Could A.I. detect mass shooters before they strike?
President Trump has called for Silicon Valley to develop digital precogs, but such systems raise efficacy concerns.
- President Donald Trump wants social media companies to develop A.I. that can flag potential mass shooters.
- Experts agree that artificial intelligence is not advanced enough, nor are current moderating systems up to the task.
- A majority of Americans support stricter gun laws, but such policies have yet to make headway.
On August 3, a man in El Paso, Texas, shot and killed 22 people and injured 24 others. Hours later, another man in Dayton, Ohio, shot and killed nine people, including his own sister. Even in a country left numb by countless mass shootings, the news was distressing and painful.
President Donald Trump soon addressed the nation to outline how his administration planned to tackle this uniquely American problem. Listeners hoping the tragedies might finally spur motivation for stricter gun control laws, such as universal background checks or restrictions on high-capacity magazines, were left disappointed.
Trump's plan was a ragbag of typical Republican talking points: red flag laws, mental health concerns, and regulation on violent video games. Tucked among them was an idea straight out of a Philip K. Dick novel.
"We must recognize that the internet has provided a dangerous avenue to radicalize disturbed minds and perform demented acts," Trump said. "First, we must do a better job of identifying and acting on early warning signs. I am directing the Department of Justice to work in partnership with local, state and federal agencies as well as well as social media companies to develop tools that can detect mass shooters before they strike."
Basically, Trump wants digital precogs. But has artificial intelligence reached such grand, and potentially terrifying, heights?
A digitized state of mind
It's worth noting that A.I. has made impressive strides at reading and quantifying the human mind. Social media is a vast repository of data on how people feel and think. If we can suss out the internal from the performative, we could improve mental health care in the U.S. and abroad.
For example, a study from 2017 found that A.I. could read the predictive markers for depression in Instagram photos. Researchers tasked machine learning tools with analyzing data from 166 individuals, some of whom had been previously diagnosed with depression. The algorithms looked at filter choice, facial expressions, metadata tags, etc., in more than 43,950 photos.
The results? The A.I. outperformed human practitioners at diagnosing depression. These results held even when analyzing images from before the patients' diagnoses. (Of course, Instagram is also the social media platform most likely to make you depressed and anxious, but that's another study.)
Talking with Big Think, Eric Topol, a professor in the Department of Molecular Medicine at Scripps, called this the ability to "digitize our state of mind." In addition to the Instagram study, he pointed out that patients will share more with a self-chosen avatar than a human psychiatrist.
"So when you take this ability to digitize a state of mind and also have a support through an avatar, this could turn out to be a really great way to deal with the problem we have today, which is a lack of mental health professionals with a very extensive burden of depression and other mental health conditions," Topol said.
Detecting mass shooters?
....mentally ill or deranged people. I am the biggest Second Amendment person there is, but we all must work togeth… https://t.co/T9OthUAsXe— Donald J. Trump (@Donald J. Trump)1565352202.0
However, it's not as simple as turning the A.I. dial from "depression" to "mass shooter." Machine learning tools have gotten excellent at analyzing images, but they lag behind the mind's ability to read language, intonation, and social cues.
As Facebook CEO Mark Zuckerberg said: "One of the pieces of criticism we get that I think is fair is that we're much better able to enforce our nudity policies, for example, than we are hate speech. The reason for that is it's much easier to make an A.I. system that can detect a nipple than it is to determine what is linguistically hate speech."
Trump should know this. During a House Homeland Security subcommittee hearing earlier this year, experts testified that A.I. was not a panacea for curing online extremism. Alex Stamos, Facebook's former chief security officer, likened the world's best A.I. to "a crowd of millions of preschoolers" and the task to demanding those preschoolers "get together to build the Taj Mahal."
None of this is to say that the problem is impossible, but it's certainly intractable.
Yes, we can create an A.I. that plays Go or analyzes stock performance better than any human. That's because we have a lot of data on these activities and they follow predictable input-output patterns. Yet even these "simple" algorithms require some of the brightest minds to develop.
Mass shooters, though far too common in the United States, are still rare. We've played more games of Go, analyzed more stocks, and diagnosed more people with depression, which millions of Americans struggle with. This gives machine learning software more data points on these activities in order to create accurate, responsible predictions — that still don't perform flawlessly.
Add to this that hate, extremism, and violence don't follow reliable input-output patterns, and you can see why experts are leery of Trump's direction to employ A.I. in the battle against terrorism.
