Tag Archive: Memory


The Alpha IMS retinal prosthesis, implanted in a human patient

DARPA, at the behest of the US Department of Defense, is developing a black box brain implant — an implant that will be wired into a soldier’s brain and record their memories. If the soldier then suffers memory loss due to brain injury, the implant will then be used to restore those memories. The same implant could also be used during training or in the line of duty, too — as we’ve reported on in the past, stimulating the right regions of the brain can improve how quickly you learn new skills, reduce your reaction times, and more.

The project, which DARPA has wittily named Restoring Active Memory, is currently at the stage where it’s seeking proposals from commercial companies that have previously had success with brain implants, such as Medtronic. As yet, we don’t know who has submitted proposals to DARPA, but it’ll probably be the usual suspects. Medtronic, which creates deep-brain simulation (DBS) implants that are almost miraculous in their ability to control the debilitating effects of Parkinson’s disease (video embedded below), is surely interested. Brown University, which famously created a brain-computer interface that is implanted into the brain and communicates wirelessly with a nearby computer, must be a contender. Companies with big R&D budgets, like IBM and GE, might be involved as well.

Continue reading

Many of us are the bearers of “bad” memories that, to this day, continue to affect our lives. Now, scientists say they have discovered a gene essential for “memory extinction,” the process by which our brain replaces older memories with new experiences.

Researchers from the Massachusetts Institute of Technology (MIT) say the discovery could help people suffering from post-traumatic stress disorder (PTSD) by replacing “fearful” memories with more positive associations.

The gene, Tet1, has been found to play a critical role in memory extinction by controlling a small group of other genes that are necessary for the process. For the study, published in the journal Neuron, the research team experimented on mice who had the Tet1 gene “knocked out,” as well as on mice who had normal levels of the gene.

In order to measure the mice’s ability to abolish memories, the mice were “conditioned” to fear a certain cage in which they received a small electric shock. Once the memory of the “cage shock” was formed, the mice were placed into the cage, but the researchers did not give them the shock.

The researchers found that after a period of time, mice with normal Tet1 levels appeared to lose their fear of the cage, indicating that new memories replaced the old ones.

Li-Huei Tsai, director of MIT’s Picower Institute for Learning and Memory, explains:

“What happens during memory extinction is not erasure of the original memory. The old trace of memory is telling the mice that this place is dangerous. But the new memory informs the mice that this place is actually safe. There are two choices of memory that are competing with each other.” Continue reading

A team of scientists reporting in the journal Biological Psychiatry has been able to erase dangerous drug-associated memories in mice and rats without affecting other more benign memories.

The new study provides a potential approach for the selective treatment of unwanted memories associated with psychiatric disorders that is both selective and does not rely on retrieval of the memory. Image credit: Katsushi Arisaka / University of California, Los Angeles.

The surprising discovery points to a clear and workable method to disrupt unwanted memories while leaving the rest intact.

“Our memories make us who we are, but some of these memories can make life very difficult. Not unlike in the movie Eternal Sunshine of the Spotless Mind, we’re looking for strategies to selectively eliminate evidence of past experiences related to drug abuse or a traumatic event. Our study shows we can do just that in mice – wipe out deeply engrained drug-related memories without harming other memories,” said senior author Dr Courtney Miller of the Scripps Research Institute.

To produce a memory, a lot has to happen, including the alteration of the structure of nerve cells via changes in the dendritic spines – small bulb-like structures that receive electrochemical signals from other neurons. Normally, these structural changes occur via actin, the protein that makes up the infrastructure of all cells.

Dr Miller’s team inhibited actin polymerization – the creation of large chainlike molecules – by blocking a molecular motor called myosin II in the brains of mice and rats during the maintenance phase of methamphetamine-related memory formation. Behavioral tests showed the animals immediately and persistently lost memories associated with methamphetamine, with no other memories affected.

Continue reading

a mouse hippocampus (where memories are stored in mammals)

Scientists have created a false memory in mice by manipulating neurons that bear the memory of a place. The work further demonstrates just how unreliable memory can be. It also lays new ground for understanding the cell behavior and circuitry that controls memory, and could one day help researchers discover new ways to treat mental illnesses influenced by memory.

