In an earlier psychology study, the researchers established that people can separately control how much they focus (by enhancing relevant information) and how much they filter (by tuning out distraction). The team’s new research, published in Nature Human Behaviour, unveils the process by which the brain coordinates these two critical functions.

Lead author and neuroscientist Harrison Ritz likened the process to how humans coordinate muscle activity to perform complex physical tasks.

“In the same way that we bring together more than 50 muscles to perform a physical task like using chopsticks, our study found that we can coordinate multiple different forms of attention in order to perform acts of mental dexterity,” said Ritz, who conducted the study while a Ph.D. student at Brown.

The findings provide insight into how people use their powers of attention as well as what makes attention fail, said co-author Amitai Shenhav, an associate professor in Brown’s Department of Cognitive, Linguistic and Psychological Sciences.

“These findings can help us to understand how we as humans are able to exhibit such tremendous cognitive flexibility — to pay attention to what we want, when we want to,” Shenhav said. “They can also help us better understand limitations on that flexibility, and how limitations might manifest in certain attention-related disorders such as ADHD.”

The focus-and-filter test

To conduct the study, Ritz administered a cognitive task to participants while measuring their brain activity in an fMRI machine. Participants saw a swirling mass of green and purple dots moving left and right, like a swarm of fireflies. The tasks, which varied in difficulty, involved distinguishing between the movement and colors of the dots. For example, participants in one exercise were instructed to select which color was in the majority for the rapidly moving dots when the ratio of purple to green was almost 50/50.

Ritz and Shenhav then analyzed participants’ brain activity in response to the tasks.

Ritz, who is now a postdoctoral fellow at the Princeton Neuroscience Institute, explained how the two brain regions work together during these types of tasks.

“You can think about the intraparietal sulcus as having two knobs on a radio dial: one that adjusts focusing and one that adjusts filtering,” Ritz said. “In our study, the anterior cingulate cortex tracks what’s going on with the dots. When the anterior cingulate cortex recognizes that, for instance, motion is making the task more difficult, it directs the intraparietal sulcus to adjust the filtering knob in order to reduce the sensitivity to motion.

“In the scenario where the purple and green dots are almost at 50/50, it might also direct the intraparietal sulcus to adjust the focusing knob in order to increase the sensitivity to color. Now the relevant brain regions are less sensitive to motion and more sensitive to the appropriate color, so the participant is better able to make the correct selection.”

Ritz’s description highlights the importance of mental coordination over mental capacity, revealing an often-expressed idea to be a misconception.

“When people talk about the limitations of the mind, they often put it in terms of, ‘humans just don’t have the mental capacity’ or ‘humans lack computing power,'” Ritz said. “These findings support a different perspective on why we’re not focused all the time. It’s not that our brains are too simple, but instead that our brains are really complicated, and it’s the coordination that’s hard.”

Ongoing research projects are building on these study findings. A partnership with physician-scientists at Brown University and Baylor College of Medicine is investigating focus-and-filter strategies in patients with treatment-resistant depression. Researchers in Shenhav’s lab are looking at the way motivation drives attention; one study co-led by Ritz and Brown Ph.D. student Xiamin Leng examines the impact of financial rewards and penalties on focus-and-filter strategies.

The study was funded by the National Institutes of Health (R01MH124849, S10OD02518), the National Science Foundation (2046111) and by a postdoctoral fellowship from the C.V. Starr Foundation.

In publishing the study in eClinicalMedicine, the authors stress that while they have identified a correlation, their research does not show a causal relationship between amblyopia and ill health in adulthood.

The researchers analysed data from more than 126,000 participants aged 40 to 69 years old from the UK Biobank cohort, who had undergone ocular examination.

Participants had been asked during recruitment whether they were treated for amblyopia in childhood and whether they still had the condition in adulthood. They were also asked if they had a medical diagnosis of diabetes, high blood pressure, or cardio/cerebrovascular disease (ie. angina, heart attack, stroke).

