Do you know someone who claims to remember their first day of kindergarten? Or a trip they took as a toddler? While some people may be able to recall trivial details from the past, laboratory research shows that the human memory can be remarkably fragile and even inventive. In fact, people can easily create false memories of their past and a new study shows that such memories can have long-term effects on our behavior.

Psychologists Elke Geraerts of the University of St. Andrews and Maastricht University, Daniel Bernstein of Kwantlen Polytechnic University and the University of Washington, Harald Merckelbach, Christel Linders, and Linsey Raymaekers of Maastricht University, and Elizabeth F. Loftus of University of California, Irvine, found that it is possible to change long-term behaviors using a simple suggestive technique.

In a series of experiments, the researchers falsely suggested that participants had become ill after eating egg salad as a child. Afterwards, the researchers offered different kinds of sandwiches to the participants, including ones with an egg salad filling. Four months later, the participants were asked to be in a separate study in which they evaluated egg salad as well as other foods. They were then given the same kinds of sandwiches that had been offered to them four months earlier.

Interestingly, participants who were told they had become ill as a child after eating egg salad showed a distinct change in attitudes and behavior towards this food after the experiment. They not only gave the food lower evaluations than participants who did not develop false memories or were in the control group, but they also avoided egg salad sandwiches more than any of the other participants four months later.

The results, appearing in the August issue of Psychological Science, a journal of the Association for Psychological Science, "clearly demonstrate that false suggestions about childhood events can profoundly change people's attitudes and behavior," wrote the authors.

These findings have significant implications for the authenticity of reports of recovered memory experiences. While previous research indicates that spontaneously recovered memories may reflect real memories of abuse, there is no such evidence for abuse memories recovered through suggestive therapy. The results might also influence obesity treatments and dieting choices. The authors suggest that it may be possible for people to learn to avoid certain foods by believing they had negative experiences with the food as a child. Overall, this study clearly demonstrates that false suggestions about childhood events can profoundly change people's attitudes and behavior.

A period of slumber helps the brain distinguish core emotions from background details

As poets, songwriters and authors have described, our memories range from misty water-colored recollections to vividly detailed images of the times of our lives. Now, a study led by researchers at Beth Israel Deaconess Medical Center (BIDMC) and Boston College offers new insights into the specific components of emotional memories, suggesting that sleep plays a key role in determining what we remember – and what we forget.

Reported in the August 2008 issue of the journal Psychological Science, the findings show that a period of slumber helps the brain to selectively preserve and enhance those aspects of a memory that are of greatest emotional resonance, while at the same time diminishing the memory's neutral background details. "This tells us that sleep's role in emotional memory preservation is more than just mechanistic," says the study's first author Jessica Payne, PhD, a Harvard University research fellow in the Division of Psychiatry at BIDMC. "In order to preserve what it deems most important, the brain makes a tradeoff, strengthening the memory's emotional core and obscuring its neutral background."

Previous studies have established the key role that sleep plays in procedural memory, demonstrating that the consolidation of procedural skills (such as typing or playing the piano) is greatly enhanced following a period of sleep. But sleep's importance in the development of episodic memories – in particular, those with emotional resonance– has been less clear.

"Emotional memories usually contain highly charged elements – for example, the car that sideswiped us on the ride home – along with other elements that are only tangentially related to the emotion, such as the name of the street we were traveling on or what store we'd just passed," explains study author Elizabeth Kensinger, PhD, an Assistant Professor in the College of Arts and Sciences at Boston College. "We were interested in examining whether sleep would affect memory for all of these elements equally, or whether sleep might allow some of the event features to decay at a faster rate than others."

The authors tested 88 college students. Study participants were shown scenes that depicted either neutral subjects on a neutral background (a car parked on a street in front of shops) or negatively arousing subjects on a neutral background (a badly crashed car parked on a similar street). The participants were then tested separately on their memories of both the central objects in the pictures and the backgrounds in the scenes. In this way, memory could be compared for the emotional aspects of a scene (the crashed car) versus the non-emotional aspects of the scene (the street on which the car had crashed.)

Subjects were divided into three groups. The first group underwent memory testing after 12 hours spent awake during the daytime; the second group was tested after 12 nighttime hours, including their normal period of nighttime sleep; and the third baseline group was tested 30 minutes after viewing the images, in either the morning or evening.

"Our results revealed that the study subjects who stayed awake all day largely forgot the entire negative scene [they had seen], with their memories of both the central objects and the backgrounds decaying at similar rates," says Payne. But, she adds, among the individuals who were tested after a period of sleep, memory recall for the central negative objects (i.e. the smashed car) was preserved in detail.

"After an evening of sleep, the subjects remembered the emotional items [smashed car] as accurately as the subjects whose memories had been tested only 30 minutes after looking at the scenes," explains Kensinger. "By contrast, sleep did little to preserve memory for the backgrounds [i.e. street scenes] and so memory for those elements reached a comparably low level after a night of sleep as it did after a day spent awake."

