Overview of the 3 box model of memory
Information must through two other boxes to get to LTM

Table of contents


3 Key Terms Relating to Memory's 3 Processes

To understand the differences between diamonds, you need to know what people call the 4 C's of diamonds: Cut, Carat, Clarity, and Color (the diamond-curious can learn more here).
To understand the differences between  your 3 memories, you need to know what you could call the 3 C's of memory:*
enCoding,  Storage (Container size and durability), and Retrieval (reCovering).

* But you probably shouldn't call them the 3 C's. If you did, 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. So, stick to the conventional terms: Encoding, Storage, and Retrieval.☺

The 3 Key Terms Defined:
  1. Encoding: Putting information into the memory (converting the information into a code that the memory will accept--as you will see, different memories use different codes. In a sense, different memories speak different languages.)
  2. Storage: Keeping information in the memory (how much can be stored-- and for how long?)
  3. Retrieval: Getting information that is in the memory out of the memory so we can use it (how well can we to access/locate/recover what is in memory?)

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 container, realize that storing information is just 1 of your memory's 3 active processes.

Point that often confuses students: Memory's 3 processes/qualities are independent--being good at one doesn't mean the memory is good at another. For example, storage capacity and retrieval ability are independent. To see why,  imagine two memories--one that is like a shoe box, and one that is like an 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 attic memory, on the other hand, would be great at storage (lots of stuff could be stored) but would be poor at retrieval (it would be hard to sort through all the junk scattered throughout a dark 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 is 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:

  1. Did the information ever get it into memory? (If not, that's an encoding failure.)
  2. Did the information fall out of memory or get corrupted/damaged in memory? (If so, that's a storage failure.)
  3. Is the information still somewhere in memory, but I am failing to find it? (If so, that's a retrieval failure.)

Short (only 3 questions!) quiz on memory's 3 processes  

The 3-box model (Your 3 memories as 3 boxes)

You don't have just one memory. Instead, you have at least 3. As you can see from the diagram below, before information can get into your permanent memory (the third box, labeled "Long-Term Memory), it must get through two other boxes: the Sensory Memory (SM) box and the Short-Term Memory (STM)  box. Put another way, before information can get into permanent memory, it (like Indiana Jones) must pass 3 challenges--each of which is more difficult than the last.

 Three box model

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 (e.g., 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 (see a 22-second animation of how encoding failures could affect any of the three boxes).

Terminology note: Synonyms for "memory" include "store" and "register." 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 store" or "short term register." Guess what two other terms you may hear for long term memory (LTM)?

  1. Long term register (abbreviated LTR)
  2. Long term store (abbreviated LTS)

Box 1: Sensory Memory (abbreviated SM)-- a very brief, exact copy of what we sense

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.
  By being able to replay the last 3-5 seconds or so of what your ears just sensed, your echoic memory

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 with rapidly disappearing ink. 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 we see more than 12 photos on a screen in a second, our iconic memory holds one image in mind until we see the next. As a result, we see "moving pictures" (i.e., "movies" or "motion pictures").  If we see fewer than 12 photos in a second, by the time we get from one image to the next, the previous image is gone from iconic memory. As a result, we see the images as separate, and see a slide show rather than a movie.

Iconic memory is not just valuable when watching movies. To get a rough idea of how confusing the world be if you didn't have both iconic memory and visual short-term memory, watch this 48-second animation/simulation.

On rare occasions, people will get confused about whether they are seeing a replay from their iconic memory or whether they are seeing a live event, so they "see" things out of order. For example, surgeons sometimes see a patient bleeding from the cut produced by their scalpel--before they see the scalpel make the cut! To experience your sensory memory (in this case, your echoic memory) changing your perception of when things occur, take 40 seconds to try this demonstration (Warning: this demo works for most people but not for everyone).

 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.

Drag and drop matching game to test your knowledge of sensory memory  (Play several rounds of this game; each round gets a little harder.)

Most of the information in SM disappears within seconds. However, the information in SM that you pay attention to will move on to the next memory: short-term memory (STM).

Box 2: Short-Term Memory (abbreviated STM, also known as "Working Memory")

Short-term memory is small: It can't hold much information. In technical terms, it has a limited capacity.