Meanwhile, their BMI (body mass index), blood glucose, and cholesterol levels were also measured and mortality was tracked.

The researchers confirmed that from 3,238 participants who reported having a ‘lazy eye’ as a child, 82.2% had persistent reduced vision in one eye as an adult.

The findings showed that participants with amblyopia as a child had 29% higher odds of developing diabetes, 25% higher odds of having hypertension and 16% higher odds of having obesity. They were also at increased risk of heart attack — even when other risk factors for these conditions (e.g. other disease, ethnicity and social class) were taken into account.

This increased risk of health problems was found not only among those whose vision problems persisted, but also to some extent in participants who had had amblyopia as a child and 20/20 vision as an adult, although the correlation was not as strong.

Corresponding author, Professor Jugnoo Rahi (UCL Great Ormond Street Institute for Child Health, UCL Institute of Ophthalmology and Great Ormond Street Hospital), said: “Amblyopia is an eye condition affecting up to four in 100 children. In the UK, all children are supposed to have vision screening before the age of five, to ensure a prompt diagnosis and relevant ophthalmic treatment.

“It is rare to have a ‘marker’ in childhood that is associated with increased risk of serious disease in adult life, and also one that is measured and known for every child — because of population screening.

“The large numbers of affected children and their families, may want to think of our findings as an extra incentive for trying to achieve healthy lifestyles from childhood.”

Amblyopia is when the vision in one eye does not develop properly and can be triggered by a squint or being long-sighted.

It is a neurodevelopmental condition that develops when there’s a breakdown in how the brain and the eye work together and the brain can’t process properly the visual signal from the affected eye. As it usually causes reduced vision in one eye only, many children don’t notice anything wrong with their sight and are only diagnosed through the vision test done at four to five years of age.

A recent report from the Academy of Medical Sciences* involving some researchers from the UCL Great Ormond Street Institute for Child Health, called on policymakers to address the declining physical and mental health of children under five in the UK and prioritise child health.

The team hope that their new research will help reinforce this message and highlight how child health lays the foundations for adult health.

First author, Dr Siegfried Wagner (UCL Institute of Ophthalmology and Moorfields Eye Hospital), said: “Vision and the eyes are sentinels for overall health — whether heart disease or metabolic disfunction, they are intimately linked with other organ systems. This is one of the reasons why we screen for good vision in both eyes.

“We emphasise that our research does not show a causal relationship between amblyopia and ill health in adulthood. Our research means that the ‘average’ adult who had amblyopia as a child is more likely to develop these disorders than the ‘average’ adult who did not have amblyopia. The findings don’t mean that every child with amblyopia will inevitably develop cardiometabolic disorders in adult life.”

The research was carried out in collaboration with the University of the Aegean, University of Leicester, King’s College London, the National Institute for Health and Care Research (NIHR) Biomedical Research Centre (BRC) at Moorfields Eye Hospital and UCL Institute of Ophthalmology and the NIHR BRC at UCL Great Ormond Street Institute of Child Health and Great Ormond Street Hospital.

The work was funded by the Medical Research Council, the NIHR and the Ulverscroft Foundation.

“The signal changed directions over time, exactly matching a road that runs past the seismometer,” said Benjamin Fernando, a planetary seismologist at Johns Hopkins who led the research. “It’s really difficult to take a signal and confirm it is not from something. But what we can do is show that there are lots of signals like this, and show they have all the characteristics we’d expect from a truck and none of the characteristics we’d expect from a meteor.”

The team will present its findings March 12 at the Lunar and Planetary Science Conference in Houston.

After a meteor entered Earth’s atmosphere over the Western Pacific in January 2014, the event was linked to ground vibrations recorded at a seismic station in Papua New Guinea’s Manus Island. In 2023, materials at the bottom of the ocean near where the meteor fragments were thought to have fallen were identified as of “extraterrestrial technological” (alien) origin.

