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One of the first bioelectronic devices to combine living bacteria with sensors has successfully improved healthy skin regeneration in mice with psoriasis

On July 14th, 2015, the New Horizons spacecraft conducted the first-ever flyby of Pluto, which once was (and to many, still is) the ninth planet of the Solar System. While the encounter was brief, the stunning images and volumes of data it obtained revealed a stunningly vibrant and dynamic world. In addition to Pluto’s heart, floating ice hills, nitrogen icebergs, and nitrogen winds, the New Horizons data also hinted at the existence of an ocean beneath Pluto’s icy crust. This effectively made Pluto (and its largest moon, Charon) members of the “Ocean Worlds” club.

Almost a decade after that historic encounter, scientists are still making discoveries from New Horizons data. In a new paper, planetary scientists Alex Nguyen and Dr. Patrick McGovern used mathematical models and images to learn more about the possible ocean between Pluto’s icy surface and its silicate and metallic core. According to their analysis, they determined that Pluto’s ocean is located beneath a surface shell measuring 40 to 80 km (25 to 50 mi), an insulating layer thick enough to ensure that an interior ocean remains liquid.

Nguyen is a graduate student in Earth, environmental, and planetary sciences in Arts & Sciences at Washington University in St. Louis (WUSTL), while Dr. McGovern is a Senior Staff Scientist with the Lunar and Planetary Institute (LPI) in Houston. Their paper, “The role of Pluto’s ocean’s salinity in supporting nitrogen ice loads within the Sputnik Planitia basin,” recently appeared in the journal Icarus. The study is part of Nguyen’s Ph.D. research at Washington University, where he is an Olin Chancellor’s Fellow and a National Science Foundation Graduate Research Fellow.

This cutaway image of Pluto shows a section through the area of Sputnik Planitia, with dark blue representing a subsurface ocean and light blue for the frozen crust. Artwork by Pam Engebretson, courtesy of UC Santa Cruz.

For decades, planetary scientists assumed Pluto was far too cold to support an interior ocean. Pluto orbits well beyond the Solar System’s “Frost Line,” the boundary beyond which volatile elements (water, carbon dioxide, ammonia, etc.) become solid. With an average surface temperature of -229 °C (-380°F), even nitrogen and methane become as solid as rock. As Nguyen indicated in a recent interview with The Source (WUSTL’s news site), “Pluto is a small body. It should have lost almost all of its heat shortly after it was formed, so basic calculations would suggest that it’s frozen solid to its core.”

But thanks to New Horizons, scientists were presented with multiple lines of evidence that suggest Pluto likely has an interior ocean. This includes cryovolcanoes, such as those observed on Ceres, Europa, Ganymede, Enceladus, Titan, Triton, and other “Ocean Worlds.” While the existence of this ocean is still subject to debate, the theory is gaining acceptance to the point that it is considered a very real possibility. For their study, Nguyen and McGovern created mathematical models to explain the cracks and bulges in the ice covering Pluto’s Sputnik Planitia Basin.

Their results indicate that an ocean could exist beneath an icy shell 40 to 80 km (25 to 50 mi) thick, which would be sufficient to ensure that Pluto could maintain a liquid water ocean in its interior despite surface conditions. They also calculated the likely density or salinity of the ocean based on the surface features and determined that Pluto’s ocean could be up to 8% denser than Earth’s oceans. This salinity level would make Pluto’s ocean comparable to the Great Salt Lake, the Dead Sea, and other high-salinity bodies of water on Earth.

According to Nguyen, any variations in this density (greater or lower) would be evident from the cracks and fractures in the Sputnik Platina Basin. “We estimated a sort of Goldilocks zone where the density and shell thickness is just right,” he said. If the ocean were less dense, the ice shell would collapse, leading to many more fractures in the surface. If it were denser, the ice sheet would be more buoyed, which would be evident from there being fewer fractures. Unfortunately, it could be many decades before another spacecraft reaches Pluto to help confirm these findings. In the meantime, the case for Pluto’s interior ocean grows stronger!

Further Reading: Washington University at St. Louis, Icarus

The post Pluto Has an Ocean of Liquid Water Surrounded by a 40-80 km Ice Shell appeared first on Universe Today.

