The human brain is remarkably adept at adjusting what we hear based on contexts, like our current environment or priorities, but it’s still unknown how exactly the brain helps us detect, filter and react to sounds.

Now, biologists at the University of Maryland are a step closer to solving that mystery. Using an animal model, the researchers found that the orbitofrontal cortex (OFC), a brain region associated with decision-making but not typically linked to hearing, plays a central role in helping the auditory cortex (a primary hearing center of the brain) adapt to changing contexts or situations. The team’s findings were published in the journal Current Biology on July 11, 2024.

“Our hearing doesn’t just depend on the sounds around us. It also relies heavily on what we’re doing and what’s important to us at that moment,” explained UMD Biology Assistant Professor Melissa Caras, the paper’s senior author. “Understanding the neural mechanisms responsible for these adjustments can also lead to a better understanding of and potential treatments for neurodevelopmental disorders like autism, dyslexia or schizophrenia — conditions where sensory regulation goes awry.”

To closely examine the brain circuitry involved in the hearing process, the researchers turned to gerbils, small mammals whose basic hearing system is similar to that of humans. The animals were exposed to sound patterns in two different contexts. In one context, the animals listened to sounds passively without needing to do anything. In the other, the animals had to perform a specific action in response to the sounds they heard. By recording and manipulating the brain activity of the animals, the team discovered that the OFC helped the animals switch between passive and active listening.

“In short, the OFC sends signals to the auditory cortex when it’s time to pay closer attention to sounds,” Caras said. “It’s not certain whether the signals are sent directly or indirectly via an intermediary brain region, but we do know that activity in the OFC is essential to how the gerbils behaved in our experiments.”

When the OFC was silenced, the animals’ auditory cortex did not switch between passive and active listening, impairing their ability to pay attention to and react to a behaviorally relevant sound.

“In terms of a more human-oriented analogy, it would be as if I told you to suddenly pay attention to your refrigerator humming in the background,” Caras explained. “If your OFC was silenced and unable to send a signal to your auditory cortex, you might have difficulty doing so because the ability to rapidly alter your sound perception would be impaired.”

While this study was conducted in animals, Caras says the findings may have notable implications for human health and well-being. The ability to quickly shift attention to important sounds is essential for many day-to-day activities including communicating with others and navigating busy or dangerous environments.

“We’re just beginning to understand how the brain fine tunes hearing sensitivity in response to sudden shifts in behavioral contexts. We plan to explore exactly how the OFC communicates with the auditory cortex and see whether it’s possible to strengthen the connection and improve hearing ability,” Caras said. “This work is paving the way for researchers and health care professionals to develop better strategies for improving hearing in both healthy individuals and those with sensory impairments.”

This research was supported by the National Institutes of Health (Award Nos. R00DC016046 and R01DC020742).

Now, however, in a study published recently in the Journal of Clinical Immunology, researchers from Tokyo Medical and Dental University (TMDU) and Kagoshima University have identified a previously undocumented manifestation among patients with 18q del syndrome: late-onset combined immunodeficiency (LOCID), affecting both B and T cells. This novel finding underscores the critical importance of routinely assessing the functionality of both B and T cells in individuals with 18q del syndrome.

Elaborating further on this novel finding, Professor Kanegane says, “In this study, we came across two patients with chromosome 18q del syndrome presenting with LOCID, which, to the best of our knowledge, has not yet been reported in patients with the syndrome.”

Patient 1 was a 29-year-old man diagnosed with 18q del syndrome. Despite initially having few infections, he developed Pneumocystis pneumonia (PCP). Array-based comparative genomic hybridization (CGH) analysis showed a deletion in the 18q21.32-q22.3 chromosome region.

Patient 2 was a 48-year-old woman who had not been previously diagnosed with 18q del syndrome. However, she was diagnosed with granulomatous lymphadenitis, and a biopsy of her lymph nodes revealed a loss of 18q21.33-qter.

