Memory is more indelible than ink. ―Anita Loos, author and screenwriter
By the end of this chapter, you will be able to:
- Identify and describe the three basic functions of memory
- Differentiate between sensory, short-term, and long-term memory
- Identify and describe methods for information retrieval
- Describe the forgetting curve and its implications for learning
- Describe strategies for deciding which course content to learn and retain
- Recognize and apply strategies for strengthening your memory
Memory is an information processing system that we often compare to a computer. Memory is the set of processes used to encode, store, and retrieve information over different periods of time.
We get information into our brains through a process called encoding, which is the input of information into the memory system. Once we receive sensory information from the environment, our brains label or code it. We organize the information with other similar information and connect new concepts to existing concepts. Encoding information occurs through both automatic processing and effortful processing.
If someone asks you what you ate for lunch today, more than likely you could recall this information quite easily. This is known as automatic processing, or the encoding of details like time, space, frequency, and the meaning of words. Automatic processing is usually done without any conscious awareness. Recalling the last time you studied for a test is another example of automatic processing. But what about the actual test material you studied? It probably required a lot of work and attention on your part in order to encode that information. This is known as effortful processing.
What are the most effective ways to ensure that important memories are well encoded? Even a simple sentence is easier to recall when it is meaningful (Anderson, 1984). Read the following sentences (Bransford & McCarrell, 1974), then look away and count backwards from 30 by threes to zero, and then try to write down the sentences (no peeking back at this page!).
- The notes were sour because the seams split.
- The voyage wasn’t delayed because the bottle shattered.
- The haystack was important because the cloth ripped.
How well did you do? By themselves, the statements that you wrote down were most likely confusing and difficult for you to recall. Now, try writing them again, using the following prompts: bagpipe, ship christening, and parachutist. Next count backwards from 40 by fours, then check yourself to see how well you recalled the sentences this time. You can see that the sentences are now much more memorable because each of the sentences was placed in context. Material is far better encoded when you make it meaningful.
There are three types of encoding. The encoding of words and their meaning is known as semantic encoding. It was first demonstrated by William Bousfield (1935) in an experiment in which he asked people to memorize words. The 60 words were actually divided into 4 categories of meaning, although the participants did not know this because the words were randomly presented. When they were asked to remember the words, they tended to recall them in categories, showing that they paid attention to the meanings of the words as they learned them.
Visual encoding is the encoding of images, and acoustic encoding is the encoding of sounds, words in particular. To see how visual encoding works, read over this list of words: car, level, dog, truth, book, value. If you were asked later to recall the words from this list, which ones do you think you’d most likely remember? You would probably have an easier time recalling the words car, dog, and book, and a more difficult time recalling the words level, truth, and value. Why? Because you can recall images (mental pictures) more easily than words alone. When you read the words car, dog, and book you created images of these things in your mind. These are concrete, high-imagery words. On the other hand, abstract words like level, truth, and value are low-imagery words. High-imagery words are encoded both visually and semantically (Paivio, 1986), thus building a stronger memory.
Now let’s turn our attention to acoustic encoding. You are driving in your car and a song comes on the radio that you haven’t heard in at least 10 years, but you sing along, recalling every word. In the United States, children often learn the alphabet through song, and they learn the number of days in each month through rhyme: “Thirty days hath September, / April, June, and November; / All the rest have thirty-one, / Save February, with twenty-eight days clear, / And twenty-nine each leap year.” These lessons are easy to remember because of acoustic encoding. We encode the sounds the words make. This is one of the reasons why much of what we teach young children is done through song, rhyme, and rhythm.
Which of the three types of encoding do you think would give you the best memory of verbal information? Some years ago, psychologists Fergus Craik and Endel Tulving (1975) conducted a series of experiments to find out. Participants were given words along with questions about them. The questions required the participants to process the words at one of the three levels. The visual processing questions included such things as asking the participants about the font of the letters. The acoustic processing questions asked the participants about the sound or rhyming of the words, and the semantic processing questions asked the participants about the meaning of the words. After participants were presented with the words and questions, they were given an unexpected recall or recognition task.
Words that had been encoded semantically were better remembered than those encoded visually or acoustically. Semantic encoding involves a deeper level of processing than the shallower visual or acoustic encoding. Craik and Tulving concluded that we process verbal information best through semantic encoding, especially if we apply what is called the self-reference effect. The self-reference effect is the tendency for an individual to have better memory for information that relates to oneself in comparison to material that has less personal relevance (Rogers, Kuiper & Kirker, 1977). Could semantic encoding be beneficial to you as you attempt to memorize the concepts in this chapter?
Once the information has been encoded, we have to retain it. Our brains take the encoded information and place it in storage. Storage is the creation of a permanent record of information.
