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   Your memory is no video camera: It edits the past with present experiences Date: February 4, 2014 Source: Northwestern University Rather, the memory rewrites the past with current information, updating your recollections with new experiences. Love at first sight, for example, is more likely a trick of your memory than a Hollywood-worthy moment. When you think back to when you met your current partner, you may recall this feeling of love and euphoria, said lead author Donna Jo Bridge, a postdoctoral fellow in medical social sciences at Northwestern University Feinberg School of Medicine. But you may be projecting your current feelings back to the srcinal encounter with this person. The study will be published Feb. 5 in the Journal of Neuroscience . This the first study to show specifically how memory is faulty, and how it can insert things from the present into memories of the past when those memories are retrieved. The study shows the exact point in time when that incorrectly recalled information gets implanted into an existing memory. To help us survive, Bridge said, our memories adapt to an ever-changing environment and help us deal with what's important now. Our memory is not like a video camera, Bridge said. Your memory reframes and edits events to create a story to fit your current world. It's built to be current.  All that editing happens in the hippocampus, the new study found. The hippocampus, in this function, is the memory's equivalent of a film editor and special effects team. For the experiment, 17 men and women studied 168 object locations on a computer screen with varied backgrounds such as an underwater ocean scene or an aerial view of Midwest farmland. Next, researchers asked participants to try to place the object in the srcinal location but on a new background screen. Participants would always place the objects in an incorrect location. For the final part of the study, participants were shown the object in three locations on the srcinal screen and asked to choose the correct location. Their choices were: the location they srcinally saw the object, the location they placed it in part 2 or a brand new location. People always chose the location they picked in part 2, Bridge said. This shows their srcinal memory of the location has changed to reflect the location they recalled on the new background screen. Their memory has updated the information by inserting the new information into the old memory.   Participants took the test in an MRI scanner so scientists could observe their brain activity. Scientists also tracked participants' eye movements, which sometimes were more revealing about the content of their memories -- and if there was conflict in their choices -- than the actual location they ended up choosing. The notion of a perfect memory is a myth, said Joel Voss, senior author of the paper and an assistant professor of medical social sciences and of neurology at Feinberg. Everyone likes to think of memory as this thing that lets us vividly remember our childhoods or what we did last week, Voss said. But memory is designed to help us make good decisions in the moment and, therefore, memory has to stay up-to-date. The information that is relevant right now can overwrite what was there to begin with. Bridge noted the study's implications for eyewitness court testimony. Our memory is built to change, not regurgitate facts, so we are not very reliable witnesses, she said.  A caveat of the research is that it was done in a controlled experimental setting and shows how memories changed within the experiment. Although this occurred in a laboratory setting, it's reasonable to think the memory behaves like this in the real world, Bridge said.  Kepler finds a very wobbly planet: Rapid and erratic changes in seasons The planet, designated Kepler-413b, precesses, or wobbles, wildly on its spin axis, much like a child's top. The tilt of the planet's spin axis can vary by as much as 30 degrees over 11 years, leading to rapid and erratic changes in seasons. In contrast, Earth's rotational precession is 23.5 degrees over 26,000 years. Researchers are amazed that this far-off planet is precessing on a human timescale. Kepler 413-b is located 2,300 light-years away in the constellation Cygnus. It circles a close pair of orange and red dwarf stars every 66 days. The planet's orbit around the binary stars appears to wobble, too, because the plane of its orbit is tilted 2.5 degrees with respect to the plane of the star pair's orbit. As seen from Earth, the wobbling orbit moves up and down continuously. Kepler finds planets by noticing the dimming of a star or stars when a planet transits, or travels in front of them. Normally, planets transit like clockwork. Astronomers using Kepler discovered the wobbling when they found an unusual pattern of transiting for Kepler-413b. Looking at the Kepler data over the course of 1,500 days, we saw three transits in the first 180 days -- one transit every 66 days -- then we had 800 days with no transits at all. After that, we saw five more transits in a row, said Veselin Kostov, the principal investigator on the observation. Kostov is affiliated with the Space Telescope Science Institute and Johns Hopkins University in Baltimore, Md. The next transit visible from Earth's point of view is not predicted to occur until 2020. This is because the orbit moves up and down, a result of the wobbling, in such a great degree that it sometimes does not transit the stars as viewed from Earth.  