The persistence of learning over time through the storage and retrieval of information. To a psychologist, evidence that learning persists takes three forms: Recall, Recognition, Relearning.
A measure of memory in which the person must retrieve information learned earlier, as on a fill in the blank test.
A measure of memory in which the person need only identity items previously learned, as on multiple choice test.
A measure of memory that assesses the amount of time saved when learning material again.
Analogies that compare human memory to a computers operations. To get memory into our brain we must:
- Get information into our brain, called encoding.
- Retain that information, called storage.
- Later get the information back out, called retrieval.
The processing of information into the memory system- for example, by extracting meaning.
The retention of encoded information over time.
The process of getting information out of memory storage.
The immediate, very brief recording of sensory information in the memory system.
Activated memory that holds a few items briefly, such as seven digits of a phone number while dialling, before the information is stored or forgotten.
The relatively permanent and limitless storehouse of the memory system. Includes knowledge, skills, and experiences.
A new understanding of short term memory that focuses on conscious, active processing of incoming auditory and visual-spatial information, and of information retrieved from long term memory. Alan Baddeley and others challenged Atkinson and Shiffrin's view of short-term memory as a small brief storage space for recent thoughts and experiences. Research shows that this stage is not just a temporary shelf for holding incoming information. Its an active desktop where you brain processes information, making sense of new input and linking it with long-term memories. Right now you are using your working memory to link information you're reading with your previously stored information.
Like all analogies, computer models have their limits. Our memories are less literal and more fragile that a computers. Moreover, most computers process information sequentially, even while alternating between tasks. Our dual-track processes many thing simultaneously (some of them unconsciously) by means of parallel processing. To focus on this complex, simultaneous processing, one information-processing models connectionism, views memories as products of interconnected neural networks.
An information-processing model that views memories as products of interconnected neural networks. Specific memories arise from particular activation patterns within these networks. Every time you learn something new, your brains neural connections change, forming and strengthening pathways that allow you to interact with and learn from your constantly changing environment.
Memory forming Process proposed three-stage model
To explain our memory-formcing process, Richard Atkinson and Richard Shiffrin (1968) proposed a three stage model:
1. We first record to-be-remembered information as a fleeting sensory memory.
2. From there, we process information into short-term memory, were ewe encode it through rehearsal.
3. Finally, information moves into long-term memory for later retrieval.
- Other psychologists have updated this model, to include important never concepts, including working memory and automatic processing.
A Modified three-step Processing model of memory
Atkinson and Shiffrin's classical three-step model helps us to think about how memories are processes, but todays research recognize other ways long-term memories form. For example, some information slips into long-term memory via a "back door" without our consciously attending to it (automatic processing). And so much active processing occurs in the short term stage that many now prefer the term working memory.
Central Executive Processing
For most of you, the pages you are reading enter working memory through vision. You might also repeat the information using auditory rehearsal. As you integrate these memory inputs with you existing long term memory, your attention is focused. Baddeley called this focused processing the central executive. Without focused attention, information often fades.
Memory of facts and experiences that one can consciously know and "declare". (Also called declarative memory).
Encoding that requires attention and conscious effort.
Unconscious encoding of incidental information, such as space, time, and frequency, and of well-learned information, such as word meanings. Other information skips our conscious encoding and barges directly into storage. This automatic processing, which happens without our awareness, produces implicit memories.
Retention, independent of conscious recollection (Also called non-declarative memory).
The two track memory system reinforces an important principle of parallel processing: Mental features such as vision, thinking, and memory seem to be single abilities, but they are not. Rather we split information into different components for separate and simultaneous processing.
What two new concepts update the classical Atkinson-Shiffrin three-stage information processing model?
1. We form some memories (implicit memories) through automatic processing, without our awareness. The Atkinson-Shiffrin model focused only on conscious, explicit memories.
2. The newer concept of a working memory emphasizes the active processing that we now know takes place in Atkinson-Shiffrin's short-term memory stage.
What are two basic functions of working memory?
1. Active processing of incoming visual and auditory information.
2. Focusing our spotlight of attention.
Our implicit memories include procedural memory for automatic skills, such as how to ride a bike, and classically conditioned associations among stimuli. Visiting your dentist, you may, thanks to a conditioned association linking the dentists office with the painful drill, find yourself with sweaty palms. You didn't plan to feel that way when you got the the dentist's office; it automatically happened.
What information do we automatically process?
With our conscious effort you also automatically process information about:
Our two-track mind engages in impressively efficient information processing. As one track automatically tucks away many routine details, the other track is free to focus on conscious, effortful processing.
Automatically Processing Space
While studying, you often encode the place on a page where certain material appears; later when you want to retrieve the information about automatic processing, you may visualize the location of that information on this page.
Automatically Processing Time
While going about your day, you unintentionally note the sequence of its events. Later, realizing you've left your coat somewhere, he event sequence your brain automatically encoded will enable you to retrace your steps.
Automatically Processing Frequency
You effortlessly keep track of how many times things happen, as you suddenly realize "This is the third time i have run into him today".
