If you are struggling to retrieve a word that you are certain is on the tip of your tongue, or trying to perfect a slapshot that will send your puck flying into a hockey net, or if you keep stumbling over the same sequence of notes on the piano, be warned: you might be unconsciously creating a pattern of failure, a new study reveals.

The research appeared on April 1 in The Quarterly Journal of Experimental Psychology.

Karin Humphreys, assistant professor in McMaster University’s Faculty of Science, and Amy Beth Warriner, an undergraduate student in the Department of Psychology, Neuroscience & Behaviour, suggest that most errors are repeated because the very act of making a mistake, despite receiving correction, constitutes the learning of that mistake.

Humphreys says the research came about as a result of her own experiences of repeatedly getting into a tip-of-the-tongue (or TOT) state on particular words. “This can be incredibly frustrating – you know you know the word, but you just can’t quite get it,” she said. “And once you have it, it is such a relief that you can’t imagine ever forgetting it again. But then you do. So we began thinking about the mechanisms that might underlie this phenomenon. We realized that it might not be a case of everyone having certain words that are difficult for them to remember, but that by getting into a tip-of-the-tongue state on a particular word once, they actually learn to go into that incorrect state when they try to retrieve the same word again.”

Humphreys and Warriner tested 30 students to see if their subjects could retrieve words after being given a definition. e.g. “What do you call an instrument for performing calculations by sliding beads along rods or grooves” (Answer: abacus). They then had to say whether they knew the answer, didn’t know it, or were in a TOT. If they were in a TOT, they were randomly assigned to spend either 10 or 30 seconds trying to retrieve the answer before finally being shown it. Two days later, subjects were tested on those same words again. One would assume that having been shown the correct word on Day 1 the subject would still remember it on Day 2. Not so. The subjects tended to TOT on the same words as before, and were especially more likely to do so if they had spent a longer time trying to retrieve them The longer time in the error state appears to reinforce that incorrect pattern of brain activation that caused the error.

“It’s akin to spinning one’s tires in the snow: despite your perseverance you’re only digging yourself a deeper rut,” the researchers explained. There might be a strategy to solve the recurrence of tip-of-the-tongue situations, which is what Warriner is currently working on for her honors thesis. "If you can find out what the word is as soon as possible—by looking it up, or asking someone—you should actually say it to yourself,” says Humphreys. “It doesn't need to be out loud, but you should at least say it to yourself. By laying down another procedural memory you can help ameliorate the effects of the error. However, what the research shows is that if you just can't figure it out, stop trying: you’re just digging yourself in deeper."

Very young brains process memories of fear differently than more mature ones, new research indicates. The findings appear in the Feb. 6 issue of The Journal of Neuroscience. The work significantly advances scientific understanding of when and how fear is stored and unlearned, and introduces new thinking on the implications of fear experience early in life.

“This important paper raises questions that are the ‘tip of the iceberg’ related to the very complex series of events that occur as we learn to fear something. In the real world, we become fearful, extinguish that fear, reacquire it at another time, and then conquer it yet again,” says John Krystal, MD, of Yale University and director of the clinical neuroscience division of the VA National Center for Post-Traumatic Stress Disorder. “Typically, we think about long-term, negative impact of fear learning, such as lifelong problems with anxiety. But this work highlights an avenue for adapting to early stresses that apparently can occur only early in life: to erase a learned fear from memory.” Krystal was not affiliated with the research.

Study co-authors Jee Hyun Kim and Rick Richardson, PhD, of the University of New South Wales in Sydney, homed in on the amygdala, using anesthesia to temporarily inactivate it and therefore isolate its role. The amygdala is critical for emotional learning and plays a central role in dulling the memory of a fear. Kim and Richardson trained rats that were 16 and 23 days old—the human equivalent of children and budding adolescents—to associate a specific sound with a mild shock to the foot. After subsequent training, when the sound was not followed by a shock, the animals’ fearful reaction to hearing the sound faded. Technically, this is known as “extinction,” and depended on the function of the amygdala.