Astronomers are still trying to explain why this planet is out of alignment with its stars. There could be other planetary bodies in the system that tilted the orbit. Or, it could be that a third star nearby that is a visual companion may actually be gravitationally bound to the system and exerting an influence. Presumably there are planets out there like this one that we're not seeing because we're in the unfavorable period, said Peter McCullough, a team member with the Space Telescope Science Institute and Johns Hopkins University. And that's one of the things that Veselin is researching: Is there a silent majority of things that we're not seeing? Even with its changing seasons, Kepler-413b is too warm for life as we know it. Because it orbits so close to the stars, its temperatures are too high for liquid water to exist, making it inhabitable. It also is a super Neptune -- a giant gas planet with a mass about 65 times that of Earth -- so there is no surface on which to stand.  Ames is responsible for the Kepler mission concept, ground system development, mission operations and science data analysis. NASA's Jet Propulsion Laboratory in Pasadena, Calif., managed Kepler mission development. Ball Aerospace & Technologies Corp. in Boulder, Colo., developed the Kepler flight system and supports mission operations with the Laboratory for  Atmospheric and Space Physics at the University of Colorado in Boulder. The Space Telescope Science Institute in Baltimore archives, hosts and distributes Kepler science data. Kepler is NASA's 10th Discovery mission and was funded by the agency's Science Mission Directorate. Researchers have analyzed carbon-rich meteorites (carbonaceous chondrites) and found amino acids, which are used to make proteins. Proteins are among the most important molecules in  life, used to make structures like hair and skin, and to speed up or regulate chemical reactions. They have also found components used to make DNA, the molecule that carries the instructions for how to build and regulate a living organism, as well as other biologically important molecules like nitrogen heterocycles, sugar-related organic compounds, and compounds found in modern metabolism. However, these carbon-rich meteorites are relatively rare, comprising less than five percent of recovered meteorites, and meteorites make up just a portion of the extraterrestrial material that comes to Earth. Also, the building-block molecules found in them usually have been at low concentrations, typically parts-per-million or parts-per-billion. This raises the question of how significant their supply of raw material was. However, Earth constantly receives other extraterrestrial material -- mostly in the form of dust from comets and asteroids. Despite their small size, these interplanetary dust particles may have provided higher quantities and a steadier supply of extraterrestrial organic material to early Earth, said Michael Callahan of NASA's Goddard Space Flight Center in Greenbelt, Md. Unfortunately, there have been limited studies examining their organic composition, especially with regards to biologically relevant molecules that may have been important for the srcin of life, due to the miniscule size of these samples. Callahan and his team at Goddard's Astrobiology Analytical Laboratory have recently applied advanced technology to inspect extremely small meteorite samples for the components of life. We found amino acids in a 360 microgram sample of the Murchison meteorite, said Callahan. This sample size is 1,000 times smaller than the typical sample size used. A microgram is one-millionth of a gram; 360 micrograms is about the weight of a few eyebrow hairs .  28.35 grams equal an ounce. Our study was for proof-of-concept, adds Callahan. Murchison is a well-studied meteorite. We got the same results looking at a very small fragment as we did a much larger fragment from the same meteorite. These techniques will allow us to investigate other small-scale extraterrestrial materials such as micrometeorites, interplanetary dust particles, and cometary particles in future studies. Callahan is lead author of a paper on this research available online in the Journal of Chromatography A.  Analyzing such tiny samples is extremely challenging. Extracting much less meteorite powder translates into having much lower amino acid concentration for analyses, said Callahan. Therefore we need the most sensitive techniques available. Also, since meteorite samples can be highly complex, techniques that are highly specific for these compounds are necessary too. The team used a nanoflow liquid chromatography instrument to sort the molecules in the meteorite sample, then applied nanoelectrospray ionization to give the molecules an electric charge and deliver them to a high-resolution mass spectrometer instrument, which identified the molecules based on their mass. We are pioneering the application of these techniques for the study of meteoritic organics, said Callahan. These techniques can be highly finicky, so just getting results was the first challenge. I'm particularly interested in analyzing cometary particles from the Stardust mission, adds Callahan. It's one of the reasons why I came to NASA. When I first saw a photo of the aerogel used to capture particles for the Stardust mission, I was hooked.
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