The earliest black holes in the Universe called primordial black holes (PBHs), are strong contenders to help explain why the Universe is heavier than it looks. There’s only one problem: these miniature monsters haven’t exactly been observed—yet. But, when astronomers do find them, they might turn out to be part of the Universe’s dark matter component.

Primordial black holes are one of several types of highly massive objects thought to exist in the Universe. We already know about stellar-mass black holes. They form during the deaths of hugely massive stars and generally end up containing up to dozens of solar masses. Then there are the supermassive black holes, embedded in the hearts of most galaxies. They sequester up to millions of solar masses.

The intermediate-mass black holes occupy the middle of the “black hole” spectrum. They’re another hot topic in black hole research circles. Appropriately enough, the masses of these black holes are between their stellar and supermassive counterparts. All these types of massive objects can collide with each other to grow bigger black holes. That generates gravitational waves that can be detected. The “ping” of each gravitational wave tells scientists a great deal about the objects colliding, including their masses.

How we might discover primordial black holes and help solve the dark matter mystery. Credit: ESA Understanding Primordial Black Holes in Context of Cosmic History

While astronomers search for PHBs, others are looking to explain why they might be part of the dark matter component of the Universe. In addition, they could explain the origin of binary black holes detected in gravitational wave observations.

A team of researchers at the University of Tokyo examined the “problem” of PBHs. Their work suggests that there should be far fewer of these objects than current models show. But, nobody knows how many existed back then. So, astronomers search them out using gravitational wave observatories. Their discovery should open a window on conditions in the early Universe when PBH formed.

These miniature ones are fascinating to think about. “Many researchers feel they are a strong candidate for dark matter, but there would need to be plenty of them to satisfy that theory,” said graduate student and team member Jason Kristiano. “They are interesting for other reasons too, as since the recent innovation of gravitational wave astronomy, there have been discoveries of binary black hole mergers, which can be explained if PBHs exist in large numbers. But despite these strong reasons for their expected abundance, we have not seen any directly, and now we have a model which should explain why this is the case.”

Modeling the Existence of Primordial Black Holes

The big question about PHBs: do (or did) they exist? And, can they be part of the dark matter component of the Universe? To answer that, Kristiano and his advisor Jun’ichi Yokoyama, searched through models of PBH formation. The best ones do not agree with the observed conditions of the leftover light fingerprint of the Big Bang. That’s called the cosmic microwave background (CMB). This is important, since PBHs formed in very early epochs of cosmic history, soon after the Big Bang. So, the team used the best model of PBH formation and applied quantum field theory to bring the model into alignment with reality.

Yokoyama explained the background behind their work. “At the beginning, the universe was incredibly small, much smaller than the size of a single atom. Cosmic inflation rapidly expanded that by 25 orders of magnitude. At that time, waves traveling through this tiny space could have had relatively large amplitudes but very short wavelengths. What we have found is that these tiny but strong waves can translate to otherwise inexplicable amplification of much longer waves we see in the present CMB,” said Yokoyama.

“We believe this is due to occasional instances of coherence between these early short waves, which can be explained using quantum field theory, the most robust theory we have to describe everyday phenomena such as photons or electrons. While individual short waves would be relatively powerless, coherent groups would have the power to reshape waves much larger than themselves. This is a rare instance of where a theory of something at one extreme scale seems to explain something at the opposite end of the scale.”

From Fluctuations to Miniature Black Holes

Those early small-scale fluctuations Yokohama describes affect some of the larger-scale fluctuations in the cosmic microwave background. Researchers can use measurements of wavelengths in the CMB to constrain the extent of corresponding wavelengths in the early Universe. That also puts some limits on any other phenomena that rely on the shorter, stronger wavelengths. And this is where the PBHs come back in.

“It is widely believed that the collapse of short but strong wavelengths in the early universe is what creates primordial black holes,” said Kristiano. “Our study suggests there should be far fewer PBHs than would be needed if they are indeed a strong candidate for dark matter or gravitational wave events.”

The next step relies on gravitational wave observatories and other types of observations. LIGO in the U.S., Virgo in Italy and KAGRA in Japan, are cooperating in observations aimed at finding the first PHBs. The results should help refine the ideas from Yokoyama’s team about PHBs and dark matter.

