Blog

We consider humans to be at the apex of social cognition. But we’re not the only animals that closely interact with each other. Marmosets, for example, are highly social creatures. In the wild, they choose to work together, sharing food and helping each other raise young.

In a new study, published Aug. 28 in Current Biology, Yale researchers, collaborating across Yale School of Medicine (YSM) and the Faculty of Arts and Sciences (FAS), created a novel approach for closely observing marmoset behavior. Combined with computational modeling, the study revealed sophisticated cooperative strategies utilized by marmoset pairs.

This new system could help improve the way psychologists study social cognition and lead to a better understanding of disorders in which it is impaired, such as autism spectrum disorder.

“This particular study established a paradigm that allows us to obtain high throughput behavioral data,” says Monika Jadi, PhD, associate professor of psychiatry at YSM and co-principal investigator. “So, we can now start probing the brain areas that are involved in social cognition and understanding how they are involved.”

The current established paradigm for studying marmoset social cognition is cumbersome and limits the amount of data researchers can obtain. “It’s not ideal for studying complex behavior dynamics,” says Steve Chang, PhD, associate professor of psychology in FAS and co-principal investigator.

Furthermore, the paradigm involves manually observing and scoring behaviors. “It’s a slow and error-prone process, which does not provide mechanistic insights into what the animals are doing,” says Anirvan Nandy, PhD, associate professor of neuroscience and co-principal investigator.

In the new study, the team used a new apparatus that they developed—Marmoset Apparatus for Automated Pulling—which requires a pair of marmosets to work together, pulling levers within a certain timeframe in order to receive a reward. The researchers also set up cameras around the apparatus, enabling them to track moment-by-moment where the animals were looking.

This rich set of behavioral data allowed the team to build a computational model for understanding the various cooperative strategies that the marmosets utilized.

Marmosets show flexibility during cooperation

The researchers discovered that marmosets used different types of strategies to cooperate. In some cases, one marmoset would monitor what the other was doing to help time its pull, which researchers refer to as a “social gaze-dependent strategy.” In other instances, the animals got into a rhythm and synchronized their pulls without looking at each other, using a “social gaze-independent strategy.”

The marmosets showed flexibility when choosing strategies. When the duo was performing well, they tended to use social gaze-independent rhythmic pulling. But at times when they struggled to synchronize, they switched to social gaze-dependent strategies. In other words, the animals would look at each other more as they strived to find a rhythm.

The primates also chose different strategies based on their partner. For instance, if one marmoset struggled to pull the lever within the allotted time frame, the researchers found that its partner would adapt, such as pulling the lever twice to give the first marmoset more time. But when paired with a new partner who did not struggle with timing, the marmoset would revert to pulling only once.

“Pulling strategies of the same monkey can alternate back and forth,” says Chang. “They are using partner identity to adjust how they are interacting with the device.”

Furthermore, the dominant member of the pair tended to pull the lever after the subordinate. “The dominant was monitoring what the subordinate was doing and timing their pulls,” says Nandy.

The findings highlighted how marmosets proactively looked for ways to cooperate with one another. “They’re motivated to figure out the best way to work together for mutual benefit,” says Chang. “And they can adjust their strategies to achieve that benefit.”

Expanding our understanding of social cognition

The researchers are now combining their new system with neural recording to better understand how neurons encode cooperative strategies. Down the road, this type of research could lead to better understanding of disorders such as autism spectrum disorder, in which individuals often struggle with behavioral rigidity.

“This work opens up a whole realm of possibilities around studying complex social cognition at large,” says Nandy.

Olivia Meisner, PhD, a former graduate student from YSM’s Interdepartmental Neuroscience Program, and Weikang Shi, PhD, a Wu Tsai Institute postdoctoral fellow, were co-first authors of the study.

This work was supported by the National Science Foundation (award DGE2139841), the National Institute of Mental Health (award R21MH126072), the National Eye Institute (award P30EY026878), and Yale University. The content is solely the responsibility of the authors and does not necessarily represent the official views of the National Institutes of Health or National Science Foundation. Additional support was provided by the Simons Foundation Autism Research Initiative and the Wu Tsai Institute.

The world has far fewer places to securely store carbon dioxide deep underground than previously thought, steeply lowering its potential to help stem global warming, according to a new study that challenges long-held industry claims about the practice.

