5. Memory :: Alzheimer’s Disease

Alzheimer’s disease is a degenerative disease of the nerve cells in the brain that causes impairment of memory and other brain functions — such as language or perception of reality. Alzheimer’s patients also experience personality changes and a decreased ability to take care of themselves. Many scientists believe that the disease is caused by the abnormal accumulation of a specific protein that eventually leads to nerve cell death. The disease appears to start in the hippocampus* (see below definitions) and spreads to other parts of the cortex as it progresses.

Alzheimer’s disease is not part of the normal aging process. There are some genetic risk factors (gene mutations) that may influence the development of the disease. The main risk factor is age. Ten percent of people over the age of 65, and 50% over the age of 85, have the disease. Some studies have shown that a lifelong love of learning and physically staying in shape are negative risk factors for getting the disease. So, even if you are genetically prone to this disease, if you stay mentally and physically in shape, you can significantly delay or prevent the onset of Alzheimer’s.

Alzheimer’s Prevention

Several recent studies have shown that mental and physical exercise throughout one’s lifetime may significantly reduce the effects of  Alzheimer’s.

Mental exercises such as crossword puzzles, brain teasers, chess, or card games help keep the mind working in top shape. This helps build what is called a “cognitive reserve.” Formal education also helps build a person’s cognitive reserve. In fact, each year of education reduces a person’s chances of getting Alzheimer’s by an average of 17%. Scientists believe this is because people with a large cognitive reserve are better able to adapt as neurons are killed by the disease. The more @ neural connections  (see below definitions)  you have, the longer it takes for the disease to make a significant impact.
It’s important to note that mental exercise cannot help significantly once Alzheimer’s has already set in. A person must have a lifetime commitment to learning in order to build up his or her cognitive reserve. It is probably not possible to completely prevent the disease in genetically susceptible people, but it is possible to delay the onset so that it will not occur in the person’s lifetime.

Mental exercise is one way to help prevent  Alzheimer’s. Another means of prevention is to remain physically fit throughout life. All of the organs in the body benefit from being physically fit, including the brain. One Harvard study of more than 18,000 participants found that people who got the most exercise showed less mental decline than those with sedentary lifestyles.

Physical exercise increases blood flow to the brain and keeps it working efficiently by stimulating the production of neurotrophins#  (see below definitions) . This is especially true for the hippocampus* which is the first area of the brain affected by Alzheimer’s disease. This increased blood flow and neuronal efficiency can reduce the natural shrinkage that occurs in the brain as it ages. An average person will lose between 15% and 25% of brain cells by the age of 90. Those people who get the most exercise will be at the bottom of that scale, while those people who never exercise will be at the top of that scale.

DEFINTIONS

# Neurotrophins are small proteins that are naturally produced in the brain and act like mental nutrients. A constant level of neurotrophins are required just to keep the neurons alive. Neurotrophins are also responsible for pruning out unwanted cells and for stimulating the growth of new @dendrites.

Stimulating your mind with new and interesting experiences causes it to increase the production of neurotrophins, which in turn increase the strength and complexity of the dendrites. It causes neurons to connect to different areas of the brain and form new patterns. The more connections you have, the more ways you have to remember a piece of information.

So, seeking out novel experiences is a great way to keep your mind in shape.

* In the middle of the brain, connected to the @cortex, is the hippocampus. Actually there are two hippocampi, one on each side of the brain. The hippocampus helps to form new memories about experienced events. It interprets incoming sensory inputs and turns them into memories. If the hippocampus is damaged, it becomes incredibly difficult to form new memories and recall old memories. In fact, it is one of the first parts of the brain that succumbs to Alzheimer’s disease.

The hippocampus also stores and processes spatial information. This is how you remember locations and know how to get from place to place. The types of people who never get lost and are good at finding shortcuts have a very active hippocampus. Taxi cab drivers tend to have a large hippocampus, indicating that if you use your spatial skills, your hippocampus can actually grow.

To prevent information overload, your hippocampus is constantly sifting through incoming sensory inputs and deciding what to save and what to discard. For a memory to get into long-term storage, it must be selected by the hippocampus. Information with emotional significance or information that relates to something we already know tends to get preferential treatment. This is why meaningfulness is important for information you want to learn.

@ Neural Connections & @ Dendrites & @ Neurons

The brain is made up of billions of nerve cells, called @ neurons. There are over 100 million neurons per square inch of your brain! Neurons communicate to nearby neighbors via electrical and chemical signals sent between axons and dendrites.

An axon is a long slender projection from a neuron which transmits signals away from the cell and towards other nearby neurons. Bundles of axons make up nerves and are the primary way that signals are transmitted throughout the body. The axons in your spinal cord can be as long as 3 feet.

A dendrite is a projection from a neuron that receives signals from the axons of its neighbors. A neuron will have a large number of dendrites but only one axon.

The interface between a dendrite and an axon is called a synapse. The signal is transmitted along the axon as an electrical impulse. Once it reaches the synapse, the release of chemical  ** Neurotransmitters  (see below definitions)  transmits the signal to the dendrites of other neurons. Each neuron will be have between 1,000 and 10,000 synapses.

** Neurotransmitters

A neurotransmitter is a chemical in the brain that helps regulate the electrical signals between neurons. Neurotransmitters exist in little pockets, inside the nerve cells, called vesicles. When an electrical signal triggers the neuron, these vesicles float to the cell membrane and release their neurotransmitters. The neurotransmitters then jump across the synapse and bind to receptors on adjacent neurons.

How the adjacent neuron reacts to the neurotransmitters depends on a number of factors. There are many different types of neurotransmitters produce different results. Some cause the adjacent neuron to trigger and others suppress triggering. It is the combined effect of all the neurotransmitters that determines what happens to the signal.

Alzheimer’s prevention pillar: Mental stimulation

Those who continue learning new things throughout life and challenging their brains are less likely to develop Alzheimer’s disease and dementia, so make it a point to stay mentally active. In essence, you need to “use it or lose it.”

Activities involving multiple tasks or requiring communication, interaction, and organization offer the greatest protection. Set aside time each day to stimulate your brain. Cross-training with these brain-boosting activities will help keep you mentally sharp:

• Learn something new. Study a foreign language, learn sign language, practice a musical instrument, read the newspaper or a good book, or take up a new hobby. The greater the novelty and challenge, the larger the deposit in your brain reserves.
• Practice memorization. Start with something short, progressing to something a little more involved, such as the 50 U.S. state capitals. Create rhymes and patterns to strengthen your memory connections.
• Enjoy strategy games, puzzles, and riddles. Brain teasers and strategy games provide a great mental workout and build your capacity to form and retain cognitive associations. Do a crossword puzzle, play board games or cards, or work word and number games, such as Scrabble or Sudoku.
• Practice the 5 W’s. Observe and report like a crime detective. Keep a “Who, What, Where, When, and Why” list of your daily experiences. Capturing visual details keeps your neurons firing.
• Follow the road less traveled. Take a new route, eat with your non-dominant hand, rearrange your computer file system. Vary your habits regularly to create new brain pathways.

Improving memory tips: Give your brain a workout

By the time you’ve reached adulthood, your brain has developed millions of neural pathways that help you process information quickly, solve familiar problems, and execute familiar tasks with a minimum of mental effort. But if you always stick to these well-worn paths, you aren’t giving your brain the stimulation it needs to keep growing and developing. You have to shake things up from time to time!

Memory, like muscular strength, requires you to “use it or lose it.” The more you work out your brain, the better you’ll be able to process and remember information. The best brain exercising activities break your routine and challenge you to use and develop new brain pathways. The activity can be virtually anything, so long as it meets the following three criteria:

1. It’s new. No matter how intellectually demanding the activity, if it’s something you’re already good at, it’s not a good brain exercise. The activity needs to be something that’s unfamiliar and out of your comfort zone.
2. It’s challenging. Anything that takes some mental effort and expands your knowledge will work. Examples include learning a new language, instrument, or sport, or tackling a challenging crossword or Sudoku puzzle.
3. It’s fun. The more interested and engaged you are in the activity, the more likely you’ll be to continue doing it and the greater the benefits you’ll experience. The activity should be challenging, yes, but not so difficult or unpleasant that you dread doing it.

Use mnemonic devices to make memorization easier

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

Mnemonic device	Technique	Example
Visual image	Associate a visual image with a word or name to help you remember them better. Positive, pleasant images that are vivid, colorful, and three-dimensional will be easier to remember.	To remember the name Rosa Parks and what she’s known for, picture a woman sitting on a park bench surrounded by roses, waiting as her bus pulls up.
Acrostic (or sentence)	Make up a sentence in which the first letter of each word is part of or represents the initial of what you want to remember.	The sentence “Every good boy does fine” to memorize the lines of the treble clef, representing the notes E, G, B, D, and F.
Acronym	An acronym is a word that is made up by taking the first letters of all the key words or ideas you need to remember and creating a new word out of them.	The word “HOMES” to remember the names of the Great Lakes: Huron, Ontario, Michigan, Erie, and Superior.
Rhymes and alliteration	Rhymes, alliteration (a repeating sound or syllable), and even jokes are a memorable way to remember more mundane facts and figures.	The rhyme “Thirty days hath September, April, June, and November” to remember the months of the year with only 30 days in them.
Chunking	Chunking breaks a long list of numbers or other types of information into smaller, more manageable chunks.	Remembering a 10-digit phone number by breaking it down into three sets of numbers: 555-867-5309 (as opposed to5558675309).
Method of loci	Imagine placing the items you want to remember along a route you know well or in specific locations in a familiar room or building.	For a shopping list, imagine bananas in the entryway to your home, a puddle of milk in the middle of the sofa, eggs going up the stairs, and bread on your bed.

Tips for enhancing your ability to learn and remember

• 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 intense focus to process a piece of information into your memory. If you’re easily distracted, pick a quiet place where you won’t be interrupted.
• Involve as many senses as possible. Try to relate information to colors, textures, smells and tastes. The physical act of rewriting information can help imprint it onto your brain.Even if you’re a visual learner, read out loud what you want to remember. If you can recite it rhythmically, even better.
• 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 something as simple as an address of someone who lives on a street where you already know someone.
• For more complex material, focus on understanding basic ideas rather than memorizing isolated details. Practice explaining the ideas to someone else in your own words.
• Rehearse information you’ve already learned. Review what you’ve learned the same day you learn it, and at intervals thereafter. This “spaced rehearsal” is more effective than cramming, especially for retaining what you’ve learned.