MEMORY AND LEARNING
Glenda Thorne, Ph.D.
What's the Matter With Martha's Memory?
Martha is a delightful child. She gets along well with her peers and has a great sense of humor. She really enjoys playing soccer and plays the game well. She would like to take piano lessons, but her schoolwork takes up so much time there is none left for lessons or the practice it would take to play well.
While Martha has never been a particularly strong student, she liked school until last year. Last year her grades began declining, and this year they are no better. It seems that no matter how much she studies for tests, she still performs poorly on them. She is beginning to study less and less, and her parents and teachers have told her that she is just not putting out enough effort. They don't seem to understand that regardless of how much effort or time she spends studying, Martha still receives poor test scores. The only reason she is passing some of her classes is because of her grades on homework and quizzes.
When Martha takes tests, she can't remember what she studied the night before. She can produce good ideas for creative writing, but she often forgets to use correct punctuation and capitalization when she writes. She has trouble remembering the steps in math problems even though she seems to understand the concepts. Martha also has a hard time remembering what she has just read and also the directions her teachers give orally in class.
Martha and her parents are very perplexed about her memory problems. They say that she is able to remember tiny details about things that happened when she was a very young child such as the color of the tie Uncle Joe wore last Thanksgiving. She is the family storyteller because she can always remember what happened during family vacations and during other family events.
Martha's parents and teachers don't seem to know how to help her. They tell her to do things such as rewriting her class notes and making cards with her vocabulary words and their definitions to use when she is studying for tests. She uses these strategies, but they are not helping her remember information when taking tests. On the other hand, when her teachers ask her questions in class about topics they have taught, it seems that she understands the concepts because she is able to respond correctly to many questions. Martha is becoming more and more upset by her poor test scores, and she is beginning to stop trying.
Why do you think Martha can remember family events but can't remember information when taking tests? Read further for the answer to this question.
WHY IS MEMORY IMPORTANT?
Try to imagine life without memories. We would have no identity. We would ask the same questions over and over because we would not be able to remember the answers to them. We would live forever in the present moment and have no recollection of our pasts, including people and experiences that are important to us, and no anticipation of the future.
In his book, Your Memory: A User's Guide, Alan Baddeley discusses the case of Clive Wearing who suffered brain damage caused from encephalitis, which led to memory loss. Clive has no long-term memory. He is only able to remember what happened just minutes ago. Therefore, Clive thinks he has just recovered consciousness over and over again. When he is presented with evidence to the contrary, he becomes upset and denies its existence.
Clive has lived in what Baddeley calls a "permanent present" since 1985. He is unable to register change or to use past events to predict future ones. He does not derive pleasure from reading books because he cannot remember the plot. He is not interested in current events because he cannot remember the context in which they occurred. He becomes lost if he leaves home.
While memory is crucial for all of us, there is no time during which memory demands are greater than the school years. The school environment, however, is not often a "memory-friendly" one. Children are presented with new information all throughout the school day and given little opportunity to consolidate new information before more new information is presented to them.
What children remember is more often than not used as the yardstick to judge what they have learned. If they perform poorly on a test because they can't retrieve what they know from long-term memory in order to answer test questions, the assumption usually is that learning has not taken place.
Just as the relationship between remembering and learning exists, there is also a relationship between remembering and understanding. If we understand something, we are often able to remember it better. Understanding enables us to know where to store the information in long-term memory (e.g., what category to place it in), and effective storage is more likely to lead to effective retrieval. Also, if we are able to retrieve previously learned information from long-term memory when we are presented with new to-be-learned information, we can make associations between the two and, therefore understand the new information better. In this way, memory facilitates understanding. If we think of the long-term memory in our brains as a network of connections, then what we are doing is making new connections between what we already know and what we are trying to learn. The denser and more complex this network is, the easier it is to store and retrieve information.
Many school children perform poorly because they do not understand the difference between understanding and remembering. They often think if they understand something, they will remember it. Think about a joke someone recently told you. It is likely that you laughed when you heard the joke because you understood it; but did you remember it? Could you retell it to someone else? For me, the answer would be an emphatic, "No!" I never remember jokes because I process them at a very superficial level with no intent to store them in my long-term memory.