"This is consistent with the possibility that the individual components of emotional memory become 'unbound' during sleep," adds Payne, explaining that "unbinding" enables the sleeping brain to selectively preserve only that information which it calculates to be most salient and worthy of remembering. A real-world example of this tradeoff, she adds, is the "weapon focus effect" in which crime victims vividly remember an assailant's weapon, but have little memory for other important aspects of the crime scene. Traumatic memories, such as the flashbacks experienced among individuals with post-traumatic stress disorder, can demonstrate similar disparities, with some aspects of an experience seemingly engraved in memory while other details are erased.

"Sleep is a smart, sophisticated process," adds Payne. "You might say that sleep is actually working at night to decide what memories to hold on to and what to let go of."

A shove, a taunt or name-calling on the playground or in the hall, away from the eyesight, earshot and authority of the teacher – childhood bullying can involve physical contact, spreading rumors and other negative behaviors committed over and over again to intimidate, humiliate and isolate the receiver of the behavior. A review of national and international research on the issue is finding a family connection to the origins of young bullies. Elizabeth Sweeney, a University of Cincinnati master's degree student in sociology, presented her findings Aug. 3 at the 103rd annual meeting of the American Sociological Association.

Sweeney reviewed research out of England, Germany, Norway, Japan, South Africa and the United States, which she reports lagged behind the European countries in examining the phenomenon of bullying prior to this decade. The majority of the research that she examined involved children between the ages of nine and 16. Sweeney says her review of the literature found that children raised by authoritarian parents – parents who are demanding, directive and unresponsive – are the most prone to act out bullying behavior. On the other hand, there were parallels showing that children raised by nurturing, warm, responsive parents were less likely to bully.

"Children who experience hostility, abuse, physical discipline and other aggressive behaviors by their parents are more likely to model that behavior in their peer relationships," she writes. "Children learn from their parents how to behave and interact with others," Sweeney says. "So if they're learning about aggression and angry words at home, they will tend to use these behaviors as coping mechanisms when they interact with their peers." Her review also found that children from middle-income families were less likely to bully than children from the high and low ends of the family income scale.

She says that while some studies suggest boys are more prone to bullying than girls, others state that it runs equally among the genders, although boys are more likely to act out bullying physically, while girls are more verbal. Sweeney adds that it is the tolerance of bullying that "has served as one of the primary contributors to its persistence and severity." She is advocating research that would delve more deeply into the issues of bullying, including in-depth interviews with children, families and school officials.

Study questions the effectiveness of the current movie-rating system

In a paper published in the August issue of the journal Pediatrics, Dartmouth researchers document the alarming numbers of young adolescents age 10-14 who are exposed to graphic violence in movies rated R for violence. They found that these extremely violent movies were seen by an average of 12.5 percent of an estimated 22 million children age 10-14. One R-rated movie, Scary Movie, was seen by an estimated 10 million children, or about 48 percent of 10-14 year olds.

"Our data reveal a disturbingly high rate of exposure among 10-14 year olds nationally to extremely violent movies," says Keilah Worth, the lead author on the study and a post-doctoral fellow at Dartmouth Medical School and at Dartmouth-Hitchcock Medical Center's Norris Cotton Cancer Center. "In Britain, no adolescent would be admitted to these movies unless they were 18. The R rating in this country is clearly not preventing our young people from seeing them."

Many scientific studies have established the connection between exposure to media violence and aggression and violence in children. For example, playing video games can lead to changes in attitudes and behavior as well as desensitization to actual violence. "We know so much about the harmful effects of exposure to violent media content, but how much exposure children actually get has been largely ignored. Now, we're learning more about the large numbers of kids seeing this material and who they are," says Worth.

For this assessment of exposure to violence in movies, the researchers used data from national telephone surveys of more than 6,500 adolescents age 10-14 in 2003. Out of 532 recent releases, the researchers chose to look at exposure to 40 of the most violent movies. The study also revealed some independent risk factors for exposure: boys, minorities, those with lower socioeconomic status, and those with lower academic performance were all more likely to see extremely violent movies. Black male adolescents were at particularly high risk of seeing these movies. For example, Blade, Training Day, and Scary Movie were seen by 37 percent, 27 percent, and 48 percent respectively of all the adolescents surveyed, compared to 82 percent, 81 percent, and 81 percent of black males.

"No expert in child development would advocate for subjecting children as young as 10 to this level of violence, yet the study shows that such exposure is commonplace in this country," says James Sargent, the senior scientist on this study and a professor of pediatrics at Dartmouth Medical School. "We should re-think the current movie rating system, which has been in place for 40 years, and was designed when kids could only see movies in theaters. Ratings need to be more prominent on all movies, whether they are seen in theaters or purchased in the store, and we need clearer messages to parents. Pediatricians and child advocates should instruct parents to strictly abide by the movie-age guidelines and to closely monitor movie viewing."