"As we psychological scientists have said repeatedly, the overwhelming majority of people with mental illness are not violent. And there is no single personality profile that can reliably predict who will resort to gun violence," Arthur C. Evans, CEO of the American Psychological Association, said in a release. "Based on the research, we know only that a history of violence is the single best predictor of who will commit future violence. And access to more guns, and deadlier guns, means more lives lost."
Social media can't protect us from ourselves
First Lady Melania Trump visits with the victims of the El Paso, Texas, shooting. Image source: Andrea Hanks / Flickr
One may wonder if we can utilize current capabilities more aggressively? Unfortunately, social media moderating systems are a hodgepodge, built piecemeal over the last decade. They rely on a mixture of A.I., paid moderators, and community policing. The outcome is an inconsistent system.
For example, the New York Times reported in 2017 that YouTube had removed thousands of videos using machine learning systems. The videos showed atrocities from the Syrian War, such as executions and people spouting Islamic State propaganda. The algorithm flagged and removed them as coming from extremist groups.
In truth, the videos came from humanitarian organizations to document human rights violations. The machine couldn't tell the difference. YouTube reinstated some of the videos after users reported the issue, but mistakes at such a scale do not give one hope that today's moderating systems could accurately identify would-be mass shooters.
That's the conclusion reached in a report from the Partnership on A.I. (PAI). It argued there were "serious shortcomings" in using A.I. as a risk-assessment tool in U.S. criminal justice. Its writers cite three overarching concerns: accuracy and bias; questions of transparency and accountability; and issues with the interface between tools and people.
"Although the use of these tools is in part motivated by the desire to mitigate existing human fallibility in the criminal justice system, it is a serious misunderstanding to view tools as objective or neutral simply because they are based on data," the report states. "While formulas and statistical models provide some degree of consistency and replicability, they still share or amplify many weaknesses of human decision-making."
In addition to the above, there are practical barriers. The technical capabilities of law enforcement vary between locations. Social media platforms deal in massive amounts of traffic and data. And even when the red flags are self-evident — such as when shooters publish manifestos — they offer a narrow window in which to act.
The tools to reduce mass shootings
Protesters at March for Our Lives 2018 in San Francisco. Image source: Gregory Varnum / Wikimedia Commons
Artificial intelligence offers many advantages today and will offer more in the future. But as an answer to extremism and mass shootings, experts agree it's simply the wrong tool. That's the bad news. The good news is we have the tools we need already, and they can be implemented with readily available tech.
"Based on the psychological science, we know some of the steps we need to take. We need to limit civilians' access to assault weapons and high-capacity magazines. We need to institute universal background checks. And we should institute red flag laws that remove guns from people who are at high risk of committing violent acts," Evans wrote.
We don't need advanced A.I. to figure this out. There's only one developed country in the world where someone can legally and easily acquire an armory of guns, and it's the only developed country that suffers mass shootings with such regularity. It's a simple arithmetic.
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Astronomers find these five chapters to be a handy way of conceiving the universe's incredibly long lifespan.
- We're in the middle, or thereabouts, of the universe's Stelliferous era.
- If you think there's a lot going on out there now, the first era's drama makes things these days look pretty calm.
- Scientists attempt to understand the past and present by bringing together the last couple of centuries' major schools of thought.