Short-term memory is short (it typically lasts about 20 seconds)

The reason information stays in STM for such a limited time seems to be due to the limited size of our STM combined with our limited attention span. Some evidence:

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 do many things without awareness, like breathing, balancing, and (sometimes) texting. 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.

Put another way, short term memory (STM) is more than just a storage container for whatever you are aware of at the moment: It is your conscious mind. So, STM  is where you do your conscious thinking--where you both speak to and listen to yourself. Because short-term memory is the work space where you do much of your mental work, STM is often called "working memory." Because working memory is your conscious mind and because your conscious mind is complex, many psychologists break down STM into several parts (to learn about those parts, look at this diagram). However, 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, unsteady, 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 is limited. Specifically,

  1. We can only pay attention to a few things at a time, so multi-tasking can't work.
  2. Examples showing that we can only pay attention to a few things at a time: Analogies to help you understand that we can't multi-task:
  3. Teachers and presenters may overwhelm their audience's STM by going  too fast or by presenting too much information on a Powerpoint slide.
  4. The complexity of the world can't fit in STM, so we oversimplify the world, leading to not seeing differences between people (as in stereotyping) and to seeing things in terms of absolutes (e.g., all good or all bad).

What is chunking and how does it allow us to keep more information in STM?

The way to get around short-term memory's size limitation is to chunk: group several different individual bits into one unit.  For example, you could group the twelve numbers "177  614  922  02  1"  into three chunks:
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. So, instead of having to remember 12 numbers, you just had to "point" to 3 groups of information you already 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 "FBI" is one chunk but "BFI" is probably 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:

But why chunk psychological information--or why chunk any other information? (Why are big chunks better?)

Because chunking, by allowing us to keep more information in STM, lets us think smarter.

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 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:

Students who chunk information when studying get better grades in colleg(Gurung<, 2005).

  • You could make an organized outline--note that such an outline is not merely a list of terms.
  • You could make concept maps.
  • You could organize your flashcards into piles with those piles becoming large chunks. ( Download a tutorial on making and using effective flashcards.)

  • 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.

    Review STM

    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!).

    Another look at STM's importance

    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 involve 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 safely. So, both short-term and long-term memory are important to living a full life. We have discussed short-term memory, which keeps us aware of our immediate present. We will now turn to long term memory, which connects our past to our present.



    You have at least 3 long term memories. Specifically, you have a

    1. procedural memory: your memory of how to do things (text, talk, sing, dance, ride a bike, drive, etc.) often learned by practicing those skills. When people talk about "muscle memory," they are often referring to procedural memories for a motor skill. However, procedural memories are not limited to motor skills. A writing, speaking, pottery-making, musical performance, acting, critical thinking, or other "skills" class may try to add to your procedural memory--as might a senior-level capstone course, internship, or practicum.  
    2. semantic memory: your dictionary/encyclopedia of impersonal, factual, general knowledge (knowing what an elephant is, who the President is). Most of your content courses in college focus on adding concepts to your semantic memory. (Trivia games like Jeopardy also test your semantic memory.)
    3. episodic (autobiographical) memory: your diary of events in your personal life (what you did last week, your life as a reality show with many episodes). In a sense, episodic memory allows you to travel back in time. Note that, unlike semantic memory, episodic memories are often tied to a place and a time--and recall may feel like a "rerun" of the original episode. For example, when you recall that George Washington was the first president of the U.S. (a semantic memory),  you don't also recall where and when you learned that fact, but when you recall Trump losing his re-election bid (an episodic memory), you may also recall  details about where you were, what you were doing, and when it was that you heard that news. 