In order for a memory to go into storage (i.e., long-term memory), it has to pass through three distinct stages: Sensory Memory, Short-Term Memory, and finally Long-Term Memory. These stages were first proposed by Richard Atkinson and Richard Shiffrin (1968). Their model of human memory, called Atkinson-Shiffrin (A-S), is based on the belief that we process memories in the same way that a computer processes information.
In the Atkinson-Shiffrin model, stimuli from the environment are processed first in sensory memory: storage of brief sensory events, such as sights, sounds, and tastes. It is very brief storage—up to a couple of seconds. We are constantly bombarded with sensory information. We cannot absorb all of it, or even most of it. And most of it has no impact on our lives. For example, what was your professor wearing the last class period? As long as the professor was dressed appropriately, it does not really matter what she was wearing. Sensory information about sights, sounds, smells, and even textures, which we do not view as valuable information, we discard. If we view something as valuable, the information will move into our short-term memory system.
One study of sensory memory researched the significance of valuable information on short-term memory storage. J. R. Stroop discovered a memory phenomenon in the 1930s: you will name a color more easily if it appears printed in that color, which is called the Stroop effect. Try an experiment: name the colors of the words presented in the image below. Do not read the words, but say the color the word is printed in. For example, upon seeing the word “yellow” in green print, you should say “green,” not “yellow.” This experiment is fun, but it’s not as easy as it seems.
Short-term memory is a temporary storage system that processes incoming sensory memory; sometimes it is called working memory. Short-term memory takes information from sensory memory and sometimes connects that memory to something already in long-term memory. Short-term memory storage lasts about 20 seconds. Think of short-term memory as the information you have displayed on your computer screen—a document, a spreadsheet, or a web page. Information in short-term memory either goes to long-term memory (when you save it to your hard drive) or it is discarded (when you delete a document or close a web browser).
You may find yourself asking, “How much information can our memory handle at once?” George Miller (1956), in his research on the capacity of memory, found that most people can retain about 7 items in short-term memory. Some remember 5, some 9, so he called the capacity of short-term memory the range of 7 items plus or minus 2. To explore the capacity and duration of your short-term memory, have a partner read the strings of random numbers below out loud to you, beginning each string by saying, “Ready?” and ending each by saying, “Recall,” at which point you should try to write down the string of numbers from memory.
Note the longest string at which you got the series correct. For most people, this will be close to 7, Miller’s famous 7 plus or minus 2. Recall is somewhat better for random numbers than for random letters (Jacobs, 1887), and also often slightly better for information we hear (acoustic encoding) rather than see (visual encoding) (Anderson, 1969).
Long-term memory is the continuous storage of information. Unlike short-term memory, the storage capacity of long-term memory has no limits. It encompasses all the things you can remember that happened more than just a few minutes ago to all of the things that you can remember that happened days, weeks, and years ago. In keeping with the computer analogy, the information in your long-term memory would be like the information you have saved on the hard drive. It isn’t there on your desktop (your short-term memory), but you can pull up this information when you want it, at least most of the time. Not all long-term memories are strong memories. Some memories can only be recalled through prompts. For example, you might easily recall a fact— “What is the capital of the United States?”—or a procedure—“How do you ride a bike?”—but you might struggle to recall the name of the restaurant you had dinner when you were on vacation in France last summer. A prompt, such as that the restaurant was named after its owner, who spoke to you about your shared interest in soccer, may help you recall the name of the restaurant.
So you have worked hard to encode (via effortful processing) and store some important information for your upcoming final exam. How do you get that information back out of storage when you need it? The act of getting information out of memory storage and back into conscious awareness is known as retrieval. This would be similar to finding and opening a paper you had previously saved on your computer’s hard drive. Now it’s back on your desktop, and you can work with it again. Our ability to retrieve information from long-term memory is vital to our everyday functioning. You must be able to retrieve information from memory in order to do everything from knowing how to brush your hair and teeth, to driving to work, to knowing how to perform your job once you get there.
There are three ways you can retrieve information out of your long-term memory storage system: recall, recognition, and relearning. Recall is what we most often think about when we talk about memory retrieval: it means you can access information without cues. For example, you would use recall for an essay test. Recognition happens when you identify information that you have previously learned after encountering it again. It involves a process of comparison. When you take a multiple-choice test, you are relying on recognition to help you choose the correct answer. Here is another example. Let’s say you graduated from high school 10 years ago, and you have returned to your hometown for your 10-year reunion. You may not be able to recall all of your classmates, but you recognize many of them based on their yearbook photos.
The third form of retrieval is relearning, and it’s just what it sounds like. It involves learning information that you previously learned. Whitney took Spanish in high school, but after high school she did not have the opportunity to speak Spanish. Whitney is now 31, and her company has offered her an opportunity to work in their Mexico City office. In order to prepare herself, she enrolls in a Spanish course at the local community center. She’s surprised at how quickly she’s able to pick up the language after not speaking it for 13 years; this is an example of relearning.