School children often think that if they understand what their teachers say about some topic or if they understand what they read in their textbooks, they will remember the information. Therefore, they don't think they need to study much for a test because they understood their teacher's discussion or the chapter in their textbook. This failure to recognize the difference between understanding and remembering frequently leads to the demise of many students. The students become frustrated and don't know what to do to improve poor test grades. Most of the students that I see clinically tell me that their major study strategy consists of reading over their notes and/or handouts prior to a test. Some tell me that they don't even do that because they "understood" the information when it was covered in class. Therefore, a prerequisite to making good grades for some students would be to know that understanding the subject matter is not enough; they must also actively engage in activities that will lead to the storage and ultimate retrieval of relevant information from long-term memory.
The following discussion will address memory processes and systems, use of mnemonics in education, metamemory, memory problems of school-age children and general principles for enhancing memory and learning.
WHAT IS MEMORY?
During the 1960's, a number of models that attempted to explain the workings and interactions of memory processes and systems were proposed by experts in the field. One model proposed by Atkinson and Shiffrin (1968) has been nicknamed the "Modal Memory Model" because it was typical of others and was probably one of the most influential (Baddeley, 1998).
The model of memory that will be presented in this article is representative of current models; however, the focus of the discussion will be how memory processes and systems relate to performance in the educational arena. The latter is derived from the author's clinical experience in assessing and working with children who have varying profiles of memory strengths and weaknesses, as well as working with parents and teachers of children who have problems in school.
Memory is generally defined as the processes of encoding, storing and retrieving information. These three processes interact with different memory systems. The memory systems that appear to be most important in the educational area are short-term memory, working memory and long-term memory. Memory is thought to begin with the encoding or converting of information into a form that can be stored by the brain. This encoding process is also referred to as registering information in memory. The memory systems that are involved in the encoding or registration of information in memory are sensory memory and short-term memory.
Information which first comes to us through our senses is stored for a very short period of time within the sensory register. Simply put, the sensory register is associated with our five senses – seeing (visual), hearing (auditory), doing (kinesthetic), feeling (tactile) and smelling (olfactory). However, the sensory buffers that have received the most attention in the research literature are the visual and auditory sensory registers.
Generally information remains in our visual memory for a very short time, approximately several hundred milliseconds. This information or "image" is somewhat like an exact replica of what we have just seen, and it fades with the passage of time (Pashler and Carrier, 1996).
Our auditory sensory register typically holds information for one or two seconds. The subjective experience of auditory sensory register is different than that of our visual sensory register. It does not seem to be experienced as a fading "image", but seems to remain intact for a brief period of time.
Most of the information that enters into our sensory registers is not processed further. The information that will be processed further is that which we pay attention to; thus attention is thought to regulate the flow of information from the sensory registers to short-term memory (Gaddes & Edgell, 1994).
Information in short-term memory can be held there indefinitely as long as it is rehearsed, and the typical cause for its loss is that it is displacement by the presence of other, new information that has been attended to (Pashler & Carrier, 1996). Generally, however, short-term memory is considered to be a temporary resting place and information is held there for approximately 30 seconds to two minutes.
The amount of information that can be held in short-term memory is relatively small. Short-term memory generally holds seven plus or minus two "chunks" of unrelated information. This is the number of digits in most telephone numbers. In order to hold more than seven plus or minus two single numbers, the numbers must be chunked. That is, they must be grouped together so that several single numbers are organized into one "conceptual" chunk. For example, the single numbers eight, nine and three could be chunked into one number, 893. Thus, if we were presented with a series of numbers to remember, we could likely recall more if we "chunked" them into groups of twos or threes. In order to keep information in short-term memory, we must continue to actively process it.
There are at least two separate subsystems of short-term memory and some research suggests there may be several more (Pashler & Carrier, 1996). The two subsystems that have been studied the most, and therefore there is clear evidence for are the visual and verbal or auditory short-term memory systems (Baddeley, 1996; Vallar & Papagno, 1995). Visual memory is memory for what we see and verbal or auditory memory is memory of what we hear.
School places many demands on the short-term memory systems, especially short-term verbal or auditory memory. Children must remember instructions given to them by their teachers, what they just heard during class lectures, discussions and conversations and what they just read in their textbooks and on the board or overhead. All of this information first enters short-term memory and must then be transferred to long-term memory.