         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. 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 of his past (he doesn't know who he was) but his procedural and semantic memories are intact. If you want to look at the opposite extreme, you can watch this 13-minute segment from "60 Minutes" about the approximately 56  people who have been identified as having fantastic episodic memories.  If you watch that video, consider 4 points:

    1. As would be expected from what episodic memory is, recall of these episodic memories often seems like reliving the past event. That is, these episodic memory wizards often seem to experience the same emotions and sensations they felt when they first experienced the event.
    2. As would be expected from episodic memory being different from semantic memory and from episodic memory being primarily an autobiographical memory, these episodic memory wizards do not have superior memory for things they do not directly experience. Their memories seem to be clearest for events in which they are the star.
    3. Interestingly, memory wizards' superior episodic memory seems to be due primarily to slow forgetting--our memory for yesterday's events rivals theirs. So, perhaps, with the right cues, we could all have impressive recall for our past experiences.
    4. The video implies that being able to say what day of the week corresponds to a certain date is a great memory feat. It could be, but a person could figure out the day of the week from the date without having a great memory. In fact, you can learn to calculate the day of the week from the date using the instructions here. Are these memory wizards using a formula on the date to compute the day of the week and then using the day of the week as a cue for triggering their memories?

    * Terminology note #1: Since you can explicitly tell  (i.e., you can declare) to others people about both your semantic memories (e.g., that George Washington was a president) and your episodic memories (e.g., what your high school graduation was like), semantic and episodic memory are often referred to as  types of  declarative memory (also known as explicit memory). Since you cannot easily declare the contents of your procedural memories (e.g., how 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., semantic memory of facts about George Washington or episodic memories of high school graduation) 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. Fortunately, you are not always completely on your own when it comes to learning a skill because a coach can give you some pointers about what you should be doing. Actually doing it well, however, will still probably take extensive practice.

    * 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 fairly simple (e.g., that thunder follows lightning) or can be complex (e.g., knowing grammatical rules such as knowing that Yoda's "strong you are" type statements have the words out of order). 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" as 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).

    LTM's storage is excellent, but there are 2 big problems with LTM:

    Problem #1 with LTM--Encoding: Getting information into LTM

    Examples of encoding problems:

        An extreme example of encoding problems--anterograde amnesia: an inability to form any new episodic memories.
    People with severe anterograde amnesia are unable to form any new memories. As a result, they are stuck in the past.
    Two well-known cases of this condition are are

                  The case of HM (note the difference between  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:
    1. How many red stripes are on the American flag? How many white stripes? (Check your answer by looking at a picture of an American flag)
    2. See the surprising thing that college students don't know about Apple
    3. Where is the nearest fire alarm to your classroom?


    Information must be encoded into STM before it can be encoded into LTM

      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.

    Getting information from STM to LTM involves 2 steps: One mental, one physical

      But even if something is encoded into STM, it may not get 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 jello. In making jello, you do the work to assemble the ingredients, but the jello becomes solid only after setting in the refrigerator for a while.  Similarly, in making 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.  (Alcohol blackouts--when a person doesn't remember what they did while they were drunk--is a case of alcohol disrupting consolidation.) The need for consolidation has two implications for studying:

    1. Your memory will  benefit by taking a 15-minute break after learning information.
    2. Getting enough sleep is very important for consolidation and thus for being able to remember information.

    Problem #2 with LTM--and the most serious problem with LTM --Retrieval: Getting information out of LTM.

    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, to remember some or all of one's personal past (i.e., episodic memories are lost).  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 retrograde amnesia:

    Admittedly, not all cases of  retrograde amnesia are due to retrieval problems. For example, if retrograde amnesia is limited to failing to remember events that occurred shortly before a concussion or to events that occurred while drinking, such cases are usually due to disrupting consolidation (consolidation is the process of rewiring of the brain to form permanent memories). Consequently, those memories were never permanently wired into the brain and will never come back. However, in most cases of retrograde amnesia in which the person forgets more than just a few hours, the forgotten episodic memories "come back," indicating that they were there all along but couldn't be retrieved.

    Common examples of retrieval problems (of information being available but not accessible). 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--because of its enormous size (and perhaps permanent duration)-- can be very impressive (see an amazing example).

    LTM Encoding: From STM to LTM

     Solving the encoding problem: How to get information from STM to LTM (Hint: The key is to actively transform the information).

            Short animation slightly exaggerating the difference between Type 1 (maintenance) and Type 2 (elaborative) rehearsal

    The way to solve the encoding problem is not by Type 1 (maintenance/rote) rehearsal: things over and over.


    Evidence that Type 1 (rote) rehearsal is not effective for moving information to LTM: In some studies, repeating things over and over does not improve recall. 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: It does not recode the information to make it meaningful or visual.

