Table of contents
To understand diamonds, you need to know about their four qualities:
Cut, Carat, Clarity, and Color--what
jewelers would call the 4 C's of diamonds.
To understand memory systems, you need to know about their three qualities: Encoding, Storage (container size and duration), and Retrieval (recovering)--what you could--but shouldn't--call the 3 c's of memory:*
*If you did call Encoding, Storage, and Retrieval "the 3 c's," how would you remember what the 3 terms are really called? Besides, what would people think? Probably that you are no different from those who talk about the 3 K's: Koding, Keeping, and re-Kollecting--except that you can spell.☺The 3 Key Terms Defined:
To help you understand what Encoding, Storage, and Retrieval are and to help you remember that they are memory's 3 active and independent processes, watch this short (26 second) animation.
Point not to overlook when focusing on memorizing definitions of each of the 3 processes: Rather than viewing your memory as just a storage space, realize that storing information is just 1 of 3 active processes that make up what we call memory.
Point that often trips up students: The 3 key qualities are independent--being good at one doesn't mean the memory is good at another. For example, a memory that has good storage capacity will not necessarily be good at retrieval. To see why, imagine two memories--one that is like a shoe box, and one that is like a poorly organized attic. The shoe box memory would be bad at storage (not much could be stored) but would be great at retrieval (if something is in the shoe box, it would be easy to find). The messy attic memory, on the other hand, would be great at storage (lots of stuff could be dumped in there) but would be poor at retrieval (it would be hard to sort through all the junk scattered throughout a dark, messy attic to find the one thing you needed). To reiterate, just as knowing a diamond's size doesn't tell you about its clarity, knowing that a memory has good sized storage space doesn't tell you that the memory is good at retrieval.
Take home lesson: If you are having a problem remembering names, class material, or some other information, the first step to solving that problem is to figure out which memory process is failing you. You may be able to pinpoint the source of your problem by asking 3 questions:
Take a short (just 4 multiple-choice questions) quiz over encoding, storage, and retrieval.
Take home lesson: If you want to improve your memory for names or school material, you should figure out which memory is letting you down. Often, people will blame their long-term memory when the information never got to long-term memory. For example, many "memory problems" are really attention problems (i.e., inattention prevented information from getting into short-term memory, which then means the information couldn't get into long-term memory). So, to identify why you are not remembering something, not only do you have to determine whether the problem is at encoding, storage, or retrieval (as discussed in the previous take home lesson), but you also have to determine which memory box is the problem because encoding, storage, and retrieval are different for each box. To see how encoding is different for each box, watch this 22-second animation.
Terminology note: Synonyms for "memory" include "register" and
So, you may hear sensory memory referred to as "sensory register" or as "sensory store."
Similarly, you may hear short-term memory referred to as "short-term register" or "short-term store."
Guess what two other terms you may hear for long-term memory (LTM)?
Imagine that you are looking at the television, but not paying attention to the
program because you are talking to a friend. Suddenly, your friend points to the
television set. Thanks to your sensory memory, you can hit a rewind
button in your mind that allows you to replay the last little bit of the program.
If you replay the audio from the program, you are using your echoic memory: the sensory memory for hearing that allows you to, in a sense, hear an echo what just happened.
Being able to use your echoic memory to replay the last 3-5 seconds of what your ears just sensed, allows you to
If you replay the image that was on the television screen, you are using your visual sensory memory (typically called iconic memory). Iconic memory is, in a sense, a picture drawn in rapidly disappearing ink. See a very short (less than a second) demonstration of how quickly information decays from iconic memory Because pictures in iconic memory are copies of what you just saw, are "drawn" automatically, and usually fade in less than half a second, it wasn't until
If slides are projected on a screen at a rate of 12 slides or more per
second, the slide on the screen stays in your iconic memory during the gap
Because you don't see a gap between the slides, you see "moving pictures" (i.e., "movies" or "motion pictures").
If slides are projected at a rate slower than 12 a second, the previous image is gone from iconic memory before you see the next image. Because you see a gap between each slide, you see a slide show rather than a movie.
Iconic memory does not seem to be related to what we consider intelligence:
|Key Characteristics of Sensory Memory|
|Types||At least 2: Your sensory memory for vision--iconic memory--and your sensory memory for hearing--echoic memory. You may also have ones for some of your other senses.|
|Encoding||Automatic: To encode information, you just need to sense the information.|
|Storage Size||Enormous (maybe as much as 14 trillion bits!)|
|Storage Duration||Short--Less than half a second for iconic memory; about 3- 5 seconds for echoic memory.|
Short-term memory is small. As you might expected from analogies between STM's limited capacity to hold information and the limited capacity of various objects-- from small buckets to small funnels to small sponges-- to hold water, STM is often described as having a limited capacity. Indeed, because STM can't hold much information, STM is often referred to as "the bottle neck of the memory system."
Short-term memory is short (it typically lasts about 20 seconds)
You are aware of everything in your STM. Without STM, you might do things, but not be aware that you were doing them. Right now, you often do many things without awareness, like breathing, balancing, and (sometimes) driving. Without STM, everything you did would be done without your being conscious of doing it. You would have no mental life, so you might act like a sleepwalking zombie robot, and you might feel nothing--as if you were always in a deep, dreamless sleep.
Although there are many aspects to STM, in this page, for simplicity's sake, we will focus on two of STM's roles: (1) holding information in consciousness and (2) being the narrow, shaky bridge through which information goes in and out of LTM.
Because working memory is limited (it holds, at most, 5-9 chunks [chunks are groups of items]), our thinking and our attention are limited. Specifically,
The way to get around the limits short-term memory's limited size puts on us
chunk: group several different individual bits into one unit. For
example, U.S. citizens
could group the twelve numbers "177 614 922 02 1" into
1776 1492 2021.