This video explores these functions of memory and provides additional examples of how they work:
As we just learned, you brain must do some work (effortful processing) to encode information and move it into short-term, and ultimately long-term memory. This has strong implications for you as a student, as it can impact your learning – if you do not do the work to encode and store information, you are likely to forget it altogether.
The forgetting curve hypothesizes the decline of memory retention over time. This curve shows how information is lost over time when there is no attempt to retain it.
In 1885, German psychologist Hermann Ebbinghaus hypothesized that the rate of forgetting is exponential. Using himself as the sole subject in his experiment, he memorized lists of three letter nonsense syllable words—two consonants and one vowel in the middle. He then measured his own capacity to relearn a given list of words after a variety of given time period. He found that forgetting occurs in a systematic manner, beginning rapidly and then leveling off, represented graphically in the Ebbinghaus forgetting curve. From this research Ebbinghaus concluded that much of what we forget is lost soon after it is originally learned, but that the amount of forgetting eventually levels off.
Research indicates that people forget 80 percent of what they learn only a day later. This statistic may not sound very encouraging, given all that you’re expected to learn and remember as a college student. Really, though, it points to the importance of a study strategy other than waiting until the night before a final exam to review a semester’s worth of readings and notes. When you learn something new, the goal is to “lock it in” sooner rather than later, and move it from short-term memory to long-term memory, where it can be accessed when you need it (like at the end of the semester for your final exam or maybe years from now).
The next section will explore a variety of strategies you can use to process information more deeply and help improve recall.
Knowledge Acquisition Strategies
Jennifer felt anxious about an upcoming history exam. This would be her first test in a college class, and she wanted to do well. Jennifer took lots of notes during class and while reading the textbook. In preparation for the exam, she tried to review all five textbook chapters along with all of her notes.
The morning of the exam, Jennifer felt nervous and unprepared. After so much studying and review, why wasn’t she more confident?
Knowing What to Know
Jennifer’s situation shows that there really is such a thing as studying too much. Her mistake was in trying to master all of the course material. Whether you take one or more than one class, it’s simply impossible to retain every single particle of information you encounter in a textbook or lecture. And, instructors don’t generally give open-book exams or allow their students to preview the quizzes or tests ahead of time. So, how can you decide what to study and “know what to know”? The answer is to prioritize what you’re trying to learn and memorize, rather than trying to tackle all of it. Below are some strategies to help you do this.
- Think about concepts rather than facts: From time to time, you’ll need to memorize cold, hard facts—like a list of math equations or a vocabulary list in a Spanish class. Most of the time, though, instructors will care much more that you are learning about the key concepts in a subject or course—such as how photosynthesis works, how to write a thesis statement, the causes of the French Revolution, and so on. Jennifer, from the scenario above, might have been more successful with her studying—and felt better about it—if she had focused on the important historical developments (the “big ideas”) discussed in class, as opposed to trying to memorize a long list of dates and facts.
- Take cues from your instructor: Pay attention to what your instructor writes on the board or includes in study guides and handouts. Although these may be short—perhaps just a list of words and phrases—they are likely core concepts that you’ll want to focus on. Also, instructors tend to refer to important concepts repeatedly during class, and they may even tell you what’s important to know before an exam or other assessment.
- Look for key terms: Textbooks will often put key terms in bold or italics. These terms and their definitions are usually important and can help you remember larger concepts.
- Use summaries: Textbooks often have summaries or study guides at the end of each chapter. These summaries are a good way to check in and see whether you grasp the main elements of the reading (each chapter of this text, for example, ends with a set of “key takeaways” that reiterate the most important concepts). If no summary is available, try to write your own—you’ll learn much more by writing about what you read than by reading alone.
Transferring Information to Long-Term Memory
In the previous discussion of how memory works, the importance of making intentional efforts to transfer information from short-term to long-term memory was noted. Below are some strategies to facilitate this process:
- Start reviewing new material immediately: Remember that people typically forget a significant amount of new information within 24 hours of learning it. As a student, you can benefit from starting to study new material right away. If you’re introduced to new concepts in class, for example, don’t wait a few days, or until the test is coming up, to start reviewing your notes and doing the related reading assignment. The sooner the better! Studying notes and writing questions or comments about what you learned right after class can help keep new information fresh in your mind.
- Study frequently for shorter periods of time: Once information becomes a part of long-term memory, you’re more likely to remember it. If you want to improve the odds of recalling course material by the time of an exam or a in future class, try reviewing it a little bit every day. Building up your knowledge and recall this way can also help you avoid needing to “cram” and feeling overwhelmed by everything you may have forgotten.
Strengthening Your Memory
We’ve discussed the importance of zeroing in on the main concepts you learn in class and of transferring them from short-term to long-term memory. But how can you work to strengthen your overall memory? Some people have stronger memories than others, but memorizing new information takes work for anyone. Below are some strategies that can aid memory.