            (Animation: Type 1 rehearsal often only maintains information in STM; Type 1 rehearsal usually recycles information back into STM rather than moving the information to 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).

    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 
    attempt number   

    Implications for aging and memory: As you get older, your 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,  So, 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). Partly for this reason, some schools prohibit juniors and seniors from taking introductory courses.

    Implications for studying:

    • 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 day  is much more effective than studying at night.
    • Because elaborative rehearsal involves working to organize it (connecting the new info bits to each other in a way that makes sense to you) and  to make it meaningful (connecting the new info to what you already know), borrowing someone else's notes (even the professor's!) is no substitute from being in class and taking your own notes.
    • When taking your own notes, (a) do not just copy down what the professor says--think, then write, (b) be active by trying to anticipate what the professor will say next (e.g., you might try to mentally answer any rhetorical questions the professor may ask, try to predict what the first thing the professor will say about the topic, or guess what example the professor will use), (c) relate the lecture's ideas and examples to yourself or to people you know, and (d) 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.
    • The advice to "don't understand it, just memorize it" is bad 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.) In contrast, meaningful information is easy to remember. Because memorizing involves making information meaningful, to remember information, understand the information, then memorize it. (To see an example of how making a paragraph meaningful makes it more memorable, read this short blog entry). 
    • The fact that information you see as meaningful is easier to remember also has implications for whether you should read the text first or listen to the lecture first. 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, you should definitely read the text before coming to class.
    • Finally, note that 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 (Baddeley, 1990). So, convert abstract, general statements into concrete, specific examples.

    3 ways to make course material concrete, specific, and personally meaningful.

    1.Come up with your own   and  analogies (e.g., think of LTM as being like a library).

    Attempt number          

    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.

    Attempt number

    3.  Make the information personally meaningful by  putting the new information in your own words. After that, summarize it. Then, because you will remember what you tell others, share your summary with anyone who will listen. (So, the next time your parents ask you about school, you can study by telling them what you learned. If your parents aren't available, you might try what Dr. Saundra McGuire suggests:  giving your mini-lecture to a stuffed toy.)


    2. Make the information
    attempts =

    Making simple diagrams or even almost illegible doodles of concepts can help your memory for course material (so don't be afraid to add doodles to your flashcards). Obviously, more elaborate visuals like cartoons, timelines, infographics, and  concept maps. (also called "mind maps"), can be even more helpful than doodles. Quotes to help you remember "picture power":

    To impress yourself by seeing your mind's amazing ability to remember images,

    Using visual images is key to almost all mnemonic devices: systematic memory aides.

     One kind of mnemonic device is the method of loci: a system in which you imagine putting the items you need to remember in certain places, and then you retrieve those items by imagining walking along a path in which you revisit those places.

    We discuss mnemonic devices in more depth here
    As you have seen, the more you think about the information (the more you recode it), 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, research on the levels of processing approach has made it clear that deeper processing of words--thinking about each word's meaning and its relevance to you-- leads to better memory for those words than shallow processing (e.g., noticing whether the words are in all capital letters, have two vowels, or rhyme 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 but that  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 this approach.

    LTM Retrieval: Getting information to LTM from STM


     Like real banks, it is easier to make deposits into our memory banks than it is to make withdrawals. 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 (retrieved).

    1. Tip-Of-the-Tongue (TOT) phenomena (as discussed earlier, words are not actually on the tip of your tongue--they are just one right retrieval cue away)
    2. Recognition is generally easier than recall (as discussed earlier, it is easier for you to recognize the names of the 7 dwarfs than it is for you to recall all 7).
    3. Savings scores: Relearning is faster than learning it. For example, suppose it took you 20 minutes to learn the 7 dwarfs the first time, but now you can't remember a single one. The good news is that it might take you only 5 minutes to learn them them all the second time-- a savings of  15 minutes (which, using the formula for savings scores as time saved/original time spent, results in a savings score of 75% --15/20 = 75%). Similarly, even if it seemed that you "forgot" everything you learned in a course, it would be much easier for you  to relearn that information than it had been to learn it the first time. Indeed, when taking advanced courses that have prerequisites, you will probably quickly relearn what you learned--but seemed to have totally forgotten--from the prerequisite courses. (So, to revise an old saying, "You can quickly re-teach an old dog old tricks.")