According to some experts in the area of memory (e.g., Baddeley, 1996, 1998; Vallar & Papagno, 1995), just as there are two subsystems of short-term memory, visual and verbal, there are two subsystems of working memory: (1) verbal working and (2) visual working memory. In addition, working memory contains a main controller or central executive that interprets information we have just been presented with and integrates this information with that which we have already stored in long-term memory (Baddeley, 1996). It is helpful to think of working memory as remembering what we are doing while doing it.
Working memory is required for a multitude of tasks in school and in life. For example, in order to understand material read, we must remember what was at the beginning of the paragraph by the time we get to the end of the paragraph. Students taking notes during a lecture must remember what their teachers have just said and are saying while they are writing. We must remember directions while carrying them out, especially those with multiple steps. When students look up a word in the dictionary, they must remember the word while looking for the definition. They must remember the question in the back of their social studies chapter while searching the chapter for the answer to the question.
During class discussions on certain topics, students must remember what is being said while retrieving information about the topic from long-term memory. While writing the answer to an essay question on a test, they must remember the question in order to give the most important information rather than information that is only tangentially related to the topic. Working memory is also needed for many higher order thinking tasks such as analysis and synthesis and problem solving. During problem solving, we must remember the problem, generate multiple potential solutions and make decisions about which of these solutions is likely to produce the desired outcome. Research has shown that performance on higher level cognitive tasks such as problem solving, reasoning and reading is more accurately predicted by performance on working memory tasks than by performance on short-term memory tasks (e.g., Kail & Hall, 2001).
The list for working memory demands goes on and on. Most of us have encountered people we thought were rude because they were always interrupting someone during conversations. However, rather than intending to be rude, it may be that some of these folks had poor working memories – they were afraid they would forget what they wanted to say, so when the thought came, they felt the need to quickly express it.
Long-term Memory Storage
Just as the sensory and short-term memory systems are associated with the process of encoding or registering information in memory, the long-term memory system is associated with the processes of storage and retrieval of information from memory. Long-term memory storage is considered to be relatively permanent. The loss of information from long-term memory is referred to as forgetting. During the l950's, a good deal of research focused on the issue of whether we forget information simply because time has passed or whether forgetting occurs because what we are learning at the present time interferes with our ability to remember information we learned at an earlier point in time (Baddeley, 1996).
During the normal school day, students are presented with new information, or at least, partially new information, approximately every 45 to 60 minutes. A child may have a 45-minute math lesson during which the process for adding fractions with is introduced. Then, before this information has had time to consolidate in long-term memory, the student moves on to science where the process of photosynthesis is introduced. This situation produces fertile ground for "forgetting".
The phenomena of interference in long-term memory storage provides good rationale for what is commonly referred to as "block scheduling". With block scheduling, students have approximately 4 classes of 90 minutes each. If teachers use the 90 minutes wisely (i.e., they do not simply lecture for 90 minutes instead of 45 minutes), they can provide students with opportunities to engage in activities that will actually enhance the consolidation of the new to-be-learned information in long-term memory. Reduction of interference also provides rationale for curricula that crosses different disciplines. For example, students studying the Roman Empire in social studies would also study artists of the Roman Empire in art class and the advanced scientific inventions of the Romans in science class.
Long-term Memory Subsystems.
Just as it was once thought that short-term memory was one system, long-term memory was also considered to be a single system. However, we now know that long-term memory is comprised of a number of interrelated subsystems.
Episodic memory is the memory subsystem that stores information about the "episodes" or events in our lives - remembering what we did during last summer's vacation, who our favorite teacher in school was, or who was at Aunt Martha and Uncle Harry's anniversary celebration. Impairments in episodic memory is the basis of classic amnesia (Baddeley, 1996).
Semantic memory is the memory subsystem that stores memory of knowledge and concepts. Formal education can be thought of as filling up our semantic memory "store". Facts such as the rules for capitalization and punctuation, what year Columbus discovered America and who Susan B. Anthony was are examples of the kinds of information that are stored in the semantic memory system. The task demands for semantic memory in the school setting are unceasing.