One strategy is rehearsal, or the conscious repetition of information to be remembered (Craik & Watkins, 1973). This strategy is linked to studying material frequently for shorter periods of time. You may not remember when or how you learned skills like riding a bike or tying your shoes. Mastery came with practice, and at some point the skills became second nature. Academic learning is no different: if you spend enough time with important course concepts and practice them often, you will know them in the same way you know how to ride a bike, almost without thinking about them. For example, think about how you learned your multiplication tables. You may recall that 6 x 6 = 36, 6 x 7 = 42, and 6 x 8 = 48. Memorizing these facts is rehearsal.
Visual aids like note cards, concept maps, and highlighted text are ways of making information stand out. Because they are shorter and more concise, they have the advantage of making the information to be memorized seem more manageable and less daunting (than an entire textbook chapter, for example). Some students write key terms on note cards and hang them around their desk or mirror so that they routinely see them and study them without even trying.
Memory devices known as mnemonics can help you retain information while only needing to remember a unique phrase or letter pattern that stands out. Mnemonic devices are memory aids that help us organize information for encoding. They are especially useful when we want to recall larger bits of information such as steps, stages, phases, and parts of a system (Bellezza, 1981).
There are different types of mnemonic devices, such as the acronym. An acronym is a word formed by the first letter of each of the words you want to remember. For example, even if you live near one, you might have difficulty recalling the names of all five Great Lakes. What if I told you to think of the word Homes? HOMES is an acronym that represents Huron, Ontario, Michigan, Erie, and Superior: the five Great Lakes.
Another type of mnemonic device is an acrostic: you make a phrase of all the first letters of the words. For example, if you are taking a math test and you are having difficulty remembering the order of operations, recalling the sentence “Please Excuse My Dear Aunt Sally” will help you, because the order of mathematical operations is Parentheses, Exponents, Multiplication, Division, Addition, Subtraction. There also are jingles, which are rhyming tunes that contain key words related to the concept, such as “i before e, except after c.”
You might use a mnemonic device to help you remember someone’s name, a mathematical formula, or the six levels of Bloom’s taxonomy.
Another strategy is chunking, where you organize information into manageable bits or chunks (Bodie, Powers, & Fitch-Hauser, 2006). Chunking is useful when trying to remember information like dates and phone numbers. Instead of trying to remember 5205550467, you remember the number as 520-555-0467. So, if you met an interesting person at a party and you wanted to remember his phone number, you would naturally chunk it, and you could repeat the number over and over, combining the strategies of chunking and rehearsal.
Connect new information to old information
Take stock of what you already know—information that’s already stored in long-term memory—and use it as a foundation for learning newer information. It’s easier to remember new information if you can connect it to old information or to a familiar frame of reference. For example, if you are taking a sociology class and are learning about different types of social groups, you may be able to think of examples from your own experience that relate to the different types.
Get quality sleep
Although some people require more or less sleep than the recommended amount, most people should aim for six–eight hours every night. School puts a lot of demands on the brain, and, like tired muscles after a long workout, your brain needs to rest after being exercised and taking in all sorts of new information during the day. Plus, while you are sleeping, your brain is still at work. During sleep the brain organizes and consolidates information to be stored in long-term memory (Abel & Bäuml, 2013). A good night’s rest can help you remember more and feel prepared for learning the next day.
Memory also relies on effective studying behaviors, like choosing where you study, how you study, and with whom you study. The following video provides specific studying strategies that can improve your memory.
ACTIVITY: Strengthening Your Memory
- Recognize and apply strategies for strengthening your memory
- We just reviewed six strategies you can use to strengthen your memory. You may be asked to recall all six at a later time (perhaps on the test for this unit!) so you will want to remember them.
- List each of these strategies and describe how you could use each one to help yourself remember all six strategies for strengthening memory. Each strategy will call for you to engage with the information in a different way to help remember it.
- Follow your instructor’s guidelines for submitting your assignment.
- Our memory has three basic functions: encoding, storing, and retrieving information.
- The Atkinson-Shiffrin (A-S) model outlines three distinct stages of memory: sensory, short-term, and long-term.
- Information stored in long-term memory can be accessed through recall, recognition, and relearning.
- The forgetting curve illustrates that without exerting any effort to remember information, we forget most of what we learn within 24 hours. Revisiting information soon after its introduction, and occasionally thereafter, can dramatically increase recall.
- In order to learn effectively, you must be able to prioritize information and focus on the most important concepts.
- There are many strategies you can use to enhance your ability to remember information, including mnemonics, rehearsal, and using visuals. Experiment with these strategies and identify what works best for you.
- Student Counseling Service. "Long and Short Term Memory." The University of Chicago. 2016. Web. 10 Feb 2016. ↵