For More Information

The Case of the Missing Black Holes
Constraining Primordial Black Hole Formation from Single-Field Inflation
Note on the Bispectrum and One-loop corrections in Single-field Inflation with Primordial Black Hole Formation

The post Where are All the Primordial Black Holes? appeared first on Universe Today.

A free AI-powered website helps clinicians more effectively match patients with the optimal antidepressant using big data.

A team of researchers have developed a new machine-learning method that detects hate speech on social media platforms with 88 per cent accuracy, saving employees from hundreds of hours of emotionally damaging work.

A new study found a distinct relationship between sleep duration, social media usage, and brain activation across brain regions that are key for executive control and reward processing.

Cultivating creativity in schools is vital for a future driven by artificial intelligence (AI). But while teachers embrace creativity as an essential 21st century skill, a lack of valid and reliable creativity tests means schools struggle to assess student achievement. Now, a new machine-learning model is providing teachers with access to high-quality, fit-for-purpose creativity tests, that can score assessments in a fraction of the time and a fraction of the cost.

Team utilizes advanced statistical techniques to project the future groundwater depletion risk.

Lenses are used to bend and focus light. Normal lenses rely on their curved shape to achieve this effect, but physicists have made a flat lens of only three atoms thick which relies on quantum effects. This type of lens could be used in future augmented reality glasses.

Landing on the far side of the moon is rarely attempted, due to difficulties communicating with Earth, but China is about to try. If successful, its Chang'e 6 mission will then bring lunar samples back home

A 2020 rule that slashed air pollution from ships may have boosted global temperatures sooner than thought, helping to explain why 2023 was so hot

I may have mentioned this case before, but it’s one that’s guaranteed to cause arguments, for it involves the Netherlands’ policy of allowing doctor-assisted suicide of patients with incurable and debilitating mental illness. The description is at the Free Press, and you can read about Zoraya ter Beck by clicking on the screenshot below:

The U.S, has no such policy, although the following states and countries have medical aid in dying for physical illnesses (see the Wikipedia article for notes and qualifications):

Physician-assisted suicide is legal in some countries, under certain circumstances, including Austria, Belgium, Canada, Luxembourg, the Netherlands, New Zealand, Portugal, Spain, Switzerland, parts of the United States (California, Colorado, Hawaii, Maine,Montana, New Jersey, New Mexico, Oregon, Vermont, Washington and Washington DC) and Australia (New South Wales, Queensland, South Australia,Tasmania, Victoria and Western Australia). The Constitutional Courts of Colombia, Germany and Italylegalized assisted suicide, but their governments have not legislated or regulated the practice yet.

I haven’t looked carefully at all these places to see if they allow physician-assisted suicide for the mentally ill, but as far as I know the Netherlands is unique in this respect. Canada was supposed to allow it, but has put it on hold.

Opposition to general euthanasia is often based on religion (“God will take you when it’s time”), and opposition to euthanasia for mental illness is based on the supposition that the illness may be temporary, so that people might recover and be glad they didn’t choose doctor-assisted suicide.

In my view, not only should people with any intractable illness that causes great pain should be allowed to die legally, and I don’t exempt mental illness. In fact, severe depression or bipolar disorder can be the equivalent of cancer: although mental illness might not kill you by itself, it can make life not worth living, so that death would seem to be an ethical choice for both the patient and the state. Further, at least in the Netherlands there are sufficient protections in place to ensure that a person who has a good chance of recovering will not be euthanized, and that the illness must be intractable as judged from previous medical interventions.

But I digress: click to read (it’s archived here):

The details:

Even as a child, Zoraya ter Beek had a persistent wish to die. Growing up in the quaint Dutch town of Oldenzaal, she never felt as if she fit in. At the age of 21, she was diagnosed with autism; a year later, she started wearing a “Do Not Resuscitate” tag around her neck. Last Wednesday, her wish was finally granted: after a three-year wait, Zoraya ended her life through physician-assisted suicide. She had just turned 29.

. . . .Zoraya received little or no support from her family. When she turned 18, she moved out of her childhood home to live with her boyfriend, Stein. He was ten years older than her, and her parents didn’t approve of the age difference. When I first contacted her, Zoraya had been estranged from her mother and three older sisters for six years. Her father died last year from cancer.