The 5 eras of the universe<p>There are many ways to consider and discuss the past, present, and future of the universe, but one in particular has caught the fancy of many astronomers. First published in 1999 in their book <a href="https://amzn.to/2wFQLiL" target="_blank"><em>The Five Ages of the Universe: Inside the Physics of Eternity</em></a>, <a href="https://en.wikipedia.org/wiki/Fred_Adams" target="_blank">Fred Adams</a> and <a href="https://en.wikipedia.org/wiki/Gregory_P._Laughlin" target="_blank">Gregory Laughlin</a> divided the universe's life story into five eras:</p><ul><li>Primordial era</li><li>Stellferous era</li><li>Degenerate era</li><li>Black Hole Era</li><li>Dark era</li></ul><p>The book was last updated according to current scientific understandings in 2013.</p><p>It's worth noting that not everyone is a subscriber to the book's structure. Popular astrophysics writer <a href="https://www.forbes.com/sites/ethansiegel/#30921c93683e" target="_blank">Ethan C. Siegel</a>, for example, published an article on <a href="https://www.forbes.com/sites/startswithabang/2019/07/26/we-have-already-entered-the-sixth-and-final-era-of-our-universe/#7072d52d4e5d" target="_blank"><em>Medium</em></a> last June called "We Have Already Entered The Sixth And Final Era Of Our Universe." Nonetheless, many astronomers find the quintet a useful way of discuss such an extraordinarily vast amount of time.</p>
The Primordial era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTEyMi9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYyNjEzMjY1OX0.PRpvAoa99qwsDNprDme9tBWDim6mS7Mjx6IwF60fSN8/img.jpg?width=980" id="db4eb" class="rm-shortcode" data-rm-shortcode-id="0e568b0cc12ed624bb8d7e5ff45882bd" data-rm-shortcode-name="rebelmouse-image" />
Image source: Sagittarius Production/Shutterstock<p> This is where the universe begins, though what came before it and where it came from are certainly still up for discussion. It begins at the Big Bang about 13.8 billion years ago. </p><p> For the first little, and we mean <em>very</em> little, bit of time, spacetime and the laws of physics are thought not yet to have existed. That weird, unknowable interval is the <a href="https://www.universeadventure.org/eras/era1-plankepoch.htm" target="_blank">Planck Epoch</a> that lasted for 10<sup>-44</sup> seconds, or 10 million of a trillion of a trillion of a trillionth of a second. Much of what we currently believe about the Planck Epoch eras is theoretical, based largely on a hybrid of general-relativity and quantum theories called quantum gravity. And it's all subject to revision. </p><p> That having been said, within a second after the Big Bang finished Big Banging, inflation began, a sudden ballooning of the universe into 100 trillion trillion times its original size. </p><p> Within minutes, the plasma began cooling, and subatomic particles began to form and stick together. In the 20 minutes after the Big Bang, atoms started forming in the super-hot, fusion-fired universe. Cooling proceeded apace, leaving us with a universe containing mostly 75% hydrogen and 25% helium, similar to that we see in the Sun today. Electrons gobbled up photons, leaving the universe opaque. </p><p> About 380,000 years after the Big Bang, the universe had cooled enough that the first stable atoms capable of surviving began forming. With electrons thus occupied in atoms, photons were released as the background glow that astronomers detect today as cosmic background radiation. </p><p> Inflation is believed to have happened due to the remarkable overall consistency astronomers measure in cosmic background radiation. Astronomer <a href="https://www.youtube.com/watch?v=IGCVTSQw7WU" target="_blank">Phil Plait</a> suggests that inflation was like pulling on a bedsheet, suddenly pulling the universe's energy smooth. The smaller irregularities that survived eventually enlarged, pooling in denser areas of energy that served as seeds for star formation—their gravity pulled in dark matter and matter that eventually coalesced into the first stars. </p>
The Stelliferous era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTEzNy9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxMjA0OTcwMn0.GVCCFbBSsPdA1kciHivFfWlegOfKfXUfEtFKEF3otQg/img.jpg?width=980" id="bc650" class="rm-shortcode" data-rm-shortcode-id="c8f86bf160ecdea6b330f818447393cd" data-rm-shortcode-name="rebelmouse-image" />
