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Taking In and Storing Information
Processes and Stages of Memory
-Memory is the input, storage, and retrieval of what has been learned or experienced. To recall information, your brain must first encode and store it.
-The first memory process is encoding , transforming of information so that the nervous system can process it.
You use your senses to encode memories.
--You use acoustic codes when you try to remember something by saying it out loud or to yourself. When you attempt to keep a mental picture of the letters, you use visual codes . You use semantic codes to remember the letters by making sense of them; remember the word rather than the individual letters.
-After information is encoded, it goes through the second memory process, storage , the process by which information is maintained over a period of time.
--How much information is stored depends on how much effort was put into encoding the information and its importance. Information can be stored for a few seconds or for much longer.
-The third memory process, retrieval , obtaining information that has been stored in memory. The ease with which information can be retrieved depends on how efficiently it was encoded and stored, and on other factors, such as genetic background and our past experiences.
-Once the senses encode a memory in the brain, the brain holds on to the input and stores it for future reference.
There are three stages of memory each with a different function and time span:
1. In sensory memory , the senses of sight, hearing, and touch are able to hold an input for a fraction of a second before it disappears.
--In 1960, researcher George Sperling used a tachistoscope, a device that presents a picture for a very brief time, to present a group of letters and numbers to people for a twentieth of a second. Sperling believed the stimulus created a visual image of the letters and that only a few could be read back before the image faded.
Psychologists refer to this visual sensory memory as iconic memory .
--Sperling told the participants that after he flashed the letters on the tachistoscope screen, he would present a tone. Upon hearing a high tone, the participants were to tell him the top row. Upon hearing a medium tone, they were to tell him the middle row. Finally, with a low tone they were to tell him the bottom row.
Participants found they were able to remember a great deal. They could recall about 75 percent of any one row if asked to do so immediately.
--Sperling proved the participant retains a brief image of the whole picture so that he or she can still read off the items in the correct row after the picture has left the screen. Psychologists refer to auditory sensory memory as echoic memory , a type of sensory memory that holds auditory information for 1 or 2 seconds.
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Sensory memory serves three functions: it prevents you from being overwhelmed; gives you some time to make a decision; and allows for continuity and stability in your world. Iconic memory makes images in your world smooth and continuous, whereas echoic memory lets you play back auditory information, giving you time to recognize sounds as words.
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The information held momentarily by the senses has not yet been narrowed down or analyzed. It is shortlived, temporary, and fragile. By the time information gets to the next stage—short-term memory—it has been analyzed, identified, and simplified so that it can be stored and handled for a longer time.
2. Things in your conscious mind at any one moment are held in short-term memory , information is limited in capacity to about seven items and in duration by the subject’s active rehearsal. It does not necessarily involve paying close attention.
-Maintenance rehearsal is used to keep information in short-term memory for more than a few seconds by repeating the information to yourself over and over again without attempting to find meaning to it.
Psychologists have measured short-term memory by seeing how long a participant can retain a piece of information without rehearsal and found that short-term memory lasts less than 20 seconds without rehearsal.
--Short-term memory is limited also in its capacity. It can hold only about seven unrelated items at one time.
The same limit is there if the unrelated items are a random set of words. When all items are grouped together as one item to make them easier to remember, this process is called chunking . One of the tricks of memorizing a lot of information quickly is to chunk together the items as fast as they come in. If we connect items in groups, we have fewer to remember. We use chunking to remember visual as well as verbal inputs.
We remember shape and appearance as much or easier than we remember the actual pieces of information.

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--Information is available, generally, for less than 20 seconds and no more than 30 seconds, assuming no rehearsal occurred. Afterwards it is stored in long-term memory or is lost. Short-term memory contains information of possible interest. Information worth holding on to must be rehearsed with the intent to learn in order to transfer it to long-term memory. Rehearsal without intent to learn yields no transfer/memory.
--The Primacy-Recency Effect refers to the fact that we are better able to recall information presented at the beginning and end of a list. You most likely remember the first few items in a list because you had more time to rehearse them, the primacy effect . You may recall the last four or five items in the same list because they were still accessible in short-term memory, the recency effect . Middle items in the list may be forgotten since your attention is split between trying to remember previous items and trying to rehearse new ones.
-Working Memory is essential for thinking and problem solving. It includes two components: short-term memory and executive attention. The short-term memory component consists of the limited information that humans can keep in mind at one time. The executive attention component is a regulatory process determining the type and amount of information that short-term memory can access. When working memory is no longer needed, that information is erased or replaced by more pertinent information.
3. Long-Term Memory refers to storage of information over extended periods of time. Information is stored by categories or features. You reconstruct what you must recall when you need it. The capacity of long-term memory appears to be limitless; it contains representations of countless facts, experiences, and sensations.