But according to Fernando, that supposition relies on misinterpreted data and the meteor actually entered the atmosphere somewhere else. Fernando’s team did not find evidence of seismic waves from the meteor.

“The fireball location was actually very far away from where the oceanographic expedition went to retrieve these meteor fragments,” he said. “Not only did they use the wrong signal, they were looking in the wrong place.”

Using data from stations in Australia and Palau designed to detect sound waves from nuclear testing, Fernando’s team identified a more likely location for the meteor, more than 100 miles from the area initially investigated. They concluded the materials recovered from the ocean bottom were tiny, ordinary meteorites — or particles produced from other meteorites hitting Earth’s surface mixed with terrestrial contamination.

“Whatever was found on the sea floor is totally unrelated to this meteor, regardless of whether it was a natural space rock or a piece of alien spacecraft — even though we strongly suspect that it wasn’t aliens,” Fernando added.

Fernando’s team includes Constantinos Charalambous of Imperial College London; Steve Desch of Arizona State University; Alan Jackson of Towson University; Pierrick Mialle of the Comprehensive Nuclear-Test-Ban Treaty Organization; Eleanor K. Sansom of Curtin University; and Göran Ekström of Columbia University.

“These findings are clear evidence that very early treatment enables unique features of the neonatal immune system to limit HIV reservoir development, which increases the prospect of HIV remission,” said NIAID Director Jeanne Marrazzo, M.D., M.P.H. “The promising signals from this study are a beacon for future HIV remission science and underscore the indispensable roles of the global network of clinicians and study staff who implement pediatric HIV research with the utmost care.”

Advances in ART have significantly reduced perinatal HIV transmission, when a child acquires HIV while in the uterus, during birth, or through consumption of milk from a lactating person. If transmission does occur, children must take lifelong ART to control replication of the virus and protect their immune systems from life-threatening complications. Typically, interruption in treatment will lead to rapid resumption of HIV replication and detectable virus in the blood within weeks. However, in 2013, a case report described an infant born with HIV in Mississippi who initiated treatment at 30 hours of life, was taken off their ART at 18 months of age and remained in remission with no evidence of detectable HIV for 27 months.

Building on the observation that very early ART initiation may limit HIV’s ability to establish reservoirs of dormant virus in infants researchers began an early-stage proof-of-concept study of very early ART in infants conducted in Brazil, Haiti, Kenya, Malawi, South Africa, Tanzania, Thailand, Uganda, the United States, Zambia, and Zimbabwe. Previous publications from the clinical study showed that ART initiated within hours of birth was safe and effective at achieving and maintaining HIV suppression. A small subset of children achieved sustained HIV suppression and met other predefined study criteria for interrupting ART. These criteria include a durable absence of HIV replication from 48 weeks of ART initiation onward, no detectable antibodies near the time of ART interruption, and having a CD4+ T-cell count (the main immune cell target of HIV) similar to those of a child without HIV. Children who met these criteria, were older than 2 years and had stopped consuming human milk were eligible to interrupt ART.

Data presented at CROI summarized the experience of six children, all aged 5 years, who were eligible for ART interruption with close health and safety monitoring. Four of the six children experienced HIV remission, defined as the absence of replicating virus for at least 48 weeks off ART. One of them experienced remission for 80 weeks, but then their HIV rebounded to detectable levels. Three others have been and remain in remission for 48, 52 and 64 weeks, respectively. However, two children did not experience remission, and their HIV became detectable within three and eight weeks after ART interruption, respectively. The two children whose HIV returned at eight and 80 weeks experienced mild acute retroviral syndrome (ARS) with symptoms including headache, fever, rash, swollen lymph nodes, tonsillitis, diarrhea, nausea and vomiting. One child had markedly low white blood cells, which are a type of immune cell. Both the ARS and white blood deficiency resolved either prior to or soon after restarting ART. The three children who experienced viral rebound resumed HIV suppression within six, eight and 20 weeks of restarting ART.

