Stories tagged memory

Dec
13
2009

Flash memory: Today's content king.
Flash memory: Today's content king.Courtesy Nrbelex

MRAM

MRAM (magnetoresistive random access memory) flips the magnetisation of a region 180 degrees relative to another permanently magnetised region to store a 0 or a 1. MRAM is nanosecond fast but if made too small and close together will "cross talk".

FeRAM

FeRAM (ferroelectric random access memory) use small external electric fields to polarize ferroelectric crystals. FeRAMs low energy requirement and speed advantage is offset by the requirement that every memory bit requires a space hogging capacitor.

PCRAM

PCRAM (phase-change random access memory) use laser light or current to change a materials structure. If the current pulse is long, the material orders itself into its crystalline state (a conductor). If the pulse is short, the material cools abruptly into the amorphous state (an insulator). These memory regions can be made quite small, but the downside is that the melting requires lots of energy.

RRAM

RRAM (resistive random access memory) use high voltages to drive off or reabsorb oxygen bound within molecules like titanium oxide. When the oxygen leaves, it leaves behind holes in the crystal and excess electrons that are available for conduction. This process requires almost no electrical current, making them very energy efficient. Another exciting property is that RRAMs can represent more than a 0 or 1. They are able to adopt any number of values for their resistance (memristors) which could make them models for the analogue computational elements (synapses) inside the human brain.

Racetrack memory

Racetrack memory moves tiny domains of magnetism along wires. The domains are moved along the wire by a current and written or read when they pass sensor heads. If the wires can be coiled into 3 D, the memory per volume will increase several hundred times.

Source: New Scientist

Billion year memory chips

Berkeley Lab researchers have created a unique ultra-high density memory storage medium that can preserve digital data for a billion years. The new technology also has the potential to pack thousands of times more data into one square inch of space than today's chips.The technology could be on the market within the next two years.

Source: A Billion Year Ultra-Dense Memory Chip (Berkeley Lab)

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The video shows an iron nanoparticle, approximately 1/50,000th the width of a human hair, that in the presence of a low voltage electrical current can be shuttled back and forth inside a hollow carbon nanotube with remarkable precision.

Apr
06
2009

What if your doctor could prescribe a pill that would erase any and all of your worst memories instantly?!

Rather than reliving it every single day, you could simply forget the time in 6th grade when you farted while doing sit-ups in gym class, and the day that your beloved cat Pookie was run down by your mother's Buick, and the boyfriend who broke your heart when he ran off to join the circus.

Rather than dwelling on bad memories, you could forget about them and move on to live the rest of your happy sunshiny life.

While it may sound like the plot of a certain indie film, brain scientists at a lab in Brooklyn are working on a scientific breakthrough that may make all of this possible. They've discovered that a chemical in the brain called PKMzeta acts like a speed dial to all of our worst (and best) memories. When a drug called ZIP is injected directly into the brain, memories are blocked and viola! No more dwelling on the painful, embarrassing, traumatic past.

Nevermind that it isn't quite that simple, or that this method has only been tested on rats, or that it involves a chemical being injected directly into the brain. It's from Brooklyn, so you know it'll be on the gifts & novelties table at Urban Outfitters just in time for the holidays. In fact, I can already see the marketing campaign involving lots of waifish models who apparently forgot to eat.

While this kind of 'made to order' miracle memory eraser won't be hitting the shelves anytime soon, there is a whole lot of money being spent on research that aims to better understand how memory works inside our brains. The reason that scientists want to know how memory works is that memory is so important to our emotions, our ability to learn, our spatial knowledge, our motor skills and much much more. When it isn't working as it should be, all kinds of problems can result.

For some people, painful and traumatic memories can wreak havoc on their emotional and social lives. Post-Traumatic Stress Disorder and Depression are examples of diseases that involve the unconscious recall of frightening or upsetting memories. If these memories could be blocked, patients might experience a dramatically improved quality of life. Bad habits are also tied to our memories, since addictive behaviors are learned. If memories of experiences with drugs and alcohol could be blocked, some addicts might stand a better chance of recovery. And for those who suffer from Alzheimer's or Dementia, improvements in the understanding of memory could lead to new methods of memory enhancement, helping to reduce the impact of these diseases.

While plenty of good things will come from this kind of research, it also raises ethical questions. Any drug that can dramatically improve or block selected parts of our memory will inevitably find a commercial market among people who may not suffer from any disease at all. Students who can afford them might start taking memory enhancing drugs right before an exam, criminals might use memory blockers to short circuit the moral questions that arise from their behavior and ordinary people might be tempted to use memory blockers to forget painful or embarrassing moments, rather than learning from them.