--Long-term memory involves all the processes previously described. The least important information is dropped and only the essentials are retained. Other, more recently stored items block your access to earlier memories, or may even replace them. Although it has become less accessible, the different elements of the information are still stored in long-term memory.
-Canadian psychologist, Endel Tulving, proposed that we have two types of memory. The first, semantic memory , is our knowledge of language, including its rules, words, and meanings. The second, episodic memory , is our memory of our own life, such as when you woke up this morning. Stored here are personal things where time of occurrence is important. Everyone’s episodic memory is unique. Tulving was merely giving names to types of memory that had already been recognized by others:
-L.R. Squire has proposed a related model of memory. Declarative memory involves both episodic and semantic memory; information you call forth consciously and use as you need it. Procedural memory does not require conscious recollection to have past learning or experiences impact our performance; skills learned as we mature, habits and things learned through classical conditioning, etc.
Memory and the Brain
-Over the years, philosophers and psychologists have used many different metaphors to help explain how memory works. Most of these assumed that memories are stored in specific locations in the brain. The metaphors changed as technology changed.
--Aristotle compared storage locations to a wax tablet, John Locke compared them to a cabinet. In the 1950s, memory was compared to a telephone exchange system, and today it is often compared to a computer. Models of memory focused on a dual-storage system, with both short-term storage and long-term storage.
-Modern studies of memory began in 1885, when German psychologist Hermann Ebbinghaus published a paper entitled Memory. Using himself as the subject, he gathered experimental data for over a year and then duplicated the entire procedure during another year before publishing.
--He came up with the idea of using 2,300 nonsense syllables (consonant-vowel-consonant combinations) to measure the amount of material that could be retained. He developed methods of controlling the degree of learning and measuring the amount of retention. He used mathematics to calculate statistical significance of his findings. His innovations in methodology and his findings on memory have stood the test of time.
--Ebbinghaus was the first to discover the shape of the learning curve ; the length of time it takes to memorize nonsense syllables increases sharply as the number of syllables increases. Distributing learning over time is more effective than trying to “cram” information in a single session. Continuing to practice material even after it has been learned has the effect of improving retention.
-Five years later, American philosopher and psychologist William James published The Principles of
Psychology , which is considered to be the first important complete psychology text. James believed memory was essential to survival, but that there was no need to retain every bit of information, which would overload

NOTES_Memory and Thought the brain with useless information. He divided all memory into two types, which he called primary and secondary memory, or “memory proper.”
--According to James, primary memory is short-lived. It allows us to experience consciousness and handle immediate concerns, such as problem solving. Secondary memory is used to manage the relatively permanent information stored in the brain. In the 1950s and 1960s, primary memory came to be known as short-term memory, and secondary memory as long-term memory.
-There is growing evidence that physiological changes occur in the brain when information is stored in long term memory, but psychologists are only beginning to identify how and where memories are stored.
-Some psychologists theorize a change in the neuronal structure of nerves occurs. Others contend that learning is based on molecular or chemical changes in the brain. The evidence is more and more clear that both sides are correct. What changes occur depend on the level at which you are examining the changes learning creates.
-Different areas of the brain are responsible for different kinds of memories. There is growing evidence that formation of procedural memories involves activity in an area of the brain called the striatum , deep in the front part of our cortex. Declarative memories result from activity in the hippocampus and the amygdala.
-It is not clear yet how individual nerve cells, neurons, establish connections with one another when learning occurs. A very complex chemical process precedes the formation of new connections between neurons. Some researchers say increases in calcium and others say decreased potassium flow are involved. Processes as diverse as increased protein synthesis, heightened levels of glucose, and other biochemical processes are involved.
Exactly how it all fits together remains an active area of research.
-As people age, their ability to retrieve memories changes, in large part due to physiological changes in the brain. A younger person’s frontal lobes are adept at focusing on important information and screening out less important events. An older person may find it more difficult to multi-task as the lobes are not as agile, finding it more difficult to discriminate between environmental stimuli and admit only those that are important.
-Over the years, there have been various theories concerning where in the brain memories are located or stored.
Since the 1920s, scientists have looked for a chemical code that produces an actual physical change, or memory trace , in the nervous system. The hypothetical means by which memory traces are stored the engram .
--American psychologist Karl S. Lashley spent three decades searching for the engram. He conducted experiments in which he removed tissue from the cortex of rats’ brains in an attempt to locate the physiological seat of memory. Rats were trained to run a maze. Their ability to remember what they had been trained to do was observed and measured after tissue had been removed from different locations on the cortex.
