Tag Archives: University of California

brain storage

Storing info in computers frees up memory in the brain, helping us learn new things better

Widespread use of computers is said to make people dumber or more prone to forgetfulness. It’s true, while we’re less inclined to memorize things such as poems or mathematical formulas, this doesn’t necessarily make it a bad thing. A study made by US psychologists found that when people save information on their computers or phones, this frees up cognitive resources that facilitates the formation of new memories.

Storing info externally so we can concentrate on other things

brain storage

Image: Kid Spot

Benjamin Storm and Sean Stone of  the University of California, Santa Cruz wanted to explore how technology and human memory intertwine – how one affects the other. Previously, literature suggested that saving information on digital recording device hinders memory of it. While this may be true, there may be a flipside that’s been less investigated.

“We tend to think of forgetting as happening when memory fails, but research suggests that forgetting plays an essential role in supporting the adaptive functioning of memory and cognition,” explains Storm.

The researchers asked 20 college students to study two PDF files, file A and B. Each file had 10 nouns that they needed to memorize. First the students had 20 seconds to study file A, then 20 seconds to study B. After closing file B, the students were immediately tested to see how many of the nouns they could remember, and only afterward tested for file A. Very important to note is that half of the students were told to save file A in a folder in the computer, while the other half wasn’t instructed at all and just closed the file after the time was up.

Those students that saved file A were better at remembering nouns from file B, according to the researchers. The findings were confirmed by a follow-up study where 48 undergrads participated. This second study not only confirmed the previous findings, but also showed that memory saving depended on how reliable the students thought of the digital storage. When students were told that the contents of file A they had just saved might not be accessible anymore, they showed no memory saving benefits compared to those who had just closed the file and nothing more. That is, when they thought saving was unreliable, students’ memory for File B was the same regardless of whether they saved File A.

“Our findings show that people are significantly better at learning and remembering new information when they save previous information,” says psychological scientist and study author Benjamin Storm of the University of California, Santa Cruz.

“The idea is pretty simple: Saving acts as a form of offloading.  By ensuring that certain information will be digitally accessible, we can re-allocate cognitive resources away from maintaining that information and focus instead on remembering new information.”

In effect, our mind is treating computers and drives as an extension of our memory, so people might actually be protecting themselves from the costs of forgetting while taking advantage of the benefits, including creativity. Though I’ve yet to find a similar study, I’m willing to bet a similar effect might be witnessed if digital files would be replaced by physical ones, i.e. telling the students they could keep a sheet of paper with the nouns from PDF A.

“Coming up with a new idea or solving a problem often requires that we think outside the box, so to speak, and forgetting previous information allows us to do that,” says Storm. “By helping us to reduce the accessibility of old information, saving may facilitate our ability to think of new ideas and solve difficult problems.”

Memory palace and the limits to human memory

Ailin Moser, daughter of 2014 Nobel Laureates May-Britt and Edvard Moser, drew this picture of a house to illustrate how the method of loci works. If you wanted to remember the countries of South America, for example, you might imagine a seal playing a brass instrument in one room in your house to remember Brazil, and chili peppers in another room to remember Chile. (Credit: Image:Ailin Moser)

Ailin Moser, daughter of 2014 Nobel Laureates May-Britt and Edvard Moser, drew this picture of a house to illustrate how the method of loci works. If you wanted to remember the countries of South America, for example, you might imagine a seal playing a brass instrument in one room in your house to remember Brazil, and chili peppers in another room to remember Chile. (Credit: Image:Ailin Moser)

In other related news, a new study published by the 2014 Nobel Laureates May and Britt Moser from the Norwegian University of Science and Technology discusses how the brain is such a great info sorter, allowing similar memories to be distinguished from one another.