      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 recognizing!) information. Specifically, you should

    What causes retrieval failures?

    Not simply the passing of time (Despite recent attempts to revive decay theory, the idea that memories decay from LTM is pretty much dead).

    Evidence that retrieval failures are not due to time alone:

    1. Grandparents can have vivid and accurate memories for long ago events while having hazy and inaccurate memories for recent events.
    2. Hypermnesia: Under certain conditions, people can have better recall for information a week or longer after they learned the information than they had shortly after they learned the information. Usually, those "certain conditions" involve being repeatedly tested on the same information. In a typical study, a participant might be given a list of 24 words to remember. A few minutes later, when asked to recall the words, the participant may recall 18 of the words. A week later, participants return to the lab and are again asked to remember the words. On the first attempt, the participant may recall only 3 or 4 words. But, with more attempts, the participant will recall more words. Indeed, by the 6th time the participant tries to recall the words, the participant may recall all 24 words--even though the participant could only recall 18 words when tested right after being given the list! Hypermnesia is possible because some of the "forgotten" information doesn't go away; it is just hard to find. If you keep looking, you can find much of that "forgotten" information.
    So, on the one hand, time, by itself, doesn't cause retrieval failures.

    On the other hand, however,  retrieval failures are often linked to time as Ebbinghaus' forgetting curve illustrates (see the curve below).

    Ebbinghaus Forgetting Curve
    From Nheise at English Wikibooks through a GNU Free Documentation License 1.2 via Wikimedia Commons

    * If you just focused on the rapid drop during the first part of Ebbinghaus's 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 great comedy.

    After noting that the forgetting curve starts off as a sharply falling line, but then becomes a curve as forgetting levels off, try to answer the following three questions. Then, check your answers by clicking on the buttons below. 

    1. What bad news about memory does the forgetting curve reveal?

    2. Answer: You can forget a great deal of information in just an hour, and you can forget about 2/3 in less than a week. This is why you must continue to test yourself over the material even after you know it. So, you need to review your class notes regularly, and you can't assume that the information you knew for the quiz is information that you will remember for the final.

    3. What good news about memory does the forgetting curve reveal?
      Answer: After a week, for most practical purposes, you stop forgetting.

    4. Does the forgetting curve support or go against the idea that we should have year-round schools to prevent the forgetting that occurs over the long summer vacation?
      Answer: Since almost all forgetting occurs in the first week, it really doesn't matter whether summer break is 2 weeks or 12 weeks.

    But if time doesn't cause retrieval failures (as suggested by hypermnesia and people having good memories for long ago events), why are retrieval failures often linked to time--as you know from the forgetting curve and your own experience? To answer that question, let's first ask: "Why do retrieval failures happen at all?"

    3 possible reasons:

    1. Interference: getting sidetracked by bumping into similar, but wrong information. This skit from SNL dramatizes how information that is perceived as similar to what you want to remember can interfere with retrieval of the desired information. 
    2. Cue-related forgetting (lacking the right cues): not knowing where to look for the information (as you'll see, being without cues--being "cue less"-- may result in being clueless when it comes to recalling information).

    3. Repression (unconscious motivated forgetting): unconsciously not wanting to remember the information.

    We will now look at each of these possible explanations for retrieval failures in more depth.

    #1. Interference: If you just throw stuff into your memory like you would throw stuff into a garbage dump, you may not be able to find what you are looking for because other stuff  is in the way. 

    Really a problem when information is perceived as 
    Attempt number  

    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 1Learns
    List A
    List B
    Tested on
    List B
    Group 2Learns
    List B
    Tested on
    List B

    Results: Group 1 does worse than Group 2 because proactive interference from List A is hurting 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.

    Classic experimental set up for  demonstrating retroactive interference:

    Group 1Learns
    List A
    List B
    Tested on
    List A
    Group 2Learns
    List A
    Tested on
    List A

    Results: Group 1 does worse than Group 2 because retroactive interference from the recently learned List B is hurting 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? Can you remember your previous phone numbers, addresses, and passwords--or have the new ones blocked access to your old ones? Do Trump's latest scandals make it hard to remember the other ones?