In a second round of training, the researchers reintroduced the fear and tried to re-extinguish it. This time around, they found, only the older rats were able to do so without the amygdala. The researchers concluded that the age at which the initial extinction training occurred was critical to whether or not the rats’ fear faded the second time independently of the amygdala. The authors suggest that in the very young, it is primarily the amygdala that extinguishes fearful memories, but that mechanisms independent of the amygdala develop later.

This raises the possibility that fears unlearned at an early enough age are, in fact, erased. As brains develop, however, and related structures near the amygdala mature, these structures take on a greater role. Thus, fear in adolescence and later in life may not be erased, but instead be, for example, inhibited by a process of overlaying neutral memories on top of the initial fear reaction. The initial memory could still exist and be called on again. “Extinction in the young brain might forever erase early traumatic learning—but accepting this hypothesis will have to wait for more research,” says Mark Bouton, PhD, of the University of Vermont, who did not participate in the esearch. “What might change as the brain develops is where and how fear learning and extinction are stored and how they can be retrieved.”

Scientists are finding new evidence that a good night's rest plays a crucial role in cementing memories formed during the day.

One new study has identified a brain region involved, along with the hippocampus, in creating memories of the day's activities during sleep. Another study suggests melatonin, a hormone involved in regulating our day-night cycle, or "circadian rhythm," acts to suppress the formation of new memories as bedtime nears, perhaps in an effort to give memories made earlier in the day a chance to be prepared for long-term storage.

Both studies are detailed in the Nov. 16 issue of the journal Science.

Duke University Medical Center neuroscientists say the places a memory is processed in the brain may determine how someone can be absolutely certain of a past event that never occurred. These findings could help physicians better appreciate the memory changes that accompany normal aging or even lead to tools for the early diagnosis of Alzheimer's disease, according to Duke neuroscientist Roberto Cabeza, Ph.D.

Information retrieved from memory is simultaneously processed in two specific regions of the brain, each of which focuses on a different aspect of an past event. The medial temporal lobe (MTL), located at the base of the brain, focuses on specific facts about the event. The frontal parietal network (FPN), located at the top of the brain, is more likely to process the global gist of the event. The specific brain area accessed when one tries to remember something can ultimately determine whether or not we think the memory is true or false, the researchers found.

"Human memory is not like computer memory -- it isn't completely right all the time," said Cabeza, senior author of a paper appearing in the Journal of Neuroscience. "There are many occasions when people feel strongly about past events, even though they might not have occurred." Cabeza wanted to understand why someone could have such strong feelings of confidence about false memories. In his experiments, he scanned the brains of healthy volunteers with functional MRI as they took well-established tests of memory and false memory. Functional MRI is an imaging technique that shows what areas of the brain are used during specific mental tasks.

During the brain scans, Cabeza found that volunteers who were highly confident in memories that were indeed true showed increased activity in the fact-oriented MTL region. "This would make sense, because the MTL, with its wealth of specific details, would make the memory seem more vivid," Cabeza said. "For example, thinking about your breakfast this morning, you remember what you had, the taste of the food, the people you were with. The added richness of these details makes one more confident about the memory's truth."

On the other hand, volunteers who showed high confidence in memories that turned out to be false exhibited increased activity in the impressionistic FPN. The people drawing from this area of the brain recalled the gist or general idea of the event, and while they felt confident about their memories, they were often mistaken, since they could not recall the details of the memory.

These findings, coupled with the findings of other studies, can help explain what happens to the human brain as it ages, Cabeza said. "Specific memories don't last forever, but what ends up lasting are not specific details, but more general or global impressions," Cabeza said. "Past studies have shown that as normal brains age, they tend to lose the ability to recollect specifics faster than they lose the ability recall impressions. However, patients with Alzheimer's disease tend to lose both types of memories equally, which may prove to be a tool for early diagnosis."

Cabeza's colleague for this research was Hongkeun Kim at Daegu University in South Korea. The research was supported by the National Institutes of Health and Daegu University.

Brown, A.M (2007). A cognitive approach to dogmatism: An investigation into the relationship of verbal working memory and dogmatism. Journal of Research in Personality, 41 (4), 946-952.