The team tested rats’ ability to distinguish between similar, but distinct locations. Experiments were performed on seven lab rats which were placed in 11 similar rooms over the course of two days. While the rats were pursuing chocolate crumbs around the tiny rooms, researchers recorded their brain activity particularly in the CA3 place cells in the hippocampus. This is a good time to mention that memories are stored in individual brain cells and, as the name suggests, place cells are neurons that fire when a particular spatial memory is called.

It was found that while the rooms were very similar to one another, the rats still managed to create separate and distinct maps for each environment. For instance, when a rat was reintroduced into a room it had explored before, that distinct spatial map from the rat’s first exposure to the room was reactivated.

“We investigated whether these memories overlapped across some rooms, but all of the memories were completely independent,” said the paper’s first author, Charlotte Alme. “This indicates that the brain has an enormous capacity for storage. The ability to create a unique memory or map for every locale explains how we manage to distinguish between very similar memories and how the brain prevents us from mixing up events.”

The findings explain why memory tricks like the method of lori work so well. The method of lori helps you memorize information by placing each item to be remembered at a point along an imaginary journey. The information can then be recalled in a specific order by retracing the same route through the imaginary journey. These  imaginary journeys are often referred to as Memory Palaces or Memory Journeys, a reference you might recall from the movie Inception. For instance, say you want to memorize a list of 24 nouns in that particular order. Simply memorizing these by heart will certainly lead to failure, unless your an autistic savant. Instead, you could add each of these nouns in a familiar story – like your morning routine. Say the first three nouns you need to memorize are “elephant”, “jacket” and “cup”. You could easily memorize these by recalling an imaginary story that fits with your morning routine. “The first thing I did when I woke up was go to the bathroom and stare at my big elephant ears for a while. Then I brushed my teeth, a quickly put on my jacket to leave for work, but had to skip my regular cup of coffee because I was in a hurry.” In this particular rendition, you might find yourself in a imaginary world where you’re leaving the house with nothing on but your underwear and jacket, but that’s sort of acceptable since you didn’t get to have your morning coffee. You get the idea, nevertheless.

The findings made by the Norwegian researchers explain why associating individual memories with different rooms in your house, for example, can make it easier to recall them later. You just need to remember by mentally walking through your house and visiting each room.

“Our paper shows that rats (and most likely humans) have a map for each individual place, which is why the method of loci works,” she said. “Each place (or room in your house) is represented by a unique map or memory, and because we have so many different maps we can remember many similar places without mixing them up.”

You might have heard about studies that try to quantify human memory storage, with some reaching figures like  2.5 petabytes (or a million gigabytes). This means if your brain worked like a digital video recorder in a television, 2.5 petabytes would be enough to hold three million hours of TV shows, meaning you would have to leave the TV running continuously for more than 300 years to use up all that storage. However, the brain isn’t a digital video recorder. It’s not even a computer, despite the often portrayed analogy. These sort of assessments and estimates are based on the number of neurons in the brain, but apart from being fun, they’re far from being insightful. It’s only until we simulate the human brain that we might have an idea of what our information storage limits are.  “A personal memory is not a blueprint but rather a  dynamic reconstruction of what happened when and where. Memories change with time,” Alme said for KurzweilAI.

The most exotic material on the planet: researchers find dust from beyond the solar system

Seven particles of dust brought back to Earth by a spacecraft nearly a decade ago appear originate from beyond our solar system. The exotic dust was identified by researchers with the help of 30,000 worldwide citizens.

An optical microscope image of a track through aerogel made by Orion, one of the dust particles believed to be from interstellar space. Photograph: D Frank/Nasa/JSC

The material was collected by the Stardust spacecraft, a 300-kilogram robotic space probe launched by NASA on February 7, 1999. Its primary mission was to collect dust samples from the coma of comet Wild 2, as well as samples of cosmic dust, and return these to Earth for analysis. It was the first such spacecraft of its kind. It featured detectors which worked like cosmic fly-paper, gathering as much dust as possible. In 2006, the shuttle parachuted the detectors onto Earth, where they started to be analyzed.