In the study, published in Science on Thursday, the MIT scientists show that they can modify a memory and have a mouse believe it experienced something it didn’t. Susumu Tonegawa, a neuroscientist at MIT, and members of his lab used mice that were genetically modified to allow for certain neurons to be activated with a flash of light; the technique enabled the researchers to activate a memory that caused a mouse to believe it had experienced electrical shocks in a particular box, even though no such thing had happened there. “The process of memory is nothing like a tape recording,” says study co-first author Steve Ramirez. “It’s really malleable and susceptible to the incorporation of new information.”

The results are “really mind-blowing,” says Sheena Josselyn, a neuroscientist at the Hospital for Sick Children in Toronto. “It shows that your memories are really just activities of different cells, and they can take the place of an actual thing that happened by just activating some cells in the brain,” she says. “People have been playing around with this idea for a while, but having a theory and showing it are two different things.”

Continue reading

5dopticalmem

Using nanostructured glass, scientists at the University of Southampton have, for the first time, experimentally demonstrated the recording and retrieval processes of five dimensional digital data by femtosecond laser writing. The storage allows unprecedented parameters including 360 TB/disc data capacity, thermal stability up to 1000°C and practically unlimited lifetime.

Coined as the ‘Superman’ memory crystal’, as the glass memory has been compared to the “memory crystals” used in the Superman films, the data is recorded via self-assembled nanostructures created in fused quartz, which is able to store vast quantities of data for over a million years. The information encoding is realised in five dimensions: the size and orientation in addition to the three dimensional position of these nanostructures.

A 300 kb digital copy of a text file was successfully recorded in 5D using ultrafast laser, producing extremely short and intense pulses of light. The file is written in three layers of nanostructured dots separated by five micrometres (one millionth of a metre).

The self-assembled nanostructures change the way light travels through glass, modifying polarisation of light that can then be read by combination of optical microscope and a polariser, similar to that found in Polaroid sunglasses.

Continue reading

Neuroscientists at The University of Texas Health Science Center at Houston (UTHealth) have taken a major step in their efforts to help people with memory loss tied to brain disorders such as Alzheimer’s disease.

Using sea snail nerve cells, the scientists reversed memory loss by determining when the cells were primed for learning. The scientists were able to help the cells compensate for memory loss by retraining them through the use of optimized training schedules. Findings of this proof-of-principle study appear in the April 17 issue of The Journal of Neuroscience.

“Although much works remains to be done, we have demonstrated the feasibility of our new strategy to help overcome memory deficits,” said John “Jack” Byrne, Ph.D., the study’s senior author, as well as director of the W.M. Keck Center for the Neurobiology of Learning and Memory and chairman of the Department of Neurobiology and Anatomy at the UTHealth Medical School.

This latest study builds on Byrne’s 2012 investigation that pioneered this memory enhancement strategy.  The 2012 study showed a significant increase in long-term memory in healthy sea snails called Aplysia californica, an animal that has a simple nervous system, but with cells having properties similar to other more advanced species including humans.

Continue reading

UCLA researchers have for the first time measured the activity of a brain region known to be involved in learning, memory and Alzheimer’s disease during sleep. They discovered that this part of the brain behaves as if it’s remembering something, even under anesthesia, a finding that counters conventional theories about memory consolidation during sleep.

The research team simultaneously measured the activity of single neurons from multiple parts of the brain involved in memory formation. The technique allowed them to determine which brain region was activating other areas of the brain and how that activation was spreading, said study senior author Mayank R. Mehta, a professor of neurophysics in UCLA’s departments of neurology, neurobiology, physics and astronomy.

In particular, Mehta and his team looked at three connected brain regions in mice — the new brain or the neocortex, the old brain or the hippocampus, and the entorhinal cortex, an intermediate brain that connects the new and the old brains. While previous studies have suggested that the dialogue between the old and the new brain during sleep was critical for memory formation, researchers had not investigated the contribution of the entorhinal cortex to this conversation, which turned out to be a game changer, Mehta said. His team found that the entorhinal cortex showed what is called persistent activity, which is thought to mediate working memory during waking life, for example when people pay close attention to remember things temporarily, such as recalling a phone number or following directions.