    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 for forgetting--the serial position curve:

    Serial position
    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 at the beginning and end, but poor at 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 Millard Filmore), 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 both proactive interference from your first statement of the fact and retroactive interference from your 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 make for retrieving the information are like hooks that help you fish for information--and the more hooks, the more likely it is you will catch the information. So, much forgetting is due to not having the right cues

    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.


    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 "jump in the lake" study demonstrating context-dependent learning, click here; to see a 2-minute youTube video describing the 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. In terms of studying, realize that the more places you study certain material, the more places that might 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 mental state can be such a strong cue that it may seem like you only know certain things when you are in certain states, 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. 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.

    #3 Repression (unconsciously motivated forgetting).

    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 "Spellbound."

     Childhood amnesia (also called infantile amnesia): Poor episodic memory for childhood (especially before age 3).

    (This  movie  is much more interesting because it incorporates the idea of childhood amnesia)

    Although we do seem to remember positive events better than disappointments, there is little evidence that repression is common and, from what you have already learned about memory,  there are 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, you might ask yourself, "What did I do last Friday?", you almost certainly did not ask yourself that question when you were less than a year old.

    3. Encoding failure: You often did not rehearse information, and when you did, you probably did not use Type 2 (elaborative) rehearsal. As a result,  that information may never have gotten into LTM.

    (See additional possible explanations for childhood amnesia)

    Using what we now know to understand how you can improve your memory by using mnemonic devices (systematic memory aides).

    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.

    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 (unfortunately, however, interference can still be a problem. For example, if you are using a mnemonic system based on a certain set of cues, the cue you are using the 100th time you use that system will be associated with 99 other items).

    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 and then (2) retrieve the information by taking a mental walk in which you visit each place.

    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 connect with a number (e.g., "bun" for one, "shoe" for two), then (2) encode information by forming, for each new item, a picture that includes both the new tem and the relevant peg word (e.g., for your first new item, you would form an image of the new item interacting with your peg word for the number "1"),  and then (3) retrieve the information by going through your list of peg words in order. Look below to see an example of how you might go through the 3 steps to use a peg-word mnemonic.

    Step 1 Step 2 (Encoding) Step 3(Retrieval)
    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. ( some alphabetical lists of pegwords).

    Then, visualize them and memorize your list 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 your first item and (2) getting the two images to interact

    Go through the pegs 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 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.

    Why aren't mnemonics used more often?

    Two important similarities:

    1. Getting information in (encoding) requires effort and skill: You need to get information into the system--and that doesn't happen automatically.  Dropping books off at the library will not automatically get information into the library's collection. Instead, you will need to bring the book to the librarian's attention and convince the librarian that the book would be a meaningful addition to the library's collection (otherwise, it will be thrown out or sold at the library's book sale). Similarly, to get information into LTM, you have to pay attention to the information, and you will probably need to make the information meaningful or visual.
    2. Getting the right information out at the right time requires organization: Whether you are talking about a library or a memory, it is hard to find one particular item among many items unless the items are organized (i.e., the information is stored with a cue so that having the cue gets you to the information).

    Two important differences:

    1. Reconstruction: Memories, unlike books, may be rewritten every time we "look" at them because memories are reconstructions. The great Connie Hawkins recognized one effect of our tendency to revise memories when he said, "The older I get, the better I used to be."
      Watch a one-minute video about an experiment in which students were tricked into "remembering" seeing "Bugs Bunny" at Disney Land.

      The bad news about reconstruction: Because memory, rather than being like a video recorder, relies on reconstruction, memories that we are confident about can be very wrong. Examples:

      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. So, you can seem to memorize more by memorizing 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. (To condense your notes that far will probably not happen in one step: You will probably have to summarize your summaries. However, you can do it: 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.) Because of reconstruction, you should either not highlight (take notes instead) or be extremely selective in your highlighting (i.e., highlight no more than 3 words per page). Students who paint their books with their hi-liters are obviously not being selective and thus not taking advantage of reconstruction.

