Memories are priceless, and the plight of dementia patients highlights how important they are to forming what makes us, well us. Now a new study has provided hope we may one day be able to restore lost memories.
Clearing the mist
A paper from researchers at MIT has demonstrated the reactivation of memories in amnesia patients with optogenetics — in which cell activity is controlled by bursts of light.
Opening up the blood-brain barrier to deliver drugs (credit: Focused Ultrasound Foundation)
The blood-brain barrier has been non-invasively opened in a human patient for the first time. A team at Sunnybrook Health Sciences Centre in Toronto used focused ultrasound to temporarily open the blood-brain barrier (BBB), allowing for effective delivery of chemotherapy into a patient’s malignant brain tumor.
The team infused the chemotherapy agent doxorubicin, along with tiny gas-filled bubbles, into the bloodstream of a patient with a brain tumor. They then applied focused ultrasound to areas in the tumor and surrounding brain, causing the bubbles to vibrate, loosening the tight junctions of the cells comprising the BBB, and allowing high concentrations of the chemotherapy to enter targeted tissues.
This animation depicts the CRISPR-Cas9 method for genome editing – a powerful new technology with many applications in biomedical research, including the potential to treat human genetic disease. Feng Zhang, a leader in the development of this technology, is a faculty member at MIT, an investigator at the McGovern Institute for Brain Research, and a core member of the Broad Institute. Further information can be found on Prof. Zhang’s website at http://zlab.mit.edu.
Images and footage courtesy of Sputnik Animation, the Broad Institute of MIT and Harvard, Justin Knight and pond5.
Treating the brain often requires invasive surgery, but a new technique involving ultrasound and air bubbles has now shown promise at delivering drugs through the blood-brain barrier.
One of the biggest challenges of medicating brain tumours is actually getting drugs into the organ. Your brain is well protected from invasion by untoward substances or life forms, and this protection limits what will enter from the bloodstream. There have been previous efforts to open up the barrier, but they often involve a surgical approach that is far from ideal.
Yes, conceivably. And if/when we achieve the levels of technology necessary for simulation, the universe will become our playground. Eagleman’s latest book is “The Brain: The Story of You” (http://goo.gl/2IgDRb).
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Transcript — The big picture in modern neuroscience is that you are the sum total of all the pieces and parts of your brain. It’s a vastly complicated network of neurons, almost 100 billion neurons, each of which has 10,000 connections to its neighbors. So we’re talking a thousand trillion neurons. It’s a system of such complexity that it bankrupts our language. But, fundamentally it’s only three pounds and we’ve got it cornered and it’s right there and it’s a physical system.
The computational hypothesis of brain function suggests that the physical wetware isn’t the stuff that matters. It’s what are the algorithms that are running on top of the wetware. In other words: What is the brain actually doing? What’s it implementing software-wise that matters? Hypothetically we should be able to take the physical stuff of the brain and reproduce what it’s doing. In other words, reproduce its software on other substrates. So we could take your brain and reproduce it out of beer cans and tennis balls and it would still run just fine. And if we said hey, “How are you feeling in there?” This beer can/tennis ball machine would say “Oh, I’m feeling fine. It’s a little cold, whatever.”
It’s also hypothetically a possibility that we could copy your brain and reproduce it in silica, which means on a computer at zeroes and ones, actually run the simulation of your brain. The challenges of reproducing a brain can’t be underestimated. It would take something like a zettabyte of computational capacity to run a simulation of a human brain. And that is the entire computational capacity of our planet right now.
There’s a lot of debate about whether we’ll get to a simulation of the human brain in 50 years or 500 years, but those would probably be the bounds. It’s going to happen somewhere in there. It opens up the whole universe for us because, you know, these meat puppets that we come to the table with aren’t any good for interstellar travel. But if we could, you know, put you on a flash drive or whatever the equivalent of that is a century from now and launch you into outer space and your consciousness could be there, that could get us to other solar systems and other galaxies. We will really be entering an era of post-humanism or trans-humanism at that point.
Ed Boyden and Karl Deisseroth won Breakthrough Prizes for their discovery of optogenetics.
Steve Williams couldn’t breathe. The former athlete had cardiomyopathy, which occasionally choked his lungs with fluid, making him gasp for air. But this felt different; Williams felt like he was dying. He was raced to an Orange County hospital, and shortly after checking in, his heart stopped. For 30 minutes, ER workers compressed his chest in an attempt to revive him. At one point, his wife Mary remembers being called into his room to say goodbye to her husband of 24 years. It seemed Williams was a dead man.
Incredibly, doctors rebooted Williams’ heart — but for three days, he was in an induced coma, his body packed in ice to minimize brain damage. When he woke up, his mental facilities were intact, but his body was ravaged. His liver was congested, fluid reappeared in his lungs, and his heart’s right and left ventricles were practically destroyed, making it hard for blood to circulate throughout his body. Without a heart transplant, he would soon die.
The brain is a great information processor, but one that doesn’t care about where information comes from.
