.
Not smoking	Smoking heightens the risk of vascular disorders that can cause stroke and constrict arteries that deliver oxygen to the brain.

You probably know already that a diet based on fruits, vegetables, whole grains, and “healthy” fats will provide lots of health benefits, but such a diet can also improve memory. Research indicates that the following nutrients nurture and stimulate brain function:

B vitamins, especially B6, B12, and folic acid	B vitamins protects neurons by breaking down homocysteine, an amino acid that is toxic to nerve cells. They’re also involved in making red blood cells, which carry oxygen. Best sources: spinach and other dark leafy greens, broccoli, asparagus, strawberries, melons, black beans and other legumes, citrus fruits, soybeans
Antioxidants: Vitamins C and E, beta carotene	Antioxidants fight free radicals, which are atoms formed when oxygen interacts with certain molecules. Free radicals are highly reactive and can damage cells, but antioxidants can interact with them safely and neutralize them. Antioxidants also improve the flow of oxygen through the body and brain. Best sources: blueberries and other berries, sweet potatoes, red tomatoes, spinach, broccoli, green tea, nuts and seeds, citrus fruits, liver
Omega-3 fatty acids	Omega-3 fatty acids are concentrated in the brain and are associated with cognitive function. They count as “healthy” fats, as opposed to saturated fats and trans fats, protecting against inflammation and high cholesterol. Best sources: cold-water fish such as salmon, herring, tuna, halibut, and mackerel; walnuts and walnut oil; flaxseed and flaxseed oil

Because older adults are more prone to B12 and folic acid deficiencies, a supplement may be a good idea for seniors; ditto an omega-3 supplement (at any age) if you don’t like eating fish. But nutrients work best when they’re consumed in foods, so try your best to eat a broad spectrum of colorful plant foods and choose fats that will help clear, not clog, your arteries. Your brain will thank you!

Does memory naturally decline with age? If so, why?

Several factors cause aging brains to experience changes in the ability to retain and retrieve memories:

• The hippocampus is especially vulnerable to age-related deterioration, and that can affect how well you retain information.
• There’s a relative loss of neurons with age, which can affect the activity of brain chemicals called neurotransmitters and their receptors.
• An older person often experiences decreased blood flow to the brain and processes nutrients that enhance brain activity less efficiently than a younger person.

However, in healthy older adults, these changes represent more of a slowing in the ability to absorb, store, and retrieve new information, not a loss. The factual information you’ve accumulated over the years remains largely intact, as does procedural memory. You can make and recall new long-term memories; the process just takes a little longer.
Of course, some older adults do develop more significant problems with memory that are the result of diseases such as Alzheimer’s or stroke; injury; poor nutrition; other physiological issues; or emotional problems.

Compensating for memory loss

Even if you are experiencing a troublesome level of memory loss, there are many things you can do to learn new information and retain it.

Keeping track of dates, schedules, tasks, phone numbers	Write it down! Leave yourself notes or make checklists. Put appointments and important dates on calendars and in a day planner or electronic organizer. Ditto for phone numbers and other contact information. If you have trouble remembering how to do something, write down the steps.
Remembering where you put things	Put the things you use regularly (keys, glasses, purse, watch) in the same spot when you’re not using them. If you have to put something down in a different place, look at the place when you put down the object and say the location out loud. If necessary, write down where things are.
Staying on top of times and places	Set an alarm clock or timer to remind you when to leave for an appointment or do something in your home. Use a map to help you get from one place to another. Enlist friends and relatives to remind you of where you need to be and things you’re supposed to do.
Learning new information	Work on your ability to focus your attention and screen out distractions: Listen closely when someone talks to you. Repeat back the information. Try to talk with people in quiet places. Focus on one thing at a time.

Preventing memory loss

The same practices that contribute to healthy aging also contribute to healthy memory.

Regular exercise	It gets more oxygen to your brain. It reduces the risk for disorders that lead to memory loss, such as diabetes and cardiovascular disease. It may enhance the effects of helpful brain chemicals and protect brain cells.
Healthy diet featuring fruits, vegetables, whole grains, and “healthy” fats	Antioxidants literally keep your brain cells from “rusting.” B vitamins protect neurons and help reduce risk of cardiovascular diseases. Avoiding saturated fats and trans fats helps cholesterol levels and reduces risk of stroke.
Managing stress	Cortisol, the stress hormone, can damage the hippocampus if stress is unrelieved. Stress makes it difficult to concentrate.
Good sleep and enough of it	Sleep is necessary for memory consolidation. Sleep disorders like insomnia and sleep apnea leave you tired and unable to concentrate during the day.
Not smoking	Smoking heightens the risk of vascular disorders that can cause stroke and constrict arteries that deliver oxygen to the brain.

In addition, two other lifestyle factors are crucial for maintaining healthy memory throughout life:

Lifelong learning and exercise of the brain

When it comes to memory, it’s “use it or lose it.” Just as physical exercise can make and keep your body stronger, mental exercise can make your brain work better and lower the risk of mental decline. Here are some ideas for brain exercise, from light workouts to heavy lifting:

• Play games that involve strategy, like chess or bridge, and word games like Scrabble.
• Work crossword and other word puzzles, or number puzzles such as Sudoku.
• Read newspapers, magazines, and books that challenge you.
• Get in the habit of learning new things: games, recipes, driving routes.
• Take a course in an unfamiliar subject.
• Take on a project that involves design and planning: a new garden, a quilt, a koi pond.