Image source: Casey Horner/unsplash<p>The era we know, the age of stars, in which most matter existing in the universe takes the form of stars and galaxies during this active period. </p><p>A star is formed when a gas pocket becomes denser and denser until it, and matter nearby, collapse in on itself, producing enough heat to trigger nuclear fusion in its core, the source of most of the universe's energy now. The first stars were immense, eventually exploding as supernovas, forming many more, smaller stars. These coalesced, thanks to gravity, into galaxies.</p><p>One axiom of the Stelliferous era is that the bigger the star, the more quickly it burns through its energy, and then dies, typically in just a couple of million years. Smaller stars that consume energy more slowly stay active longer. In any event, stars — and galaxies — are coming and going all the time in this era, burning out and colliding.</p><p>Scientists predict that our Milky Way galaxy, for example, will crash into and combine with the neighboring Andromeda galaxy in about 4 billion years to form a new one astronomers are calling the Milkomeda galaxy.</p><p>Our solar system may actually survive that merger, amazingly, but don't get too complacent. About a billion years later, the Sun will start running out of hydrogen and begin enlarging into its red giant phase, eventually subsuming Earth and its companions, before shrining down to a white dwarf star.</p>
The Degenerate era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTE1MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYxNTk3NDQyN30.gy4__ALBQrdbdm-byW5gQoaGNvFTuxP5KLYxEMBImNc/img.jpg?width=980" id="77f72" class="rm-shortcode" data-rm-shortcode-id="08bb56ea9fde2cee02d63ed472d79ca3" data-rm-shortcode-name="rebelmouse-image" />
Image source: Diego Barucco/Shutterstock/Big Think<p>Next up is the Degenerate era, which will begin about 1 quintillion years after the Big Bang, and last until 1 duodecillion after it. This is the period during which the remains of stars we see today will dominate the universe. Were we to look up — we'll assuredly be outta here long before then — we'd see a much darker sky with just a handful of dim pinpoints of light remaining: <a href="https://earthsky.org/space/evaporating-giant-exoplanet-white-dwarf-star" target="_blank">white dwarfs</a>, <a href="https://earthsky.org/space/new-observations-where-stars-end-and-brown-dwarfs-begin" target="_blank">brown dwarfs</a>, and <a href="https://earthsky.org/astronomy-essentials/definition-what-is-a-neutron-star" target="_blank">neutron stars</a>. These"degenerate stars" are much cooler and less light-emitting than what we see up there now. Occasionally, star corpses will pair off into orbital death spirals that result in a brief flash of energy as they collide, and their combined mass may become low-wattage stars that will last for a little while in cosmic-timescale terms. But mostly the skies will be be bereft of light in the visible spectrum.</p><p>During this era, small brown dwarfs will wind up holding most of the available hydrogen, and black holes will grow and grow and grow, fed on stellar remains. With so little hydrogen around for the formation of new stars, the universe will grow duller and duller, colder and colder.</p><p>And then the protons, having been around since the beginning of the universe will start dying off, dissolving matter, leaving behind a universe of subatomic particles, unclaimed radiation…and black holes.</p>
The Black Hole era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTE2MS9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYzMjE0OTQ2MX0.ifwOQJgU0uItiSRg9z8IxFD9jmfXlfrw6Jc1y-22FuQ/img.jpg?width=980" id="103ea" class="rm-shortcode" data-rm-shortcode-id="f0e6a71dacf95ee780dd7a1eadde288d" data-rm-shortcode-name="rebelmouse-image" />
Image source: Vadim Sadovski/Shutterstock/Big Think<p> For a considerable length of time, black holes will dominate the universe, pulling in what mass and energy still remain. </p><p> Eventually, though, black holes evaporate, albeit super-slowly, leaking small bits of their contents as they do. Plait estimates that a small black hole 50 times the mass of the sun would take about 10<sup>68</sup> years to dissipate. A massive one? A 1 followed by 92 zeros. </p><p> When a black hole finally drips to its last drop, a small pop of light occurs letting out some of the only remaining energy in the universe. At that point, at 10<sup>92</sup>, the universe will be pretty much history, containing only low-energy, very weak subatomic particles and photons. </p>
The Dark Era<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yMjkwMTE5NC9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTY0Mzg5OTEyMH0.AwiPRGJlGIcQjjSoRLi6V3g5klRYtxQJIpHFgZdZkuo/img.jpg?width=980" id="60c77" class="rm-shortcode" data-rm-shortcode-id="7a857fb7f0d85cf4a248dbb3350a6e1c" data-rm-shortcode-name="rebelmouse-image" />
Image source: Big Think<p>We can sum this up pretty easily. Lights out. Forever.</p>
UNC School of Medicine researchers identified the amino acid responsible for the trip.
- Researchers at UNC's School of Medicine have discovered the protein responsible for LSD's psychedelic effects.
- A single amino acid—part of the protein, Gαq—activates the mind-bending experience.
- The researchers hope this identification helps shape depression treatment.