Sight, scent, taste, sound, touch — all of our precious senses, once communicated to the brain, are transformed into simple electrical pulses. Although we consciously perceive the world through light rays and sound waves, the computing that supports those experiences is all one tone — electrical.
Simply put, all of our senses are the same to our brain.
Facebook is now tackling a problem that has evaded computer scientists for decades: how to build software that can beat humans at Go, the 2,500-year-old strategy board game, according to a report today from Wired. Because of Go’s structure — you place black or white stones at the intersection of lines on a 19-by-19 grid — the game has more possible permutations than chess, despite its simple ruleset. The number of possible arrangements makes it difficult to design systems that can look far enough into the future to adequately assess a good play in the way humans can.
“We’re pretty sure the best [human] players end up looking at visual patterns, looking at the visuals of the board to help them understand what are good and bad configurations in an intuitive way,” Facebook chief technology officer Mike Schroepfer said. “So, we’ve taken some of the basics of game-playing AI and attached a visual system to it, so that we’re using the patterns on the board—a visual recognition] system—to tune the possible moves the system can make.”
The project is part of Facebook’s broader efforts in so-called deep learning. That subfield of artificial intelligence is founded on the idea that replicating the way the human brain works can unlock statistical and probabilistic capabilities far beyond the capacity of modern-day computers. Facebook wants to advance its deep learning techniques for wide-ranging uses within its social network. For instance, Facebook is building a version of its website for the visually impaired that will use natural language processing to take audio input from users — “what object is the person in the photo holding?” — analyze it, and respond with relevant information. Facebook’s virtual assistant, M, will also come to rely on this type of technology to analyze and learn from users’ requests and respond in a way only humans could.
With modern innovations such as artificial intelligence, virtual reality, wi-fi, tablet computing and more, it’s easy for man to look around and say that the human brain is a complex and well-evolved organ. But according to Author, Neuroscientist and Psychologist Gary Marcus, the human mind is actually constructed somewhat haphazardly, and there is still plenty of room for improvement.
“I called my book Kluge, which is an old engineer’s word for a clumsy solution. Think of MacGyver kind of duct tape and rubber bands,” Marcus said. “The thesis of that book is that the human mind is a kluge. I was thinking in terms of how this relates to evolutionary psychology and how our minds have been shaped by evolution.”
Marcus argued that evolution is not perfect, but instead it makes “local maxima,” which are good, but not necessarily the best possible solutions. As a parallel example, he cites the human spine, which allows us to stand upright; however, since it isn’t very well engineered, it also gives us back pain.
“You can imagine a better solution with three legs or branches that would distribute the load better, but we have this lousy solution where our spines are basically like a flag pole supporting 70 percent of our body weight,” Marcus said.
“The reason for that is we’re evolved from tetrapods, which have four limbs and distribute their weight horizontally like a picnic table. As we moved upright, we took what was closest in evolutionary space, which is what took the fewest number of genes in order to give us this new kind of system of standing upright. But it’s not what you would have if you designed it from scratch.”
While Marcus’ book talked about the typical notion in evolutionary psychology that we have evolved to the optimal, he also noted that the human mind works as a function of two pathways, both the optimal performance and our brains’ history. To that end, he sees evolution as a probabilistic process of genes that are nearby, which aren’t necessarily those that are best for a given solution.
“A lot of the book was actually about our memories. The argument I made was that, if you really want a system of brain that does the thing humans do, you would want a kind of memory system that we find in computers, which is called location addressable memory,” Marcus explained.
“With location addressable memory, I’m going to store something in location seven or location eight or nine, and then you’re guaranteed to be able to go back to that thing you want when you want it, which is why computer memory is reliable. Our memory is not even remotely reliable. I can forget what I was going to say or forget where I parked my car. Our memories are nothing even close to the theoretical optimum that a computer shows us.”
Enhancing our minds, and our memories, won’t happen overnight, Marcus said. One might have a “brain like a computer” in theory, but he believes a more evolved, computer-like human brain is thousands of years away.
“There is what I call ‘evolutionary inertia’ that says once something is in place, it’s very hard for evolution to change it. If you change one or two genes, you might have an organism that survives. If you change several hundred, most likely, things are gonna’ break.”
In other words, evolution is the ultimate resourceful engine. Most evolutionary changes are small, since the brain tends to tweak the existing parts rather than start from scratch, which would be a more costly and rather inefficient solution in a survival-of-the-fittest-type world.
Given that genetic science hasn’t worked through a way to rewire the human brain, Marcus poses that better solution toward cognitive enhancement might be found in implants. Rather than generations from now, he believes that advancement could happen in our lifetimes.
“There are now actual cognitive enhancements, if you count motor control substitutes. Neural prostheses are here in limited ways. We know roughly how to make them. There’s a lot of fine detail that needs to be sorted,” Marcus said. “We certainly know how to write computer programs that can translate between interfaces. The big limiting step in improving our memory or enhancing our memory is, we just don’t really understand how information is stored in the brain. I think (a solution for that) is a 50-year project. It’s certainly not a 50,000 year project.”