Encoding and Effortful Processing
Automatic processing happen so effortlessly that it is difficult to shut off. When you see words in your native language, perhaps on the side of a delivery truck, you can't help but read them and register their meaning. Learning wasn't automatic. You may recall working hard to pick out letters and connect them to certain sounds. But with experience and practice, your reading became automatic. We learn to drive, to text, to speak a new language with effort, but then these tasks become automatic.
How does sensory memory work?
Effortful processing begins with sensory memory, which feeds our active working memory. Our sensory memory records a momentary image of a scene or an echo of a sound.
Momentary Photographic Memory
When George Sperling flashed a group of letters for one twentieth of a second, people could recall only about half of the letters. But when signalled to recall a particular row immediately after the letters had disappeared, they could do so with near perfect accuracy. This experiment demonstrated iconic memory, a fleeting sensory memory of visual stimuli. For a few twentieth of a second, our eyes register a photographic or picture image of a scene, and we can recall any part of it in amazing detail. But if Sperling delayed delayed the tone signal, by more than half a second, the image faded and participants again only recalled about half the letters. Our visual screen clears quickly, as new images are superimposed over old ones.
A momentary sensory memory of visual stimuli; a photographic or picture image memory lasting no more than a few tenths of a second.
A momentary sensory memory auditory stimuli; if attention is elsewhere, sounds and words can still be recalled within 3 or 4 seconds. For example picture yourself in conversation, as your attention veers to the TV. If your mildly irked companion tests you by asking "What did i just say?"you can recover just the last few words from your minds echo chamber.
Organizing items into familiar, manageable units; ofter occurs automatically.
memory aids, especially those techniques that use vivid imagery and organizational devices.
Capacity of Short-Term and Working Memory
George Miller proposed that short-term memory can retain about seven information bits. Other researchers have confirmed that we can, if nothing distracts us, recall about 7 digits, or about 6 letters or five words. Without the active processing that we now understand to be part of the "working memory" concept, short-term memories have a limited life. Working memory capacities varies, depending on age and other factors. Compared with children and older adults, young adults have more working memory capacity, so they can use their mental workspace more efficiently. This means their ability to multitask is relatively greater. But whatever age, we do better and more efficient work when focused, without distractions, on one task as a time.
Working memory capacity and Intelligence Level
Unlike short term memory capacity, working memory capacity appears to reflect intelligence level. Imagine seeing a letter in the alphabet, then a simple question, then another letter, followed by another question and so on. In such experiments, those who could juggle the most mental balls- who could remember more despite the interruptions- tended in every day life to exhibit high intelligence and an ability to maintain their focus. When beeped to report in at various times, they were less likely to report that their mind was wandering.
Short-Term Memory Decay
Unless rehearsed, verbal information may be quickly forgotten.
Effortful Processing Strategies
Chunking and mnemonics techniques combined can be great memory aids for unfamiliar materials. In each case, we chunk information into a more familiar form by creating a word (or acronym) from the first letters of the to be remembered items. Hierarchies and Distributed Practice.
When people develop expertise in an area, they process information not only in chunks, but also in hierarchies composed of a few broad concepts divided and subdivided into narrower concepts and facts. Organizing knowledge into hierarchies helps us retrieve information efficiently. When the words are organized into categories, recall was two to three times better. Such results show the benefits of organizing what you study.
We retain information better when encoding id distributed over time. Massed Practice (cramming) can produce speedy short term learning and feelings of confidence although, those who learn quickly forget quickly. Distributed Practice produces better long-term recall. After you've studied long enough to master the material, further study becomes inefficient. Better to spend that extra reviewing time later. Spreading you learning over several months , rather than over a short term, can help you retain information for a lifetime. One effective way to distribute practice is repeated self-testing, a phenomenon called the testing effect. Spaced study and self-assessment beat cramming and rereading.
Organization benefits memory
When we organize words or concepts into hierarchal groups we remember them better than when we see them presented randomly.
Levels of Processing
Memory researchers have discovered that we process verbal information at different levels, and that depth of processing affects our long term retention. Shallow processing encodes on a very basic level, such as a word's letters or, at a more intermediate level, a word's sound. Deep encoding encodes semantically, based on the meaning of the words. The deeper (more meaningful) the processing, the better our retention.
The tendency for distributed study or practice to yield better long-term retention than is achieved through messed study or practice.
Enhanced memory after retrieving, rather than simply reading, information. Also sometimes referred to as a retrieval practice effect for test-enhanced learning.
Encoding on a basic level based on the structure or appearance of words.
Encoding semantically, based on the meaning of the words; tends to yield the best retention.
Making Material Personally Meaningful
If new information is not meaningful or related to our experience, we have trouble processing it. We have especially good recall for information we can meaningfully relate to ourselves. The amount remembered depends both on the time spent learning and on your making it meaningful fro deep processing.
Information deemed "relavent to me" is processed more deeply and remains more accessible.
A neural centre located in the limbic system; help process explicit memories for storage. Explicit memories for facts and episodes are processed in the hippocampus and fed to other brain regions for storage.