In the "1776, 1492, 2021" example, you grouped the information into chunks by connecting the presented information to organized units of information that you already had stored in your permanent memory. Specifically, instead of having to remember 12 numbers, you just had to "point" to 3 chunks of information you had stored in your permanent memory. If you can't connect new information to units you already have stored in permanent memory, you will not be able to chunk that information until you create those units (so, for Americans, "FBI" is one chunk but "BFI" probably is not). You can create a new unit by cementing together isolated information bits and then storing those connected bits as one unit in your permanent memory. For example, you could link together the many individual words that define "iconic memory" and then store those words in your permanent memory as a single unit. After you have done that, you will be able to hold the entire definition of that term as a single chunk in STM by "pointing" to the place in your permanent memory where you have that definition stored. Note that when you first encountered iconic memory's definition, it was "too big" for your STM, but now--or soon--it will only take up one chunk of your STM's 5-9 chunk capacity. So, once you learn a psychological term, you increase your ability to chunk psychological information.Visual analogies illustrating that chunking makes it easier to keep more information in STM:
To see the power of chunking, consider experts. Experts have formed large chunks of information related to their field. As a result, they can hold a large amount of that information in their head while still having room in their working memory to think about that information. So, when thinking about their field, they can think about many things at once (e.g, chess experts, physicians, and football coaches can quickly absorb much more information about their field than the average person can--if the experts can chunk that information). Note, however, that if experts are thinking about things outside of their field--where they can't chunk as well--their thinking is much more limited (one of many reasons why supposedly smart people do stupid things).
Some chunks that you may have learned that have made you more expert:
who chunk information when studying get better grades in college (Gurung, 2005).
How can you chunk information so that you can get better grades? You could turn the many terms you have to learn into a smaller number of groups of terms by
|STM Myth||STM Fact|
|Short term memory lasts an hour or maybe even a couple of days.||Short term memory lasts about 20 seconds.|
|Short term memory can hold 5 to 9 items.||Short term memory can hold 5 to 9 chunks.|
|Short-term memory is big enough that people can multi-task effectively.||Because of STM's limitations, people are terrible at multi-tasking.|
|If information is in STM long enough, it will automatically
go into permanent memory.
|Maintaining information in STM for a long time
does not necessarily move that information to permanent memory.
Learn more about STM: To get a better understanding of what short-term memory is and how understanding short-term memory can help you think and learn better, read Scott Young's article on working memory (long, but useful!).
Reflect on STM's importance
Realize that STM, as the narrow bottle neck of the memory system, not only puts limits on how much information you can put into LTM at one time (so professors shouldn't speak to quickly or put too much information on a PowerPoint slide) but also limits how much information you can get out of LTM at one time (click to see visual analogy). At one level, you know that STM sharply limits how much information from LTM that you can bring up at once: You wouldn't ask your partner to name 20 things they love about you (unless you wanted to be depressed)--and you would certainly hope that a professor wouldn't call on you to name 10 important psychological discoveries. However, you may not have realized that, because all your relevant knowledge about a situation will sometimes be too big for STM to hold, all your relevant knowledge can't always come to mind when you need it. As a result, you will make mistakes even though you knew--or at least your LTM knew--better. Note that if you are distracted, preoccupied, emotional, sleep-deprived, or otherwise impaired, you will have less room in STM for information from LTM and thus will be even more likely to make mistakes due to not using what you know.
Without chunking, almost everyone can hold between 5 and 9 items in short-term memory. So, when President Trump was given a test in which he had to repeat five words, failing on that task would have been very bad. Succeeding on the task, however, was not terribly impressive. To judge the difficulty of that test, you can see it here.
President Trump implied that he did not use a strategy for remembering the 5 words: "Person, Woman, Man, Camera, TV." Instead, he attributed his ability to recall of those words to having a great memory. President Trump could have made it easier on himself by chunking the 5 individual words into one or two chunks. If you had to remember "Person, Woman, Man, Camera, TV," how would you turn those 5 items into one or two chunks?
Most of the questions on the test that President Trump took involved memory. Some of the questions tested short-term memory; other questions (e.g., testing whether one could identify the animal in a picture as an elephant) tested long-term memory. As you can imagine, if someone did poorly on that test, their mind would be very limited. Indeed, such a test might be used to determine whether a person could live on their own. So, both short-term and long-term memory are important to living a full life. We have discussed short-term memory; we will now turn to long-term memory.
You have 3 main long term memories:
Without your episodic long term memory, you would live only in the present plus the few seconds that short term memory would buy you. (To you, your life would be an empty book.) To see how challenging that would be, consider the case of Clive Wearing, a man without the ability to form new episodic long term memories (note that his procedural memory is fine: he can sing, conduct, read, write, etc.). For a thrilling fictional example that demonstrates the importance of episodic memories and the difference between episodic and other memories, watch "The Bourne Identity" in which the Matt Damon character has lost all episodic memories (he doesn't know who he was), but his procedural and semantic memories are intact. If you want to look at extremely good episodic memories, you can watch this 13-minute segment from "60 Minutes" about the approximately 56 people who have been identified as having fantastic episodic memories for almost every day in their lives (from adolescence to now) If you watch that video, consider 5 points:
* Terminology note #1: Since you can explicitly tell (i.e., you can declare to ) others the contents of both your semantic memories (e.g., you can declare that George Washington was a president) and your episodic memories (e.g., you can declare that your high school graduation was held in the gym or on Zoom), semantic and episodic memory are often referred to as types of declarative memory (also called explicit memory). Since you cannot easily declare the contents of your procedural memories (e.g., you know how to ride a bike but can't tell others what you know that allows you to ride a bike), procedural memory is a type of non-declarative memory. To make the distinction between declarative and procedural memories clear, psychologists often say that the difference between declarative and procedural memories is the difference between "knowing that" (e.g., knowing that George Washington was president [semantic memory] or knowing that your high school graduation was in the gym [episodic memory]) and "knowing how" (e.g., your ability to text, read, sing, or dribble a basketball). Because procedural memory is acquired through practice and is not verbal, those who can perform a skill often can't teach it. (For example, if you are learning a foreign language, a young child from that country might pronounce the language's sounds better than you do but be unable to tell you how to move your lips and tongue to pronounce those sounds.) Fortunately, you are not always completely on your own when it comes to learning a skill because a good teacher or coach can give you some pointers about what you should be doing. Actually doing it well, however, will still take extensive practice.