The study, published Wednesday in the journal Nature, found that global carbon storage capacity was 10 times less than previous estimates after ruling out geological formations where the gas could leak, trigger earthquakes or contaminate groundwater, or had other limitations. That means carbon capture and storage would only have the potential to reduce human-caused warming by 0.7 degrees Celsius (1.26 Fahrenheit) — far less than previous estimates of around 5-6 degrees Celsius (9-10.8 degrees Fahrenheit), researchers said.

“Carbon storage is often portrayed as a way out of the climate crisis. Our findings make clear that it is a limited tool” and reaffirms “the extreme importance of reducing emissions as fast and as soon as possible,” said lead author Matthew Gidden, a research professor at the University Maryland’s Center for Global Sustainability. The study was led by the International Institute for Applied Systems Analysis, where Gidden also is a senior researcher in the energy, climate and environment program.

The study is the latest knock on a technology, for years promoted by oil and gas industry, that has often been touted as a climate solution. Today, carbon capture is far from being deployed at scale, despite billions of dollars in investments around the world, and the amount of carbon currently captured is just a tiny fraction of the billions of tons of carbon dioxide emitted every year.

Challenging assumptions

The 2015 Paris Agreement called for limiting average global temperature increase to 2 degrees Celsius (3.6 degrees Fahrenheit), but ideally below 1.5C (2.7F), compared to the early 1800s.

Many scenarios for achieving that have relied on carbon removal and storage, assuming the potential was “very large” because previous estimates didn’t account for vulnerable areas that might not be suitable, said study co-author Alexandre Koberle, a researcher at the University of Lisbon.

“That was never systematically challenged and tested,” said Koberle, adding that the study was the first to examine which areas should be avoided, leading to what they call a “prudent potential” that minimizes risks to people and the environment.

That’s not to say that carbon capture and storage isn’t important to keep global temperatures in check — but countries must prioritize how they use the limited storage and do so in conjunction with fast and deep emissions reductions, researchers said.

The technology ideally should be used for sectors that are difficult to decarbonize, such as cement production, aviation and agriculture, rather than to extend the life of polluting power plants or to prolong the use of oil and gas, Koberle said.

Industry officials defended carbon capture and storage as having an inherently low risk and say emerging technologies, such as storing carbon dioxide in basalt formations where it becomes mineralized, could dramatically increase total storage volumes.

What’s more, its use is “not optional if we hope to address global warming,” said Jessie Stolark, executive director of the Carbon Capture Coalition, adding that it must be combined with other ways to reduce emissions and balanced with the need for reliable and affordable energy.

Rob Jackson, head of the Global Carbon Project, a group of scientists who monitor greenhouse gas emissions, praised the study for its cautionary perspective. And though he’s optimistic that carbon capture technology itself will work, he believes very little will ever be stored “because I don’t think we’re willing to pay for it.”

“If we aren’t willing to cut emissions today, why do we expect that people in the future will just automatically pay to remove our pollution?” Jackson said. “We’re just continuing to pollute and not addressing the root of the problem.”

How it works

Carbon dioxide, a gas produced by burning fossil fuels, traps heat close to the ground when released to the atmosphere, where it persists for hundreds of years and raises global temperatures.

Industries and power plants can install equipment to separate carbon dioxide from other gases before it leaves the smokestack, or it can be captured directly from the atmosphere using giant vacuums.

Captured carbon is compressed and shipped to a location where it can be injected deep underground for long-term storage in deep saline or basalt formations and unmineable coal seams — though about three-fourths is pumped back into oil fields to build pressure to help extract more oil.

In the U.S., such projects have faced criticism from some conservatives, who say it is expensive and unnecessary, and from environmentalists, who say it has consistently failed to capture as much pollution as promised and is simply a way for producers of fossil fuels like oil, gas and coal to continue their use.

The most commonly used technology allows facilities to capture and store around 60% of their carbon dioxide emissions during the production process. Anything above that rate is much more difficult and expensive, according to the International Energy Agency.

Gidden, the lead author, said it’s clear that scaling up carbon storage will be important to achieving net-zero emissions and to eventually reduce them, and said the use of basalt formations is promising. But the world cannot wait for that to happen before acting decisively to slash fossil fuel emissions.

“If we prolong our dependence on fossil fuels for too long with the expectation that we will offset that by simply storing carbon underground, we’re likely saddling future generations with a nearly impossible task of dealing with not only our mess, but limited ways of cleaning it up,” he said.

___

The Associated Press’ climate and environmental coverage receives financial support from multiple private foundations. AP is solely responsible for all content. Find AP’s standards for working with philanthropies, a list of supporters and funded coverage areas at AP.org.