Retaining information in the brain
Despite the brains vast capacity for storage, we do not store information as libraries store their books, in discrete, precise locations. Instead, many parts of the brain interact as we encode, store, and retrieve information the forms our memories.
Explicit Memory System: The Frontal Lobes
As with perception, language, emotion and much more, memory requires brain networks. The network process that processes and stores your explicit memories includes your frontal lobes and hippocampus. When you summon up a mental encore of a past experience, many brain regions send input to your frontal lobes for working memory processing. The left and right frontal lobes process different types of memories. Recalling a password and holding it in memory, for example, would activate the left frontal lobe. Calling up a visual party scene would more likely activate the right frontal lobe.
Explicit Memory System: Hippocampus
Cognitive neuroscientists have found that the hippocampus, a temporal-lobe neural centre located in the limbic system, is the brains equivalent of a "save" button for explicit memories. Brain scans such as PET scans of people recalling words, and autopsies of people who had amnesia, have revealed that new explicit memories of names, images, and events are laid down via the hippocampus.
Damage to the Hippocampus
Damage to this area disrupts recall of explicit memories. Chickadees and other birds can store food in hundreds of places and return to these unmarked caches months later- but not if their hippocampus has been removed. With left hippocampus damage, people ahem trouble remembering verbal information, but they have no trouble recalling visual designs and locations. With right hippocampus damage, the problem is reversed.
Subregions of the hippocampus also serve different functions. One part is active as memory champions engage in spatial mnemonics. The rear area, which processes spatial memory, grows bigger and longer a London cabbie has navigated the street maze.
Hippocampus memory storage capacity
Memories are not permanently stored in the hippocampus. Instead, this structure seems to act as holding dock where the brain registers and and temporarily holds the elements of a remembered episode- its smell, feel, sound and location. Then, like older files shifted to the basement storage, memories migrate for storage elsewhere.
Removing a rats hippocampus
Removing a rats hippocampus 3 hours after it learns the location of some tasty new food disrupts this process and prevents long term memory formation; removal 48 hours later does not.
Hippocampus and Sleep
Sleep supports memory consolidation. During deep sleep, the hippocampus processes memories for later retrieval. After a training experience, the greater the hippocampus activity during sleep, the better the next days memory will be. Researchers have watched the hippocampus and brain cortex displaying simultaneous activity rhythms during sleep, as if they were having a dialogue. They suspect that the brain is replaying the days experiences as it transfers them to the cortex for long term memory storage. Cortex areas surrounding the hippocampus support the processing and storing of explicit memories.
Implicit-Memory System: The Cerebellum and Basal Ganglia
Your hippocampus and frontal lobes are processing sites for explicit memories. But you could lose those areas and still, thanks to automatic processing, lay down implicit memories for skills and conditioned associations. Our implicit memory system, enabled by the cerebellum and the basal ganglia, helps explain why the reactions and skills we learn during infancy reach far into our future. Yet, as adults, our conscious memory for the first 3 years is blank, an experience called infantile amnesia.
Implicit-Memory System: Cerebellum
The cerebellum plays a key role in forming and storing the implicit memories created by classical conditioning. With a damaged cerebellum, people cannot develop certain conditioned reflexes, such as associating tone with an impending puff of air- and thus, do not blink in the anticipation of the puff. When researchers surgically disrupted the function of different pathways of the cerebellum of rabbits, the rabbits became unable to learn a conditioned eye-blink response. Implicit memory formation needs the cerebellum.
Implicit-Memory System: The Basal Ganglia
The basal ganglia, deep brain structures involved in motor movement, facilitate formation of our procedural memories for skills. The basal ganglia device input from the cortex but do not return the favour of sending information back to the cortex for conscious awareness of procedural learning. If you have learned to ride a bike, thank your basal ganglia.
An experience that refers to the fact that as adults, our conscious memory for the first 3 years is blank. In one study, events children experienced and discussed with their mothers at age 3 were 60% remembered at age 7 but only 34% at age 9. Two influences contribute to infantile amnesia: First, we index must of our explicit memory using words that nonspeaking children have not learned. Second, the hippocampus is on of the last brain structures to mature.
Your friend has experienced brain damage in a accident. He can remember how to tie his shoes but has a hard time remembering anything you told him during conversation. Whats going on here?
Our explicit (declarable) memories differ from our implicit memories of skills and procedures. Our implicit memories are processed by more ancient brain areas, which apparently escaped damage during the accident.
A clear memory of an emotionally significant moment or event.
The Amygdala, Emotions and Memory
Our emotions trigger stress hormones that influence memory formation. When we are excited or stressed, these hormones make more glucose energy available to fuel brain activity, signalling the brain that something important has happened. Moreover, stress hormones provoke the amygdala (two limbic system, emotion-processing clusters) to initiate a memory trace in the frontal lobes and basal ganglia and to boost activity in the brains memory-forming areas. Emotional arousal and sear certain events into the brain, while disrupting memory for neutral events around the same time.
Emotions and Memory
Emotions often persist without our conscious awareness of what caused them. In one ingenious experiment, patients with hippocampus damage (which left them unable to for new explicit memories) watched a sad film and later a happy film. After the viewing they did not consciously recall the films, but the sad or happy emotions persisted.