Abstract: This study investigated the relationship of working memory to open and closed belief systems. Two hundred college students completed a working memory span test to measure verbal working memory, and Rokeach’s Dogmatism Scale (1956). Regression analysis was undertaken to determine the contribution of verbal working memory to dogmatism. A negative correlation was found between dogmatism scores and working memory scores (p = .002) confirming the hypothesis that those participants who display a larger working memory capacity would show lower levels of dogmatic beliefs than participants displaying a smaller working memory capacity. Error analysis was employed to determine the significance of inhibition processes; indicating that capacity limits in verbal working memory, and not processing deficits, were primarily responsible for poor working memory scores. Dogmatism was not found to be related to gender, age, ethnicity, religious affiliation, academic major, or level of education.

In the 1980's, a spate of high profile child abuse convictions gave way to heightened concern about false memory reports given by children. Take, for example, the case of Kelly Michaels, a preschool teacher who was convicted on 115 counts of sexual abuse based on the testimony of 20 of her pupils. After serving seven years of her 47 year sentence, Michaels' conviction was overturned after the techniques used to interview the children were shown to be coercive and highly suggestive.

Since then, a sizeable literature on children's false memories has accumulated and until recently, the picture that had emerged was quite consistent: false memories of events were found to decrease with age throughout childhood and adolescence. In other words, as we grow into adulthood, our memory accuracy improves.

However, psychologists Charles Brainerd and Valerie Reyna of Cornell University believe that the relationship between age and memory accuracy may not be so simple. Drawing upon fuzzy-trace theory — the popular psychological theory that humans encode information on a continuum from verbatim to "fuzzy" traces that convey a general meaning — Brainerd and Reyna predicted that false memories may actually increase with age under certain circumstances. In other words, adults would have less accurate memories than children. [read more]

Sleep not only protects memories from outside interferences, but also helps strengthen them, according to research that will be presented at the American Academy of Neurology’s 59th Annual Meeting in Boston, April 28 – May 5, 2007.

The study looked at memory recall with and without interference (competing information). Forty-eight people between the ages of 18 and 30 took part in the study. All had normal, healthy sleep routines and were not taking any medications. Participants were divided evenly into four groups—a wake group without interference, a wake group with interference, a sleep group without interference and a sleep group with interference. All groups were taught the same 20 pairs of words in the initial training session.

The wake groups were taught the word pairings at 9 a.m. and then tested on them at 9 p.m. after 12 hours awake. The sleep groups were taught the word pairs at 9 p.m. and tested on them at 9 a.m. after a night of sleep. Just prior to testing, the interference groups were given a second list of word pairs to remember. The first word in each pair was the same on both lists, but the second word was different, testing the brain’s ability to handle competing information, known as interference. The interference groups were then tested on both lists.

The study found that people who slept after learning the information performed best, successfully recalling more words. Those in the sleep group without interference were able to recall 12 percent more word pairings from the first list than the wake group without interference. With interference, the recall rate was 44 percent higher for the sleep group.

"This is the first study to show that sleep protects memories from interference," said study author Jeffrey Ellenbogen, MD, with Harvard Medical School in Boston, MA, and Fellow of the American Academy of Neurology. "These results provide important insights into how the sleeping brain interacts with memories: it appears to strengthen them. Perhaps, then, sleep disorders might worsen memory problems seen in dementia."

Memorizing a series of facts is one thing, understanding the big picture is quite another. Now a new study demonstrates that relational memory – the ability to make logical “big picture” inferences from disparate pieces of information – is dependent on taking a break from studies and learning, and even more important, getting a good night’s sleep.

Led by researchers at Beth Israel Deaconess Medical Center (BIDMC) and Brigham and Women’s Hospital (BWH), the findings appear on-line in today’s Early Edition of the Proceedings of the National Academy of Sciences (PNAS).

“Relational memory is a bit like solving a jigsaw puzzle,” explains senior author Matthew Walker, PhD, Director of the Sleep and Neuroimaging Laboratory at BIDMC and Assistant Professor of Psychology at Harvard Medical School (HMS). “It’s not enough to have all the puzzle pieces – you also have to understand how they fit together.”