If visuals help you,
mouse over this text to review STM and the two basic types of LTM: procedural and declarative.
* Terminology note #2: In addition to procedural memory, you have another non-declarative memory: implicit memory. Implicit memory involves, without trying, learning certain rhythms, sequences, or patterns through repeated experience: Your mind is automatically identifying patterns that allow you to know what will probably come next. The patterns that this "nexting" is based on can be simple (e.g., that thunder follows lightning) or can be complex (e.g., knowing grammatical rules such as knowing that when Yoda said "Ready are you?", he should have said "Are you ready?"). Accurate intuitions, such as a fire chief sensing that a fire is not responding in a typical way, so he orders the squad to flee the building seconds before the building collapses; a wife knowing her husband's mood just from hearing him say "hello" when he answers the phone; or you knowing that a conversation is about to end, are due to implicit memory (for a review of the types of LTM, see this diagram).
Examples of encoding problems:
An extreme example of encoding problems--anterograde amnesia:
a type of amnesia in which there is an inability to form new memories.
Some people with severe anterograde amnesia are unable to form any new semantic or episodic memories. As a result, they are stuck in the past.
Two well-known severe cases of total anterograde amnesia are
The case of HM (note the difference between STM and LTM). If you want a more dramatic depiction of his case, click here.
The case of Clive Wearing, that was linked to above in the section on episodic memory. If you saw that video but don't remember seeing it, you have probably experienced an encoding failure. Your encoding failure was probably due to not paying attention -- because unless you were black out drunk when you watched it, you are probably not experiencing anterograde amnesia.☺
Movies with relatively accurate depictions of the symptoms and effects of anterograde amnesia:
Three less extreme examples of encoding problems from your experience that may show that you have failed to encode something you've seen numerous times:
As you learned when we discussed STM, you don't pay attention to most of the information your senses pick up, so most of that information doesn't get encoded into STM. If information doesn't get into STM, it won't get into LTM. Unfortunately, research suggests that most students do not get important lecture content into STM. Fortunately, as mentioned earlier, research also suggests that most students can easily increase their ability to attend to lectures (and thus get lecture information into STM so that it has a chance to get into LTM) by sitting up front and by keeping their cell phones out of sight.
Consolidation--Getting information from STM to LTM-- involves 2 steps: One mental, one physical
But even if you pay attention to something and therefore encode that information into STM, you may not get that information into LTM. Getting the information from STM to LTM involves both your mind and your body. As you'll see, your mind will often have to do some mental work to encode information into LTM. After that, your brain will need some time to complete the encoding. In a sense, forming a solid memory is like making jell-o. To make jell-o, you do the work to assemble the ingredients, but the jell-o becomes solid only after setting in the refrigerator for a while. Similarly, to make a solid memory, your mind needs to do the work to integrate the information, but the memory becomes solid only after it has set in the brain for a while. The process of rewiring the brain to form a solid memory is called consolidation. (An alcohol blackout--in which a person doesn't remember what happened while the person was drunk--is a case of alcohol disrupting consolidation, as is the inability of a concussion victim to remember what happened shortly before being hit in the head.) The need for consolidation has two implications for studying:
Information is often available in long term memory (it is in the long term memory box), but not accessible (you can't get it out of the memory box at the moment you need it).
An extreme example of retrieval problems--some cases of retrograde amnesia: an inability, for a while, what you once knew. Often, retrograde amnesia only affects episodic memory--it often only hurts the ability to remember some or all of one's personal past. Retrograde amnesia is a key element in the plots of many soap operas and movies (e.g., "Overboard," "Bourne Identity," "Forgotten," "The Long Kiss Goodnight," "Regarding Henry," and "Who Am I?). Real life examples of severe retrograde amnesia are rare, but here's one example: Missing Delaware woman turns up in Toronto homeless shelter (short newspaper report of someone who had retrograde amnesia).Retrieval problems must be to blame in retrograde amnesia cases in which the memories eventually "return." Obviously, the memories did not "come back" in the sense that they left the person and then returned. Instead, the memories were there all along, but the person could not retrieve them. However, if the retrograde amnesia is permanent, the problem may not be a retrieval problem. In those cases, suspect that the "forgotten" memories do not exist, especially if
Common examples of retrieval problems (of information being available [stored] but not accessible [retrievable]). Note that many of these examples involve being able to recognize the information but not being able to recall it:
If you can solve the encoding and retrieval problems, long term memory, you can take advantage of LTM's virtually limitless storage capacity to do some amazing things--like this guy has done).
Solving the encoding problem: How to get information from STM to LTM (Hint: The key is to actively transform the information).