Stress and Memories
Significantly stressful events can form almost indelible memories. After traumatic experiences- a wartime ambush, a house fire, a rape- vivid recollections of the horrific event may intrude again and again. It is as if they were burned in: Stronger emotional experiences make for stronger, more reliable memories. This makes adaptive sense. memory serves to predict the future and to alert us to potential dangers. Conversely, weaker emotions, means weaker memories. People given a drug that blocks the effects of stress hormones will later have more trouble remembering the details of the upsetting story.
Emotion-Triggered Hormone Changes and Memory
Emotion-triggered hormonal changes help explain why we long remember exciting or shocking events, such as our first kiss or our whereabouts when learning of a loved ones death. This perceived clarity of memories of surprising, significant events leads some psychologists to call them flashbulb memories. Our flashbulb memories are noteworthy for their vividness and the confidence with which we recall them. But as we relieve, rehearse, and discuss them, the memories can come to err, as misinformation seeps in.
Synaptic Changes and Memory Processing
The quest to understand the physical basis of memory- how information becomes embedded in brain matter- has approved study of the synaptic meeting places where neurons communicate with one another via their neurotransmitter messengers. When learning occurs, there is a release of more of the neurotransmitter serotonin onto certain neurons. These cells then become more efficient at transmitting signals. In experiments with people, rapidly stimulating certain memory circuit connections has increased their sensitivity for hours or even weeks to come. The sending neuron now needs less prompting to release its neurotransmitter, and more connections exist between neurons. This increased efficiency of potential neuron firing, called long-term potential (LTP), provides a neural basis for learning and remembering associations.
Evidence to confirm that long-term potential (LTP) is a physical basis for memory
- Drugs that block LTP interfere with learning.
- Mutant mice engineered to lack an enzyme needed for LTP can't learn their way out of a maze.
- Rats given a drug that enhances LTP will learn a maze with half the usual number of mistakes.
- Injecting rats with a chemical that blocks LTP erases recent learning.
Electroconvulsive Therapy (ECT)
After long term potential has occurred, passing an electric current through the brain won't disrupt old memories. But the current will wipe out very recent memories. Such as in the experience both of laboratory animals and severely depressed people given electroconvulsive therapy (ECT). A blow to the head can do the same. Football players and boxers momentarily knocked unconscious typically have no memory of events just before the knock out. Their working memory had no time to consolidate the information into long-term memory before the lights went out.
Development of Memory Altering Drugs
Some memory-biology explorers have helped found companies that are competing to develop memory altering drugs. The target market for memory boosting drugs includes millions of people with Alzheimers disease, millions with mild cognitive impairment that often becomes Alzheimers , and countless millions who would love to turn back the clock on age-related memory decline. From expanding memories perhaps will come bulging profits.
One approach to improving memory focuses on drugs that boost the LTP enhancing neurotransmitter glutamate. Another approach involves developing drugs that boost production of CREB, a protein that also enhances the LTP process. Boosting CREB production might trigger increased production of of other proteins that help reshape synapses and transfer short term memories into long term memories.
Memory Blocking Drugs
Other people wish for memory blocking drugs. Among them are those who would welcome a drug that, when taken after a traumatic experience, might blunt intrusive memories. In mice, blocking CREB producing amygdala neurons has apparently erased an auditory fear memory. In another experiment, victims of car accidents, rapes and other traumas received, for 1o day following their horrific event, with one such drug, propranolol, or a placebo. When tested 3 months later, half the placebo group but none of the drug treated people showed signs of stress disorder.
Long -Term Potentiation (LTP)
An increase in a cells firing potential after brief, rapid stimulation. Believed to be a neural basis for learning and memory.
Which brain area responds to stress hormones by helping to create stronger memories?
Retrieval: Getting information out
After the magic of brain encoding and storage, we still have the daunting task of retrieving the information.
Measures of Retention
Recall, Recognition, and Relearning speed are three ways that psychologists measure retention of memories. Long after you cannot recall most of the people in your high school graduating class, you may still be abel to recognize their yearbook pictures from a photographic lineup and pick their names from a list of names. In one experiment, people who graduated 25 years earlier could not recall many of their old classmates, but they could recognize 90% of their pictures and names. Tests of recognition and the time spent relearning demonstrate what we remember more than what we can recall.
Our recognition memory is impressively quick and vast. before our mouth can form answers to any of millions of questions, the mind knows, and knows that it knows.
Speed at Relearning
Our speed at relearning also reveals memory. Hermann Ebbinghaus showed his more than a century ago in his learning experiments, using nonsense syllables. He randomly selected a sample of syllables, practiced them and tested himself. The day after learning such a list, Ebbinghaus could recall a few of the syllables. But they weren't entirely forgotten. The more he repeated the list aloud on day 1, the fewer receptions he required to relearn the list on day 2. Additional rehearsal (overlearning) of verbal information increases retention, especially when practice is distributed over time.
If you want to be sure to remember what you're learning for an upcoming test, would it be better to use recall or recognition to check your memory? Why?