“This is the first study to rigorously replicate and expand upon the outcomes observed in the Mississippi case report,” said lead study virologist Deborah Persaud, M.D., professor of pediatrics at the Johns Hopkins University School of Medicine, and director of the Division of Pediatric Infectious Diseases at Johns Hopkins Children’s Center, Baltimore. “These results are groundbreaking for HIV remission and cure research, and they also point to the necessity of immediate neonatal testing and treatment initiation in health care settings for all infants potentially exposed to HIV in utero.”

The latest findings show that very early ART initiation has varying but favorable outcomes on control of HIV. While ARS was generally mild and resolved in both cases, the authors cautioned that close monitoring for this potential event is needed in ongoing and future HIV remission research involving ART interruption. The children participating in this study took ART regimens with medicines that have been part of standard first-line therapy for decades. Further research is planned or underway to understand how these observations could differ in children receiving newer, more potent generations of antiretroviral drugs, and to identify biomarkers to predict the likelihood of HIV remission or rebound following ART interruption. Additional studies are also needed to understand the mechanisms by which neonatal immunity and very early ART initiation limited the formation of HIV reservoirs and contributed to the remission observed in this study.

“ART shifted the HIV care paradigm, but treatment is a long road, especially for children as lifetime HIV survivors” said Adeodata Kekitiinwa, MBChB, MMed, emeritus clinical associate professor in the Department of Pediatrics at Baylor College of Medicine, study investigator of record and clinical research site leader in Kampala, Uganda. “This trial takes us a step closer to realizing another paradigm shift in which our approach to ART could be so effective that it might be used for a season of life, rather than its entirety.”

This ongoing research is being conducted by the International Maternal Pediatric Adolescent AIDS Clinical Trials (IMPAACT) Network, which is funded by the National Institute of Allergy and Infectious Diseases (NIAID), part of the National Institutes of Health, with co-funding from the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD), and the National Institute of Mental Health (NIMH).

The research was led by study co-chairs Ellen Chadwick, M.D., professor of pediatrics at Northwestern University Feinberg School of Medicine, and Yvonne Bryson, M.D., professor of pediatrics at the David Geffen School of Medicine and Mattel Children’s Hospital at UCLA, and director of the Los Angeles Brazil AIDS Consortium. Dr. Kekitiinwa, Boniface Njau, M.S., study coordinator at Kilimanjaro Christian Medical Centre in Tanzania and Teacler Nematadzira, MBChB, site investigator at the University of Zimbabwe-University of California San Francisco Collaborative Research Program continue to lead the study teams overseeing care of children who experienced HIV remission. Jennifer Jao, M.D., M.P.H., professor of pediatrics at Northwestern University Feinberg School of Medicine has since assumed a study co-chair role with Dr. Chadwick. The full IMPAACT P1115 study team consists of hundreds of staff across 30 NIAID- and NICHD-supported sites in the 11 study countries.

A bunch of little red dots found in a tiny region of our night sky might be an unexpected breakthrough for the James Webb Space Telescope (JWST) within its first year of service. These objects were indistinguishable from normal galaxies through the ‘eyes’ of the older Hubble Space Telescope. “Without having been developed for this specific purpose, the JWST helped us determine that faint little red dots-found very far away in the Universe’s distant past-are small versions of extremely massive black holes. These special objects could change the way we think about the genesis of black holes,” says Jorryt Matthee, Assistant Professor at the Institute of Science and Technology Austria (ISTA), and lead author of the study. “The present findings could bring us one step closer to answering one of the greatest dilemmas in astronomy: According to the current models, some supermassive black holes in the early Universe have simply grown ‘too fast’. Then how did they form?”