The way to solve the encoding problem is not by using Type 1 (maintenance/rote) rehearsal: things over and over.As you have seen, the more you think about the information (i.e., the more you recode information or add to that information), the more likely it is to get into memory. The depth of processing approach (also called the levels-of-processing approach) focuses on the memory benefits of thinking deeply about information. For example, levels-of-processing research has made it clear that deeper processing of words--thinking about a word's meaning and its relevance to you-- leads to better memory of those words than shallow processing (e.g., superficial processing such as merely noticing whether the word is in all capital letters, has two vowels, or rhymes with another word). Some advocates of the depth of processing approach have acted like there is just one memory system, but that shallow processing puts the information on the surface of memory where it can easily be blown away whereas deeper processing anchors the information deeper in memory. That is, rather than thinking of information being in 3 different memories (sensory memory, short-term memory, and long-term memory), some think of one memory in which information can be planted at different depths in memory--and the more deeply information is rooted, the longer it will be remembered. Looking at this diagram will help you see the idea behind the one memory with different levels approach.
Evidence that Type 1 rehearsal (also called maintenance rehearsal) is not effective for moving information to LTM: In some studies, repeating things over and over does not improve recall. For example, even though you have seen pennies thousands of times, you may not be able to draw one from memory. You may not even be able to pick the correct penny out of a line-up of fakes. (So, maintenance rehearsal is a tried--but not true--way of remembering information. To slightly overstate things, what some students call "memorizing" isn't memorizing!)
Reason that Type 1 rehearsal is not effective for moving information to LTM: It does not recode the information to make it meaningful or visual. (This short animation may help you remember that Type 1 rehearsal usually recycles information back into STM rather than moving that information into LTM.)
To get information into LTM efficiently, you must connect the new information to information already in your memory. As psychologists would say, you should encode the information by using Type 2 rehearsal (also called elaborative rehearsal). Short animation slightly exaggerating the difference between Type 1 (maintenance) and Type 2 (elaborative) rehearsal
Specifically, in elaborative rehearsal (Type 2 rehearsal), you think about the information to add to it (to elaborate on it) in one of two ways:
1. Make information
2. Make the information
Implications for aging and memory:
- As you get older, your semantic memory should improve because it should be easier to make information meaningful. It should be easier to make information meaningful because making information meaningful involves connecting new information to old information and, as you age, you should have more old information to which you can connect new information. Partly for this reason, some schools prohibit juniors and seniors from taking introductory courses.
- Similarly, studying hard in your introductory courses should make it easier for you when you need to learn new information in your advanced courses (because you have more "old information" to connect to the new information).
Implications for in-class behavior and note-taking:
- Because making information meaningful involves both (a) working to connect new bits of information to each other in a way that makes sense to you and (b) working to connect the new information to what you already know,
borrowing someone else's notes (even the professor's!) is no substitute for being in class and taking your own notes. If you skip the mental work of elaborative rehearsal, you miss out on retaining the information.
- Because elaborative rehearsal involves thinking, unless the professor is going pretty fast, do not just copy down what the professor says. Instead, think, then write--and realize that what you do write down without thinking will be worthless until you think about it. So, if you skip thinking about something in lecture, be sure to make up for that lapse by thinking about that information especially deeply when you study it.
- To encourage elaborative rehearsal during class, be mentally active in class by trying to (1) think of the answer to any question the professor asks, (2) think about how the information in the lecture relates to the information in the previous lecture, and (3) think about how a story, an example, or demonstration connects to an important point.
- To make the information meaningful, relate the lecture's ideas and examples to yourself or to people you know.
Implications for studying:
- Because elaborative rehearsal involves making information meaningful, read through your notes shortly after class to make sure they make sense. If parts don't make sense, try to fill them in using the book, the internet, or a friend's notes.
- Because elaborative rehearsal is an active process that requires hard mental work, you should study in a place without distractions and at a time when you have energy and focus. So, studying in bed is a bad idea--and, for many students, studying during the day is much more effective than studying at night (However, a quick review of the information before going to bed may help consolidation). Similarly, studying right after you get up is usually not very effective--you will usually need to be up for at least an hour before your mind fully wakes up.
- Because memorizing often involves making information meaningful, understand information before trying to memorize it. (To see an example of how making a paragraph meaningful makes it more memorable, read this short blog entry or try to memorize this story). In other words, the well-meaning advice "don't understand it, just memorize it" is bad advice because meaningless information is very hard to remember: Imagine having to learn pages of words from a language you didn't know or having to learn pages of "nonsense syllables" like these: "XOV" "BEF", and "KUQ". (For an example of how hard meaningless information is to memorize, see the man who couldn't remember his wife's name.)
- Should you listen to the lecture first or read the text first? To answer this question, realize that (a) you need to understand information to make it meaningful and (b) you usually need to make information meaningful to memorize it. So, if you are having more trouble understanding the text than understanding the lectures, you may wish to hear the lectures before reading the text--although I would still advise at least skimming the chapter before before going to class. If, on the other hand, you are having more trouble understanding the lectures than you are understanding the text, you should definitely read the text before coming to class.
- Thinking critically about what you are studying will help your memory for that information because elaborative rehearsal is thinking.
- Skim the chapter before reading it so you can see how the chapter's information might be meaningful and so that you can activate memories for information already in your memory that you will be able to associate with information in the chapter.
- Because meaningful information tends to be specific rather than general (In some studies, participants are twice as likely to remember specific statements rather than general statements), refine your notes by converting abstract, general statements into concrete, specific examples.
3 general strategies for adding meaning to course material.
1.Come up with your own as well as coming up with or finding analogies that make sense to you (e.g., think of LTM as being like a library).
2. Ask questions such as how is the new information to and how is it different from what you have already learned.
For example, ask "How is Sensory Memory similar to STM--and how it is different?" You could also ask "Why is this information important?", "Why should I believe--or not believe--this?", or "Is there a better way to organize this information?" In general, asking and answering "why" and "how" questions will help you--especially in more advanced classes.
3. Make the information personally meaningful by putting the new information in your own words. One way to force yourself to put information in your own words is to tell other people what you have learned. So, the next time your parents ask you about school, you can study by telling them what meaningful things you learned in class. In addition to putting information in your own words, summarize it. Summarizing material forces you to think about what the most meaningful and mportant points are.