It would be better to test your memory with recall (such as short answers or fill in the blank questions) rather than recognition (such as with multiple choice questions). Recalling information is harder than recognizing it, so if you can recall it that means your retention of the material is better than if you could only recognize it, and your chances of test success are therefore greater.
Imagine a spider suspended in the middle of her web, held up by many strands extending outward away from her in all directions to different points. If you were to trace a pathway to the spider, you would first need to create a path from one of these anchor points and then follow the strand down her web. The process of retrieving information follows a similar principle, behave memories are held in storage by a web of associations, each piece of information you associate with it other bits of information about your surroundings, mood, seating position, and so on. These bits can serve a retrieval cues that you can later use to access the information. The more retrieval cues you have, the better your chance of finding a route to the suspended memory.
The best retrieval cues come from associations we form at the time we encode a memory- smells, tastes, and sights that can evoke our memory of the associated person or event. To call us visual cues when trying to recall something, we may mentally place ourselves in the original context. Often our associations are activated without our awareness. Philosopher-psychologist William James referred to this process Priming; as the wakening of associations. Priming is often memoryless memory- invisible memory, with our your conscious awareness. Priming can influence behaviours as well. Priming effects are not always positive. Money may prime our materialism and self-interest rather than the social norms that encourage us to help.
Putting yourself back into the context where you experienced sometime can prime your memory retrieval. In several experiments, Carolyn Rovee-Collier found that a familiar context can activate memories even in 3 month olds. After infants learned that kicking a crib mobile would make it move (via a connection ribbon from the ankle), the infants kicked more when tested again in the same crib with the same bumper than when in a different context.
Closely related to context-dependant memory is state-dependent memory. What we learn in one state- be it drunk or sober- may be more easily recalled when we are again in that state. What people learn when drunk they don't recall well in any state (alcohol disrupts storage). But they recall it slightly better when again drunk. Someone who hides money when drunk may not remember the location until drunk again.
Mood Congruent Memory
The tendency to recall experiences that a re consistent with ones current good or bad mood. Our mood states provide an example of state dependance. Emotions that accompany good or bad events become retrieval cues. Thus, our memories are somewhat mood congruent. Your gloomy mood may facilitate recalling other bad times. Being depressed sours memories by priming negative associations, which we then use to explain our current mood.
Mood-Memory Connection and Depression
Knowing this mood-memory connection, we should not be surprised that in some studies currently depressed people have recalled their parents as rejective, punitive, and guilt promoting, whereas formerly depressed peoples recollections more closely resemble positive descriptions given by those who never suffered depression. When teens were down, their parents seemed inhuman; as their mood brightened, their parents morphed from devils into angels. Yet, in a good or bad mood, we persist in attributing to reality our own changing judgments, memories and interpretations. In a bad mood, we may read someones look as a glare and feel even worse. In a good mood, we may encode the same look as interest and feel even better. Passions exaggerate.
The retrieval effect and moods
The retrieval effect helps explain why our moods persist. When happy, we recall happy events and therefore see the world as a happy place, which helps prolong our goo mood. When depressed, we recall sad events, which darkens our interpretations of current events. For those of us with predisposition to depression, the process can help maintain a vicious, dark cycle.
The effects of context memory
Words heard underwater are best recalled underwater; words heard on land are best recalled on land. i.e We have greater recall when learning and testing contexts are the same.
Serial Position effect
Our tendency to recall best the first and last items in a list. Another memory-retireval quirk, the serial position effect, can leave us wondering why we have larger holes in our memory of a list of recent events. Imagine its your first day in a new job, and your manager is introducing new coworkers. As you meet each person, you silently repeat everyones name, starting from the beginning. As the last person smiles and turns away, you feel confident you'll be able to greet your new coworkers by name the next day. Don't count on it. Because you have spent more time rehearsing the earlier names than the later names, those are the names you will probably recall more easily the next day. In experiments, when people view a list of items especially quickly and well (a recency effect), perhaps because those last items are still in working memory. But after a delay, when they have shifted their attention away from the last items, their recall is best for the first items (a primacy effect).
An inability to form new memories. Having no memories and possibly no sense of elapsed time. Although incapable of recalling new facts or anything they have done recently, can still learn nonverbal tasks. Shown hard-to-find figures in pictures, they can quickly spot them again later. They can find their way to the bathroom, though without being able to tell you where it is. They can learn to do a jigsaw puzzle and read mirror image writing, and they have even been taught complicated job skills. They can be classical conditioned. However, they do all of these things with no awareness of having learned them. Their automatic processing ability remained intact.
An inability to retrieve information from ones past. Like Alzheimers patients, whose explicit memories for people and events are lost, they can form new implicit memories. They can learn how to do something, But they will have no conscious recall of learning their new skill.
Ami all the applause for memory- all the efforts to understand it, all the books on how to improve it- have any voices been heard in praise of forgetting? William James was a such a voice: "If we remember everything, we should on most occasion be as ill off as if we we remembered nothing". A good memory is helpful, but so is the ability to forget. If a memory enhancing pill becomes available, it must not be too effective. More often, however, our unpredictable memory dismays and frustrates us. Memories are quirky.
