It happens to all of us: We think we learned of the Sept. 11 attacks from a radio report, when, in fact, the news came from a co-worker; we’re sure the robber running from the bank was tall, when actually he was short; we remember waking up at 7 yesterday, when 8 is closer to the truth. Such “false memories,” unavoidable in everyday life, can have disastrous consequences in courtrooms and other settings where exactitude matters. We create these false memories, according to Harvard psychologist Daniel Schacter , because our brains are designed to tell stories about the future. “Memory’s flexibility is useful to us, but it creates distortions and illusions,” says Schacter, the William R. Kenan Jr. Professor of Psychology. “If memory is set up to use the past to imagine the future, its flexibility creates a vulnerability — a risk of confusing imagination with reality.” Schacter, author of two books on memory, was recently honored with the Distinguished Scientific Contribution Award from the American Psychological Association (APA) . In a review paper in a forthcoming edition of the journal American Psychologist , Schacter argues that the time machine of the brain is really a virtual reality simulator. Our memories are designed to flexibly imagine the future, Schacter says, but not to record the past verbatim — so they are inherently prone to predictable errors, which experiments reveal. Misremembering happens to us all the time, Schacter says, because our minds rely on patterns to reconstruct memories — and the patterns often lead us astray. Routine behaviors, called “schemas” by the psychologist Frederic Bartlett in his classic “Remembering” (1932), distort our memories by making us assume events happened the way they usually do. For example, we may “remember” that we biked to work today because we ordinarily do, when today we actually drove. Our memories are also biased by our emotions. “Positivity bias” is an example of such a memory distortion. Since we have a tendency to remember emotionally charged events, our memories are crowded more with emotional events than with ordinary things from our daily lives — and these tend to be biased toward the positive, while negative memories slip away. In a recent study with postdoctoral researcher
Exposure therapy for irrational fear of spiders seems to be more effective if it is followed by sleep, according to a recent study in the Journal of Psychiatric Research . The results have implications for treatment of phobias, social anxiety, and post-traumatic stress disorder. Psychotherapy for fear, the research suggests, should be coupled with healthy sleep. Our brains seem to use sleep, perhaps REM sleep specifically, to lay down new emotional memories. Sixty-six young women took part in the study of arachnophobia and sleep. The research, led by Edward Pace-Schott , clinical instructor in psychology at Harvard Medical School (HMS), in collaboration with Rebecca M.C. Spencer at the University of Massachusetts, Amherst, focused on sleep’s role in reducing fear of spiders in undergraduate women. The goal was to see how “fear extinction” is affected by sleep, wakefulness, and time of day. Fear extinction is an active process of building a new emotional memory; in this case, a memory of spiders not associated with danger or harm. The 66 women were divided into four groups: sleep, wake, morning, evening. Each group watched a YouTube video of a spider — a minute long, 14 times. Such “exposure therapy” is a standard treatment for irrational fears, designed to train the phobic patient not to startle at spiders. The “morning” and “evening” groups were controls to rule out the possibility that time of day, rather than sleep, has a role in fear: These groups watched the spider videos two hours apart in either the morning or evening, while the wake and sleep groups watched them 12 hours apart, after a day awake or a night of sleep. Randomly, in 60 percent of the viewings, a loud noise would go off. The researchers measured startle response to the noise, using a sensor on the hand that measures palm-sweat. After a delay — 12 hours or two depending on the group — the women watched more spider videos: six of the same spider from before, six of a new one. The researchers again measured the women’s fear, of both the old and new spider, to see how sleep affected fear. Fear in the laboratory is measured by four variables, Pace-Schott said: heart rate, hand sweat (“skin conductance response”), subjective emotion (disgust, fear, unpleasantness), and muscle tone, measured in the facial muscle for frowning. Sleep helped to mellow the women’s fears, Pace-Schott and his colleagues found, by strengthening the memory formed during exposure therapy. Hand-sweat response to the video and the spider’s rating in terms of “fearfulness, disgust, and