MIT researchers Steve Ramirez and Xu Liu recently made history when they successfully implanted a false memory into the mind of a mouse. The proof was a simple reaction from the rodent, but the implications are vast. They placed the furry little creature inside a metal box, and it froze, displaying a distinct fear response. The mouse was reacting as if it had received an electrical shock there, when it hadn’t at all.
What makes it more riveting is that their success was considered a long-shot. The hypothesis was that not only could they identify those neurons associated with encoding memory, but could essentially rewrite one. Experts say that this an impressive feat which helps uncover more of the mystery of how memory operates. Though neuroscientists have considered such a possibility for years, they never thought this kind of experiment could actually work.
This breakthrough was possible due to research out of Oxford which discovered exactly how short-term memories are transferred into long term memory. But the MIT researchers took it into an entirely new direction. Memories are actually stored in not one area, but certain groups of neurons known as engrams. Ramirez and Liu came together in 2010 and designed a new method for exploring live brains, to identify specific engrams. The neuroscientists used a newly minted technique called optogenetics, which employs lasers to stimulate genetically engineered cells designed to react to them.
Areas where the memory resides are highlighted in purple.
The scientists and their team injected a biochemical cocktail into the brains of special, genetically engineered mice. The cocktail contained a gene with a light sensitive protein called channelrhodopsin-2. This was injected into the dentate gyrus—the area in the hippocampus where memory is encoded. Then they implanted filaments into the mice’s skulls. These acted as a conduit for a laser. The researchers found they could reactivate a memory by flooding certain neurons with laser light.
In order to prove that they could identify certain engrams, they reactivated a memory associated with fear. After the experiment, the mice’s brain tissues were examined under a microscope. Those associated with a specific memory glowed green due to the injected chemical. Liu compared it to a “starry night” where you could view “individual stars.” The engram that glowed was associated with an electroshock to the foot, and so triggered the startle or fear response.
Now that they knew which engram was associated with fear, they set up an experiment to test it. After injecting the cocktail into the same region of the brain, they placed the mouse inside a metal box. This box was safe. The mouse was able to explore for 12 whole minutes with no problems. The next day, it was put in a different box but received an electric shock instead. These two boxes differed in color, shape, and scent, researchers assure. The following day, the same mouse was placed inside the safe box again, and would have remembered it as safe. But researchers activated the foot shock memory using a laser, initiating the fear response.
Networks of neurons lighting up.
Is a similar procedure conceivable for humans? According to Ramirez, “Because the proof of principle is there…the only leap left between there and humans is just technological innovation.” Today, over 20 labs around the world are building upon this research. In fact, a French team recently implanted false memories in the brains of sleeping mice. Howard Eichenbaum, the director of the Center for Neuroscience at Boston University, is going in another direction. He is working on recreating longer and larger memories, those experiences which unfold over time.
There are many positive implications such as the ability to take the bite out of or even erase those painful memories attached to PTSD, depression, and other psychiatric disorders. There may be applications for Alzheimer’s, reverse engineering memories lost to the disease. It even holds promise for those suffering from substance abuse disorder, allowing them to forget their addiction.
Even so, there are negative connotations too. As our memory is the glue which holds our identities together, wouldn’t erasing a memory, even a bad one, indelibly erase a portion of the person themselves? Though painful, our negative memories define us. Of course, those hobbled by depression or haunted by PTSD could come to see it as a saving grace. Today, scientists aim not to erase technically, at least at first, but to rewrite a memory in a manner that promotes, rather than impedes, mental health. But the potential is there. There are further implications.
A neuron associated with the fear response is illuminated.
What about implanting false memories in witnesses to change the outcome of trials? Many in the past have been convicted when they were innocent, exonerated later due to the advent of DNA testing. False memory implantation might lead to a new and ruthless form of witness tampering. Films like Inception or Eternal Sunshine could become a reality. But if you erase the memory of a bad ex from your past, do the lessons you’ve learned about love go with it?
There are implications in terms of state control and even the sovereignty of one’s own mind. Such a procedure under a totalitarian regime could manufacture false patriotism, even wipe clean the memories of revolutionaries in order to make them loyal to the state. The ability to actually do this is thought to be four to five decades away. Yet the federal research group DARPA says it is a mere four years from a brain implant capable of altering PTSD-related memories. Theoretically, such technology could be used to silence dissent.