The specks have all the hallmarks of being created in interstellar space. If the analysis is confirmed, it would be the first time interstellar particles are brought back to Earth to be studied. The dust was probably created by a supernova explosion millions of years ago and shaped by exposure to the harsh extremes of space.

“These are very precious particles,” said Andrew Westphal, a physicist at the University of California in Berkeley, who worked on the dust.

Virtually everything we know about interstellar matter, either ground based, or with space telescopes; studying it directly could provide valuable insights.

 “We seem to be getting our first glimpse of the surprising diversity of interstellar dust particles, which is impossible to explore through astronomical observations alone,” Westphal added.

Aside for these exotic particles, researchers found  more than 50 other particles of spacecraft debris in the Stardust detectors, according to a report published in ScienceAnton Kearsley, a microanalyst who took part in the study at the Natural History Museum in London, says that identifying them is a huge challenge:

“In the end, 30,000 people around the world worked through thousands of digital microscope images of the main part of the collector, the aerogel, and eventually found the tracks that included interstellar dust particles,” he said.

“As the results came in, the numbers and sizes of dust grains were not what we’d expected, and many seemed to have come from strange directions,” he added. “Only by careful plotting of impact directions was the team able to identify the seven particles that must have come from outside the solar system.”

Newton's laws, atoms.

Researchers detect the smallest force ever recorded

Researchers have detected the smallest force ever recorded – 42 yoctonewtons – using a system of super-cooled atoms.

Yocto-what?

Newton force quantum scale

Newton’s laws don’t really stand anymore when you get to small enough scales. Mechanical oscillators translate an applied force into measureable mechanical motion. The Standard Quantum Limit is imposed by the Heisenberg uncertainty principle, in which the measurement itself perturbs the motion of the oscillator, a phenomenon known as “quantum back-action.”
Credit: Image by Kevin Gutowski

The Newton, named after sir Isaac Newton, is the international unit of measure for force. 1 Newton is equal to 1 kilogram times 1 meter over 1 second square (1N = 1 kg * 1 m / s^2). A yoctonewton is one septillionth of a newton – or in other words, 0.000000000000000000000001 newtons.

Scientists working at the Lawrence Berkeley National Laboratory (Berkeley Lab) and the University of California (UC) Berkeley used a system of lasers and a cloud of ultracold atoms to measure the force.

“We applied an external force to the center-of-mass motion of an ultracold atom cloud in a high-finesse optical cavity and measured the resulting motion optically,” says Dan Stamper-Kurn, a physicist who holds joint appointments with Berkeley Lab’s Materials Sciences Division and the UC Berkeley Physics Department. “When the driving force was resonant with the cloud’s oscillation frequency, we achieved a sensitivity that is consistent with theoretical predictions and only a factor of four above the Standard Quantum Limit, the most sensitive measurement that can be made.”

This is not just a significant breakthrough in itself, but it could have significant results in the future. As scientists study (directly or indirectly) more and more tiny things, more accurate ways of detecting forces and interactions are necessary. For example, at the Laser Interferometer Gravitational-Wave Observatory (LIGO), scientists are attempting to record motions as small as one thousandth the diameter of a proton.

Changing things by measuring them

However, there’s a big problem with measuring tiny things. As you get to smaller and smaller scales, quantum effects start to kick in – and they can really mess things up. According to the Heisenberg uncertainty principle, you change the outcome of a value if you measure it – yes, that’s how quantum mechanic works sometimes. As these measurements of force are done with mechanical oscillators, when you get to the quantum scale, the measurement itself affects the osscilator. This barrier is called the Standard Quantum Limit (SQL). In the past couple of decades, scientists have come up with a myriad of creative (yet imperfect) ways of working around the SQL. However, none of them came even close, failing by over 6 orders of magnitude! Until now, that is.

“We measured force with a sensitivity that is the closest ever to the SQL,” says Sydney Schreppler, a member of the Stamper-Kurn research group and lead author of the Science paper. “We were able to achieve this sensitivity because our mechanical oscillator is composed of only 1,200 atoms.”

