Posts Tagged ‘memory’
The Recently Discovered Molecules That Could End Up Affecting Your Memory
Check out io9's feature for more on molecules like CaMKII, which leads to the inability to recall short-term memories associated with fear. (Curious about the moral side of that? Check out position.)
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Researchers Weave Wearable Memory Out of Copper
Scientists at NASA's Ames Research Center have created a proof-of-concept design for a flexible memory fabric made of platinum and woven copper and copper-oxide wires that form a memory circuit. In tests, this e-textile system was able to store information for more than 100 days, and was completely reversible and rewriteable.
To really become something we'd want to put on in the morning, though, the fabric needs to add a power source, sensors and computing ability. While a full-fledged computing suit may still be far away, the advances in textile tech are mounting, and it's only a matter of time.
[PhysOrg]
Researchers Weave Wearable Memory Out of Copper
Scientists at NASA's Ames Research Center have created a proof-of-concept design for a flexible memory fabric made of platinum and woven copper and copper-oxide wires that form a memory circuit. In tests, this e-textile system was able to store information for more than 100 days, and was completely reversible and rewriteable.
To really become something we'd want to put on in the morning, though, the fabric needs to add a power source, sensors and computing ability. While a full-fledged computing suit may still be far away, the advances in textile tech are mounting, and it's only a matter of time.
[PhysOrg]
"Time Cells" In the Brain Keep Track of Events, Firing As Time Goes By
In a new study involving rats, researchers at Boston University monitored neurons in the hippocampus, the center of memory and learning. Howard Eichenbaum and colleagues trained rats to perform a three-part task, which included a delay in the middle, . They learned to associate an object with an scent (a ball with oregano, for instance), and then they were presented with the object. The rats entered a separate chamber for 10 seconds, after which a doorway led them to a flowerpot full of scented sand. If the scent was the same as the object they’d been shown, the rats would dig for a food reward. The 10-second delay was at the heart of the study.
Eichenbaum et. al surgically implanted electrodes in the rats’ hippocampus, and monitored signals from 300 distinct neurons as the rats completed their work. During the delay, the researchers watched about a third of the cells continue to fire in a cascading pattern — suggesting the neurons were keeping track as time went by.
The hippocampus is known to have “place cells,” which keep track of locations and recalibrate when spatial cues are altered, the . In the same way, the time neurons continued to fire when the researchers lengthened the delay, “retiming” when temporal cues are altered. The hippocampus is considered the brain’s memory center, so it makes sense that there would be some mechanism for monitoring the variables that memory depends upon.
The neurons kept track of time in varying tests, but their firing patterns and the specific groups involved changed slightly, depending on which object was presented. This shows the neurons disambiguate different events, the researchers say: “(They) compose unique, temporally organized representations of specific experiences.” The research is reported in the journal Neuron.
So next time you say you’ve lost track of time, remember that you really haven’t — your biological clock has been ticking all the while.
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Controversy Should Not Stop Us From Developing Memory-Erasing Drugs, Neuroethicist Argues
The field of memory-altering drugs has been marching forward for years, and we’ve seen several recent developments that can change our recollection of fear or trauma. In one example, rats given a brain injection had their ; in another, researchers recently learned that a drug that suppresses stress hormones can interfere with the .
These types of drugs would have several uses, like helping military personnel overcome post-traumatic stress syndrome and return home to lead healthy lives; helping crime victims rehabilitate; and treating psychological disorders that might stem from some type of childhood trauma.
But many ethicists argue these kinds of drugs should not be developed. People have memories for a reason, and changing or erasing them alters something that makes us all human. Not to mention that a tool that can erase memories could easily be abused by people doing things they’d like to forget themselves, or that they would like others to forget.
Now neuroethicist and Brooklyn Law School professor Adam Kolber argues in this week’s issue of that this debate should stop. These drugs should be developed and made available as quickly as possible, he writes.
“Thoughtful regulation may some day be appropriate, but excessive hand-wringing now over the ethics of tampering with memory could stall research into preventing post-traumatic stress in millions of people. Delay could also hinder people who are already debilitated by harrowing memories from being offered the best hope yet of reclaiming their lives.”
He acknowledges concerns that changing one’s memories could change one’s identity, that giving people too much power to change their minds could “make their lives less genuine.” He also notes that soldiers may be less hesitant to kill if they knew they could erase the experience afterward. But still, he argues that memory-altering or memory-erasing treatments could do much more good than harm.
Of course, other neuroscientists disagree with his claims. The debate has mushroomed into the neuroscience blogosphere, with the British blogger noting that some people who experience bad things do it as part of a profession — rescue workers, for instance, would certainly know they might be exposed to traumatic experiences, and their choice to do so in the name of helping others is an expression of their identities. Kolber, for his part, responds on his own blog with other examples — like patients who remember their surgeries (about 20,000 to 40,000 people in the U.S., apparently).
Over at iO9, Kolber explains how these drugs could be used and how doctors and patients would decide when it's right to use them. for his full responses, and to read Kolbert's full commentary (login required).
Do you think memory-erasing drugs are a good idea? If you could fill a prescription for eternal sunshine pills, would you?
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IBM Demos Phase Change Memory That Reliably Packs Multiple Data Bits Into Single Cells
Like flash, PCM is a non-volatile memory technology. But PCM has the potential to blow flash performance out of the water. PCM could boost overall performance of backbone IT systems by orders of magnitude. Computers could boot instantaneously. The cloud could grow at rates that might actually keep up with all the stuff we’re shoveling into the cloud.
But phase change memory isn’t the simplest nut to crack (for fuller explanations of how it works, click through the link below. Or try ). Simply put, PCM takes advantage of the change in resistance that takes place when a material changes phases, in this case from a crystalline structure to an amorphous one. Crystalline structures exhibit high resistance and amorphous low resistance.
This range of resistance allows computer scientists to store more than one bit per memory cell, hence the huge jump in memory and performance. So in the IBM research to which we refer, scientists were able to store the bit combos “00,” “01,” “10,” and “11” in four distinct resistance levels of a single bit. It’s like a four-for-one deal.
The problem with PCM is that the resistance in the amorphous state tends to drift, rising over time and leading to read errors. That’s the real problem that was solved here: IBM’s novel read/write processes, rather than restricting resistance drift, are now coding in a drift-tolerant way. If the resistance shifts, it’s no big deal; the PCM’s long-term retention of usable, retrievable data is still solid.
This demo has been going on successfully for five months, long enough that IBM feels confident that it has a solution that really can hold data in PCM for extended periods. Of course research is ongoing, but if it proves as reliable as this first demo suggests, PCM could potentially become as ubiquitous as flash is today, doing a whole lot more with a lot less space.
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With an Artificial Memory Chip, Rats Can Remember and Forget At the Touch of a Button
The device can mimic the brain’s own neural signals, thereby serving as a surrogate for a piece of the brain associated with forming memories. If there is sufficient neural activity to trace, the device can restore memories after they have been lost. If it’s used with a normal, functioning hippocampus, the device can even enhance memory.
In the study, scientists at Wake Forest University and the University of Southern California trained rats to learn a task, pressing one lever after another to receive water. In a series of tests, the rats pressed one lever and were then distracted. They had to remember which one they’d already pressed and therefore which lever to press next, left or right, in order to receive their reward.
The team attached electrodes to the rats’ brains, connected to two areas in the hippocampus, called CA1 and CA3. Prior research has shown that the hippocampus converts short-term memory into long-term memory. The team recorded the signals between these regions as the rats performed their tasks, and then they drugged the rats so that the hippocampus regions could not communicate. The rats forgot which lever to press next, said Theodore Berger, a biomedical engineering professor at USC and lead author of the study, which is published in the Journal of Neural Engineering.
“The rats still showed that they knew ‘when you press left first, then press right next time, and vice-versa,’” Berger said. “And they still knew in general to press levers for water, but they could only remember whether they had pressed left or right for 5-10 seconds.”
Then, the team made an artificial hippocampus, which could duplicate the normal neural signals between the CA1 and CA3 regions. They turned it on, and replayed the previously recorded signal from CA1 — like a recorded message from the brain. The rats remembered.
“Flip the switch on, and the rats remember. Flip it off, and the rats forget,” Berger said.
Although this is a long way from being tested in humans, the research shows that if there’s enough information about the neural coding of memories, the signal patterns can be recorded and duplicated, and restored later through a neural implant. This could be difficult to do in patients with severely limited memory, as the points out — there needs to be a memory trace that can be recorded and amplified. But for patients with dementia, enhancing the memory-formation process can be useful — remembering where you put the keys, for instance, or where the bathroom is located. Simple memories like those could keep people independent for longer periods.
The researchers want to test the device in monkeys next, according to USC.