unpleasantness” were low among women who got 12 hours of overnight sleep — as they had been at the end of the exposure therapy session. Staying awake for 12 hours had the opposite effect: The twenty-three women who stayed awake for a full day after watching the spider videos had a strong hand-sweat response to the old spider when they saw it again at the end of the day as well as a return of strong ratings of “fearfulness, disgust, and unpleasantness.” Sleep also protected the women against fear of a new spider: The “awake” group found a new spider even more frightening than the spider they saw before, while the sleepers did not. The sleep-dependent learning process had physiological effects: Not only did the sleepers say they felt less fearful, but their heart rates and skin-conductance changed. When asked what stage of sleep might be involved in learning fear extinction, Pace-Schott pointed to recent research on REM, the phase when most dreaming occurs. (REM is rapid eye movement sleep, named for the twitching of the eyes that occurs during dreaming.) In REM, a network of emotional brain regions is activated. These regions overlap the regions disrupted in anxiety disorders. This suggests, Pace-Schott says, that REM may be reprocessing emotional memory. Previous research has shown that when people are deprived of REM sleep, they are unable to form fear extinction memories after therapy. “REM may be the stage of sleep during which extinction memory is stabilized and strengthened,” Pace-Schott said. The timing of sleep relative to psychotherapy is of interest because there may be only certain “windows of time” when sleep can strengthen extinction memory. “If extinction memory is strengthened by sleep,” he said, “then we want exposure therapy to happen close to bedtime.” The one downside of this approach, Pace-Schott acknowledges, is that we know people are more reactive to fear in the evening. If people are more frightened before bed, then exposure therapy may give them insomnia. So a better strategy may be to have people take a nap after therapy. The key point, Pace-Schott says, is that “sleep … be good quality — including both REM and slow-wave sleep.”
A new technique inspired by elegant pop-up books and origami will soon allow clones of robotic insects to be mass-produced by the sheet. Devised by engineers at Harvard, the ingenious layering and folding process enables the rapid fabrication of not just microrobots, but a broad range of electromechanical devices. In prototypes, 18 layers of carbon fiber, Kapton (a plastic film), titanium, brass, ceramic, and adhesive sheets have been laminated together in a complex, laser-cut design. The structure incorporates flexible hinges that allow the three-dimensional product — just 2.4 millimeters tall — to assemble in one movement, like a pop-up book. The entire product is approximately the size of a U.S. quarter, and dozens of these microrobots could be fabricated in parallel on a single sheet. “This takes what is a craft, an artisanal process, and transforms it for automated mass production,” says Pratheev Sreetharan, who co-developed the technique with J. Peter Whitney. Both are Harvard Graduate School of Arts and Sciences doctoral candidates at the School of Engineering and Applied Sciences (SEAS). Sreetharan, Whitney, and their colleagues in the Harvard Microrobotics Laboratory at SEAS have been working for years to build bio-inspired, bee-sized robots that can fly and behave autonomously as a colony. Appropriate materials, hardware, control systems, and fabrication techniques did not exist prior to the RoboBees project, so each must be invented, developed, and integrated by a diverse team of researchers. Less than a year ago, the group was using a painstaking and error-prone method to fold, align, and secure each of the minuscule parts and joints. “You’d take a very fine tungsten wire and dip it in a little bit of superglue,” explains Sreetharan. “Then, with that tiny ball of glue, you’d go in under a microscope like an arthroscopic surgeon and try to stick it in the right place.” “Until recently, the manual assembly process was the state of the art in this field,” Sreetharan adds. The same result can now be achieved — without human error — through locking mechanisms and dip soldering. The new process also enables the use of cured carbon fiber, which is rigid and easy to align, rather than uncured carbon fiber, which Sreetharan compares to “wet tissue paper.” “Our new techniques allow us to use any material including polymers, metals, ceramics, and composites,” says principal investigator Robert Wood , an associate professor of electrical engineering at SEAS and a core faculty member at the Wyss Institute for Biologically Inspired Engineering at Harvard . “The ability to incorporate