Forgetting and the two-track mind
For some, memory loss is severe and permanent. Such sad cases of retrograde amnesia and anterograde amnesia confirm that we have two distinct memory systems, controlled by different parts of the brain.
Much of what we sense we never notice, and what we fail to encode, we will never remember. Age can effect encoding efficiency. The brain areas that jump into action when young adults encode new information are less responsive in older adults. The slower encoding helps explain age-related memory decline. But no matter how young we are, we selectively attend to a few of the myriad sights and sounds continually bombarding us. Without effort, many potential memories never form.
Even after encoding something well, we sometimes later forget it. To study the durability of stored memories, Ebbinghaus (1885) learned more lists of nonsense syllables and measured how much he retained when relearning each list from 20 minutes to 30 days later. The results confirmed by later experiments, was his famous forgetting curve: The course of forgetting is initially rapid, then levels off with time. One explanation of these forgetting curves is a gradual fading of the physical memory trace. Cognitive neuroscientists are getting closer to solving the mystery of the physical storage of memory and are increasing our understanding of how memory storage could decay. memories may be inaccessible for any reasons. Some were never acquired (not encoded). Others were discarded (stored memories decay). And others are out of reach because we can't retrieve them.
Often, forgetting is not memories faded but memories un-retrieved. We store in long term memory whats important to us or what we have rehearsed. But sometimes important events defy our attempts to access them. Given retrieval cues we may easily retrieve the elusive memory. Retrieval problems contribute to the occasional memory failures of older adults. Retrieval problems occasionally stem from interface and perhaps, from motivated forgetting.
As you recall more and more information, your mental attic never fills, but it surely gets cluttered. An inability to tune out clutter helps people focus, and focusing helps us recall information. Those who are better at forgetting (as verified by diminished brain activity in a pertinent brain area) also focus more on the to-be-remebered pairs and recalled them better on later tests.
Proactive (forward acting) Interference
The disruptive effect of prior learning on the recall of new information. If you buy a new combination lock, your memory of the old combination may interfere.
Retroactive (backward acting) Interference
The disruptive effect of new learning on the recall of old information. If someone sings new lyrics to the tune of an old song, you may have trouble remembering the original words. It is rather like a second stone tossed in a pond, disrupting the waves rippling out from the first. Information presented in the hours before sleep is protected from retroactive interference because the opportunity for interfering events is minimized. The hour before sleep is a good time to commit information to memory, though information presented in the seconds just before sleep is seldom remembered. If your considering learning while sleeping, forget it. we have little memory for information played aloud in a room during sleeping, although the ears do register it.
Old and new learning do not always compete with each other, of course. Previously learned information often facilitates our learning of new information. This phenomenon is called positive transfer.
A typical student faces eight demands for passwords. we are plagued by proactive interference from irrelevant old passwords and retroactive interference from other newly learned passwords. Those perhaps too little concerned about password theft use other survival strategies. First, they duplicate. the average student uses four different passwords to meet those eight needs. Second, they harness retrieval cues. Surveys reveal jay about half of our passwords include a familiar name or date. Others often involve familiar phone or identification numbers. In online banking or other situations where security is essential, experts advise making a mix of letters and numbers. After composing such a password, rehearse it, then rehearse it a day later, and continue rehearsing it at increasing intervals. In such ways, long term memories will form and be retrievable at the cash and copy machines.
In psychoanalytic theory, the basic defence mechanism that banishes from consciousness anxiety arousing thoughts, feelings, and memories.
To remember our past is often to revise it. As we process information we filter, alter, or lose much of it. Sigmund Freud might have argued that our memory systems self censored this information. he propose that we repress painful or unacceptable memories to protect our self-concept and to minimize anxiety. But the repressed memory lingers, he believed, and can be retrieved by some later cue or during therapy. Repression was essential to Freud's theory and was a popular idea in the mid-twentieth century psychology. One Norwegian study found that educated people tend to believe in repressed memories more than do those with less formal education. Peoples efforts to intentionally forget neutral material often succeed, but not when the to-be-forgotten material is emotional. Thus, we may have intrusive memories of very traumatic experiences we would most like to forget.
What are three ways we forget, and how does each of these happen?
1. *Encoding Failure*: Information never entered our memory system because we were not paying attention to it, or the information was entered inaccurately.
2. *Storage Decay*: Information fades from our memory.
3. *Retrieval Failure*: We cannot access stored information accurately, sometimes due to interference or motivated forgetting.
Memory Construction Errors
Memory is not precise. We infer our past from stored information plus what we later imagined, expected, saw, and heard. We don't just retrieve memories, we reweave them. Information acquired after an event alters memory of the event. We often construct memories as we encode them, and every time we relay a memory, we replace the original with a slightly modified version.
Incorporating misleading information into ones memory of an event. In many experiments around the world, others have witnessed an event, received or not received misleading information about it, and then taken a memory test. The repeated result is a misinformation effect: Exposed to misleading information, we tend to misremember. So powerful is the misinformation effect that we can influence later attitudes and behaviours. Because the misinformation effect happens outside our awareness, it is nearly impossible to sift the suggested ideas out of the larger pool of real memories. Perhaps you recall describing a childhood experience to a friend, and filling in memory gaps with reasonable guesses and assumptions, and after more retellings, those guessed details- now absorbed into our memories- may feel as real as if we had actually experienced them.