Adds lead author Jeffrey Ellenbogen, MD, a postdoctoral fellow at HMS and sleep neurologist at BWH, “People often assume that we know all of what we know because we learned it directly. In fact, that’s only partly true. We actually learn individual bits of information and then apply them in novel, flexible ways.” For instance, if a person learns that A is greater than B and B is greater than C, then he or she knows those two facts. But embedded within those is a third fact – A is greater than C – which can be deduced by a process called transitive inference, the type of relational memory that the researchers examined in this study.

Earlier research by Walker and colleagues had shown that sleep actively improves task-oriented “procedural memory” – for example, learning to talk, to coordinate limbs, musicianship, or to play sports. Because relational memory is fundamental to knowledge and learning, Walker and Ellenbogen decided to explore how and when this “inferential” knowledge emerges, hypothesizing that it develops during “off-line” periods and that, like procedural memory, would be enhanced following a period of sleep.

So, the researchers tested 56 healthy college students, each of whom was shown five pairs of unfamiliar abstract patterns – colorful oval shapes resembling Faberge eggs. The students were then told that some of the patterns were “correct” while others were “incorrect,” for example, Shape A wins over Shape B, Shape B wins over Shape C, and so on. All of the students learned the individual pairs but were not told that there was a hidden “hierarchy” linking all five of the pairs together.

After a 30-minute study period, the students were separated into three groups to test their understanding of the larger “big picture” relationship between the individual patterns: Group One was tested after a period of 20 minutes; Group Two was tested after a 12-hour period; and Group Three was tested after a 24-hour time span. In addition, approximately half of the students in Group Two slept during the 12-hour period, while the other half remained awake. All of the students in Group Three had a full night’s sleep.

The test results showed striking differences among the three groups, especially between the students who had a period of sleep and those who remained awake. “Group One, the students who were tested soon after their initial learning period, performed the worst,” says Walker. “While they were able to learn and recall the component pieces [for example, Shape A is greater than Shape B, Shape B is greater than Shape C] they could not discern the hierarchical relationships between the pieces [Shape A is greater than Shape C] – they couldn’t yet see ‘the big picture.’” Groups Two and Three, on the other hand, demonstrated a clear understanding of the interrelationship between the pairs of shapes.

“These individuals were able to make leaps of inferential judgment just by letting the brain have time to unconsciously mull things over,” he says. But, perhaps most notable, he adds, when the inferences were particularly difficult, the students who had had periods of sleep in between learning and testing significantly outperformed the other groups. “This strongly implies that sleep is actively engaged in the cognitive processing of our memories,” notes Ellenbogen. “Knowledge appears to expand both over time and with sleep.”

Concludes Walker, “These findings point to an important benefit [of sleep] that we had not previously considered. Sleep not only strengthens a person’s individual memories, it appears to actually knit them together and helps realize how they are associated with one another. And this may, in fact, turn out to be the primary goal of sleep: You go to bed with pieces of the memory puzzle, and awaken with the jigsaw completed.”


20 April 2007
Beth Israel Deaconess Medical Center News

A Brown University-led research team has, for the first time, recorded activity inside the cells of the hippocampus while simultaneously measuring activity in the neocortex. Recordings from these two brain regions – seats of memory creation and storage – revealed a surprisingly complex pattern of activity. These findings, in the Proceedings of the National Academy of Sciences, are part of a growing body of evidence that challenges traditional theories of the role of sleep in learning and memory. [read more]

A common drug [propranolol] administered in the first hours following trauma to patients deemed to be at risk of developing post-traumatic stress disorder (PTSD) reduced the occurrence of PTSD, according to a study led by researchers at the University of Lille, France [in 2003].

While the study involved a small number of subjects, its results are encouraging, says its senior author, Charles Marmar, MD, associate chief of staff for mental health at the San Francisco VA Medical Center and professor and vice chair of psychiatry at University of California, San Francisco.