Two implications for how you should study:
Quotes to motivate you to add pictures to what you are learning and to help you remember "picture power":
- Making simple diagrams or even making almost illegible doodles of concepts can help your memory for course material (so don't be afraid to add doodles to your notes or flashcards). More elaborate visuals, such as cartoons, timelines, infographics, concept maps (also called "mind maps"), and sketchnoting can be even more helpful.
- Do not skip diagrams and visuals in your text. Instead, go through the chapter at least once looking only at its visuals.
- "Hear a piece of information and three days later you'll remember 10% of it. Add a picture and you'll remember 65%." --Kevin Horsley, Memory Grandmaster
- "Our brain is mainly a image processor, not a word processor." -- Peter Hollis, SuperLearner
- "A picture is worth a thousand words."
To impress yourself by seeing your own mind's amazing ability to remember images,
Other evidence for the power of images:
(We discuss mnemonic devices in more depth here )
- People with naturally great memories use imagery
- Solomon Shereshevsky, who could remember practically anything word-for-word within minutes and who was frustrated by seeming to be unable to forget anything, had synesthesia: he not only heard words, he also saw images when he heard those words.
- Jill Price, who was the first person in the world documented to have hyperthymesia ( remarkable episodic memory; as of now, only about 60 people in the world seem to have an episodic memory that is good enough to earn that label) also has synesthesia.
- Using visual images is key to almost all mnemonic devices: systematic memory aides. For example, one mnemonic device is the method of loci (method of places): a system in which you visualize putting the items you need to remember in places along a path, and then you retrieve those items by seeing yourself revisiting those places as you again visualize yourself walking along that path.
Like real banks, it is easier to make deposits into our memory banks than it is to make withdrawals (Much information is forgotten, but not gone). Below are 3 examples of retrieval--but not storage-- failures. In technical terminology, the following 3 examples illustrate that information available (stored) in memory is not always accessible (retrievable).
Because retrieval is such a big problem (and because tests ask you to take information out of memory rather than put information into memory), much of your study time should focus on retrieving--not merely recognizing!--information. Specifically, you should
Evidence that retrieval failures are not due to time alone:
|Typical Hypermnesia Experimental Procedure and Results|
|Typical Procedure||Study List of 24 Words.||Recall words|| Experimenter: "Experiment is over, but would you like to come in next
week for another memory experiment?"
| "Recall words from last week."
|Recall 2||Recall 3||Recall 4||Recall 5||Recall 6|
|Typical Number of Words Recalled||18||3||6||11||14||18||24|
So, on the one hand, time, by itself, does not cause retrieval failures.
On the other hand, however, retrieval failures are often linked to time as Ebbinghaus' forgetting curve illustrates (see the graph below).
* If you just focused on the rapid drop during the first part of Ebbinghaus' forgetting curve, forgot about savings (that relearning is much faster than the original learning), and did not realize that meaningful information is retained much longer than the nonsense syllables that Ebbinghaus used in his forgetting studies, you might think that this comedian's idea for a 5-minute university was a great idea rather than just a great comedy routine.
After noting that the forgetting curve starts off as a sharply falling line, but then becomes a curve as forgetting levels off, answer the following three questions. Then, check your answers by clicking on the buttons below.
3 proposed reasons:
We will now look at each of these three explanations for retrieval failures in more depth.
Really a problem when information is perceived as
So, when studying information, you should try to make the information different from what you already know before you try to memorize it. Similarly, if you are using imagery to memorize something, you might try to make your image unusual in some way, such as making it much bigger than such normal objects really are.
2 types of interference:
Proactive interference: Old (Previously learned) information hurts retrieval of new information.
Classic experimental set up for demonstrating proactive interference:
|Group 1||Learns |
|Tested on |
|Group 2||Learns |
|Tested on |
Results: Group 1 does worse than Group 2 because proactive interference from List A acts to interfere with Group 1's recall of List B. How much worse? That will depend on how similar the two lists are-- the more similar, the worse Group 1's recall.
Think of other examples of proactive interference. Hints:
Retroactive interference: Newly (Recently) learned information acts to hurt memory for old information ("retro" means "backwards").
Classic experimental set up for demonstrating retroactive interference:
|Tested on |
|Tested on |
Results: Group 1 does worse than Group 2 because retroactive interference from the recently learned List B acts to interfere with Group 1's recall of List A. Will the act of learning about retroactive interference recently act to interfere with your memory of proactive interference? Have your more recent phone numbers, addresses, and passwords interfered with access to your old ones?
Animation to help you understand the difference between proactive and retroactive interference
Practice distinguishing proactive interference from retroactive interference
A phenomenon that shows both types of interference
and also shows how passing of time can't account
forgetting--the serial position curve:
Graph Courtesy of Creative Commons License 3.0 via Wikimedia Commons
Questions to think about when looking at the serial position curve
Given that recall is good for the beginning and for the end, but poor for the middle (e.g., we can easily remember the first U.S. President [Washington] and, despite what repression would predict, the last former President [Trump], but may have trouble remembering middle presidents like Chester Arthur), what does this mean in terms of
Your knowledge of interference can help you refute lies. The problem with trying to refute a lie is that to refute it, you usually repeat it--and repeating it may actually make people remember the lie. The solution is a "truth sandwich" in which you state the facts, refute the lie, and then state the facts again. That way, the lie is subjected to proactive interference from your first statement of the fact and retroactive interference from your final restatement of the fact. In short, just like with the serial position curve, people will remember the beginning and the end of what you said (the fact) rather than what you said in the middle (the lie).
Short (less than 1 minute) video to help you understand interference and the serial position curve.