As a young adult, Zoraya felt unable to study, or embark on a career. She told me Stein, who is an IT programmer, was worried about how she felt, and encouraged her to get therapy. Over the course of a decade, she tried everything to relieve the symptoms of her mental illness—including, at last, 33 rounds of electroconvulsive therapy, where electric currents jolt the brain.

Zoraya’s last treatment was in August 2020, after which she says her psychiatrist told her: “There’s nothing more we can do for you. It’s never going to get any better.”

“After we heard that, we all kind of knew what that meant,” Zoraya told me, referring not only to herself but her boyfriend, her friends, and her doctors. “I was always very clear: if it doesn’t get better, I can’t do this.”

I ask you: who would insist that this young woman, in deep pain from mental illness that could not be cured or even helped, stay alive? And why?

And so Zoraya went ahead:

Earlier this month, she told The Guardian: “People think that when you’re mentally ill, you can’t think straight, which is insulting.”

“In the Netherlands,” she added, “we’ve had this law for more than 20 years. There are really strict rules, and it’s really safe.”

Zoraya had great faith in not only the law but also the medical profession.

“Doctors want to help people feel better,” she told me. “Doctors don’t become doctors to kill people, even if that’s what you’re wishing for.”

Nevertheless, Zoraya had a plan B—or, as she called it, an “escape plan”—in case her application didn’t get final approval. It was a suicide kit, which she told me she’d obtained from Exit International, an NGO that advocates for the legalization of voluntary euthanasia.

In the end, she didn’t need it. Zoraya had hoped to be euthanized on her birthday, May 2. But there had been some last-minute bureaucratic delays. Nevertheless, her assisted suicide was approved a couple of weeks ago.

Another argument against assisted suicide for the mentally ill is that it could lead to a “slippery slope,” in which people who aren’t that ill, or pretend that they’re suffering, use it as an exit when they could be cured. But although the number of cases of euthanasia for mental illness is increasing, I know the Netherlands’ criteria are sufficiently strict to halt any slope. The increasing numbers reflects, I think, the public’s increasing acceptance of euthanasia as a humane way to end a miserable life, as well as increasing dissemination of information:

The fact is an increasing number of people suffering from mental illness in the Netherlands are choosing to end their lives. Zoraya is right that the assisted dying law has been around for years, but even as recently as 2010, there were only two recorded cases of medically assisted suicide that involved psychiatric suffering. Last year, there were 138.

But Zoraya is all on board with the regulations as they are, and agrees that they should be strict. And so, with the help of a doctor, she ended her life:

Zoraya told me she didn’t want a funeral, because she didn’t think her friends would want to say goodbye. But she did want her boyfriend to be with her at the end. When I spoke to her, she described how she wanted to die:

I will take my place on the couch. [The doctor] will once again ask if I am sure, and she will start up the procedure and wish me a good journey. Or, in my case, a nice nap, because I hate it if people say, “Safe journey.” I’m not going anywhere.

On Wednesday, a friend of hers posted an announcement on X: “Zoraya passed away today at 1:25 p.m. Or as she saw it herself: she went to sleep.”

Few details of her death have been reported—except that her boyfriend was at her side.

It’s sad to envision this, but we are not at the point where conditions like Zoraya’s can be treated. But again, who can gainsay that she did what was best for her? Who could be so churlish as to say she must stay alive.

The answer: the faithful.

If you want to see religious jobs who argue that prayer and recognize the value of suffering should have kept her alive, read this article in the Catholic Herald: “Zoraya ter Beek deserved doctors who cherished her life as precious.”  A quote from that:

As Catholics, we have a powerful message to tell that there is value to be found in suffering: when we step into church, we are met with the sight of Christ crucified, and are reminded of the agony he bore because he loved us. In fact, it’s because Christ experienced being human that we can be sure that he understands and cares for us in our suffering. Still, most of us are not lawmakers. We’re not campaigners or politicians. Trying to justify our Catholic beliefs to the world can seem overwhelming – almost pointless, when our faith is so often denigrated.