any type and number of material layers, along with integrated electronics, means that we can generate full systems in any three-dimensional shape,” Wood says. “We’ve also demonstrated that we can create self-assembling devices by including pre-stressed materials.” By the numbers Folding joints: 22 Assembly scaffold folding joints: 115 Total device folding joints: 137 Number of brass pads for “glue” points: 52 Total number of “glue” points: 24 Mass: 90 mg By mass, one U.S. quarter = 63 Harvard Monolithic Bees The implications of this novel fabrication strategy go far beyond these micro-air vehicles. The same mass-production technique could be used for high-power switching, optical systems, and other tightly integrated electromechanical devices that have parts on the scale of micrometers to centimeters. Moreover, the layering process builds on the manufacturing process currently used to make printed circuit boards, which means that the tools for creating large sheets of pop-up devices are common and abundant. It also means that the integration of electrical components is a natural extension of the fabrication process — particularly important for the size- and weight-constrained RoboBees project. “In a larger device, you can take a robot leg, for example, open it up, and just bolt in circuit boards. We’re so small that we don’t get to do that. I can’t put a structural mechanism in here and have it serve no electrical function.” Pointing to the carbon-fiber box truss that constitutes the pop-up bee’s body frame, Sreetharan says, “Now, I can put chips all over that. I can build in sensors and control actuators.” Essentially, tiny robots can now be built by slightly bigger robots. Designing how all the layers will fit together and fold, however, is still a very human task, requiring creativity and expertise. Standard computer-aided design (CAD) tools, typically intended for either flat, layered circuit boards or 3-D objects, do not yet support devices that combine both. Once the design is complete, though, fabrication can be fully automated, with accuracy and precision limited only by the machining tools and materials. “The alignment is now better than we can currently measure,” says Sreetharan. “I’ve verified it to better than 5 microns everywhere, and we’ve gone from a 15 percent yield to — well, I don’t think I’ve ever had a failure.” The full fabrication process is described in the Journal of Micromechanics and Microengineering . Co-authors, beside Whitney, Sreetharan, and Wood, include Kevin Ma, a graduate student at SEAS; and Marc Strauss, a research assistant in Wood’s lab. The Harvard Office of Technology Development is now developing a strategy to commercialize this technology. As part of this effort, the office has filed patent applications on this work and is engaging with entrepreneurs, venture capitalists, and companies to identify disruptive applications in a range of industries. The work was supported by the U.S. Army Research Laboratory, the National Science Foundation (through the Expeditions in Computing program), and the Wyss Institute.
What Goes On In The Mind Of A Sniper? — BBC A young cowboy from Texas who joined the elite US Navy Seals became the most deadly sniper in American history. In a book published this month he provides an unusual insight into the psychology of a soldier who waits, watches and kills. As US forces surged into Iraq in 2003, Chris Kyle was handed a sniper rifle and told to watch as his marine battalion entered an Iraqi town. A crowd had come out to greet them. Through the scope he saw a woman, with a child close by, approaching his troops. She had a grenade ready to detonate in her hand. “This was the first time I was going to have to kill someone. I didn’t know whether I was going to be able to do it, man, woman or whatever,” he says. Read more …. My Comment : I am going to get the book, but I suspect that it will only give a small picture of what Chris Kyle must have been going through while fighting in Iraq
Honduras Named Murder Capital Of The World — Miami Herald TEGUCIGALPA, Honduras — Sitting in the plant-filled patio of his home outside the capital, anti-corruption crusader Gustavo Alfredo Landaverde uttered what few people have the courage to say out loud in this poor Central American nation: “We are rotten to the core,” he said of the drug-related graft infecting virtually every layer of law enforcement in Honduras. “We are at the border of an abyss. These are criminal organizations inside and out.” The soft-spoken, bespectacled former deputy drug czar had been fired, sued for libel and saw his last boss murdered. “I have asked myself: ‘Why am I still alive?’” Read more …. My Comment : Honduras is the poster child of what happens to a a nation if the drug culture and drug cartels take over.