Short (one minute) animation showing the implications of interference for how you should study.
Look at some terms that you might have trouble remembering because of interference
#2 Cue-Dependent Forgetting: Inadequate cues as a cause of retrieval failure
Cues trigger memories. In a sense, the cues you have for retrieving the information are like hooks that help you fish for information: The more hooks, the more likely it is you will catch the information. Given the importance of cues, it is not surprising that much forgetting is due to not having the right cues. Not having cues, like not having the address of a person you want to visit or not having the file name for the computer file you want to access, makes it unlikely that you will find what you need.
Examples of retrieval failures due to lack of cues:
- Often, after you say you "don't remember" something, a friend reminds you by giving you a cue ("Remember, we talked about this on Wednesday") rather than by repeating the original information.
- Similarly, students may miss a test question even though they know the information because the relevant information doesn't come to mind when they are answering the question.
- Cues are often used to help people suffering from retrograde amnesia recover their lost memories.
Implications for studying and test-taking:
- When studying, add cues to the information: If you have essay, short-answer, or fill-in tests that rely on retrieving information, you may find it almost as valuable to memorize cues that will jog your memory for the information as it is to memorize the information itself. If you use flash cards correctly or if you use the Cornell note taking system, you are probably already learning both the information and cues for the information.
Seven additional ways to remember both cues and information:
- Create acronyms. When you memorize an acronym, you memorize a cue for the words you want to remember--the first letter of those words (e.g., "HOMES" to remember the great lakes [Huron, Ontario, Michigan, Erie, Superior], "RoyGBiv" to remember the colors of the rainbow [Red, orange, yellow, Green, Blue, indigo, violet], "ETC" to remember 3 tips for remembering [Elaborative rehearsal, Testing, Chunking], or "MOST" [Make meaningful, Organize, Select, Test], or POTS [Personalize, Organize, Test, Space out your practice], or FORCE [Focus, Organize, Retrieve, Create Cues, Elaborate], or ...).
- Memorize at least one good example because examples can serve as cues. So, the more examples you connect to a concept, the more cues you will have, and thus the more likely you will be to retrieve the information. However, if you don't have many examples, one may do--especially if that example is vivid and specific.
- If, when you are testing yourself, you blank on an answer, ask yourself, "What cue can I use to recall this information if I blank on the actual test?"
- Organize material from your notes and text. You could put related concepts into groups (by putting your flash cards into piles, making an outline, or making a concept map) and then give each group a distinctive name. That way, you have at least two cues for the information: (1) the name you gave that category and (2) the other items in the group. Alternatively, you could integrate material from the text with your class notes or you could reorganize your class notes. Whichever organizing strategy you use will probably help: Compared to students who get low scores on tests, students who get high scores spend about 4 times as much time organizing course information.
- Put key terms on one sheet of paper. On that sheet, have four columns: one column for the term, a second column for the definition, a third column for an example, and a fourth column for a person associated with the term (for some courses, you may skip this fourth column). For each term, practice covering up all but one column and trying to recall the information in the remaining columns. Studying this way should give you three effective cues for each term: its definition, your example, and the person associated with the term.
- As you study, think of a question for which the concept you are studying would be the answer. That question will be the cue for the information. The better you are at guessing what test questions will be, the better this cue will be.
- It might pay to, during your final review sessions, to imagine yourself in the classroom taking the test. That way, you have given yourself a cue (the classroom) for the information that will be present when you take the test.
- When blanking on a test question, give yourself a chance to use cues by
- Looking at other questions to see if those questions cue your memory for the information.
- Leaving the question and then coming back to it. If you are not retrieving the information, the cues you are using are not taking you to the right place in your memory. Rather than continuing to use the same ineffective cues that are taking you to the wrong "address" in your memory, you are probably better off coming back to the question at which time different cues may come to mind. If it is an essay question and you are still blanking when you return to it, start writing: The act of writing may generate cues (especially if your study sessions included writing answers to questions). If you really can't think of anything to write, start writing by rephrasing the question, defining some key terms that might be relevant, or answering a related question. (Even if you don't end up recalling the relevant information, you may still get partial credit.)
- Realizing that you may have the information in a visual form, so close your eyes and try to picture a diagram, table, picture, or video related to the question.
- If you are failing to recall a word for a fill-in-the-blank type test question, go through the alphabet. The word must start with one of those 26 letters, so you will say the right word's first letter which may jog your memory for the right word.
- As you will see in the next section, because physical context is a cue, you could think back to where you were when you learned the information.
Physical context --where you were when you learned the information--is a cue that helps retrieval. How do you jog a friend's memory? Often, by talking about where they were when the event occurred. How would you jog your memory for events that occurred when you were in fourth grade? You might go back--either physically or mentally--to your fourth grade classroom.
Everyone seems to know about the power of physical context except the police who have witnesses go down to the station to make a statement rather than having witnesses make their statements at the scene of the crime. (To read a one-paragraph description of the famous "jump in the lake" study demonstrating context-dependent learning in a fun way, click here; to see a 2-minute youTube video describing that same experiment, click here)
How can you take advantage of the physical context effect to do well in school?
As we just mentioned, if you are blanking on question, it may help to think back to where you were when you learned the information. The more vividly you can mentally recreate the context, the more likely you are to cue the memory. For example, you might try to see yourself studying at your desk in your sweats, drinking from your water bottle. As we also already mentioned, you might imagine yourself in the classroom while studying the information. Finally, and perhaps most importantly, realize that the more places you study certain material, the more places there are to cue that information, and the better your recall for that material should be. So, take your flashcards with you when you leave your room.