To top it all off, since our good and bad memories are not neatly sorted for doctors to target, erasing painful memories would probably mean getting rid of some of the good ones as well. Sometimes it's hard to tell which is which, since good or bad, your memories make you who you are today.

Source: New York Times

Dec
28
2008

Graphene memory is smaller

Graphene transistors: Graphene is an atomic-scale chicken wire made of carbon atoms.
Graphene transistors: Graphene is an atomic-scale chicken wire made of carbon atoms.Courtesy Carbophiliac
Computer memory devices become cheaper, faster, and smaller every year. A team of researchers at Rice University led by James Tour has found a method of creating a new type of memory from a strip of graphite only 10 atoms thick. Individual memory bits smaller than 10 nanometers that have only two terminals will allow super thin sheets of memory to be stacked in layers, multiplying the storage capacity.

Graphene memory is resistant to heat and cold

The graphene memory is able to operate in a very wide temperature range. The researchers have tested the system to minus 75 to over 200 degrees Celsius.

Graphene memory is faster and lasts longer

Researchers say that the new switches are faster than the lab's testing equipment can measure and they promise long life as well.

"We’ve tested it in the lab 20,000 times with no degradation,” said Tour. “Its lifetime is going to be huge, much better than flash memory."

Graphene memory is cheap and easy to produce

"The processes uses graphene deposited on silicon via chemical vapor deposition making for easy construction that can be done in commercial volumes with methods already available," says Tour.

Abstract of Rice University article in Nature

Here, we report that two-terminal devices consisting of discontinuous 5–10 nm thin films of graphitic sheets grown by chemical vapour deposition on either nanowires or atop planar silicon oxide exhibit enormous and sharp room-temperature bistable current–voltage behaviour possessing stable, rewritable, non-volatile and non-destructive read memories with on/off ratios of up to 107 and switching times of up to 1 mus (tested limit). Nature Materials

Source: Rice University News

Sep
09
2008

That hint of a smile?: That's from the happy memories. Those people in the background? Those are the bad memories getting ready.
That hint of a smile?: That's from the happy memories. Those people in the background? Those are the bad memories getting ready.Courtesy Bistrosavage
Scientists have discovered what I’m calling a magic potion that has the remarkable affect of strengthening memories you acquire before drinking it, and weakening the recollection of events that occur afterwards.

The name of this potion? We call it whisky.

We also call it beer, wine, and liquor of all stripes. Indeed, we call it alcohol.

What’s new here? Time and time again, we wake up wearing women’s clothing (or not wearing women’s clothing) and we think, “Sure, I’m wearing a dress, but how exactly did this happen? The last thing I remember is drinking some sort of magic potion…” The effects of alcohol on the memories of what happens afterwards are pretty well documented, even if the memories themselves aren’t. What’s new is the finding that consuming alcohol seems to reinforce memories formed before drinking. Memories like, “this is a sharp new pair of men’s slacks I’m wearing,” or “it doesn’t look like I’m going to embarrass myself tonight.”

Although the specific mechanisms through which alcohol affects memory are still not fully understood, the research works pretty well in explaining why people tend to continue drinking even if they’ve had bad experiences with it in the past—pleasant memories associated with pre-drinking time, like socializing with friends, are very strong, while the less enjoyable experiences after drinking, like struggling to unlock what may or may not be the door to your own apartment, quickly fade away.

The findings also seem to correspond with a study I did a post on last year regarding sad, drunk rats. The major difference, as far as I can see, has to do with the fact that rats very rarely wear women’s clothing. (I assume this is only because of the scarcity of specialty stores.)

French researchers have found a link between smoking and memory loss for people between the ages of 35 and 55.

Jun
12
2008

Do you remember us?: "I'm Ringo." "I'm Paul." "I'm George." "And I'm John, and we're the Beatles."
Do you remember us?: "I'm Ringo." "I'm Paul." "I'm George." "And I'm John, and we're the Beatles."Courtesy biggeststars
Scientific studies, for the most part, aren’t all that much fun, right? We get poked and prodded by high tech equipment, injected with foreign substances and shaken or stirred about

But how about recalling your favorite memories related to Beatles music? Yes, there is such a study going on right now and you can get involved at absolutely no cost.

More precisely, the Magical Memory Tour wants to analyze the dynamics of human memory using Beatles songs, movies, concerts and news clips as the focal point. By visiting the research project website, you can include your own specific Beatles memories, read and rate other peoples memories and learn about human memory works.

The researchers will be analyzing which types of experiences evoked from Beatles moments create the most intense memories. More specifically, they want to see how experiences from our lives can be associated with music, personality and public perception of the Beatles.

FYI: Here is a list of the top 10 topic areas of memories associated with the Beatles that the project has amassed through the website so far:

1. John Lennon - in memoriam
2. Help!
3. Television appearances
4. Yellow Submarine
5. The White Album
6. Revolver
7. Magical Mystery Tour
8. Yesterday
9. The Beatles Songbook
10. Octopuses Garden

And of course, you’re always welcome to share your favorite Beatles memories here with other Science Buzz readers.

Neuroscientist Joseph LeDoux has found a way for rats to overcome their fears by blocking their memories. This may lead to treatments for humans.

Dec
04
2007

What are you looking at smarty pants?: So you humans think you're smarter than me, huh? Well I dare you to challenge me in a memory test. Common, I dare you.
What are you looking at smarty pants?: So you humans think you're smarter than me, huh? Well I dare you to challenge me in a memory test. Common, I dare you.Courtesy deVos
Next time you’re having a short-term memory crisis, like trying to remember where you last put your car keys, try to think more like a chimp.

At least that’s a conclusion you can draw from the recent study done by Japanese researchers. Young chimps outperformed human adults in a two different tests of short-term memory abilities.

Here’s what happened. Researchers used three 5-year-old chimps that had been taught the numeric order of the numerals 1 to 9. They also had a group of a dozen adult humans.

Participants saw the nine numbers displayed on a computer screen. The moment that they touched “1,” the other numerals turned into white boxes and the participants had to touch those boxes in numeric order.

While there was no difference in the accuracy of the task between chimps and humans, the chimps could do it faster. And chimp Ayumu was by far the best, so researchers pitted him against humans in another task.

In the second test, the numbers 1 to 5 flashed briefly on the screen and then changed to white boxes. Participants again had to touch the boxes in the order of their corresponding numeral.

When the time between number and box was set at seven-tenths of a second, both Ayumu and the chimps were accurate about 80 percent of the time. But when the time between the flash was cut by one-third or one half, Ayumu was still accurate about 80 percent of the time while the humans dropped down to 40 percent.

In even further testing, three humans were given six weeks of training on the number flashing tests, but still could not catch up to the speed or accuracy of the chimps.

Here's a link to a collection of video footage of the chimps and humans doing the memory tasks.

The researchers think there are two main factors accounting for this significant difference between chimps and humans.

1) Through evolution of our brains, humans have developed language abilities that have squeezed out some brain processing for short-term memory like this tests gauge.

2) Young humans might be a fairer test against young chimps. Memory of images and shapes is skill more often found in children, but diminishes with age. In further testing, the researchers found that young chimps were better at the tests than older chimps.

The conclusion I’m drawing from all of this – I don’t want to square off against a young chimp in a game of Concentration, that’s for sure.

What do you think about all of this? Share your thoughts here with other Science Buzz readers.

Here's the link to the USA Today story on this research project.

Sep
30
2007

Drowning his sorrows: Sorry, little buddy, but it won't work.  (Photo courtesy of AlexK100 on flickr.com)
Drowning his sorrows: Sorry, little buddy, but it won't work. (Photo courtesy of AlexK100 on flickr.com)
Scientists are giving alcohol to little ratsies and discovering that drinking may, in fact, strengthen memory. At first glance, this flies in the face of hundreds of years of college students waking up with skinned knees, burned fingers, and mystery bruises, and then wondering how they possibly could have obtained them, but the methods employed by Ohio State researchers are hilarious enough, in a casual cruelty kind of way, that one has to take notice.

The researchers found that moderate consumption of alcohol seems to benefit memory, while the consumption of large amounts tends to impair it, except in situations involving “heightened emotion.”

These conclusions were reached by giving rats liquid food solutions containing 0, 2.5, or 5 percent alcohol. According to their report, “the lower dose of alcohol is equivalent to a couple of glasses of wine a day and produces blood-alcohol levels well below typical legal driving limits. The higher dose gave the rats equivalent blood-alcohol levels well above the driving limits.”

I wasn’t aware rats were even legally able to drive in the first place, but, then again, I’ve never been to Ohio.

The moderate drinking rats were found to have improved “neutral” memory (like the ability to recall the location of objects), as well as “emotional” memory (the emotional incident apparently being an electric shock to the foot). The heavy drinking rats were less able to remember the location of objects, but recalled the emotional memory (electrocution) very well.

The researchers think that the benefit of moderate drinking may be from the brain sensing the alcohol as a mild injury, and becoming stronger as a response – sort of like physical exercise, where muscles are challenged and then strengthen.

Apparently the idea of “drinking to forget” only works if you’re a very committed drinker, and even then you probably won’t forget your divorce. Finding your keys will be more difficult, though.

This all, of course, leaves the rats in something of a bind. With self-medication out of the picture, one wonders how they’re supposed to deal with the boozy food, as well as the constant electrocutions and memory tests. Talk therapy might be less than adequate.