“The big surprise here is that this kind of persistent activity is happening during sleep, pretty much all the time.” Mehta said. “These results are entirely novel and surprising. In fact, this working memory-like persistent activity occurred in the entorhinal cortex even under anesthesia.”

Continue reading

Is it possible to know where you’ve been when you don’t have a brain? Depending on your definition of “know,” the answer may be yes. Researchers have shown that the slime mold, an organism without anything that resembles a nervous system (or, for that matter, individual cells), is capable of impressive feats of navigation. It can even link food sources in optimally spaced networks. Now, researchers have shown it’s capable of filling its environment with indications of where it has already searched for food, allowing it to “remember” its past efforts and focus its attention on routes it hasn’t explored.

And it does this all using, as the authors put it, “a thick mat of nonliving, translucent, extracellular slime.” As you might expect, given the name.

Slime molds are odd creatures: organisms that have a nucleus and complex cells, but are evolutionarily distant from the multicellular animals and plants. When food is plentiful, they exist as single-celled, amoeba-like creatures that forage on the food. But once starvation sets in, the cells send out a signal that causes them to aggregate and fuse. This creates an organism that’s visible to the naked eye and all a single cell, but filled with nuclei containing the genomes of many formerly individual cells. That turns out to be advantageous, because this collective can move more efficiently, and go about foraging for food. In the course of this foraging, the organism leaves behind a trail of slime.

Continue reading

Researchers at Rice University are designing transparent, two-terminal, three-dimensional computer memories on flexible sheets that show promise for electronics and sophisticated heads-up displays.

The technique based on the switching properties of silicon oxide, a breakthrough discovery by Rice in 2008, was reported today in the online journal Nature Communications.

The Rice team led by chemist James Tour and physicist Douglas Natelson is making highly transparent, nonvolatile resistive memory devices based on the revelation that silicon oxide itself can be a switch. A voltage run across a thin sheet of silicon oxide strips oxygen atoms away from a channel 5 nanometers (billionths of a meter) wide, turning it into conductive metallic silicon. With lower voltages, the channel can then be broken and repaired repeatedly, over thousands of cycles.

That channel can be read as a “1″ or a “0,” which is a switch, the basic unit of computer memories. At 5 nm, it shows promise to extend Moore’s Law, which predicted computer circuitry will double in power every two years. Current state-of-the-art electronics are made with 22 nm circuits.

The research by Tour, Rice’s T.T. and W.F. Chao Chair in Chemistry as well as a professor of mechanical engineering and materials science and of computer science; lead author Jun Yao, a former graduate student at Rice and now a post-doctoral researcher at Harvard; Jian Lin, a Rice postdoctoral researcher, and their colleagues details memories that are 95 percent transparent, made of silicon oxide and crossbar graphene terminals on flexible plastic.

The Rice lab is making its devices with a working yield of about 80 percent, “which is pretty good for a non-industrial lab,” Tour said. “When you get these ideas into industries’ hands, they really sharpen it up from there.”

Continue reading

The Design Museum has partnered with Swarovski for an experiment examining the perception of memories in the digital age. Digital Crystal: Swarovski At Design Museum includes 15 incredible installations from contemporary designers recovering the lost connection between objects and time. Deyan Sudjic, director of the Design Museum, explains main idea behind the exhibition:

Digital Crystal: Swarovski at the Design Museum explores the meaning of memory in the digital age, with the demise of the analogue era our relationship and connection with personal memory, photographs, diaries, letters, time and ephemera is changing. The exhibition takes this as its starting point, to question the future and our relationship with the changing world, where it seems all too easy to lose connection with the tangible and the real, as we move ever faster to a digital age where memory and the personal possessions we once held so highly are now online or gone in an instant.

Each designer responded to the brief in extremely different ways. Ron Arad created Lolita (pictured below), a chandelier with more than 2,000 Swarovski crystals and 1,000 white LEDs, which convert the object into a giant interactive pixel board. The chandelier was originally created for Swarovski Crystal Place in 2004, but Arad has repurposed his creation to display tweets (#DigitalCrystal) and SMS messages.