Individual differences exist in the effectiveness of both the episodic and semantic memory systems (Bors & McLeod, 1996). For example, my husband and I differ greatly in our ability to store and thus retrieve information in these two memory subsystems. We frequently travel and he is able to remember in vivid detail the places we go and what we do and see. I, on the other hand, rely on pictures for my memory storage bank. In fact, I usually own the job of putting our vacation photographs in albums and I sometimes have to ask him where we were when certain pictures were taken. We were once taking a Saturday afternoon drive in Mississippi and he asked me if I remembered going to a certain restaurant. I had absolutely no recollection of this experience – none – and he could even remember what we had to eat. My husband's semantic memory for some things, however, is just as unreliable as my episodic memory. For example, he asks me our sons' telephone numbers over and over and over again.
Many children who struggle in school have relative weaknesses with their long-term semantic memory system. The parents of many children I work with tell me that one of their child's strengths is his/her good memory. These same parents also often tell me that their child has difficulty remembering what he has just read or what his homework assignment is. When I ask them for examples of their child's "good" memory, they almost always tell me that their child can remember some event that took place years ago or what they did when they went to grandma's house two summers ago. Thus, these children often have quite good episodic memories, but unreliable semantic memories.
Individual differences in semantic and episodic memory provide good rationale for the need for teachers to use multiple, varied learning activities in the classroom, such as projects, group work and field trips. These provide an "episodic" or experiential context within which to place semantic information.
Procedural memory is the memory subsystem that stores the learning of skills, both perceptual-motor and cognitive. Perceptual-motor skills are those such as driving a car, bike-riding and swinging a golf club. Cognitive procedural learning involves skills such as reading and problem solving. While semantic learning can be thought of as storing knowledge of "what", procedural learning can be thought as storing knowledge about "how" (Baddely, 1996).
Squire (1992) also proposed another subsystem of nondeclarative memory called priming. Priming refers to the phenomenon that once an object has been perceived or processed, it can be more easily perceived or processed the next time it is encountered (Baddeley, 1996).
Priming has relevance in the educational environment, particularly with regard to the use of advance organizers prior to the presentation of new to-be-learned information. Advance organizers might include reviewing the vocabulary prior to reading a chapter or book, reading the objectives at the beginning of chapters and/or the questions at the end of chapters prior to reading the chapters and discussing the to-be-learned material prior to having students read about it.
In summary, long-term memory consists of two systems – declarative and nondeclarative. Declarative memory can be further delineated into the episodic and semantic systems. The nondeclarative system includes procedural learning and priming. The characteristics and functions of each specific memory system have important implications for learning and the educational setting.
Imagery and Visual-Spatial Representations in Memory
The evidence that forming mental images can enhance performance on a variety of memory and learning tasks is abundant. In fact, we know that good readers make mental images or "running movies" in their heads as they read to facilitate comprehension. Much of our memory of events, situations and people from our past occurs through visual-spatial representations. For example, if you think of the birthday on which you were given your favorite-of-all-time bike, you likely recall the visual image of your bike, remembering its color and other features. You might also have a mental picture of how excited you were when your parents rolled the bike into the living room to make a grand presentation to you.
Long-term Memory Retrieval
Retrieval refers to the phenomenon of accessing information that has been stored in memory. How well information is encoded and stored in memory determines how likely it is to be accessed or retrieved. In addition, information and events that are stored with the new information, often referred to as cues, affect the ease with which information can be retrieved (Roediger and Guynn, 1996). Currently, many psychologists believe that retrieval processes are crucial in determining how well information can be remembered or recalled (Roediger and Guynn, 1996).
Retrieval practice for students can be conducted in several ways. One way that is commonly used by teachers is reviewing information prior to testing. But review should not only consist of the teachers' summaries of the information covered; it should also require students to answer review questions asked by teachers, thus "retrieving" the information from long-term memory. Another way in which students may engage in retrieval practice is to make up their own tests, and then answer the questions on their self-made test. A third way to engage students in retrieval practice is to have them ask questions to each other when studying together or to have a parent, family member or tutor ask them questions about the to-be-learned information.
