10.5
How We Remember
Some stage performers with amazing recall abilities rely on complicated schemes to keep track of information, such as associating a person's name with a common household object or visualizing a map of all the zip codes in the United States. We are not going to spend time discussing these strategies because for ordinary memory tasks, such tricks are often no more effective than rote repetition, and sometimes they are actually worse (Wang, Thomas, & Ouellette, 1992). Most memory researchers do not use such techniques themselves (Hébert, 2001); after all, why bother to memorize a grocery list using a fancy strategy when you can write down what you need to buy?
The Nine Secrets of Learning discussed elsewhere in the book are based on well-established principles of memory that help us keep track of information so that it sticks in our minds and will be there when we need it. In this section we'll dig into the science behind those secrets, and examine the processes that contribute to making memories “stick.” The video Making It Stick provides helpful hints on this topic from leading experts in memory research.
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Making It Stick
Encoding, Rehearsal, and Retrieval
People who want to give their powers of memory a boost sometimes use mnemonics [neh-MON-iks], formal strategies and tricks for improving memory. (Mnemosyne, pronounced neh-MOZ-eh-nee, was the ancient Greek goddess of memory.) Some mnemonics take the form of easily memorized rhymes (e.g., “Thirty days hath September/April, June, and November . . .”). Others use formulas (e.g., “Every good boy does fine” for remembering which notes are on the lines of the treble clef in musical notation). Still others use visual images or word associations. Mnemonics may also reduce the amount of information by chunking it, which is why many companies use words for their phone numbers instead of unmemorable numbers. In various ways, mnemonics contribute to the processes of encoding, storing, and retrieving information.
Effective Encoding Our memories, as we have seen, are not exact replicas of experience. Sensory information is summarized and encoded as words or images almost as soon as it is detected. When you hear a lecture, you may hang on every word (we hope you do), but you do not memorize those words verbatim. You extract the main points and encode them.
To remember information well, you have to encode it accurately in the first place. With some kinds of information, accurate encoding takes place automatically, without effort. Think about where you usually sit in your psychology class. When were you last there? You can probably provide this information easily, even though you never made a deliberate effort to encode it. But many kinds of information require effortful encoding: the plot of a novel, the procedures for assembling a cabinet, the arguments for and against a proposed law. To retain such information, you might have to select the main points, label concepts, or associate the information with personal experiences or with material you already know. Experienced students know that most of the information in a college course requires effortful encoding, otherwise known as studying. The mind does not gobble up information automatically; you must make the material digestible.
Pay Attention!
Rehearsal An important technique for keeping information in short-term memory and increasing the chances of long-term retention is rehearsal, the review or practice of material while you are learning it. When people are prevented from rehearsing, the contents of their short-term memories quickly fade (Peterson & Peterson, 1959). You are taking advantage of rehearsal when you look up a phone number and then repeat it over and over to keep it in short-term memory until you no longer need it. And when you can't remember a phone number because your phone always remembers it for you, you are learning what happens when you don't rehearse!
A poignant demonstration of the power of rehearsal occurred during a session with H. M. (Ogden & Corkin, 1991). The experimenter gave H. M. five digits to repeat and remember, but then she was unexpectedly called away. When she returned after more than an hour, H. M. was able to repeat the five digits correctly. He had been rehearsing them the entire time.
Short-term memory holds many kinds of information, including visual information and abstract meanings. But most people, or at least most hearing people, seem to favor speech for encoding and rehearsing the contents of short-term memory. The speech may be spoken aloud or to oneself. When people make errors on short-term memory tests that use letters or words, they often confuse items that sound the same or similar, such as d and t, or bear and bare. These errors suggest that they have been rehearsing verbally.
Some strategies for rehearsing are more effective than others. Maintenance rehearsal involves merely the rote repetition of the material. This kind of rehearsal is fine for keeping information in STM, but it will not always lead to long-term retention. A better strategy if you want to remember for the long haul is elaborative rehearsal, also called elaboration of encoding (Cermak & Craik, 1979; Craik & Tulving, 1975). Elaboration involves associating new items of information with material that has already been stored or with other new facts. It can also involve analyzing the physical, sensory, or semantic features of an item.
Suppose that you are studying the concept of working memory. Simply memorizing the definition is unlikely to help much. But if you can elaborate the concept, you are more likely to remember it. The word working should remind you that working memory is involved in tasks that require effort and attention. And what benefits do effort and attention bring? Yes, that is why working memory is related to the ability to concentrate, resist distraction, and solve problems. Many students try to pare down what they are learning to the bare essentials, but knowing more details about something makes it more memorable; that is what elaboration means.
A related strategy for prolonging retention is deep processing, or the processing of meaning (Craik & Lockhart, 1972). If you process only the physical or sensory features of a stimulus, such as how the word hypothalamus is spelled and how it sounds, your processing will be shallow even if it is elaborated. If you recognize patterns and assign labels to objects or events (“Hypo means ‘below,’ so the hypothalamus must be below the thalamus”), your processing will be somewhat deeper. If you fully analyze the meaning of what you are trying to remember (perhaps by encoding the functions and importance of the hypothalamus), your processing will be deeper yet. Shallow processing is sometimes useful; when you memorize a poem, for instance, you will want to pay attention to (and elaborately encode) the sounds of the words and the patterns of rhythm in the poem and not just the poem's meaning. Usually, though, deep processing is more effective. That is why, if you try to memorize information that has little or no meaning for you, the information may not stick.
When actors learn a script, they do not rely on maintenance rehearsal alone. They also use elaborative rehearsal and deep processing, analyzing the meaning of their lines and associating their lines with imagined information about the character they are playing.
Retrieval Practice Many students think that the way to remember course material is simply to study it once thoroughly, or maybe twice, so they can retrieve the correct answers on an exam. Unfortunately, within just a few weeks or months after the exam, some of those answers will have vanished like steam on a bathroom mirror. Retrieval practice, the repeated retrieval of an item of information from memory, is necessary if a memory is to undergo consolidation and remain available for a long time. After all, that's the goal of learning.
In a college course, a good way to ensure retrieval practice is to take short quizzes after you have learned some material but before the big exam. In a series of experiments in which students learned words in foreign languages, after a student had learned a word it was (1) repeatedly studied but dropped from further testing, (2) repeatedly tested but dropped from further studying, or (3) dropped from studying and testing. To the surprise of the students themselves, studying after learning had no effect on their subsequent ability to recall the foreign words. But repeated testing, which caused them to repeatedly retrieve the words from memory, had a large benefit (Karpicke, 2012; Karpicke & Roediger, 2008). So when your professors and your textbook authors want to keep quizzing you, it's only for your own good!