The cosmic points of no return

Scientists have long considered black holes a mathematical curiosity until their existence became increasingly evident. These strange cosmic bottomless pits could have such compact masses and strong gravities that nothing can escape their force of attraction-they suck in anything, including cosmic dust, planets, and stars, and deform the space and time around them such that even light cannot escape. The general theory of relativity, published by Albert Einstein over a century ago, predicted that black holes could have any mass. Some of the most intriguing black holes are the supermassive black holes (SMBHs), which could reach millions to billions of times the mass of the Sun. Astrophysicists agree that there is an SMBH at the center of almost every large galaxy. The proof that Sagittarius A* is an SMBH in the center of our Galaxy with over four million times the Sun’s mass, earned the 2020 Nobel Prize in Physics.

Too massive to be there

However, not all SMBHs are the same. While Sagittarius A* could be compared to a sleeping volcano, some SMBHs grow extremely rapidly by engulfing astronomic amounts of matter. Thus, they become so luminous that they can be observed until the edge of the ever-expanding Universe. These SMBHs are called quasars and are among the brightest objects in the Universe. “One issue with quasars is that some of them seem to be overly massive, too massive given the age of the Universe at which the quasars are observed. We call them the ‘problematic quasars,'” says Matthee. “If we consider that quasars originate from the explosions of massive stars-and that we know their maximum growth rate from the general laws of physics, some of them look like they have grown faster than is possible. It’s like looking at a five-year-old child that is two meters tall. Something doesn’t add up,” he explains. Could SMBHs perhaps grow even faster than we originally thought? Or do they form differently?

Small versions of giant cosmic monsters

Now, Matthee and his colleagues identify a population of objects that appear as little red dots in JWST images. Also, they demonstrate that these objects are SMBHs, but not overly massive ones. Central in determining that these objects are SMBHs was the detection of Hα spectral emission lines with wide line profiles. Hα lines are spectral lines in the deep-red region of visible light that are emitted when hydrogen atoms are heated. The width of the spectra traces the motion of the gas. “The wider the base of the Hα lines, the higher the gas velocity. Thus, these spectra tell us that we are looking at a very small gas cloud that moves extremely rapidly and orbits something very massive like an SMBH,” says Matthee. However, the little red dots are not the giant cosmic monsters found in overly massive SMBHs. “While the ‘problematic quasars’ are blue, extremely bright, and reach billions of times the mass of the Sun, the little red dots are more like ‘baby quasars.’ Their masses lie between ten and a hundred million solar masses. Also, they appear red because they are dusty. The dust obscures the black holes and reddens the colors,” says Matthee. But eventually, the outflow of gas from the black holes will puncture the dust cocoon, and giants will evolve from these little red dots. Thus, the ISTA astrophysicist and his team suggest that the little red dots are small, red versions of giant blue SMBHs in the phase that predates the problematic quasars. “Studying baby versions of the overly massive SMBHs in more detail will allow us to better understand how problematic quasars come to exist.”

A “breakthrough” technology

Matthee and his team could find the baby quasars thanks to the datasets acquired by the EIGER (Emission-line galaxies and Intergalactic Gas in the Epoch of Reionization) and FRESCO (First Reionization Epoch Spectroscopically Complete Observations) collaborations. These are a large and a medium JWST program in which Matthee was involved. Last December, the Physics World magazine listed EIGER among the top 10 breakthroughs of the year for 2023. “EIGER was designed to study specifically the rare blue supermassive quasars and their environments. It was not designed to find the little red dots. But we found them by chance in the same dataset. This is because, by using the JWST’s Near Infrared Camera, EIGER acquires emission spectra of all objects in the Universe,” says Matthee. “If you raise your index finger and extend your arm completely, the region of the night sky we explored corresponds to roughly a twentieth of the surface of your nail. So far, we have probably only scratched the surface.”

Matthee is confident that the present study will open up many avenues and help answer some of the big questions about the Universe. “Black holes and SMBHs are possibly the most interesting things in the Universe. It’s hard to explain why they are there, but they are there. We hope that this work will help us lift one of the biggest veils of mystery about the Universe,” he concludes.