As Catholics, we must continue to remind ourselves of the power of prayer; not exclusively praying for a change of heart of those in positions of power who may choose to legalise assisted dying, though that is of course important, but rather praying in order to cultivate closeness to God in our own lives. We must rely on God first, and only then can we show others that we can help them bear their pain. We must confide in the one who bore the greatest pain for us, and petition, in prayer, to be given the strength to imitate his goodness and his compassion in our own lives. Finally, we must never lose hope, even in cases where a person appears determined to die. We must pray for them to the very end, for by God’s grace, no soul is ever truly beyond saving.

This is the maliciousness of religion: keep the suffering going, for superstition tells us that God will make it all right in the end.  It’s horrible.

Here she is in a video made by The Free Press:

Humans from many cultures tend to associate the nonsense words “bouba” and “kiki” with different shapes – and now it seems that 3-day-old chicks have the same inclinations

Astronomy is a profession that, so far, has only been done at night, at least on Earth. Light from the Sun overwhelms any light from other stars, making it impractical for both professional and amateur astronomers to look at the stars during daytime. There are several disadvantages to this, not the least of which is that many potentially exciting parts of the sky aren’t visible at all for large chunks of the year as they pass too close to the Sun. To solve this, a team from Macquarie University, led by graduate student Sarah Caddy, developed a multi-camera system for a local telescope that allows them to observe during daytime.

The University has a system known as the Huntsman Telescope, named after the famous Australian spider species. Its design was inspired by the Dragonfly Telescope Array, initially designed by researchers at the University of Toronto and Yale, among other institutions. Both telescopes feature an array of 10 telephoto lenses from Canon, the camera manufacturer, arranged in a honeycomb pattern.

Typically, the telescope is used for nighttime astronomy at the Siding Spring Observatory, about a seven-hour drive from Sydney. However, Ms. Caddy thought it could do better and potentially continue observations during the day.

An image of Betelgeuse during the day using the Huntsman Telescope.
Credit – Macquarie University

They originally tested their ideas, which focused on a number of broadband filters and a single-lens test version of the Huntsman telescope. This allowed them to optimize things like exposure times and timing and show a proof of concept that they then wrote up in a paper in the Publications of the Astronomical Society of Australia. 

In particular, Ms. Caddy and her colleagues are excited about several use cases. One is tracking particular stars that might soon undergo an exciting event. Betelgeuse comes to mind, as astronomers expect it to undergo a supernova sometime “soon,” though soon in astronomical terms could mean anywhere between tomorrow and 10 million years from now. If Betelgeuse happens to be on the other side of the Sun when it goes supernova, without daylight astronomy, there would be months of a gap where we would miss out on collecting data on the supernova that happened nearest to us in recorded history, and astronomers everywhere would be frustrated.

This is exactly why the Huntsman team used a daytime image of Betelgeuse as part of their proof of concept. While it might not look like a typical image of the star that is 650 light years away, the fact that it is visible at all during the daytime is striking.

Betelgeuse is one of the most interesting stars in the sky – a potential supernova that goes through occasional dimming periods, as Fraser explains.

Another use case is the tracking of satellites. As the orbital space around Earth becomes increasingly crowded, there’s a higher likelihood that satellites will begin colliding, which could eventually result in something as severe as Kessler syndrome, which we’ve discussed before here at UT. Unfortunately, astronomers can only track satellites during the night, so if one of their orbits happens to shift for some reason during a day cycle, it would be impossible for them to suggest changes to the orbital paths of other satellites that are close by.

Unless you have daytime astronomy, which allows you to track satellites during the day, there’s a significantly decreased risk of two running into each other unexpectedly. This data can be combined with radar readings to help avoid catastrophic collisions, no matter how crowded orbital space gets.

This proof of concept is a step toward making those observations a reality. As it is more fully tested, the southern sky will become much more accessible, and it could pave the way for other daytime astronomy projects in other parts of the world.

Learn More:
Macquarie University – Stargazing in broad daylight: How a multi-lens telescope is changing astronomy
Caddy, Spitler & Ellis – An Optical Daytime Astronomy Pathfinder for the Huntsman Telescope
UT – Astro-Challenge: Adventures in Daytime Astronomy
UT – Why Can We See the Moon During the Day?

Lead Image:
Macquarie’s Huntsman Telescope can potentially observe space during the day.
Credit – Macquarie University

The post A New Telescope Can Observe Even in Broad Daylight appeared first on Universe Today.