"The study is based on the new theory that PTSD is most likely to occur in patients who experience a particularly severe and prolonged response to trauma. If this model proves accurate after five or ten replications of studies like this one, it could have very profound ramifications. From a public health perspective, if you could identify the subgroup of people who are susceptible to PTSD, giving them this course of medication -- which is brief, very well tolerated and inexpensive -- could be very effective prevention [following major trauma] and may have great social relevance." The study appears in the November 1 issue of Biological Psychiatry. [read rest of article]

Also: The Memory Pill (60 Minutes video -- 26 Nov 2006)
Bad Memory? Wipe It Clean With New Pill (16 Jan 2006)

As a night of bad sleep can have an adverse effect on an adult’s performance at work the next day, an insufficient amount of rest can also have a negative impact on how well middle or high school students perform in the classroom. A study published in the February 15th issue of the Journal of Clinical Sleep Medicine (JCSM) finds that adolescents who experience sleep disturbances are more likely to receive bad grades in school.

James F. Pagel, MD, of the University of Colorado School of Medicine, examined the results of 238 school district-approved questionnaires, filled out by students attending middle school or high school, which included a high frequency of sleep complaints. According to the surveys, students with lower grade point averages (GPAs) were more likely to have restless, aching legs when trying to fall asleep, difficulty concentrating during the day, snoring every night, a hard time waking up in the morning, sleepiness during the day, and falling asleep in class.

"While a series of previously-conducted studies all found that adolescents reporting inadequate sleep, irregular sleep patterns, and/or poor sleep quality do not perform as well in school as students without sleep complaints, this study provides additional evidence indicating that sleep disturbances occur at high frequencies in adolescents and significantly affect daytime performance, as measured by GPA," said Pagel.

Both restless legs and difficulty concentrating during the day are symptoms associated with the diagnosis of Attention Deficit Hyperactivity Disorder (ADHD), a diagnosis that can be associated with poor school performance. It is important for parents to discuss their teen’s sleep-related problem with a primary care physician, and to have their teen screened for ADHD if necessary, added Pagel.

Teens are advised to follow these recommendations to getting a good night’s sleep, which will help lead to better school performance:

• Get a full night’s sleep on a regular basis. Do not stay up all hours of the night to "cram" for an exam, do homework, etc. If extracurricular activities at school are proving to be too time-consuming, consider cutting back.
  
• If you are not asleep after 20 minutes, then get out of the bed and do something relaxing, such as reading a book or listening to music, until you are tired enough to go back to bed.
  
• Get up at the same time every morning.
  
• Avoid taking naps after school if you can. If you need to lie down, do not do so for more than an hour.
  
• Keep a regular schedule.
  
• Don’t read, write, eat, watch TV, talk on the phone or play cards in bed.
  
• Do not have any caffeine after lunch.
  
• Do not go to bed hungry, but don’t eat a big meal before bedtime either.
  
• Avoid any rigorous exercise within six hours of your bedtime.
  
• Try to get rid of or deal with things that make you worry.
  
• Make your bedroom quiet, dark and a little bit cool.

See also: Sleep well before learning something new, an article discussing how sleep deprivation can severely hamper the brain’s ability to learn.

Don’t Talk to a Friend While Reading This; Multi-Tasking Adversely Affects the Brain’s Learning Systems, UCLA Scientists Report

Multi-tasking affects the brain's learning systems, and as a result, we do not learn as well when we are distracted, UCLA psychologists report this week in the online edition of Proceedings of the National Academy of Sciences.

"Multi-tasking adversely affects how you learn," said Russell Poldrack, UCLA associate professor of psychology and co-author of the study. "Even if you learn while multi-tasking, that learning is less flexible and more specialized, so you cannot retrieve the information as easily. Our study shows that to the degree you can learn while multi-tasking, you will use different brain systems.

"The best thing you can do to improve your memory is to pay attention to the things you want to remember," Poldrack added. "Our data support that. When distractions force you to pay less attention to what you are doing, you don't learn as well as if you had paid full attention."

Tasks that require more attention, such as learning calculus or reading Shakespeare, will be particularly adversely affected by multi-tasking, Poldrack said.

The researchers used functional magnetic resonance imaging (fMRI) to examine brain activity and function, a technique that uses magnetic fields to spot active brain areas by telltale increases in blood oxygen.