While the amount of tissue removed affected rats’ memories, the location from which it was removed did not appear to have any effect.
--Lashley concluded that memories are not stored in a specific location but distributed throughout the cortex.
His failure to find the engram may have been a result of his choice of memory task or his choice of the brain region to study. His work demolished previous theories on brain function and learning, including a theory that the brain functioned like a type of switchboard.
-Other experimental psychologists have posited that the engram may be located in the cerebellum or the hippocampus, or even in our RNA. Various experiments have been conducted on a number of animal species, but the search for the engram continues. Its existence remains hypothetical.
Retrieving Information
Recognition, Recall, and Relearning
-The brain has a tremendous capacity for storing and retrieving information. The problem of memory is to store many thousands of items in such a way that you can find the particular item you need when you need it.
-The solution to memory retrieval is organization. Psychologists do not yet know how it is organized, but they are studying the processes of retrieval for clues.
-Human memory is organized to make recognition easy; people can say with great accuracy whether something is familiar to them. This suggests much more information is stored in memory than one might think.
Step 1: Recognition provides insight into how information is stored in memory. A single item of information may be indexed under several headings so that it can be reached in many ways.

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Step 2: Recall is the active reconstruction of information. Each word and bit of information must be retrieved separately from memory. It involves a person’s knowledge, attitudes, and expectations. Remembering is an active process guided by experience, knowledge, and cues we receive from the environment.
--Recall is influenced by reconstructive processes and may be altered or distorted, depending on our experiences, attitudes, and inferences from other information. o One type of mistake is called confabulation
, when a person “remembers” information never stored in memory. We fill in the gaps by making up what is missing and we may be wrong without realizing it. o Occasionally our memories are reconstructed in terms of our schemas , conceptual frameworks we use to make sense of the world. They are sets of expectations about something based on our past experiences.
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Elizabeth Loftus and J.C. Palmer conducted a classic study on the roles schemas play in memory reconstruction. Participants in this study watched a film of a two-car accident then were asked to fill out a questionnaire about the accident. One of the questions had four different versions using the words:
“contacted,” “hit,” “bumped,” and “smashed.” Participants each recalled a different speed rating according to the word. The schemas people used—whether the cars contacted, hit, bumped, or smashed—affected the way they reconstructed the crash. o Flashbulb memory is memory usually involving shocking or emotional events and requires special kinds of encoding when events are extreme and/or personal. The details of people’s flashbulb memories are not always accurate, although people generally perceive them as accurate. o Eidetic memory is the ability to remember with great accuracy visual information on the basis of short term exposure. o Photographic memory involves the ability to form sharp visual images after examining a picture or page for a short time and then recalling the entire image later. o State-dependent learning occurs when you recall information easily because you are in the same physiological or emotional state or setting as you were when you originally encoded the information.
--Memory of an event can be distorted in the process of remembering it. Shocking events can disrupt our ability to form a strong memory. Without a strong, clear memory of the event, you are more likely to incorporate after-the-fact information into the recall.
Step 3: Relearning is a measure of both declarative and procedural memory. If you can relearn information with fewer recitations than someone with ability similar to yours, you are benefiting from your earlier learning.
--Psychologists measure relearning in terms of savings. If it takes ten attempts before something is remembered completely, but after five relearning trials only takes five attempts, then five trials have been saved. Relearning previously acquired knowledge can thus enhance future learning.
Forgetting
-Everyone experiences a failure of memory from time to time. When information once entered long-term memory is unable to be retrieved, it is said to be forgotten. Forgetting may involve interference, repression or decay , fading away of memory over time.
--Items quickly decay in sensory storage and short-term memory. It is not certain whether long-term memories ever decay. A head injury or electrical stimulation of certain brain parts can cause memory loss. The memories lost are the most recent ones; older memories seem to remain. Interference or repression causes people to lose track of memories but meditation, hypnosis, or brain stimulation suggests that it can be retrieved.
Interference is blocked or erased memory by previous or subsequent memories. This blocking is of two kinds: proactive and retroactive. In proactive interference an earlier memory blocks you from remembering later information. In retroactive interference a later memory or new information blocks you from remembering information learned earlier. Both types are separate concepts.
--Interference erases some memories permanently and in other cases the old data has not been lost. The information is in your memory somewhere for you to retrieve it.
According to Sigmund Freud, a person may subconsciously block memories of an embarrassing or frightening experience, called repression . The material still exists in the person’s memory, but it has made inaccessible because it is so disturbing.
-Some also forget information due to amnesia , a loss of memory after a head injury, brain damage, result of drug use, or severe psychological stress. Infant amnesia is the relative lack of memories from early in life. Most memories from early childhood seem to fade away.