We asked New Scientist staff to pick their favourite science fiction books. Here are the results, ranging from 19th-century classics to modern day offerings, and from Octavia E. Butler to Iain M. Banks

One of the things that worried me about the protestors (i.e., the encampers), most of whom were affiliated with the consortium UChicago United for Palestine (UCUP, one of whose subgroups is the Students for Justice in Palestine), is that they will attempt to disrupt graduation on Saturday by making noise, chanting, and generally creating a ruckus with their pro-Palestinian vigor. These were, after all, the people who were largely behind the Encampment, and their main function seems to be disrupting campus activities. Even though they’ve gained nothing I can see from all legal or illegal demonstrations, and in fact have angered a lot of people with their performative activism, they’ve vowed to keep on keeping on, and that includes disrupting graduation. (The Encampment didn’t make the administration yield to any of the protestors’ demands.)

As The Chicago Tribune reported yesterday, the University of Chicago is withholding the degrees of four students who participated in the encampment, all pending resolution of formal disciplinary hearings about their participation. This doesn’t mean they won’t graduate if the hearings exculpate them, but if they’re found guilty they don’t get their degrees. As the Tribune said:

A U. of C. spokesman said the school could not comment on individual student disciplinary matters, but noted that the process is standard practice after a formal complaint is reviewed by the university’s Disciplinary Committee.

“The recent protests on campus brought about multiple formal complaints alleging that students violated University policies, including by engaging in disruptive conduct,” the university said. “Once a formal complaint is received and, if the Disciplinary Committee faculty lead concurs that the complaint is credible, the matter may be referred to the Standing Disciplinary Committee on Disruptive Conduct to determine if policies have been violated.”

The four students are still able to participate in graduation and other end-of-year events, and their degrees can be later conferred depending on the resolution of the disciplinary process. But if the committee finds that certain policies have been violated, their degrees could be denied, despite four years of coursework and tuition.

Undergraduate tuition for the prestigious institution exceeds $67,000, and rises to more than $93,000 after including housing, food and other miscellaneous expenses.

The four students under investigation (the article implies there are others as well), along with many in the community in general, are furious that any such punishments are being levied on those who violated University rules. (The old notion of taking your punishment for civil disobedience seems to have vanished.)

My own view, which I’ve expressed here often, is that punishments for the guilty are needed if we’re going to tamp down the degree of illegal disruption on campus. So far the University doesn’t seem to have had much stomach for punishment, but that, of course, will only guarantee that disruption of campus life will continue.  The war in Gaza is going to last a while, and it’s easy to see that unless there are sanctions on the table, illegal disruptions could continue for several years. (I’m not, of course, opposed to pro-Palestinian demonstrations so long as they don’t violate the “time, place, and manner” rules of the University. Legal demonstrations are a manifestation of the free speech for which the University of Chicago is famous.)

Unfortunately, UCUP is not only threatening to disrupt graduation (an illegal activity), but is making concrete plans to do so. Have a gander at these two posts from the UCUP Instagram page (each screenshot links to the post):

Note: “Be sure to bring drums and noise makers as we rally for Rafah.” You know what that means: a lot of shouting, chanting, and banging during a ceremony that is really important to many graduates.

You might expect that UCUP would let these graduates enjoy the formal termination of their studies here, but you would expect wrongly. UCUP wants to disrupt, and are apparently heedless that they would lose sympathy from the community if they screw up graduation.  But changing minds is not, I think, their main aim.

Here’s another screenshot.

Rally at 10 AM on Saturday, with the location to be arranged (it’ll be given out on private chatrooms). Since the convocation (the ceremony) is scheduled to start at 9:15 a.m., this will be right when the ceremony is under way. I’ll be around to report what happens.

We are rapidly entering the era of neuromodulation – using electrical and magnetic fields in order to increase or decrease the activity of specific regions and circuits in the brain. Such treatments are already shown to be effective in treating some Parkinson’s symptoms, depression, OCD, migraines, and other neurological and psychiatric conditions. Computational models of brain anatomy and the connectome have dramatically increased the utility of neuromodulation. We are still on the steep part of the curve, and it will be interesting to see how far this modality goes in the next 10-20 years.