What is Bicycle Day?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="d346092205da3c9ed10bad283222c9f1"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/L32mAiLXnLs?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Back in the world of clinical science, LSD has always showed promise. That trend continues as restrictions are finally easing up. Understanding LSD's effects on our brain's complex system of networks is an important step toward discovering therapeutic actions. As Roth <a href="https://www.inverse.com/mind-body/how-lsd-binds-to-the-brain-study" target="_blank">says</a> of his research,</p><p style="margin-left: 20px;">"Now we know how psychedelic drugs work – finally! Now we can use this information to, hopefully, discover better medications for many psychiatric diseases."</p><p>Using X-ray crystallography, Roth's team discovered a single amino acid—a building block of the protein, Gαq—responsible for binding to serotonin receptors. As LSD is only a partial agonist, they also experimented with a full-agonist designer psychedelic in order to observe complete receptor activation. This amino acid appears to be the master switch for the psychedelic experience. </p><p>While psilocybin has been in the news, the psychedelic renaissance is expanding in all directions. Phase 1 clinical trials on the <a href="https://newatlas.com/science/landmark-clinical-trial-lsd-mdma-mindmed/" target="_blank">combination</a> of LSD, MDMA, and psychotherapy will soon commence. LSD's effects on <a href="https://clinicaltrials.gov/ct2/show/NCT03866252" target="_blank" rel="noopener noreferrer">Major Depressive Disorder</a> and <a href="https://www.sciencealert.com/first-clinical-trial-shows-micro-doses-of-lsd-can-increase-a-person-s-pain-tolerance" target="_blank">pain management</a> are ongoing. With the <a href="https://www.bloomberg.com/news/articles/2020-09-18/-magic-mushroom-company-moves-toward-mainstream-in-nasdaq-ipo" target="_blank" rel="noopener noreferrer">first psychedelics company</a> to IPO on the American stock market, along with hundreds of millions of dollars of investment flowing into similar companies and organizations, the push for legalized psychedelics intensifies. </p>
Credit: ynsga / Shutterstock<p>Researchers are actively attempting to remove the hallucinogenic component of psychedelics for widespread therapeutic usage—<a href="https://www.healtheuropa.eu/could-ibogaine-offer-a-revolutionary-long-term-solution-to-addiction/100635/" target="_blank">trials</a> using ibogaine for addiction treatment, for example. Identifying the chemical effects of psychedelics on our brains is an essential step in that process.</p><p>Of course, believing psychedelics <em>only</em> matters to brain chemistry is problematic as well. The rituals associated with their use are just as relevant. The "<a href="https://en.wikipedia.org/wiki/Set_and_setting" target="_blank">set and setting</a>" model espoused by Timothy Leary reminds us that biology isn't everything; environmental factors play just as important a role in mental health. </p><p>Isolating specific chemicals without understanding the impact of the drug <em>and</em> the environment overlooks the holistic nature of the psychedelic experience. For example, ketamine trials <a href="https://bigthink.com/surprising-science/ketamine-depression" target="_self">were rushed</a> and could potentially backfire; we can't afford to make that mistake again. </p><p>Still, understanding the pathways LSD utilizes is an important step forward. As Roth says, "Our ultimate goal is to see if we can discover medications which are effective, like psilocybin, for depression but do not have the intense psychedelic actions." In a world where more people are growing anxious and depressed by the day, every intervention should be explored.</p><p> --</p><p><em>Stay in touch with Derek on <a href="http://www.twitter.com/derekberes" target="_blank">Twitter</a>, <a href="https://www.facebook.com/DerekBeresdotcom" target="_blank" rel="noopener noreferrer">Facebook</a> and <a href="https://derekberes.substack.com/" target="_blank" rel="noopener noreferrer">Substack</a>. His next book is</em> "<em>Hero's Dose: The Case For Psychedelics in Ritual and Therapy."</em></p>
A team of researchers have discovered the brain rhythmic activity that can split us from reality.
- Researchers have identified the key rhythmic brain activity that triggers a bizarre experience called dissociation in which people can feel detached from their identity and environment.
- This phenomena is experienced by about 2 percent to 10 percent of the population. Nearly 3 out of 4 individuals who have experienced a traumatic event will slip into a dissociative state either during the event or sometime after.
- The findings implicate a specific protein in a certain set of cells as key to the feeling of dissociation, and it could lead to better-targeted therapies for conditions in which dissociation can occur.