    2. Need for overlearning: Once a library book is in the right place and we know how to retrieve it, we can always retrieve it. However, even if we have retrieved information from LTM before, we may not be able to retrieve that material later. Thus, we must engage in overlearning: Studying after you already know it. Effective overlearning is mostly practicing retrieval.

    Why do we need to overlearn? We need to overlearn--which should be called "Super Reviewing" to defeat the forgetting curve. Put another way, since retrieval is the big problem in LTM, we need to practice retrieval. For students, this usually means taking practice tests and quizzing each other. (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.") In a sense, practicing retrieval is like mowing the path to the information. Ideally, you would practice retrieving what you had learned every day. At the very least, 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).

     How can you practice overlearning? One way is by writing out answers to essay questions based on course material. If you don't want to write out answers, you should say your answers aloud to a critical friend or to a recording device. Alternatively, you could outline answers or develop a rubric for grading the answers to such questions (if you have a study partner, you could use your rubric to grade your partner's answers). If sample essay questions aren't readily available from your text, your professor, your classmates, or online, you could create your own essay questions or you may be able to get them from the Psychology Problem Solver series.  Note that you can practice overlearning almost any time: You can recite answers to questions as you walk between classes or wait in line.

    7 Memory Myths That Hurt Your GPA

    (Myths that may explain the surprisingly weak relationship between time studied and exam scores)
    Myth Fact
    1. Repetition alone is an effective strategy for getting information into LTM. Repetition (Type 1 rehearsal, also called maintenance rehearsal) is especially ineffective for getting information into LTM when you are
    • Rereading.
    • Multi-tasking.
    • Not understanding what you are studying.
    • Not organizing what you are studying (e.g., not using tables, diagrams, sketches, or concept maps to organize information).
    • Not distinguishing similar concepts from each other.
    • Recopying your notes.
    • Re-typing your notes.
    • Repeating definitions word-for-word that you do not understand.
    • Listening to music, watching television, texting, facebooking, etc.
    • Not making up concrete examples of the concepts you are learning.
    2. Cramming is effective. Spreading out your studying is much more effective, especially for 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. The more mental effort you put into encoding a memory, the  more likely it is that you will be able to retrieve that memory.  In short, good memorizing involves thinking, not mindless coloring.
    4. It is wasteful to skim a chapter before reading it. You should figure out how the chapter is organized, what the main ideas are, and what you will learn before you read it. In previewing the chapter, you should go over the chapter outline (if there is one), read the introduction, look at the major headings, and read the chapter summary.
    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 suggests that testing yourself, if you answer yourself aloud or in writing, is about 6 times more effective than re-reading.)
    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."
    • Only memorize what you can't reconstruct: If asked to remember what will happen when you go to a restaurant, you would not spend time memorizing facts that you could reconstruct (e.g., that the restaurant had tables, chairs, and menus). Instead, you would focus on things you couldn't reconstruct. Similarly, if you were asked to memorize "2 4 6 8 10 12 14 16 18 20 22 24 26 28 30," you would just memorize a rule that would allow you to reconstruct the series ("even numbers between 2 and 30") rather than memorizing each number.
    • Using an analogy (e.g., thinking about long term memory as a library) can help you understand, encode, and retrieve information.
    • Creating an example of a concept that you can visualize (a mental youTube of the concept) will be more memorable and useful than memorizing the exact wording of an abstract definition. Indeed, a vivid, specific example is worth 1000 definitions.

    10 Additional Review/Explore/Apply Activities

    1. Match memories to their characteristics using this interactive table.
    2. Master this interactive outline.
    3. Take a fun memory test that will review key concepts and give you some studying tips.
    4. Look at the study tips page and see how that page's tips apply the memory principles you have learned --or see how to apply memory principles to remembering names and jokes.
    5. Have some fun at this site.
    6. Explore mnemonics at this site.
    7. Take this short memory quiz
    8. Read superlearner Scott Young's "The Complete Guide to Memory"
    9. Listen to "Memory Tips" podcast.
    10. Complete the study grid below.

    Study Grid: Long Term Memory
    Stage of processing Problems: What can go wrong?Example(s) of problemsHow can problems be prevented?







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