In their experiments, they set up two equal and opposite optical fields and applied them onto a gas of rubidium atoms optically trapped and chilled to nearly absolute zero. The response is measured using a probe beam with a wavelength of 780 nanometers.

“When we apply an external force to our oscillator it is like hitting a pendulum with a bat then measuring the reaction,” says Schreppler. “A key to our sensitivity and approaching the SQL is our ability to decouple the rubidium atoms from their environment and maintain their cold temperature. The laser light we use to trap our atoms isolates them from external environmental noise but does not heat them, so they can remain cold and still enough to allow us to approach the limits of sensitivity when we apply a force.”

He believes that they can go even closer to the SQL, though not much closer.

“A scientific paper in 1980 predicted that the SQL might be reached within five years,” Schreppler says. “It took about 30 years longer than predicted, but we now have an experimental set-up capable both of reaching very close to the SQL and of showing the onset of different kinds of obscuring noise away from that SQL.”

Brain Movie

Brain imaging reveals the movies inside our mind

Brain Movie

Mixing in a typical fMRI brain scanner with advanced computer modeling simulations, scientists at the University of California have managed to achieve the the unthinkable – render the visual expressions triggered inside the brain and play them like a movie. This is the forefront technology which will one day allow us to tap inside the mind of coma patients or be able to watch the dream you had last night and still vaguely remember, just like a plain movie. Quite possibly one of the most fascinating SciFi ideas might become a matter of reality in the future.

“This is a major leap toward reconstructing internal imagery,” said Professor Jack Gallant, a UC Berkeley neuroscientist and coauthor of the study published online today (Sept. 22) in the journal Current Biology. “We are opening a window into the movies in our minds.”

This comes right on the heels of a recent, comparatively amazing study, from Princeton University who’ve managed to tell what study participants were thinking about, using a fMRI and a lexical algorithm. The neuroscientists from University of California have taken this one big step farther by visually representing what goes on inside the cortex.

A Sci-Fi dream come true that might show your dreams, in return

They first started out with a pictures experiment, showing participants black and white photos. After a while the researchers’ system allowed them to pick with absolute accuracy  which picture the subject was looking at. For this latest one, however, scientists had to surrmount various difficult challenges which come with actually decoding brain signals generated by moving pictures.

“Our natural visual experience is like watching a movie,” said Shinji Nishimoto, lead author of the study and a post-doctoral researcher in Gallant’s lab. “In order for this technology to have wide applicability, we must understand how the brain processes these dynamic visual experiences.”

Nishimoto and two other research team members served as subjects for the experiment, as they stepped inside the fMRI for the experiments which requires them to sit still for hours at a time. During their enclosed space inside the fMRI, the scientists were presented with a few sets of Hollywood trailers, while blood flow through the visual cortex, the part of the brain that processes visual information, was measured. The brain activity recorded while subjects viewed the first set of clips was fed into a computer program that learned, second by second, to associate visual patterns in the movie with the corresponding brain activity.

A movie of the movie inside your head. Limbo!

The second phase of the experiment is where it all becomes very interesting, as it implies the movie reconstruction algorithm. Scientists fed 18 million seconds of random YouTube videos into the computer program so that it could predict the brain activity that each film clip would most likely evoke in each subject. Then based on the brain imaging delivered by the fMRI, the computer program would morph various frames it had already learn into what it believed best describes the brain pattern. The result was nothing short of amazing. Just watch the video below.

This doesn’t mean that this new technology developed by UC scientists is able to read minds or the likes and visually tape ones memories on a display. Such technology, according to the researchers, is decades away, but their studies will help pave the way for future such developments. As yet, the technology can only reconstruct movie clips people have already viewed.

“We need to know how the brain works in naturalistic conditions,” he said. “For that, we need to first understand how the brain works while we are watching movies.”

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