But there is one technical challenge – reaching the deep brain structures where many of the potentially targeted conditions can be found. The problem is that any electrical or magnetic field has to go through the more superficial brain tissue to get to the deeper structures. The current solution to this problem is to use invasive techniques, such as placing wires in the brain. So called “deep brain stimulation” is now done routinely, using guided stereotactic techniques, but a non-invasive way to accomplish the same goal could lead to a dramatic increase in the utility of neuromodulation.

Researchers have now published a proof of concept study looking at what they call transcranial temporal interference stimulation (tTIS).  The idea of tTIS is actually rather simple – it exploits the phenomenon of interference. Waves, regardless of what kind of waves they are, display certain core behaviors, one of which is interference. Wave are basically additive. If a peak hits a peak you get a bigger peak. If the peak of one wave coincides with the trough of another wave, the two waves will cancel each other out. This is how noise cancelling headphones work, for example.

Brain activity has a rather low frequency, and hence responds to low frequency modulation. Much higher frequencies will not coincide with brain waves and therefore have little net effect on brain activity. With tTIS, therefore, you can use two electrical stimulations that are both high frequency but off by a small amount. In the current study they used one frequency of 2000 hz and one of 2080 hz. These are both too high to directly affect brain function, so they can pass through brain tissue harmlessly. You can then aim these beams so that they intersect on the desired deep brain tissue. There the 2000 hz will essentially be subtracted from the 2080 hz, leaving an 80 hz electrical frequency. And that is a frequency which does cause neuromodulation. Voila – non-invasive deep brain stimulation.

In the study they stimulated the striatum of 24 healthy human subjects during reinforcement learning tasks. They found that at 80 hz the tTIS interfered with reinforcement motor learning, while at 20 hz (or sh am stimulation) there was no effect. The subjects had to use the force of their grip on a hand-grip force sensor to control a cursor track a moving object. The hypothesis is that the activity of the striatum is causative of improvement in the task performance through reinforcement motor learning. They found that at 80 hz the subjects did not improve with motor learning, while at 20 hz or sham stimulation they did.

This brings up a nice feature of tTIS as a research tool (and other forms of neuromodulation). These studies are really easy to double blind. The subject has no idea what frequency of electrical stimulation they are receiving. This is now even more true for tTIS, because the effect comes from the small difference between two electrical frequencies – imperceptible to the subject.

It’s also a good example of the power of different technologies working in tandem. Here we use functional MRI scanning to see what’s happening in the brain, tTIS to modulate brain activity, and computers to model what is happening and which parts of the brain are doing what. Increasingly this computer modeling is incorporating AI to help make sense of lots of noisy data. The result is a dramatic increase in the pace of the kinds of research that can benefit from such technologies.

Think about how useful this is for neuroscience research. I wonder what that part of the brain does. Well, let’s turn it off or stimulate it and find out. The goal is to achieve not just a map of the brain or a map of all the connections in the brain, but a functional map of the brain – what are all the modules and circuits and what do they do? How does their function work as part of the whole, and what effect do they have on other circuits in the brain. This research will still take a long time, because the brain is horrifically complex, and there is a lot of neurodiversity out there. But the pace is accelerating.

Then, with this information we can make computer models to test how our models of the brain work, and to further test our hypotheses. Eventually, perhaps, the end result of all this research will be a complete computer model of a human brain. The question is – as I have speculated before – will this computer model of the human brain be, essentially, a human brain? Will it be capable of consciousness? I see no reason why not, as long as it is functioning. In fact, this is one pathway to achieving general AI, just modeling the human brain.

Imagine how useful this computer model will be to research. We would then have unlimited power to adjust the functional parameters of every aspect of brain function to see the effect this has on the whole. But then, if the computer model can be reasonably argued to be conscious, we would run into ethical considerations. Would we need consent from the computer model to mess with its function? Would that consent be free? What if we just keep making copies of the computer model with small tweaks until we get one that consents? What if we name it “Colossus” and put it in charge of our nuclear launch codes? It will be interesting times.

The post Non-Invasive Deep Brain Stimulation first appeared on NeuroLogica Blog.

A star in a distant galaxy appears to have been almost torn apart in a close shave with a supermassive black hole, not once but twice – and astronomers hope to see it happen again