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--Psychologists have proposed several theories to explain infant amnesia. Freud thought that infant memories are repressed because of the emotional traumas of infancy. Others believe that infants do not yet understand language so their memories are nonverbal, whereas later memories are verbal once language is learned. Others claim that the hippocampus may not be mature enough in infancy to spark memories or that infants have not yet developed a sense of self to experience memories.
Improving Memory
-Scientists have identified three phases in the “life” of long-term memory: acquisition, storage, and retrieval.
Information must first be acquired , or learned. Once you have acquired a piece of new information, your brain must process it and place it in storage . It must be possible to retrieve that memory later to have any value.
-Techniques for improving your memory are based on the efficient organization of the things you learn and on chunking information into easily handled packages, or chunks.
-Using repetition, or maintenance rehearsal, can help you remember for a short period of time. Words are merely repeated with no attempt to find meaning.
-A more efficient way of remembering new information involves elaborative rehearsal. You relate the new information to what you already know. The more meaningful something is, the easier it will be to remember.
-You remember things more vividly if you associate them with things already stored in memory or with a strong emotional experience. The more categories a memory is indexed under, the more accessible it is.
--If an input is analyzed and indexed under many categories, each association can serve as a trigger for the memory. If you associate the new information with strong sensory experiences and a variety of other memories, any of these stimuli can trigger the memory. The more senses and experiences you use when trying to memorize something, the more likely it is that you will be able to retrieve it—a key to improving memory.
-A good way to protect a memory from interference is to overlearn it, keep rehearsing it even after you think you know it well. Another way to prevent interference while learning new material is to avoid studying similar material together.
-Your memory will also improve by spacing out your learning. Study a few times over a long period of time rather than trying to absorb large amounts of information at one sitting. Distributed practice, or spreading out learning over time, results in stronger memories that are easier to retrieve, the spacing effect .
-How you originally learn or remember something influences how readily you recall that information later. If a bit of information is associated with a highly emotional event or if you learned this bit of information in the absence of interference, you will more easily recall that information because of the strength of that memory.
-Techniques for using associations to memorize information are called mnemonic devices . The ancient Greeks memorized speeches by mentally walking around their homes or neighborhoods and associating each line of a speech with a different spot, the Method of Loci . Once they made the associations, they could recall the speech by mentally retracing their steps and picking up each line.
-Another useful mnemonic device is to form mental pictures. Mnemonic devices are not magical. They involve extra work; making up words, stories, and so on. The effort of trying to do this may help you remember things.
Memory aids , or little things people do to help improve their ability to remember things, have probably existed since the beginning of time. Tying a string around your finger and writing notes on your hand are simple and have a limited ways of aiding stimulus recall.
-Organize large blocks of information in a way meaningful for you. We can usually remember only five to nine items at a time, try to organize the information you need to remember into groups of no more than seven items.
When grouping information, make it have personal meaning for you and try to put the information in sequence
(alphabetical, chronological, etc.). See if you can come up with a mnemonic device to remember information.
-Capture the essence of a lecture by creating a summary of its contents. Brief but complete note taking should summarize the key points, new vocabulary, and any diagrams or tables not included or modified in your text.
--Go over your notes as soon as possible after class and fill in additional facts and examples. If you have trouble understanding anything that was said, clarify it with a classmate or your teacher. It is crucial that you take your own notes during lecture since copying notes from a friend limits the effectiveness of those notes.

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-Review your notes within one or two days helps you cut down on the amount of information you have to relearn before a quiz/test. When you review, your notes help you find what is most important in your textbook.
--Summarizing your notes in your own words can help you better understand and remember. Practicing and rehearsing things after learning them is called overlearning, which helps with mastery.
-There are a number of drugs designed to enhance memory but there’s really no demonstrated effective replacement for regular meals, proper drinks, and a reasonable amount of rest. There is very little evidence that pills targeted at improving learning and memory will replace the effort such effects require.
--Ginkgo biloba has been used for thousands of years as a medicinal herb. There is evidence that it may enhance memory in healthy people.
--Vitamin B12 is essential in maintaining healthy nerve cells. That the vitamin is found in animal products, such as fish, meat, eggs, and milk, means that strict vegetarians may develop a B12 deficiency, which has been found to cause memory loss. There is no evidence that taking a vitamin supplement enhances memory in people who get enough B12 in their normal diet.
-There is no quick or easy method to improving memory. No pill or dietary supplement can take the place of diligence and studying. Paying attention and keeping your mind focused on the task at hand is crucial to later recall of information. Your memory is a function of your body, and benefits when you take proper care of yourself. A healthy diet and plenty of rest are vitally important to a fully functioning memory.