Meanwhile, a psychology professor at New York University, Dr. Gary Marcus, has proposed inserting a microchip into the human brain to allow for a human-internet interface, making the mind a search engine as well as improving one’s memory. Perhaps you could backup files to prevent tampering. But wouldn’t it also allow a hacker to say hack your brain? An important ethical dialogue must begin now. A superstructure and strict protocol must be erected. And yet, chances are those operating outside of its boundaries may still violate it. Though this technique shows promise, strong regulation and oversight must be enacted to prevent human rights violations and miscarriages of justice.
For where we are right now on manipulating memory and the moral implications click here:
Arches of chaos in space manifolds.
Humanity could be making its way through the Solar System much faster thanks to the discovery of a new superhighway network among space manifolds. Don't get your engines roaring along this "celestial autobahn" just yet, but the researchers believe the new pathways can eventually be used by spacecraft to get to the outer reaches of our Solar System with relative haste.
The celestial highway could get comets and asteroids from Jupiter to Neptune in less than a decade. Compare that to hundreds of thousands or even millions of years it might ordinarily take for space objects to traverse the Solar System. In a century of travel along the new routes, a 100 astronomical units could be covered, project the scientists. For reference, an astronomical unit is the average distance from the Earth to the Sun or about 93 million miles.
The international research team included Nataša Todorović, Di Wu, and Aaron Rosengren from the Belgrade Astronomical Observatory in Serbia, the University of Arizona, and UC San Diego. Their new paper proposes a dynamic route, going along connected series of arches within so-called space manifolds. These structures, coming into existence from gravitational effects between the Sun and the planets, stretch from the asteroid belt to past Uranus.
The most pronounced of these structures are linked to Jupiter by its strong gravitational pull, explained UC San Diego's press release. They influence the comets around the gas giant as well as smaller space objects called "centaurs," with are like asteroids in size but exhibit the composition of comets.
This animation shows space manifolds over a hundred years. Each frame of the animation shows how the arches and substructures appear over three-year increments.
Credit: Nataša Todorović, Di Wu and Aaron Rosengren/Science Advances
"Space manifolds act as the boundaries of dynamical channels enabling fast transportation into the inner- and outermost reaches of the Solar System," write the researchers. "Besides being an important element in spacecraft navigation and mission design, these manifolds can also explain the apparent erratic nature of comets and their eventual demise."
A closer image of the manifolds showing colliding and escaping objects.
Credit: Science Advances
The researchers discovered the structures by analyzing collected numerical data on the millions of orbits in the Solar System. The scientists figured out how these orbits were contained within known space manifolds. To detect the presences and structure of the space manifolds, the team employed the fast Lyapunov indicator (FLI), used to detect chaos. The scientists ran simulations to compute how the trajectories of particles approaching different planets like Jupiter, Uranus and Neptune would be affected by possible collisions and the manifolds.
While the results are encouraging, the next step is to figure out how these arches can be used by spacecraft for much speedier travel. It's also not clear how similar manifolds work near Earth. Also unclear is how they impact our planet's run-ins with asteroids and meteorites or any of the man-made objects floating up in space near us.
Check out the new paper "The arches of chaos in the Solar System" in Science Advances.
Robert Erdmann, a senior scientist working for the Rijksmuseum, cannot help but smile when I ask him to explain — in as much detail as possible — how exactly he used artificial intelligence to recreate long-lost portions of Rembrandt van Rijn's most famous painting, The Night Watch (1642). "Most people just want the elevator pitch," he tells me over Zoom.
The Night Watch is a mammoth of a painting, and it used to be even bigger. In 1715, it came into the possession of the bureaucrats in charge of Amsterdam's Town Hall. In order to fit it on their wall, they sliced off all four outer edges of Rembrandt's priceless masterpiece, inadvertently creating the compromised version we know today.
Rembrandt's "The Night Watch," with the missing edges shown in black.Credit: Courtesy of Robert Erdmann / Rijksmuseum
The missing pieces of "The Night Watch" were never recovered, but we know what they looked like thanks to Gerrit Lundens, a contemporary of Rembrandt who copied the painting when it was complete. These missing sections depict the top of the arch, a balustrade at the bottom, and two soldiers of Frans Banninck Cocq's militia company that stood at the far left.
Though the absence of these elements does not make "The Night Watch" any less impressive, their presence greatly alters the painting's look and feel. The balustrade emphasizes the company's movement forward. Together, the four missing pieces shift the principal figures — Cocq and Willem van Ruytenburch — to the right, creating a more compelling composition.
Copy of "The Night Watch" by Gerrit Lundens.Credit: Courtesy of Robert Erdmann / Rijksmuseum
As part of Operation Night Watch, a multimillion-dollar restoration mission, the Rijksmuseum set out to recreate these missing pieces of the painting to show visitors The Night Watch as Rembrandt had originally constructed it. One easy way to do this would be to upload the smaller Lundens copy into Photoshop, blow it up by a factor of five, print it out, and call it a day.
