Learning and Memory: How Do We Remember and Why Do We Often Forget?

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The advantage of a bad memory is that one enjoys several times the same good things for the very first time.
—Friedrich Nietzsche

MEMORY SITUATION #1: Immediately after your assistant has given you the number of an important client, you hang up, but before you can dial, someone asks you for the time. After announcing the time, you ready your index finger to dial the client’s phone number, which has escaped from memory. After asking for the number a second time, you scowl at all oncoming strangers to ward off any mental interlopers prior to dialing.

MEMORY SITUATION #2: After returning from a 15th wedding anniversary cruise with twelve Mediterranean ports of call, you effusively describe your vacation to a neighbor. However, when asked about your exact itinerary, you stare blankly. (If it’s any consolation, you could recognize the cities if you heard them.)

MEMORY SITUATION #3: After studying all night for an important college exam, you purchase a jumbo cup of double-caffeinated Kenyan coffee. After getting stuck in traffic, you finally arrive at the campus, find a parking spot and sprint into the exam room with only seconds to spare. With the test now sitting directly in front of you, the first question is unbelievably easy, but suddenly you cannot retrieve the answer. The harder you try, the more elusive it becomes, playing a game of mental hide-and-seek with you.

Are you losing your memory? Are these the first signs of dementia? Chances are, neither.

When our memory is strained, these can be the unsurprising, as well as embarrassing, results. Stress and multitasking are among the chief causes of memory lapses. In the first memory situation, interference prevents recall. In the second situation, a lack of memory maintenance hampers retrieval along with exceeding the “7 items +/- 2” memory rule. Our third case of memory failure most likely reflects the consequences of stress, poor nutrition and exhaustion more than it involves academic difficulty or memory loss. Nearly every aspect of our daily lives are influence in a significant way by memory.

Are memory and recall really so complicated? The bigger question is, “How do we remember and why do we often forget?” Like health, everyone’s memory is impacted by an infinite number of variables that can lead to a wide range of outcomes depending upon the circumstances. Familiarity with those conditions and the accompanying terms used to describe them is helpful to parents and teachers. (See: “Useful Memory Terminology for Parents and Educators.”)

In a contemporary world where exchanges of massive amounts of information have become the norm, students are inundated by far more information than learners from just one generation earlier. Dr. James Appleberry, president of the American Association of State Colleges and Universities, predicted that by the year 2020, human knowledge or information will double every 73 days. For decades, Jupiter was described in science textbooks as a planet with 13 moons. With improved celestial observation technology, the figure for Jupiter was recently revised to 63 moons, giving it the largest retinue of moons with “reasonably secure” orbits of any planet in our solar system. While the facts continue to change, the best techniques for remembering, fortunately, do not.


Memories are the internal mental records that we maintain, which give us instant access to our personal past, complete with all of the facts that we know and the skills that we have cultivated. Encoding, storage and retrieval are the three primary stages of the human memory process. (Forgetting may constitute the fourth stage of memory, although forgetting is technically a setback in memory retrieval).

During the encoding stage, information is sent to the brain, where it is dissected into its most significant composing elements. An ensemble of brain cells processes incoming stimuli and translates that information into a specialized neural code. In the storage phase of memory formation, the brain must retain encoded data over extended periods of time. Retrieval constitutes the right of entry into the infinite world of stored information, where we bring old information out of permanent memory back into working memory, which can be mentally manipulated for usage.

Theoretically, learning is the capability of modifying information already stored in memory based on new input or experiences. Since memory is contingent upon prior learning, the first step in memory is learning, which occurs when our sensory systems send information to the brain. Our sensory system can hold numerous items simultaneously, but only momentarily. Learning is an active process that involves sensory input to the brain, which occurs automatically, and an ability to extract meaning from sensory input by paying attention to it long enough to reach working (short-term) memory, where consideration for transfer into permanent (long-term) memory takes place.

Sensory information enters consciousness naturally in two subtypes, both of which are somewhat fleeting. Iconic memories of visual information have a duration of 0.3 seconds, while echoic memories of auditory information will last about four to five seconds. The brain shows more partiality to iconic information. (See: “Visualization and Memory Lists”). Vision has a much longer history in the human experience than does the printed word. By exploiting this competency, students learn quickly when they can visualize the concept while studying, by directed use of the mind’s eye, where mental pictures can be developed.

Writing words in the air on an imaginary blackboard forces students not only to visualize the order of letters in a word, but to maintain visually what they have already written in working memory as they continue to write. From first grade to medical school, this technique is equally effective. When young learners are taught to construct diagrams that show relationships (graphic organizers), their memory of content improves substantially. Robert Marzano found that these “nonlinguistic representations” can increase achievement scores by 27 percentile points.

We constantly perceive vast amounts of information each minute, but we make no attempt to recall very much of it. Equally important, we cannot remember information that we failed to encode for memory storage in the first place.

Once the elements that make up an experience are classified according to their special traits, each part is shunted to a different brain region for further detailed analysis, where a comparative search for recognizable similarities to previously encountered information begins. The various pieces of new information get stored in neural circuits distributed throughout the cerebral cortex. Because the elements making up a memory reside in multiple cortical areas, the stronger the network linking the associated pieces together, the more resistant to it will be to forgetting.

As the brain transacts learning events, physical changes occur both within brain circuitry and in its structure-function correlations. Here the brain parts company with the popular comparisons to a digital video recorder. Memory is quite fluid, and, over time, the brain continues to revisit and reorganize stored information with each subsequent experience in a cyclical fashion, reprogramming its contents through a repetitive updating procedure known as brain plasticity. This is advantageous, since improvements are made repeatedly to existing data. Prior knowledge is revised based on new input, resulting in a more accurate representation of the current world, increasing one’s probability of thriving. The flip side of these constant memory revisions is that eyewitness accounts often become less reliable with the passage of time.

With new experiences, we amend, rather than maintain and protect, our past memories — occasionally changing them beyond recognition. The newly stored information has been altered, forming new and modified representations of events and our malleable knowledge, which serve as our guides to the environment.

When first exposed to a new song, we establish new neural connections — of the sounds, the emotional pleasure, where we heard this new song, the lyrics, the title, the artist, similar songs, etc. — to represent this novel sensory experience. However, upon hearing the same song on a second occasion, it is processed as a neurologically different experience, where established connections are re-activated as recognition. We now recall the song, which did not occur upon first exposure, sing along with now recognizable lyrics (also impossible during the initial exposure) and later reproduce the lyrics in the absence of any song being played. All new learning pathways are built from existing circuits and are accompanied by changes in brain physiology as a result of experience.

Although academic language describes learning as the “acquisition of knowledge,” new information instead gets integrated into the complex web of existing data, rather than acquired and stored in isolation. Thus, integrating the curriculum enhances content retention when subject matter enjoys the benefit of multiple integrated connections.

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  2. IMPLICIT (non-declarative) MEMORIES

    Is it possible to strength implicit memories by Visualization (for already have some extend of practice) ? e.g. car driving , have done practice few times reverse parking , then by visualizing further without physically doing it , would strength implicit memory on that ? Would it strength neuro paths ?

  3. This is a nicely written summary of a lot of good information about how the brain works.

    Understanding how YOU learn is also a helpful ancillary support mechanism, though.

    My memory for academic things is “loose” and I am not visual in nature, so simply seeing something is not all that good for my recall. I need the auditory mode to be working along with some kind of kinesthetic anchoring system to get and keep memories. Not so hard, but my whole entire educational history was un-marked by any understanding of how to put things together.

    Memonics are one way to improve memory. Writing is another (to add the auditory kinesthetic). Group discussions of materials can work really well for some (study groups can be a good tactic if the group understands the learning dynamics). Team learning is also useful.

    Some of us are more distracted than others when learning.

    Understanding state-dependent-learning (your example of adding coffee changing the biological state making recall MORE difficult) and learning some other individual tricks is quite useful.

    I wish our schools taught more about “Learning to Learn” and less about “Teaching to the Test.” Once one knows a bit more about one’s personal learning style, and a few memory tricks like recall and spaced repetition and similar, we could dramatically improve performance in the classroom and life.

    WHY do people have to pay money to go to a Dale Carnegie course (for example) to learn the simple mechanisms and mechanics of remembering people’s names, for example. Why can we teach, “1 – run – (situation), 2 – zoo (situation 2) and so forth to children so that they can have some strategies for improving memory and thus performance?

    Why don’t we teach speed-reading or photo-reading in the schools? Why should we force our kids to memorize all the stupid dates – “1015 – The Magna Carta” — when it is SO easy to take one’s phone and get all the information?


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