Participants in the study, who were in their 20s, learned a simple classification task by trial-and-error. They were asked to make predictions after receiving a set of cues concerning cards that displayed various shapes, and divided the cards into two categories. With one set of cards, they learned without any distractions. With a second set of cards, they performed a simultaneous task: listening to high and low beeps through headphones and keeping a mental count of the high-pitch beeps. While the distraction of the beeps did not reduce the accuracy of the predictions — people could learn the task either way — it did reduce the participants' subsequent knowledge about the task during a follow-up session.

When the subjects were asked questions about the cards afterward, they did much better on the task they learned without the distraction. On the task they learned with the distraction, they could not extrapolate; in scientific terms, their knowledge was much less "flexible."

This result demonstrates a reduced capacity to recall memories when placed in a different context, Poldrack said.

"Our results suggest that learning facts and concepts will be worse if you learn them while you're distracted," Poldrack said.

Different forms of memory are processed by separate systems in the brain, he noted.  When you recall what you did last weekend or try to remember someone's name or your driver's license number, you are using a type of memory retrieval called declarative memory. (Patients with Alzheimer disease have damage in these brain areas.) When you remember how to ride a bicycle or how to play tennis, you are using what is called procedural memory; this requires a different set of brain areas than those used for learning facts and concepts, which rely on the declarative memory system. The beeps in the study disrupted declarative memory, said Poldrack, who also studies how the types of memory are related.

The brain's hippocampus — a sea-horse-shaped structure that plays critical roles in processing, storing and recalling information — is necessary for declarative memory, Poldrack said. For the task learned without distraction, the hippocampus was involved. However, for the task learned with the distraction of the beeps, the hippocampus was not involved; but the striatum was, which is the brain system that underlies our ability to learn new skills.

The striatum is the brain system damaged in patients with Parkinson disease, Poldrack noted. Patients with Parkinson's have trouble learning new motor skills but do not have trouble remembering the past.

"We have shown that multi-tasking makes it more likely you will rely on the striatum to learn," Poldrack said. "Our study indicates that multi-tasking changes the way people learn."

The researchers noted that they are not saying never to multi-task, just don't multi-task while you are trying to learn something new that you hope to remember. Listening to music can energize people and increase alertness. Listening to music while performing certain tasks, such as exercising, can be helpful. But tasks that distract you while you try to learn something new are likely to adversely affect your learning, Poldrack said.

"Concentrate while you're studying," he said.


UCLA News
25 July 2006

Bad judgments about people can affect memories of them, Cornell study finds
By Susan S. Lang

Viewing a person as dishonest or immoral can distort memory, a Cornell study suggests. So much so, that when we attempt to recall that person's behavior, it seems to be worse than it really was.

"In other words, our study shows that morally blaming a person can distort memory for the severity of his or her crime or misbehavior," said David Pizarro, assistant professor of psychology at Cornell.

Pizarro and three colleagues gave 283 college students a story about a man who walked out on a restaurant bill, including what the man ate and drank and the amount of his bill. Half the participants read that the man walked out on the bill because he "was a jerk who liked to steal," and half read that the man left without paying because he received an emergency phone call.

"One week later the people who were told he was a jerk remembered a higher bill -- from 10 to 25 percent more than the bill actually was. Those who were told he had an emergency phone call remembered a slightly lower-than-actual bill," said Pizarro, the first author of a study to be published in a forthcoming issue of the journal Memory and Cognition. His co-authors include University of California (UC)-Irvine's Elizabeth Loftus, whose groundbreaking work put memory distortion on the map in the late 1980s when she showed that subjects viewing a film clip of a car accident estimated the speed of the cars differently depending on whether such words as hit, collided or mashed were used in the question.

Previous studies have found that leading questions can influence memory of an incident, and that thinking that someone is good (or bad) in one area tends to influence judgments about them in other areas.

"But this is the first study that we know of that looked at how blame might affect memory regarding objective facts, which you usually think of as less susceptible to distortion," Pizarro said. "It suggests that negative evaluations are capable of exerting a distorting effect on memory as well."

The findings have particular implications for eyewitness testimonies, Pizarro noted. "Spontaneous evaluations made by an eyewitness about a defendant may influence their memories about the event in question -- memories that often serve as the very data that judges and juries use as input into their judgments of guilt."

In addition, eyewitnesses who hear information about the moral character of a defendant, "even long after the events have occurred," may misremember the events in question, such as the severity of the crime, putting perpetrators at greater risk.

Cornell Chronicle Online
13 March 2006

Following up the sleep paralysis article I posted last July is a web video I recently found -- Abducted: How People Come to Believe They Were Kidnapped By Aliens. This is a 50 minute informal presentation by Susan Clancy, a postdoctoral fellow in Psychology at Harvard University, who interviewed "alien abductees" and researched alien abductions for six years. She wrote a book detailing her research findings, which she discusses in this presentation.

UCI researchers have found that a single brief memory is actually processed differently in separate areas of the brain – an idea that until now scientists have only suspected to be true. The finding will influence how researchers examine the brain and could have implications for the treatment of memory disorders caused by disease or injury. [read article]

Today@UCI (Press Release)
2 February 2006

The hippocampus's role in memory may help explain why we cannot remember our early childhood, and why stress affects our memory later in life. [read the article]

APA Monitor
November 2005

A new Memorial-based study is the first to systematically mark the onset of "childhood amnesia" in children rather than adults. The research shows that by our tenth birthday our early pre-school memories have receded into an inaccessible past.

It's a result, the lead researcher says, that further deepens the mystery around the fate of our earliest autobiographical memories.

"I expected that they would differ, but there's a striking similarity in the age of the earliest memory for adults and ten-year-olds," says Dr. Carole Peterson, a psychologist at Memorial University of Newfoundland. Her study, funded by NSERC, was published in the August issue of the journal Memory.

The results extend what Dr. Peterson calls the paradox of surrounding childhood amnesia – adults’ inability to recall autobiographical events that occurred before the age of four. Four- and three-year-olds can readily recall events from their second year. Yet, by the age of ten these earliest memories have receded behind what's been dubbed the "reminiscence bump."

"We don't have any good models to explain this. The memories were there and had been verbally accessible. So, why aren't they there any more?" says Dr. Peterson, who since the 1970s has explored the dynamics of children's autobiographical memories.

For this study, Dr. Peterson and undergraduate students Valerie Grant and Lesley Boland asked 136 participants ages six to 19 for their earliest memories. It's a sample size that Dr. Peterson says provides statistically significant results.

The researchers found that six- to nine-year-olds recalled earlier events (from when they were about three) than did older children. However, there were no differences in the age of earliest memory among the older groups. Their earliest memories were from about three and a half years of age. Thus, by ten years old, participants’ memories had entered an "adult" state of remembering.

So what are our earliest memories?

While previous researchers have found that a large number of adults' earliest memories are emotion laden, Dr. Peterson's group "found that the majority of the early memories were about relatively mundane experiences." These ranged from the memory of looking at a flower growing out of a crack in the pavement to walking across a narrow bridge over a river. Only teenaged girls 14 to 19 had a preponderance (about 40 per cent) of negative first memories.

"It's not at all clear why some things get into long-term memory and some do not," says Dr. Peterson.

The researchers also found few differences between age groups in how earliest events are remembered. All of the participants recalled events with about the same level of narrative complexity, generally describing a "snapshot of a moment in time."

"Perhaps it’s the level of narrative skill possessed at the age at which the memory was encoded, not the current narrative skill, that determines the structure of a recollection," write the authors.

The research is part of Dr. Peterson's larger, ongoing research on children's autobiographical memories. The present findings have prompted a collaborative study exploring the earliest memories of autistic children to determine the role of self-awareness – one possible factor put forward by some researchers – in determining the onset of childhood amnesia. Autistic children are thought to lack a strong sense of self.

While the bulk of our pre-school memories will surely slip over the memory threshold, Dr. Peterson says that parents can play a role in determining which of their children's memories become lifelong ones. The more parents talk to children about particular experiences, the greater the chance that this verbal reinforcement will extend early memories.

"Talking a lot about your experiences, encoding them in language, has an impact on preserving the memory, there's no doubt about that," says Dr. Peterson. "But this doesn't solve the mystery of why it is that something that you could remember and talk about at one stage, disappears later."

Memorial University of Newfoundland
4 October 2005