Easy, but far from adequate. As Erdmann puts it: "There's nothing wrong with using an artist like that. However, the final product would still contain traces of that artist's own style." For Erdmann, the only viable solution was to create a series of neural networks — software that mimics the human brain through the use of artificial neurons — to transform the Lundens copy into an "original" Rembrandt.
Humans, unlike computers, aren't able to make perfect copies. Faithful though Lundens' painting is — especially in its visual detail, for example, the number of buttons on a coat, plumes on a feather, or engravings on a halberd — it still contains a myriad of miniscule differences that prevented Erdmann from simply copy-pasting it onto the original.
Perspective was the first and arguably most important item on Erdmann's list. "The geometric correspondence is pretty good at the bottom of the copy," he says. "At the top, that correspondence starts to fall apart; the composition looks stretched out, supposedly because Lundens was unable to reach the top of the painting to get its precise measurements."
Lundens' copy, adjusted for perspective by the AI.Credit: Courtesy of Robert Erdmann / Rijksmuseum
After creating a neural network that could identify corresponding elements in both versions of The Night Watch — from faces and hands to clothing and weapons — Erdmann made a second neural network that could stretch, rotate, foreshorten, compress, and decompress the Lundens copy so that its measurements matched the Rembrandt original as closely as possible.
According to Erdman, this step was "a guide to where we should place the figures on the left, because they need to be consistent with the extrapolation from the original Night Watch." Aside from aligning the two paintings, Erdmann's adjustments also transformed the facial structure of figures like Cocq, bringing them closer to Rembrandt's expert rendering.
Detail of the Lundens copy before perspectival adjustments.Credit: Courtesy of Robert Erdmann / Rijksmuseum
Detail of the Lundens copy after perspectival adjustments.Credit: Courtesy of Robert Erdmann / Rijksmuseum
Just as a painter must tone their canvas before they can work on composition and color, so too did Erdmann have to get the dimensions right before he could move on to the third and final stage of his coding process. Erdmann's next part of the neural network involved — to paraphrase his elevator pitch — sending the artificial intelligence algorithm to art school.
"Not unlike how you might translate a text from Dutch to English, we wanted to see if we could transform Lundens' painterly style and palette into Rembrandt's," he explains, comparing the learning curve to a quiz. To educate it, the AI was given random tiles from the Lundens copy and asked to render the tiles in the style of Rembrandt.
As with any pedagogical situation, Erdmann evaluated the AI's efforts with a corresponding grade. The closer its output matched the contents of the original Night Watch, the higher the grade it received. When grading, Erdmann considered things like color, texture, and representation (i.e., how well does this frowning face resemble a frowning face, or this sword an actual sword?).
"Once you've defined what makes a good copy, you can train the network on thousands and thousands of these tiles," Erdmann goes on. There are 265 gigabytes of memory of thousands of attempts stored, which demonstrates improvement in quality over a very short time. Within less than a day, the error margin between the AI and the real Rembrandt grew so small it became insignificant; the training was complete.
Lundens copy when adjusted for perspective and Rembrandt's style by AI.Credit: Courtesy of Robert Erdmann / Rijksmuseum
Along the way, the AI had developed a thorough understanding of what made Rembrandt Rembrandt. When translating Lundens' copy, it used a less saturated color palette and thicker, sketchier brushstrokes. It even adopted the painter's signature use of chiaroscuro — a technique involving sharp contrasts between light and shadow.
Then it was time for the final exam. Using the knowledge gained from copying Rembrandt, Erdmann ordered the AI to transform the four outer edges of the Lundens copy — removed from the original Night Watch — into Rembrandt's signature style. The result, an unprecedented collaboration between man and machine, is now on display in the Eregalerij of the Rijksmuseum.
Detail of the completed "Night Watch." The two figures on the left were added from the adjusted Lundens copy.Credit: Courtesy of Robert Erdmann / Rijksmuseum
The missing pieces, resuscitated by AI, were printed onto canvas and varnished so that they had a similar gloss to the rest of the painting. The pieces were then attached to metal plates, which were placed in front of the original Night Watch at a distance of less than one centimeter, thus creating an optical illusion for visitors without actually touching Rembrandt's work.
While conservation science is evolving rapidly, the achievements of people like Erdmann are still eclipsed by the artistic genius of the painters whose work they try to preserve, which is a shame because Erdmann's software can be just as inventive as Rembrandt's brushwork. At the very least, Erdmann's problem-solving skills would have made the master proud.