Continue reading

“This is the first time anyone has found a way to store information over seconds about both temporal sequences and stimulus patterns directly in brain tissue,” says Dr. Strowbridge. “This paves the way for future research to identify the specific brain circuits that allow us to form short-term memories.” Their study, entitled “Mnemonic Representations of Transient Stimuli and Temporal Sequences in Rodent Hippocampus In Vitro,” is slated for publication in the October issue of Nature Neuroscience, and is currently available online. Memories are often grouped into two categories: declarative memory, the short and long-term storage of facts like names, places and events; and implicit memory, the type of memory used to learn a skill like playing the piano. In their study, the researchers sought to better understand the mechanisms underlying short-term declarative memories such as remembering a phone number or email address someone has just shared. Using isolated pieces of rodent brain tissue, the researchers demonstrated that they could form a memory of which one of four input pathways was activated. The neural circuits contained within small isolated sections of the brain region called the hippocampus maintained the memory of stimulated input for more than 10 seconds. The information about which pathway was stimulated was evident by the changes in the ongoing activity of brain cells.

Continue reading

Scientists say they’ve been able to control specific memories in mice in research that they hope could help treat diseases such as schizophrenia and post traumatic stress disorder.

It’s long been known that stimulating various regions of the brain can trigger behaviors and even memories – but understanding how these brain functions develop and occur normally has been much harder.

“The question we’re ultimately interested in is: How does the activity of the brain represent the world?” says Scripps Research neuroscientist Mark Mayford.

“Understanding all this will help us understand what goes wrong in situations where you have inappropriate perceptions. It can also tell us where the brain changes with learning.”

The team set out to manipulate specific memories by inserting two genes into mice.

Continue reading

New connections between brain cells emerge in clusters in the brain as animals learn to perform a new task, according to a study published in Nature. Led by researchers at the University of California, Santa Cruz, the study reveals details of how brain circuits are rewired during the formation of new motor memories.

The researchers studied mice as they learned new behaviors, such as reaching through a slot to get a seed. They observed changes in the motor cortex, the brain layer that controls muscle movements, during the learning process. Specifically, they followed the growth of new “dendritic spines,” structures that form the connections (synapses) between nerve cells.

“For the first time we are able to observe the spatial distribution of new synapses related to the encoding of memory,” said Yi Zuo, assistant professor of molecular, cell and developmental biology at UC Santa Cruz and corresponding author of the paper.

In a previous study, Zuo and others documented the rapid growth of new dendritic spines on pyramidal neurons in the motor cortex during the learning process. These spines form synapses where the pyramidal neurons receive input from other brain regions involved in motor memories and muscle movements. In the new study, first author Min Fu, a postdoctoral researcher in Zuo’s lab, analyzed the spatial distribution of the newly formed synapses.

Continue reading

Efforts to help people with learning impairments are being aided by a species of sea snail known as Aplysia californica. The mollusk, which is used by researchers to study the brain, has much in common with other species including humans. Research involving the snail has contributed to the understanding of learning and memory.

At The University of Texas Health Science Center at Houston (UTHealth), neuroscientists used this animal model to test an innovative learning strategy designed to help improve the brain’s memory and the results were encouraging. It could ultimately benefit people who have impairments resulting from aging, stroke, traumatic brain injury or congenital cognitive impairments.

Continue reading

Doorwayblog

Ever get up to retrieve something from another room only to completely forget what you needed after crossing the doorway?

You’re not alone, and scientists think forgetful trips between rooms result from how our brains interpret spatial information.

Researchers already know that walking from one space to another makes people more likely to forget tasks when compared to others who don’t make such a transition. Called “location-updating effect,” the phenomenon also causes people transitioning between rooms (even virtual ones) to take more time while attempting to recall items from memory.

Moving from one space to another seems to cue the brain to refresh itself and pay attention to the new space, making it harder to recall information from the previous space. By then, the previous experience is already filed away in the brain’s working memory, which is why recalling what you need can seem unnecessarily arduous.

Continue reading

Follow

Get every new post delivered to your Inbox.

Join 256 other followers

%d bloggers like this: