Sleep loss moderates link between youth impulsivity and mature-rated media usage

Sleep is essential for mental health, mood regulation, and healthy behavior in adolescents

Reports and Proceedings

AMERICAN ACADEMY OF SLEEP MEDICINE

DARIEN, IL – A new study to be presented at the SLEEP 2023 annual meeting found that objectively measured short sleep duration partially moderates the association between impulsivity and mature-rated media usage in early adolescents.

Results show that higher impulsivity was predictive for more R-rated movie watching, and shorter sleep duration was predictive for more mature video gaming and R-rated movie watching one year later. Only 19% of participants slept more than 8 hours on average. Structural equation modeling found that sleep duration moderates the association between impulsivity and R-rated movie watching after controlling for bedtime screen use, parental monitoring, and demographic covariates.

“We found that impulsive adolescents with shorter sleep duration are more likely to be exposed to R-rated content,” said lead author Linhao Zhang, who is a doctoral student in the department of human development and family science at the University of Georgia in Athens.

The American Academy of Sleep Medicine recommends that children 6 to 12 years of age should sleep 9 to 12 hours on a regular basis to promote optimal health. Teens should sleep 8 to 10 hours on a regular basis.

The three-year longitudinal study involved 2,757 early adolescents between the ages of 9 and 13 years; 50.7% were male. Their average age at the three-year follow-up was 12.9 years. Participants wore a Fitbit watch for at least seven days at the two-year follow-up to provide an objective estimate of sleep duration. They completed a questionnaire about impulsivity at the two-year follow-up, and questionnaires about R-rated movie watching and mature video gaming at both the two-year and three-year follow-up.

According to the authors, exposure to mature-rated media in youth is associated with decreased empathy and aggressive behaviors later in life. Shorter sleep duration is associated with decreased emotional regulation and attention span, making it a potential target to improve mental health, mood, and behavior in teens.

“Our results show that sleep duration may be a modifiable factor for prevention and intervention efforts, especially in adolescents at higher risk for excessive mature-rated media usage,” said Zhang.

The study involved a collaboration between research teams at the University of Georgia — led by Assaf Oshri, who has a doctorate in developmental psychology — and SRI International, led by postdoctoral fellow Orsolya Kiss. The study was supported by funding from the National Institutes of Health.

The research abstract was published recently in an online supplement of the journal Sleep and will be presented Tuesday, June 6, during SLEEP 2023 in Indianapolis. SLEEP is the annual meeting of the Associated Professional Sleep Societies, a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society.

 

###

 

Abstract Title: Sleep duration moderates the link between youth impulsivity and mature-rated media usage one year later

Abstract ID: 0214 Poster Presentation Date: Tuesday, June 6, 12 p.m. to 1:15 p.m. EDT, Board 25

Presenter: Linhao Zhang

 

For a copy of the abstract or to arrange an interview with the study author or a sleep expert, please send an email to media@aasm.org.

 

About the Associated Professional Sleep Societies, LLC

The APSS is a joint venture of the American Academy of Sleep Medicine and the Sleep Research Society. The APSS organizes the SLEEP annual meeting each June (sleepmeeting.org).

About the American Academy of Sleep Medicine

Established in 1975, the AASM advances sleep care and enhances sleep health to improve lives. The AASM has a combined membership of 12,000 accredited sleep centers and individuals, including physicians, scientists and other health care professionals who care for patients with sleep disorders. As the leader in the sleep field, the AASM sets standards and promotes excellence in sleep medicine health care, education and research (aasm.org).

About the Sleep Research Society

The SRS is a professional membership society that advances sleep and circadian science. The SRS provides forums for the exchange of information, establishes and maintains standards of reporting and classifies data in the field of sleep research, and collaborates with other organizations to foster scientific investigation on sleep and its disorders. The SRS also publishes the peer-reviewed, scientific journals Sleep and Sleep Advances (sleepresearchsociety.org).

Deep-brain stimulation during sleep

strengthens memory

Researchers also report first direct evidence supporting main theory for how human memory is consolidated during sleep

Peer-Reviewed Publication

UNIVERSITY OF CALIFORNIA - LOS ANGELES HEALTH SCIENCES

While it’s known that sleep plays a crucial role in strengthening memory, scientists are still trying to decode how this process plays out in the brain overnight. 

New research led by scientists at UCLA Health and Tel Aviv University provides the first physiological evidence from inside the human brain supporting the dominant scientific theory on how the brain consolidates memory during sleep. Further, the researchers found that targeted deep-brain stimulation during a critical time in the sleep cycle appeared to improve memory consolidation. 

The research, published June 1 in Nature Neuroscience, could offer new clues for how deep-brain stimulation during sleep could one day help patients with memory disorders like Alzheimer’s disease, said study co-author Itzhak Fried, MD, PhD. This was achieved by a novel “closed-loop” system that delivered electrical pulses in one brain region precisely synchronized to brain activity recorded from another region. 

According to the dominant theory for how the brain converts new information into long-term memories during shuteye, there’s an overnight dialogue between the hippocampus – the brain’s memory hub – and the cerebral cortex, which is associated with higher brain functions like reasoning and planning. This occurs during a phase of deep sleep, when brain waves are especially slow and neurons across brain regions alternate between rapidly firing in sync and silence. 

“This provides the first major evidence down to the level of single neurons that there is indeed this mechanism of interaction between the memory hub and the entire cortex,” said Fried, the director of epilepsy surgery at UCLA Health and professor of neurosurgery, psychiatry and biobehavioral sciences at the David Geffen School of Medicine at UCLA. “It has both scientific value in terms of understanding how memory works in humans and using that knowledge to really boost memory.” 

The researchers had a unique opportunity to test this theory of memory consolidation via electrodes in the brains of 18 epilepsy patients at UCLA Health. The electrodes had been implanted in the patients’ brains to help identify the source of their seizures during hospital stays typically lasting around 10 days.  

The study was conducted across two nights and mornings. Just before bedtime, study participants were shown photo pairings of animals and 25 celebrities, including easily identifiable stars like Marilyn Monroe and Jack Nicholson. They were immediately tested on their ability to recall which celebrity was paired with which animal, and they were tested again in the morning after a night of undisturbed sleep. 

On another night, they were shown 25 new animal and celebrity pairings before bedtime. This time, they received targeted electrical stimulation overnight, and their ability recall the pairings was tested in the morning. To deliver this electrical stimulation, the researchers had created a real-time closed-loop system that Fried likened to a musical conductor: The system “listened” to brain’s electrical signals, and when patients fell into the period of deep sleep associated with memory consolidation, it delivered gentle electrical pulses instructing the rapidly firing neurons to “play” in sync.  

Each individual tested performed better on memory tests following a night of sleep with the electrical stimulation compared to a night of undisturbed sleep. Key electrophysiological markers also indicated that information was flowing between the hippocampus and throughout the cortex, providing physical evidence supporting of memory consolidation. 

“We found we basically enhanced this highway by which information flows to more permanent storage places in the brain,” Fried said. 

Fried in 2012 authored a New England Journal of Medicine study that for the first time showed that electrical stimulation can strengthen memory, and his work has continued to explore how deep brain stimulation could improve memory, now moving into the critical stage of sleep. He recently received a $7 million NIH grant to study whether artificial intelligence can help pinpoint and strengthen specific memories in the brain. 

“In our new study, we showed we can enhance memory in general,” Fried said. “Our next challenge is whether we have the ability to modulate specific memories.” 

Yuval Nir of Tel Aviv University co-supervised the study with Fried. Other authors include lead author Maya Geva-Sagiv, as well as Emily Mankin, Dawn Eliashiv, Natalie Cherry, Guldamla Kalender and Natalia Tchemodanov from UCLA, and Shdema Epstein from Tel-Aviv University.

---

JOURNAL

Nature Neuroscience

DOI

10.1038/s41593-023-01342-3. 

ARTICLE TITLE

Augmenting hippocampal–prefrontal neuronal synchrony during sleep enhances memory consolidation in humans

ARTICLE PUBLICATION DATE

1-Jun-2023

COI STATEMENT

M.G.-S., Y.N. and I.F. are co-inventors of a US patent related to this investigation. The authors declare no other competing interests.

Cross-cultural analysis reveals evolution and persistence of body-based measurement systems

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

Body-based units of measure have cognitive and behavioral advantages over standardized measurement systems, according to a new cross-cultural analysis of the use of body-based measurement in more than 180 cultures worldwide, particularly in the design of ergonomic technologies. The findings reveal new insights into body-based measurement as a cultural phenomenon and may help explain the long-term persistence of their use for centuries after the emergence of standardized measurement systems were invented. The ability to measure things plays a central role in how humans understand and interact with the surrounding world and are important drivers in cultural complexity and technological evolution. Today, interchangeable units of measure are ubiquitous in the modern world and permeate every aspect of daily life. Worldwide, it’s thought that many early standardized measurement systems evolved from body-based units of measure – measurement units that are determined by using components of the human body, such as the length of forearm and hand (cubit) or width of two outstretched arms (fathom). However, despite their importance in cultural and technological evolution, body-based measurements as a cultural phenomenon remain understudied and poorly understood. Using the Human Relations Area Files (HRAF) ethnographic database, Roope Kaaronen and colleagues identified the development and use of body-based measurements in 186 cultures worldwide, revealing both similarities and diversity in the use of measurement units based on the human body. According to the findings, variations of the fathom, handspan, and cubit were most frequent and exhibited striking cross-cultural similarities. Kaaronen et al. also discovered that body-based units were especially common in the design of ergonomic technologies like clothing, skis, kayaks, or bows, for example. The analysis revealed that body-based units were still used worldwide thousands of years after the emergence of standardized units and were, in some instances, superior to standard units of measurement. The authors argue that the shift from body-based measurement systems to standardized systems could reflect a larger break in human cultural evolution due to increased focus on industrial production. Consequently, traditional units of measure may be threatened by the broader cultural extinction event driven by globalization, industrialization, and colonization, write Kaaronen et al. In a related Perspective, Stephen Chrisomalis highlights the limitations of the study and its findings. “Datasets such as HRAF, used by Kaaronen et al., are skewed toward ethnographically known societies from the 19th and 20th centuries,” writes Chrisomalis. “Future studies must employ cognitive cross-cultural research that is sensitive to how technologies change across time, not merely synchronic patterns in the modern world.”

---

JOURNAL

Science

DOI

10.1126/science.adf1936 

ARTICLE TITLE

Body-based units of measure in cultural evolution

ARTICLE PUBLICATION DATE

2-Jun-2023

ROBOTICS

Autonomous realignment and self-healing in multilayer soft electronic devices

Peer-Reviewed Publication

AMERICAN ASSOCIATION FOR THE ADVANCEMENT OF SCIENCE (AAAS)

By combining two dynamic polymers, researchers present a new method for achieving autonomous realignment and self-healing in multilayered soft electronic devices and robots, according to a new study. Like human skin, self-healing polymers allow soft electronic and robotic devices to recover autonomously from various forms of damage. Such devices are often multilayered and embedded with conductive or dielectric materials to achieve functional properties while also maintaining the soft mechanical properties of the self-healing polymer matrix. However, self-healing devices often require manual realignment of individual layers after damage to properly align different functional components within the polymer, as even slightly misaligned layers can limit the functional recovery of a device. Achieving autonomous realignment and self-healing in complex, multilayered soft devices has remained a challenge. Here, Christopher Cooper and colleagues demonstrate an autonomous self-healing of multilayered soft electronic devices by combining two orthogonal self-healing polymers with identical dynamic hydrogen-bonding interactions but with immiscible polymer backbones. According to Cooper et al., composition gradients between the two polymers enable interlayer adhesion between the otherwise immiscible layers while enabling self-recognition and healing of different functional layers. To test the design, the authors fabricated thin film devices with conductive, dielectric, and magnetic particles and demonstrate their ability to functionally self-heal after mechanical damage to 96% of their initial capacitance. What’s more, Cooper et al. showed that the approach could also be used to magnetically guide the self-assembly of soft robots and underwater circuits.

---

JOURNAL

Science

DOI

10.1126/science.adh0619 

ARTICLE TITLE

Autonomous alignment and healing in multilayer soft electronics using immiscible dynamic polymers

ARTICLE PUBLICATION DATE

2-Jun-2023

Layers of self-healing electronic skin realign autonomously when cut

The advance presages a new era of robots and prosthetics wrapped in self-healing synthetic materials imbued with human-like sense of touch

Peer-Reviewed Publication

STANFORD WEARABLE ELECTRONICS INITIATIVE

 

IMAGE: A DEPTH-PROFILED DIGITAL MICROSCOPE PHOTOGRAPH OF A 5-LAYER ALTERNATING LAMINATE FILM OF IMMISCIBLE DYNAMIC POLYMER FILMS WHICH HAVE BEEN DAMAGED, AUTONOMOUSLY ALIGNED, SELF-HEALED AND THEN PULLED APART ON A NON-SELF-HEALING SUBJECT (TO SHOW THE LOCATION OF THE DAMAGE). view more 

CREDIT: BAO GROUP, STANFORD U.

by Andrew Myers

Human skin is amazing. It senses temperature, pressure, and texture. It’s able to stretch and spring back, time and again. And it provides a barrier between the body and bad things in the world—bacteria, viruses, toxins, ultraviolet radiation and more. Engineers are, accordingly, keen to create synthetic skin. They imagine robots and prosthetic limbs that have skin-like qualities—not the least of which is skin’s remarkable ability to heal.

“We’ve achieved what we believe to be the first demonstration of a multi-layer, thin film sensor that automatically realigns during healing. This is a critical step toward mimicking human skin, which has multiple layers that all re-assemble correctly during the healing process,” said Chris Cooper, a Ph.D. candidate at Stanford University who, along with postdoctoral researcher Sam Root, is co-author of a new study in Science announcing the advance.

Layering is critical to mimicking skin’s many qualities. “It is soft and stretchable. But if you puncture it, slice it, or cut it— each layer will selectively heal with itself to restore the overall function,” Root says. “Just like real skin.” 

Skin, too, is formed of layers. It has just evolved immune mechanisms that rebuild the tissue with the original layered structure through a complex process involving molecular recognition and signaling.

“With true ‘skin’ the layers should realign naturally and autonomously,” Cooper says.

Root says the team, led by Professor Zhenan Bao at Stanford University, might be able to create multi-tiered synthetic skin with individually functional layers as thin as a micron each, perhaps less. Thin enough that a stack of 10 or more layers would be no thicker than a sheet of paper. “One layer might sense pressure, another temperature, and yet another tension,” says Root. The material of different layers can be engineered to sense thermal, mechanical, or electrical changes.

A Novel Approach

“We reported the first multi-layer self-healing synthetic electronic skin in 2012 in Nature Nanotechnology,” says Bao. “There has been a lot of interest around the world in pursuing multi-layer synthetic skin since then.” What sets their current work apart is that the layers self-recognize and align with like layers during the healing process, restoring functionality layer by layer as they heal. Existing self-healing synthetic skins must be realigned manually—by humans. Even a slight misalignment in layers might compromise functional recovery.

The secret is in the materials. The backbone of each layer is formed of long molecular chains connected periodically by dynamic hydrogen bonds, similar to those holding the double-helix of DNA strands together, that allow the material to stretch repeatedly without tearing. Rubber and latex are two well-known natural polymers, but there are countless synthetic polymers, too. The key is to design polymer molecular structures and choose the right combination for each layer—first layer of one polymer, the second of another and so forth.

The researchers used PPG (polypropylene glycol) and PDMS (polydimethylsiloxane, better known as silicone). Both have rubber-like electrical and mechanical properties and biocompatibility and can be mixed with nano- or microparticles to enable electric conductivity. Critically, the chosen polymers and their respective composites are immiscible — they do not mix with one another yet, due to the hydrogen bonding, they adhere to one another well to create a durable, multilayer material.

Both polymers have the advantage that when warmed they soften and flow, but solidify as they cool. Thus, by warming the synthetic skin, the researchers were able to speed the healing process. At room temperature, healing can take as long as a week, but when heated to just 70°C (158°F), the self-alignment and healing happen in about 24 hours. The two materials were carefully designed to have similar viscous and elastic responses to external stress over an appropriate temperature range.

“Skin is slow to heal, too. I cut my finger the other day and it was still healing four or five days later,” Cooper says. “For us, the most important part is that it heals to recover functions without our input or effort.”

A Step Further

With a successful prototype, the researchers then took things a step further, working with Professor Renee Zhao at Stanford University, adding magnetic materials to their polymer layers, allowing the synthetic skin to not only heal but also to self-assemble from separate pieces. “Combining with magnetic field-guided navigation and induction heating,” says Zhao, “we may be able to build reconfigurable soft robots that can change shape and sense their deformation on demand.” (Watch the video.)

“Our long-term vision is to create devices that can recover from extreme damage. For example, imagine a device that when torn into pieces and ripped apart, could reconstruct itself autonomously,” Cooper says, showing a short video of several pieces of stratified synthetic skin immersed in water.  Drawn together magnetically, the pieces inch toward one another, eventually reassembling. As they heal, their electrical conductivity returns, and an LED attached atop the material glows to prove it.

Among their next steps, the researchers will work to make the layers as thin as possible and toward creating layers of varying function. The current prototype was engineered to sense pressure, and additional layers engineered to sense changes in temperature or strain could be included.

In terms of future vision, the team imagines, potentially, robots that could be swallowed in pieces and then self-assemble inside the body to perform non-invasive medical treatments. Other applications include multi-sensory, self-healing electronic skins that form-fit to robots and provide them with a sense of touch.

Ph.D. Candidate Christopher B. Cooper and postdoctoral scholar Samuel E. Root are members of the Bao Group and co-lead authors of this research. Other Stanford co-authors include postdoctoral scholar Lukas Michalek; graduate student Shuai Wu; postdoctoral scholar Jian-Cheng Lai; postdoctoral scholar Muhammad Khatib; Ph.D. Candidate Solomon T. Oyakhire; Renee Zhao, Assistant Professor of Mechanical Engineering and, by courtesy, of Materials Science and Engineering; Jian Qin, Assistant Professor of Chemical Engineering; and Zhenan Bao, K. K. Lee Professor and Professor, by courtesy, of Materials Science and Engineering and of Chemistry. Bao, Qin, & Zhao are members of Stanford Bio-X and the Wu Tsai Neurosciences Institute. Bao and Zhao are also members of the Stanford Cardiovascular Institute and the Wu Tsai Human Performance Alliance. Bao is also a member of the Maternal & Child Health Research Institute (MCHRI), an affiliate of the Precourt Institute for Energy and the Stanford Woods Institute for the Environment, and faculty fellow of Sarafan ChEM-H.

This work was supported by Army Research Office Materials Design Program; National Science Foundation; Department of Defense, National Defense Science & Engineering Graduate Fellowship Program; Walter Benjamin Fellowship Program, Deutsche Forschungsgemeinschaft; and TomKat Center Fellowship for Translational Research at Stanford University. Part of this work was performed at the Stanford Nano Shared Facilities, supported by the National Science Foundation. Use of the Stanford Synchrotron Radiation Lightsource, SLAC National Accelerator Laboratory, for SAXS experiments was supported by the US Department of Energy, Office of Science, Office of Basic Energy Sciences. This work used Expanse computing resources at the San Diego Supercomputer Center through allocation MAT220035 from the Advanced Cyberinfrastructure Coordination Ecosystem: Services & Support program, which is supported by National Science Foundation grants.

The eWEAR-TCCI awards for science writing is a project commissioned by the Wearable Electronics Initiative (eWEAR) at Stanford University and made possible by funding through eWEAR industrial affiliates program member Shanda Group and the Tianqiao and Chrissy Chen Institute (TCCI®).

  

Pieces of synthetic skin are drawn together magnetically; electrical conductivity returns as they heal, and the LED lights.

CREDIT

Bao Group, Stanford U.

Magnetic assembly and welding [VIDEO] |

Underwater circuit assembly of [VIDEO] 

---

JOURNAL

Science

DOI

10.1126/science.adh0619 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Autonomous alignment and healing in multilayer soft electronics using immiscible dynamic polymers

ARTICLE PUBLICATION DATE

2-Jun-2023

Newborn baby inspires sensor design that simulates human touch

Researchers find potential key to high-sensitivity, broad-range sensors after inventing device to measure baby’s weight

Peer-Reviewed Publication

PENN STATE

 

IMAGE: TESTING THE IONTRONIC SENSOR'S ABILITY OF TACTILE SENSING VIA A ROBOTIC HAND AND A BALLOON. view more 

CREDIT: CHENG GROUP

UNIVERSITY PARK, Pa. — As we move into a world where human-machine interactions are becoming more prominent, pressure sensors that are able to analyze and simulate human touch are likely to grow in demand.  

One challenge facing engineers is the difficulty in making the kind of cost-effective, highly sensitive sensor necessary for applications such as detecting subtle pulses, operating robotic limbs, and creating ultrahigh-resolution scales. However, a team of researchers has developed a sensor capable of performing all of those tasks.  

The researchers, from Penn State and Hebei University of Technology in China, wanted to create a sensor that was extremely sensitive and reliably linear over a broad range of applications, had high pressure resolution, and was able to work under large pressure preloads.  

“The sensor can detect a tiny pressure when large pressure is already applied,” said Huanyu “Larry” Cheng, James L. Henderson Jr. Memorial Associate Professor of Engineering Science and Mechanics at Penn State and co-author of a paper on the work published in Nature Communications. “An analogy I like to use is it’s like detecting a fly on top of an elephant. It can measure the slightest change in pressure, just like our skin does with touch.” 

Cheng was inspired to develop these sensors due to a very personal experience: The birth of his second daughter.   

Cheng’s daughter lost 10% of her body weight soon after birth, so the doctor asked him to weigh the baby every two days to monitor any additional loss or weight gain. Cheng tried to do this by weighing himself on a regular home weight scale and then weighing himself holding his daughter to measure the baby’s weight.   

"I noticed that when I put down my daughter in her blanket, when I was no longer holding her, you didn’t see the change in weight,” Cheng said. “So, we learned that trying to use a commercial scale doesn't work, it didn’t detect the change in pressure.”  

After trying many different approaches, they found that using a pressure sensor consisting of gradient micro-pyramidal structures and an ultrathin ionic layer to give a capacitive response was the most promising.  

However, there was a continued issue they faced. The high sensitivity of the microstructures would decrease as the pressure increased, and the random microstructures that were templated from natural objects resulted in uncontrollable deformation and a narrow linear range. In simple terms, when pressure was applied to the sensor, it would change the sensor’s shape and therefore alter the contact area between the microstructures and throw off the readings.   

To address these challenges, the scientists designed microstructure patterns that could increase the linear range without decreasing the sensitivity — they essentially made it flexible, so it could still function in the gradience of pressures that exist in the real world. Their study explored the use of a CO2 laser with a Gaussian beam to fabricate programmable structures such as gradient pyramidal microstructures (GPM) for iontronic sensors, which are soft electronics that can mimic the perception functions of human skin. This process reduces the cost and process complexity compared with photolithography, the method commonly used to prepare delicate microstructure patterns for sensors.  

Cheng credits Ruoxi Yang, a graduate student in his lab and first author of the study, as the driver of this solution.  

"Yang is a very smart student who introduced the idea to solve this sensor issue, which is really something like a combination of many small pieces, smartly engineered together,” Cheng said. “We know the structure must be microscale and must have a delicate design. But it is challenging to design or optimize the structure, and she worked with the laser system we have in our lab to make this possible. She has been working very hard in the past few years and was able to explore all these different parameters and be able to quickly screen throughout this parameter space to find and improve the performance.”  

This optimized sensor had rapid response and recovery times and excellent repeatability, which the team tested by detecting subtle pulses, operating interactive robotic hands, and creating ultrahigh-resolution, smart weight scales and chairs. The scientists also found that the proposed fabrication approaches and design toolkit from this work could be leveraged to easily tune the pressure sensor performance for varying target applications and open opportunities to create other iontronic sensors, the range of sensors that use ionic liquids such as an ultrathin ionic layer. Along with enabling a future scale where it would be easier for parents to weigh their baby, these sensors would have other uses as well.   

“We were also able to detect not only the pulse from the wrist but also from the other distal vascular structures like the eyebrow and the fingertip,” Cheng said. “In addition, we combine that with the control system to show that this is possible to use for the future of human robotic interactional collaboration. Also, we envision other healthcare uses, such as someone who has lost a limb and this sensor could be part of a system to help them control a robotic limb.”  

Cheng noted other potential uses, such as sensors to measure a person’s pulse during high-stress work situations such as search-and-rescue after an earthquake or carrying out difficult, dangerous tasks in a construction site.   

The research team used computer simulations and computer-aided design to help them explore ideas for these novel sensors, which Cheng notes is challenging work given all the possible sensor solutions. This electronic assistance will continue to push the research forward.   

“I think in the future it is possible to further improve the model and be able to account for more complex systems and then we can certainly understand how to make even better sensors,” Cheng said.   

Aside from Cheng and Yang, other authors on the study from Penn State include Ankan Dutta, Bowen Li, Naveen Tiwari, Wanqing Zhang, Zhenyuan Niu, Yuyan Gao, Daniel Erdely and Xin Xin, and from Hebei University, Tiejun Li.  

---

JOURNAL

Nature Communications

DOI

10.1038/s41467-023-38274-2 

METHOD OF RESEARCH

Experimental study

SUBJECT OF RESEARCH

Not applicable

ARTICLE TITLE

Iontronic pressure sensor with high sensitivity over ultra-broad linear range enabled by laser-induced gradient micro-pyramids

ARTICLE PUBLICATION DATE

1-Jun-2023

New study shows how adaptations to living in a cold climate promoted social evolution

Peer-Reviewed Publication

UNIVERSITY OF BRISTOL

 

IMAGE: IMAGE OF GOLDEN SNUB NOSE MONKEYS (RHINOPITHECUS ROXELLANA) view more 

CREDIT: GUANLAI OUYANG

For the first time ever, scientists have uncovered evidence that a species’ long-term adaptation to living in an extremely cold climate has led to the evolution of social behaviours including extended care by mothers, increased infant survival and the ability to live in large complex multilevel societies.

The new study, published today in the journal Science, was led by researchers from Northwest University in China and a team including the University of Bristol (UK) and the University of Western Australia, and examined how langurs and odd-nosed monkeys, part of the Asian colobine family, that can be found from tropical rainforests to snow-covered mountains, adapted over time.

These species were chosen by the researchers as they exhibit four distinct types of social organisation and provide a good model for examining the multiple mechanisms that have driven their social evolution from a common ancestral state to the diverse systems present today.

By integrating ecological, geological, fossil, behavioural and genomic analyses, the team found that colobine primates inhabiting colder environments tend to live in larger, more complex groups. More specifically, glacial periods during the past six million years promoted the selection of genes involved in cold-related energy metabolism and neuro-hormonal regulation.

They found that odd-nosed monkeys living in extremely cold locations had developed more efficient hormonal (dopamine and oxytocin) pathways that may lengthen maternal care, leading to longer periods of breast-feeding and an overall increase in infant survival.

These adaptive changes also appear to have strengthened relationships between individuals, increased tolerance between males and enabled the evolution from independent one-male, multi-female groups to large complex multilevel societies.

Dr Kit Opie, is one of the study’s authors from the Department of Anthropology and Archaeology at the University of Bristol. He said: “Our study identified, for the first time, a genetically regulated adaptation linked to the evolution of social systems in primates.

“This finding offers new insights into the mechanisms that underpin behavioural evolution in primates and could be used to address social evolutionary changes across a wide range of species including humans.

“In addition we would like to examine how changes in social and mating behaviour in many primate species may be the result of genetic changes due to past environments as well as other social and environmental factors.”

Dr Cyril Grueter is also an author of the study from the Department of Anatomy, Physiology and Human Biology at the University of Western Australia. He said: “With climate change becoming an hugely important environmental pressure on animals, it is hoped that this study will raise awareness for the need to investigate what course social evolution will take as the prevailing climate changes.” 

“Our finding that complex multilevel societies have roots stretching back to climatic events in the distant evolutionary past also has implications for a reconstruction of the human social system which is decidedly multilevel.”

Golden snub nose monkeys 2 (IMAGE)

UNIVERSITY OF BRISTOL

Image of golden snub nose monkeys

CREDIT

Guanlai Ouyang

---

JOURNAL

Science

SUBJECT OF RESEARCH

Animals

ARTICLE TITLE

‘Adaptations to a cold climate promoted social evolution in Asian colobine primates’

ARTICLE PUBLICATION DATE

1-Jun-2023

 Study tracks social, genetic evolution in Asian colobine primates

Peer-Reviewed Publication

UNIVERSITY OF ILLINOIS AT URBANA-CHAMPAIGN, NEWS BUREAU

 

IMAGE: MOTHER AND JUVENILE GOLDEN SNUB-NOSED MONKEY (RHINOPITHECUS ROXELLANA). view more 

CREDIT: PHOTO BY PAUL GARBER

CHAMPAIGN, Ill. — Asian colobines, also known as leaf-eating monkeys, have been on the planet for about 10 million years. Their ancestors crossed land bridges, dispersed across continents, survived the expansion and contraction of ice sheets and learned to live in tropical, temperate and colder climes.

A new study reported in the journal Science finds parallels between Asian colobines’ social, environmental and genetic evolution, revealing for the first time that colobines living in colder regions experienced genetic changes and alterations to their ancient social structure that likely enhanced their ability to survive.

“Virtually all primates are social and live in social groups,” said study co-author Paul A. Garber, a professor emeritus of anthropology at the University of Illinois Urbana-Champaign and an expert on primate biology, evolution and conservation. “But the groups differ in size and cohesiveness. There are those that live in units of two or three individuals and others living in communities of up to 1,000 individuals.”

Asian colobines have evolved a variety of social structures. However, genomic studies suggest that the harem unit of organization, which consists of one male with two or more females and their offspring, was the ancestral norm for Asian colobines, Garber said. The males are intolerant of other males and will fight to protect their territories. In some species, females remain in their natal group. In others, both males and females leave to join or form a new harem.

Over time, more complex societies formed. Among a group of Asian colobines known as “odd-nosed monkeys,” for example, two genera “still form harems, but they’re not territorial,” Garber said. “This means their group territories can overlap and there are times they may come together to forage, rest and travel.” One branch of these odd-nosed monkeys, the “snub-nosed monkeys” form what is referred to as a multilevel or modular society in which several harems remain together year-round and form a large and cohesive breeding band.

The largest such society the team recorded included about 400 individuals. In the case of the golden snub-nosed monkeys, breeding between individuals belonging to different harems was common, occurring about 50% of the time. 

The researchers wanted to examine how the interplay of environment, genes and behaviors like territoriality and cooperation allowed Asian colobines to survive in such varied habitats.

“The team used extremely diverse data sets, many of which we generated ourselves,” Garber said. “These include ecological and paleogeological data, the fossil record, and behavioral and genomic data.”

By overlaying social structure and habitat data, the team found that Asian colobine groups that inhabit colder areas – many of them at high elevations – also tend to form larger and more complex societies made up of harems that coordinate their daily activities and often cooperate with one another. The changes in social structure over time corresponded with genetic changes, the researchers found. The most socially complex multilevel societies also evolved changes in genes regulating cold-related energy metabolism and neurohormones that are known to play a critical role in social bonding.

Several factors contributed to the colobines’ social evolution into larger, more cooperative societies, Garber said.

“Because these primates are long-lived and individuals may remain in the same band for periods of years and even decades, you have the opportunity for high levels of reciprocal cooperation,” he said.

Habitat also played a role, he said. Smaller groups in tropical areas can afford to be territorial because food is more predictable, and they can sustain themselves in a fairly restricted area. However, life at higher altitudes is more challenging.

Black-and-white snub-nosed monkeys in some parts of China, for example, live at elevations up to about 13,500 feet.

“These are low-oxygen environments,” Garber said. “The coldest temperatures at night drop below zero. For a primate, that’s cold.”

Historically, predators of snub-nosed monkeys were large mammals like snow leopards, tigers and bears.  Predation risk was likely lowered by the cooperative efforts of males from multiple harems, Garber said. In addition, plant resources consumed by snub-nosed monkeys are more spread out, making their extremely large territories – which can extend up to 6-8 square miles (15-20 square kilometers) – harder to defend by small groups.

In addition to changes in genes that code for lipid metabolism and adaptations associated with cold stress, colobines living at high elevations also saw genetic changes that bolstered hormones – such as oxytocin and dopamine – that are known to play a role in maternal behavior and social relationships.

“The snub-nosed monkeys seem to have a longer mother-infant bond, which probably increased infant survival in cold environments,” Garber said. “Oxytocin is an important neurohormone in all social bonding. We think it promoted social affiliation, cohesion and cooperation among adults as well.”

Each of these adaptive changes appears to have bolstered affiliation between harems, allowing Asian colobines to form larger multilevel societies when local conditions made it necessary for them to cooperate to survive, the researchers report.

The National Science Foundation of China, the Chinese Academy of Sciences and the Department of Science and Technology of Shaanxi Province supported this research.

Corresponding authors of the study are Xiao-Guang Qi, of Northwest University, Xi’an, China; Cyril C. Grueter, of the University of Western Australia, Perth; Dongdong Wu, of the Chinese Academy of Sciences, Kunming, China; and Baoguo Li, of Northwest University, China.

Garber also is affiliated with the Program in Ecology, Evolution and Conservation Biology, the  Center for Global Studies and the Center for Latin American and Caribbean Studies at the U. of I.

An adult male black and white snub-nosed monkey (Rhinopithecus bieti).

CREDIT

Photo by Paul Garber 

Editor’s notes: 

Upon publication, the paper “Adaptations to a cold climate promoted social evolution in Asian colobine primates” is available online and from the U. of I. News Bureau.

DOI: 10.1126/science.abl8621

---

JOURNAL

Science

DOI

10.1126/science.abl8621 

METHOD OF RESEARCH

Data/statistical analysis

ARTICLE TITLE

Adaptations to a cold climate promoted social evolution in Asian colobine primates

ARTICLE PUBLICATION DATE

1-Jun-2023