Even repeatedly imagining non-existant actions and events can create false memories. Digitally altered photos have also produced this imagination inflation. In experiments researchers have altered photos from a family album to show some family members taking a hot-air ballon ride. After viewing these photos (rather than photos showing just the balloon), children reported more false memories and indicated high confidence in those memories. When interviewed several days later, they reported even richer details of their false memories.
Misinformation and Imagination Effects
Misinformation and Imagination effects occur partly because visualizing something and actually perceiving it activate similar brain areas. Imagined events also later seem more familiar, and familiar things seem more real. The more vividly we can imagine things, the more likely they are to become memories.
Attributing to the wrong source an event we have experienced, heard about, read about, or imagined. (also called source misattribution). Source amnesia, along with the misinformation effect, is at the heart of many false memories. Among the frailest part of the memory is its source. We may recognize someone but have no idea where we have seen the person. We may dream an event and later be unsure whether it really happened. Authors and songwriters often suffer from it. They think an idea came from their own creative imagination, when in fact they are unintentionally plagiarizing something they earlier read or heard.
The eerie sense that "Ive experienced this before". Cues from the current situation may subconsciously trigger retrieval of an earlier experience. Source experience also helps explain deja vu. It happens most commonly to well educated, imaginative young adults, especially when bored or stressed. Th key to deja vu seems to be familiarity with a stimulus without a clear idea of where we encountered it. Normally we experience feeling of familiarity (thanks to the temporal lobe processing) before we consciously remember details (thanks to the hippocampus and frontal lobe processing). When these functions (and brain regions) are out of sync, we may experience a feeling of familiarity with our conscious recall. Our amazing brains try to make sense of such an improbable situation, and we get an eerie feeling that we're reliving some earlier part of our life. Our source amnesia focuses us to do our best to make sense of an odd moment.
Inducing Deja Vu in the Laboratory
Alan Brown and Elizabeth Marsh (2009) devised an intriguing way to induce deja vu in the laboratory. They invited participants to view symbols on a computer screen and to report whether they had seen them before. What the viewers didn't know was that these symbols had been earlier subliminally flashed on the screen, to briefly for conscious awareness. The result? Half the participants reported experiencing deja vu- a sense of familiarity without knowing why. Brown and Marsh suggest that real-life experiences may include glancing very briefly at a visual scene, looking away without consciously processing it, then looking again- only to feel the uncanny sense of having seen it before.
Discerning true and false memories
Because memory is reconstruction as well as reproduction, we can't be sure whether a memory is real by how real it feels. Much as perceptual illusions may seem like real perceptions, unreal memories feel like real memories.
False memories created by suggested misinformation and misattributed sources not only can feel as real as true memories, they can be very persistent. We more easily remember the most than the words themselves. Memory contractions helps explain why 79% of 200 convicts exonerated by later DNA testing had been misjudged on faulty eye witness identification. It explains why "hypnotically refreshed" memories or crimes so easily incorporate errors, some of which originate with the hypnotists leading questions. It explains why dating partners who fall in love overestimate their first impressions of one another, while those who break up breakup underestimate their earlier linking. How people feel today tends to be how they recall they have always felt (our tendency to hindsight bias). Maturation makes liars of us all.
Children's eyewitness recall
If memories can be sincere, yet sincerely wrong, might chiders recollections of sexual abuse be prone to error? Studies of children's memories have made it aware of how easily children memories can be moulded. For example, they asked 3 year olds to show on anatomically correct dolls where a paediatrician had touched them. Of the children who had no received gentle examinations, 55 pointed either to their genital or anal areas. In other experiments, the researchers studied the effect of suggestive interviewing techniques. In one study, children chose a card from a deck of possible happenings, and an adult read the card to them. In interviews, the same adult repeatedly asked children to think about several real and fictitious events. After 10 weeks of this, a new adult asked the same question. The stunning result: 58% of preschoolers produced false (often vivid) stories regarding one or more events they had never experienced. Given such detailed stories, professional psychologists who specialize in interviewing children could not reliably separate the real memories from the false ones. Nor could the children themselves.
Repressed or Constructed Memories of Abuse?
There are two tragedies related to adult recollections of child abuse. One happens when people don't believe abuse survivors who tell their secret. The other happens when innocent people are falsely accused. The research on course amnesia and the misinformation effect raises corners about therapist-guided recovered memories. Patients exposed to such techniques may then form an image of a threatening person. with further visualization, the image grows more vivid. The patient ends up stunned, angry, and ready to confront or sue the remembered abuser. The equally stunned parent or relative vigorously denies the accusation.
Critics of Memory Work techniques
Critics are not questioning the professionalism of most therapists. Nor are the questioning the accusers sincerity; even if false, their memories are heartfelt. Critics charges are specifically directed against clinicians who use memory work techniques such as "guided imagery", hypnosis, and dream analysis to recover memories. Irate clinicians have countered that those who argue that recovered memories of abuse never happen are adding to abused peoples trauma and playing into the hands of child molesters. In an effort to find a sensible common ground that might resolve psychology's "memory war", professional organizations have conveyed study panels and issued public statements. those committed to protecting abused children and those committed to protecting wrongly accused adults have agreed that sexual abuse happens, injustice happens, forgetting happens, recovered memories are common place, memories of things happening before the age of 3 are unreliable, memories recovered under hypnosis or the influence of drugs are especially unreliable, memories whether true or false can be emotionally upsetting.
Sexual Abuse Happens
And it happens more often then we once supposed. Although sexual abuse can leave its victims at risk for problems ranging from sexual dysfunction to depression, there is no characteristic "survivor syndrome"- no group of symptoms that lets us spot victims of sexual abuse.
Some innocent people have been fatly convicted. And some guilty people have evaded responsibility by casting doubt on their truth-telling accusers.
Many of those actually abused were either very young when abused or may not have understood the meaning of their experience- circumstances under which forgetting is common. Forgetting isolated past events, both negative and positive, is an ordinary part of everyday life.
Recovered memories are commonplace
Cued by remark or experience, we all recover memories of long-forgotten events, both pleasant and unpleasant. What many psychologists debate is two-fold: Does the unconscious mind sometimes forcibly repress painful experiences? (memories that surface naturally are more likely to be verified).
Memories of things happening before the age of 3 are unreliable
We cannot reliably recall happenings from our first 3 years. As noted earlier, this infantile amnesia happens because our brain pathways have not yet developed enough to form the kinds of memories we will form later in life. Most psychologists- including most clinical and counselling psychologists- therefore doubt "recovered" memories of abuse during infancy. The older a child was when suffering sexual abuse, and the more severe the abuse, the more likely it is to be remembered.
Memories recovered under hypnosis or the influence of drugs are especially unreliable
Under hypnosis, people will incorporate all kinds of suggestions into their memories, even memories of "past lives".
Memories, whether real or false, can be emotionally upsetting
Both the accuser and the accused may suffer when what was born of mere suggestion becomes, like an actual trauma, a stinging memory that drives bodily stress. Some people unconscious in unremembered accidents know this all too well. They have later developed stress disorders after being haunted by memories they constructed from photos, news reports, and friends accounts.
The Debate over repression and childhood sexual abuse
The debate over repression and childhood sexual abuse, like many other scientific debates, has stimulated new research and new theories. It has been contended that victims of most childhood sexual abuse do not repress their abuse; rather, they simply stop devoting thought and emotion to it. McNally and Geraerts agree that victims do sometimes and spontaneously recall memories of childhood abuse. But these memories usually occur outside of therapy. Moreover, people who recall abuse spontaneously rarely form false memories when in a lab setting. Conversely, those who form memories of abuse during suggestive therapy tend to have vivid imaginations and score hight on false memory tests in the lab.
The letting go of the memory of childhood sexual abuse occurs mostly when:
- The experience, when it occurred, was strange, uncomfortable, and confusing, rather than severely traumatic.
- The abuse happened once or only a few times.
- Victims have not spent time thinking about the abuse, either because of their own resilience or because no reminders are available.
What- given the commonality of source amnesia- might life be like if we remembered all our waking experiences and all our dreams?
Real experiences would be confused with those we dreamed. When meeting someone, we might therefore be unsure we were reacting to something they previously did or to something we dreamed they did.
Improving Memory Applied Findings
1. Study Repeatedly
2. Make the material meaningful
3. Activate retrieval cues
4. Use mnemonic devices
5. Minimize interference
6. Sleep more
7. Test your knowledge, both to reverse it and to find out what you don't yet know
To master material, use distributed (spaced) practice. To learn a concept, give yourself many separate study sessions. New memories are weak; exercise them and they will strengthen. Reading complex material with minimal rehearsal yields little retention. Rehearsal and critical reflection help more. It pays to actively study.
Make the material more meaningful
You can build a network of retrieval cues by taking text and class notes in your own words. Apply the concepts to your own life. Form images. Understand and organize information. Relate the material to what you have already learned or experienced. Mindlessly repeating someone else words won't supply may retrieval cues. On an exam, you may find yourself stuck when a question uses phrasing different from the words you memorized.
Activate Retrieval Cues
Mentally re-create the situation and the mood in which your original learning occurred. Jog your memory by allowing one thought to cue the next.
Use Mnemonic Devices
Associate words with peg-words. Make up a short story that incorporates vivid images of the items. Chunk information into acronyms. Create rhythmic rhymes.
Study before sleep. Do not schedule back-to-back study times for topics that are likely to interfere with one another, such as Spanish and French.
During sleep, the brain reorganizes and consolidates information for long-term memory. Sleep deprivation disrupts this process.
Yes your knowledge, both to rehearse it and to find out what you don't yet know
Don't be lulled into overconfidence by your ability to recognize information. Outline sections on a black page. define the terms and concepts listed at each chapters end before turning back to their definitions. Take practice tests.