What is dissociation?<span style="display:block;position:relative;padding-top:56.25%;" class="rm-shortcode" data-rm-shortcode-id="bd2f1f29418bd4805bf1282001dca814"><iframe type="lazy-iframe" data-runner-src="https://www.youtube.com/embed/XF2zeOdE5GY?rel=0" width="100%" height="auto" frameborder="0" scrolling="no" style="position:absolute;top:0;left:0;width:100%;height:100%;"></iframe></span><p>Dissociation is an experience commonly described as a feeling of sudden detachment from the individual's identity and environment, almost like an out-of-body experience. This mysterious phenomena is experienced by about 2 percent to 10 percent of the population.</p><p>"This state often manifests as the perception of being on the outside looking in at the cockpit of the plane that's your body or mind — and what you're seeing you just don't consider to be yourself," explained senior author Karl Deisseroth, MD, PhD, <a href="https://med.stanford.edu/news/all-news/2020/09/researchers-pinpoint-brain-circuitry-underlying-dissociation.html" target="_blank" rel="noopener noreferrer">in a Stanford Medicine news release</a>. Deisseroth is a professor of bioengineering and of psychiatry and behavioral sciences, as well as a Howard Hughes Medical Institute investigator.</p><p>Nearly three-quarters of individuals who have experienced a traumatic event will slip into a dissociative state either during the event or in the hours or even weeks that follow, according to Deisseroth. Most of the time, the dissociative experiences end on their own within a few weeks of the trauma. But the eerie experience can become chronic, such as in cases of post-traumatic stress disorder, and extremely disruptive in daily life. The state of dissociation can also occur in epilepsy and be invoked by certain drugs. </p><p>Until now, no one has known what exactly is going on inside the brain triggering and sustaining the feeling of dissociation — and so it has been a challenge to figure out how to stop it and develop effective treatments. </p>
New Research: The Molecular Underpinnings of Dissociation<img type="lazy-image" data-runner-src="https://assets.rebelmouse.io/eyJhbGciOiJIUzI1NiIsInR5cCI6IkpXVCJ9.eyJpbWFnZSI6Imh0dHBzOi8vYXNzZXRzLnJibC5tcy8yNDQyNjk3My9vcmlnaW4uanBnIiwiZXhwaXJlc19hdCI6MTYwNTQ3MTI1NX0._nJoxm1eDcTsHsy1Y27JxNl2uR5hlbEYDWYoQlO0EAU/img.jpg?width=1245&coordinates=0%2C121%2C0%2C121&height=700" id="26e86" class="rm-shortcode" data-rm-shortcode-id="1094af23e35a498a8a6b691f1d0cbfaf" data-rm-shortcode-name="rebelmouse-image" alt="neurons" />
Neurons from a mouse spinal cord
Credit: NICHD on Flickr<p>Last week, in a study published in <a href="https://www.nature.com/articles/s41586-020-2731-9" target="_blank">Nature</a><a href="https://www.nature.com/articles/s41586-020-2731-9">,</a> Deisseroth and his colleagues at Stanford University uncovered a localized brain rhythm and molecule that underlies this state.</p><p>"This study has identified brain circuitry that plays a role in a well-defined subjective experience," said Deisseroth. "Beyond its potential medical implications, it gets at the question, 'What is the self?' That's a big one in law and literature, and important even for our own introspections."</p><p>The authors' findings implicate a specific protein existing in a particular set of cells as key to the feeling of dissociation. </p><p>The research team first used a technique called widefield calcium imaging to record brain-wide neuronal activity in lab mice. They observed and analyzed changes in those brain rhythms after the animals had been administered a range of drugs that are known to cause dissociative states: ketamine, phencyclidine (PCP), and dizocilpine (MK801). At a certain dosage of ketamine, the mice behaved in a way that suggested that they were likely experiencing dissociation. For example, when the animals were placed on an uncomfortably warm surface, they reacted to it by flicking their paws. However, they signaled that they didn't care enough about the unpleasantness to do what they would typically do in such a situation, which is to lick their paws to cool them off. This suggested a dissociation from the surrounding environment.</p><p>The drug produced oscillations in neuronal activity in a region of the mices' brain called the retrosplenial cortex, an area essential for various cognitive functions such as navigation and episodic memory (a unique memory of a specific event). The oscillations occurred at about 1-3 hertz (three cycles per second). The authors then examined the active cells in more detail by using two-photon imaging for higher resolution. This revealed that the oscillations were occurring only in layer 5 of the retrosplenial cortex. Next, the researchers recorded neuronal activity across other regions of the brain. </p><p>"Normally, other parts of the cortex and subcortex are functionally connected to neuronal activity in the retrosplenial cortex," Ken Solt and Oluwaseun Akeju wrote in <a href="https://www.nature.com/articles/d41586-020-02505-z#ref-CR1" target="_blank">Nature</a>. "However, ketamine caused a disconnect, such that many of these brain regions no longer communicated with the retrosplenial cortex."</p><p>The scientists then used optogenetics, a method of manipulating living tissue with light to control neural function, to stimulate neurons in the mice's retrosplenial cortex. When the scientists did this at a 2-hertz rhythm, they were able to cause dissociative behavior in the animals analogous to the behavior caused by ketamine without using drugs. The experiments conducted by the team displayed how a particular type of protein, an ion channel, was essential to the generation of the hertz signal that caused the dissociative behavior in mice. Scientists are hopeful that this protein could be a potential treatment target in the future. </p>