Mental state can be a cue. Your emotional and physiological state--happy or sad, drunk or sober--can be a cue. In fact, your physiological state can be such a strong cue that it may seem like you only know certain things when you are in the same physiological state you were in when you learned the information, a phenomenon called state dependent learning (also called state dependent memory--but which should be called state dependent retrieval). State dependent retrieval has been demonstrated with alcohol, marijuana, stimulants, and barbiturates. The evidence for mood-dependent learning is not strong--even though mood dependent retrieval "feels right"--what we remember when we are depressed seems different from what we remember when we are happy; what we remember about someone when we are mad at them seems different from what we can remember when we are happy with them. Because of state-dependent retrieval, you would want to be as caffeinated and happy when you study as you are when you take the exam. (If, however, you can't be happy during the exam, don't worry: As we just mentioned, mood dependent learning/retrieval is not a strong, well-documented fact.)
Repression might possibly explain:
- Some cases of retrograde amnesia where psychological trauma seems to have prevented people from remembering parts (or, in rare cases, all) of their past (i.e., a bad event seems to have hurt their episodic--autobiographical--memory). Despite retrograde amnesia rarely occurring in real life (and even more rarely being caused by repression), retrograde amnesia is common in movies--and is frequently attributed to repression. Movies that use retrograde amnesia and attribute it to repression include famous movies that may be based on real cases such as "The Three Faces of Eve" and "Sybil" (however, the real Sybil claims her multiple personalities were faked), as well as such classics as Hitchcock's "Spellbound."
- Childhood amnesia (also called infantile amnesia): Poor episodic memory for the first 3 years of life. (Childhood amnesia is one reason some people claim parenting is a thankless job. On being reunited with a child that they took care of 24/7 during infancy, more than one caretaker has been shocked to get the following greeting from that child, "Sorry, I'm not allowed to talk to strangers.")
Problems with explaining forgetting as being due to repression
- There is little evidence that repression is common (although we do seem to remember positive events better than negative events).
- Repression is far from the only explanation for childhood amnesia. Indeed, from what you have already learned about memory, you could probably think of at least 3 other explanations for "childhood amnesia":
1. Interference: your old memories have been buried by retroactive interference from the numerous more recent events have occurred since you were an infant.
2. Cue-dependent forgetting: Even if, when you were 1 or 2, you had cues that helped you recall information, those cues were probably very different from the ones you use now. For example, although, today, asking yourself, "What did I do last Friday?" could be a useful cue for triggering memories, such a cue would have been worthless to your 11-month-old self.
3. Encoding failure: When you were 1 or 2, you often did not rehearse information, and when you did, you probably did not use Type 2 (elaborative) rehearsal. Ineffectively rehearsed information may never have gotten into LTM.
Most mnemonic devices (memory systems) work by solving the 2 major problems with LTM:
1. They usually solve the encoding problem by using imagery, a way of doing Type 2 rehearsal. (They elaborate on material by adding pictures to it.)
2. They solve the retrieval problem by building in retrieval cues. Because the cues are built in, you don't have cue-related forgetting. Because you know where to look (you look where the cue is), you aren't bumping into the wrong information, so you may not have interference problems (Interference, however, can become a problem. To understand how, click on the following link: Why aren't mnemonics used more often? ).
Two examples of mnemonic devices:
Example 1: The method of loci (the method of places) in which you (1) encode each piece of information by creating a mental picture that links the information to a place along a familiar path and then (2) retrieve the information by taking a mental walk along that path.
Example 2: The peg-word mnemonic: A method is which you (1) form mental images of and then memorize a list of "peg words" -- a list of words that are easy to visualize and that you can put in order ( e.g., a common system ties each peg word to a number: "bun" for one, "shoe" for two, etc.), then (2) encode information by forming, for each new item, a picture that includes both the new item and the relevant peg word (e.g., for your first new item, you would form an image of the new item interacting with your first peg word ), and then (3) retrieve the information by going through your list of peg words in order. Look at the table below to see an example of how you might go through the 3 steps to use a peg-word mnemonic.
Step 1 (Set up your cues) Step 2 (Encoding--link the new information to your cues) Step 3(Retrieval--Go to your cues) Get an ordered list of peg words. Normally, your first word should be associated with "1", your second word with "2" etc. (examples of number-based peg lists) If, however, you hate numbers, you could choose a list of peg words in which the first word is associated with "A", the second with "B", etc. (examples of some alphabetical lists of pegwords).
Then, visualize your peg words and memorize them in either numerical or alphabetical order.
Link new material to peg words using imagery.
Picture the first new item interacting with first peg word, the second new item with second peg word, etc. You may need to use some creativity to (1) make an image representing each new item and (2) getting each new image to interact with its corresponding peg word (ideally, in a vivid and bizarre way)..
Go through the pegs (your cues) in order. Start by picturing the peg word associated with "1." Your first item should pop into your head. Keep going until you have gone through all your peg words. Example "1" as "bun"
Example: Connect bun to your image of sensory memory (in this case, the image of "sensory register" is a cash register that senses with its ear). The interaction (not pictured) is that the sensory register wants to eat the bun.
Example: Visualize the peg word for "1" (bun) and you should see sensory register trying to eat the bun.
**Note that you only need to do Step 1 once. After you have set up all the pegs, you don't have to do that ever again. So, once your system is set up, you will be able to remember items in order by just doing Steps 2 and 3.
If mnemonic systems are so powerful, why aren't mnemonics used more often?
Two important similarities between LTM and a library:
The good news about reconstruction: By noting what you can
reconstruct and memorizing only what you can't, it can seem like you
have remembered everything without memorizing much.
If visuals help you,
mouse over this text How can
you use overlearning to do better in school? One way is to repeatedly write out answers to essay questions based on course material. If you
tire of writing out answers, you
could say your answers aloud to a critical friend or to a
recording device. Alternatively, instead of writing entire
essays, you could outline answers to essay questions or develop rubrics
for grading answers to those essay questions (if you have a study partner, you could
use your rubric to grade your partner's essays). If sample essay questions
from your text, your professor, or online, you could create
your own essay questions or you may be able to get them from the
Psychology Problem Solver series.
Four amazing facts about reconstruction: the process of using your knowledge of how the world works to take some bits of stored information to create a "complete" memory.
Experimental evidence for reconstruction
So, oddly enough, the key to seeming like you have memorized more is to memorize less! For example, imagine that a friend tries to memorize every word of a 30-page chapter whereas you boil down that chapter to less than a page of notes from which you can reconstruct the chapter. You will memorize less than a page of notes but appear to know much more than your friend. But can you really summarize an entire chapter in one page of notes? Yes. In fact, one highly paid memory expert advises his clients to finish the term with one page of notes from which they can reconstruct the entire term's information.
How do you boil down a long chapter to less than one page of notes?
Why do you need to overlearn? You need to overlearn--which
should be called "Super Reviewing"-- to defeat
the forgetting curve. (Perhaps it was
the forgetting curve and the power of overlearning that caused
Quintilian to write, "Nothing is so much strengthened by practice,
or weakened by neglect, as memory.") Put another
way, since retrieval is the big problem in LTM, you need to practice
retrieval. For students, this usually means taking practice tests
and quizzing each other. In a sense, practicing retrieval is like mowing the
memory's retrieval path. Because of the need for overlearning, you should retrieve
newly learned information at least 3 times after learning it (e.g., a day after
learning it, a
week after learning it, and a month after learning it).
Two important similarities between LTM and a library:
The good news about reconstruction: By noting what you can
reconstruct and memorizing only what you can't, it can seem like you
have remembered everything without memorizing much.
If visuals help you,
mouse over this text
How can you use overlearning to do better in school? One way is to repeatedly write out answers to essay questions based on course material. If you tire of writing out answers, you could say your answers aloud to a critical friend or to a recording device. Alternatively, instead of writing entire essays, you could outline answers to essay questions or develop rubrics for grading answers to those essay questions (if you have a study partner, you could use your rubric to grade your partner's essays). If sample essay questions aren't available from your text, your professor, or online, you could create your own essay questions or you may be able to get them from the Psychology Problem Solver series.Another way to practice overlearning is to repeat parts of lectures to your parents, a stuffed animal, or a recording device. Tutoring also provides a chance to overlearn. Note that since everything you need to overlearn is already in your head, you can practice overlearning almost any time. For example, you can recite answers to questions or recite the main points of a lecture while walking between classes or while waiting in line.
|1. Repetition alone is an effective strategy for getting information into LTM.||Repetition (Type 1 rehearsal, also called maintenance rehearsal) is not an effective way to get information into LTM.
Common ways of wasting study time by using maintenance rehearsal include
Instead of using Type 1 rehearsal, you should do things that will encourage Type 2 (elaborative) rehearsal
|2. Cramming is effective.||Spreading out your studying (spreading out your studying is called distributed practice) is much more effective than cramming (cramming is called massed practice), especially for (a) complex information and (b) long term retention. So, cramming might help you on a quiz, but it will get you in trouble if you need to know the information for the final exam, for a later course, or for your future career.|
|3. Highlighting your text is an effective memory strategy.||Passive strategies are not effective. Memorizing involves
thinking--not mindlessly coloring your book with a highlighter. So, stop
highlighting.* Instead, take notes on your book that engage you in a
conversation/argument with the author, such as notes starting with "What you mean is _____," "I disagree with you
because ______," "But earlier you said ____," "The main
point is _____", and "Would ____ also
be an example of _____?" The key is not to copy
material from the text (that's just highlighting the hard way) but
to reflect and then write. So, if you are writing
something about a paragraph before you have finished that paragraph,
stop, finish reading the paragraph, and then, if you can justify doing
so, write your note.
*If you can't break the habit of highlighting, commit to (1) highlighting only important points (or going back later with a different color highlighter to highlight the important points) and (2) going back and reviewing what you highlighted. Ideally, you would also try to reconstruct the rest of the page from your highlighting. and you would make notes based on what you highlighted.
|4. It is wasteful to skim a chapter before reading it.||Before reading a chapter, you should figure out how that chapter is organized, what the main ideas are, and what you will learn by reading it. So, to preview the chapter, read the chapter outline (if there is one), read the chapter's introduction, look at the major headings, and read the chapter summary. These "pre-reading/ previewing" activities will help you in three ways. First, previewing the chapter makes it more likely that you will engage in elaborative rehearsal when you read the chapter because you will be more able to make the material meaningful and you will be more likely to access relevant knowledge you already have that you can connect to the text's information. Second, previewing the chapter to see how the chapter is organized makes it more likely that you will organize what you read. Organizing what you read--by storing connected chunks of information rather than many isolated bits of information and by having cues that will help you retrieve that connected information--will help you recall that information. Third, previewing the chapter, by giving you the big picture, should make it easier for you to figure out which information is important and must be memorized (e.g., a main point) and which information is less important or capable of being reconstructed (e.g., a second example of the same point).|
|5. Testing yourself over the material before the exam is a bad idea.||Testing yourself over the material is the most effective way to learn the material. Research shows that testing yourself, if you answer yourself aloud or in writing, is about 6 times more effective than re-reading and that students' grades are positively correlated with how much they recite.|
|6. "Don't try to understand it, just memorize it."||Understanding information makes information easier to remember. (It is hard to remember "S hortt ermm emo ryih ol dsev nks " until you see it as "Short term memory holds seven chunks.")|
|7. "You have to memorize everything word for word." "||
|Study Grid: Long Term Memory|
|Stage of processing||Example(s) of problems||How can problems be prevented?|
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