Other memory research has shown that information is more likely to be retrieved from long-term memory if it is stored with a retrieval cue and this cue is used at the time the information is recalled (e.g., Roediger and Guynn, 1996). For example, one study provided subjects with category labels such as "articles of clothing" and "types of birds". The words in the "articles of clothing" category might be "blouse" and "sweater". The words in the "types of birds" category might be "crow" and "parakeet". After the category labels and words were presented, one group of subjects was simply given a blank sheet of paper and asked to write as many words as they could remember. The other group of subjects was given the 24 category names and asked to write as many words as they could remember. Subjects in the first group recalled an average of 19.3 words while subjects in the second group recalled an average of 35.9 words (Tulving and Pearlstone cited in Roediger and Guynn, 1996). This study highlights the distinction between long-term memory storage and retrieval. When the conditions under which storage took place were the same, retrieval cues almost doubled the number of words subjects could recall.
An implication of the cued retrieval for educators is that new information should be presented with many cues so that its retrieval is enhanced. These cues can take the form of many of the activities that have been previously discussed, such as activating prior relevant knowledge, placing information within conceptual categories, making information personally relevant, and/or presenting information within an experiential context. Thus, not only are these important activities for encoding and storage, they are also crucial for optimal retrieval of the learned information.
According to Baddeley (1996), recognition usually leads to more accurate retrieval of information than recall does. This is because the word or information that has been learned actually serves as a cue, facilitating or enhancing access to its memory trace. For example, if a student is presented with the question, "What is the region of the brain that controls vision", this is a recall task. If a word bank is provided and the student reads the words "occipital lobes" from the list, these words serve as a retrieval cue and are likely to facilitate access to the memory trace that contains the information, "the region of the brain that controls vision is the occipital lobes". Thus, the difference between performance on recognition and recall tasks may be used to help determine whether a particular instance of memory failure is likely due to a breakdown in storage or to a breakdown in the ability to retrieve the information because retrieval deficits are often diminished with recognition testing (Baddeley, 1996).
An important phenomenon for educators to understand when using retrieval cues is that the likelihood of recalling items associated with any specific category (i.e., cue) is reduced as the number of items in that category is increased. Additionally, research has shown that in order for retrieval cues to be effective in facilitating the recall of information, they must have been present when the learning took place.
The Use of Mnemonics in Education
With the increasing focus on higher order thinking in education, the word "memorization" has become somewhat distasteful. Memorization, however, is necessary in the early stages of learning. For example, it is commonly understood that students need to memorize their multiplication facts and spelling and punctuation rules. Additionally, if students are to engage in thinking about the implications of war for civilization, they must first know something about specific wars, such as why they were fought and what the short- and long-term consequences were.
Mnemonic learning might serve as a useful way of getting information into long-term memory. When mnemonics are used during encoding of information, they may provide visual imagery or verbal elaborations that act as cues for recalling information that is low in imagery or in meaningfulness. Visual imagery mnemonics can be ones that learners generate themselves when instructed to form mental pictures to make the material presented to them more memorable, or they can be actual pictures they have been provided with to enable them to form images from what they actually see rather than from what they imagine (Belleza, 1996).
There are several ways in which mnemonic methods can be used in the classroom. First, school children can be taught to generate their own mnemonic devices that they can spontaneously use to help them remember information presented in their classes. Second, mnemonic methods can be induced by instructing children to use a mnemonic strategy to remember a specific set of information prior to its presentation. Third, the teacher can impose mnemonic elaboration upon the student by visually presenting an elaboration (e.g., a picture or drawing) that will both encode the information and organize it in memory.
Metamemory refers to knowledge about how one's own memory processes work. It is important for school children to identify and understand their own memory profiles – their memory strengths and weaknesses. Metamemory can be thought of as a component of metacognition or knowing about knowing. Students need to be taught the difference between understanding information and remembering it. They need to know general information about memory such as that encoding activities affect subsequent storage and retrieval of information, that retrieval practice is as important as encoding practice and that elaborative rehearsal is more effective than maintenance rehearsal. They also need to know specific information about their own memory profile such as that their episodic memory system may be better than their semantic memory system or vice versa and that their visual memory may be better than their auditory memory or vice versa.
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Glenda Thorne is a psychologist and vice-president of Services at the Center for Development and Learning (CDL). Her email address is firstname.lastname@example.org.