Both patients exhibited hypogammaglobulinemia, characterized by abnormally low levels of immunoglobulins (IgG, IgA, IgM, and IgE). Patient 1’s serum immunoglobulin levels were significantly below normal ranges. He reported IgG of 188 mg/dL (normal: 870-1,700 mg/dL), IgA of 105 mg/dL (normal: 110-410 mg/dL), IgM of 26 mg/dL (normal: 33-190 mg/dL), and IgE of <5 IU/mL (normal: 232 IU/mL). His CD4⁺ T cells had a decreased percentage of naïve T cells, accounting for only 3.58% of the total CD3⁺CD4⁺ cell population. Moreover, his T-cell receptor excision circles (TREC) levels and Ig κ-deleting recombination excision circle (KREC) levels were extremely low at 25.27 copies/105 cells (normal: > 565 copies/105 cells) and 93.36 copies/105 cells (normal: ≥ 456 copies/105 cells) respectively, indicating poor T-cell production.

Similar conditions were noted for patient 2, who reported IgG of 8 mg/dL, IgA of 9 mg/dL, IgM of 131 mg/dL, and IgE of 0.3 IU/mL. Her CD4⁺ T cells and naïve CD4⁺ T cells were depleted, with naïve T cells accounting for only 6% of the CD3⁺CD4⁺ cell population. Her TREC levels were 0 copies/10⁵ cells, and her KREC levels were 11.4 copies/10⁵ cells.

Importantly, CD4⁺ and CD8⁺ T cells failed to divide in response to phytohemagglutinin (PHA) stimulation, indicating severe functional impairment of T cells in both the patients.

Based on their immune profiles and clinical history, both of them were diagnosed with LOCID, a condition where both humoral (antibody-mediated) and cell-mediated immune responses were impaired, making them highly susceptible to infections.

This novel finding is significant, as Dr. Tomomasa, the co-authored of this study, states, “While cases involving deletion of the same region as those of the two patients presented in this study have been reported earlier, patients with 18q del syndrome developing LOCID have never been reported. We speculate that these patients simply have not yet developed LOCID or that they might not have been adequately assessed for it.”

On the basis of these results, the researchers recommend annual testing for both cellular and humoral immunity in patients with 18q del syndrome. This proactive approach can allow for the early detection of combined immune deficiencies, facilitating timely interventions and personalized treatment strategies. Ultimately, such regular monitoring can significantly improve clinical outcomes and enhance the quality of life for individuals diagnosed with 18q del syndrome.

These are the questions that a team of mechanical engineers and computer scientists at the University of California San Diego sought to answer in a study presented recently at the ICRA 2024 conference in Japan.

“To our knowledge, this is the first study investigating robots that infer human perception of risk for intelligent decision-making in everyday settings,” said Aamodh Suresh, first author of the study, who earned his Ph.D. in the research group of Professor Sonia Martinez Diaz in the UC San Diego Department of Mechanical and Aerospace Engineering. He is now a postdoctoral researcher for the U.S. Army Research Lab.

“We wanted to create a framework that would help us understand how risk-averse humans are-or not-when interacting with robots,” said Angelique Taylor, second author of the study, who earned her Ph.D. in the Department of Computer Science and Engineering at UC San Diego in the research group of Professor Laurel Riek. Taylor is now on faculty at Cornell Tech in New York.

The team turned to models from behavioral economics. But they wanted to know which ones to use. The study took place during the pandemic, so the researchers had to design an online experiment to get their answer.

Subjects-largely STEM undergraduate and graduate students-played a game, in which they acted as Instacart shoppers. They had a choice between three different paths to reach the milk aisle in a grocery store. Each path could take anywhere from five to 20 minutes. Some paths would take them near people with COVID, including one with a severe case. The paths also had different risk levels for getting coughed on by someone with COVID. The shortest path put subjects in contact with the most sick people. But the shoppers were rewarded for reaching their goal quickly.

The researchers were surprised to see that people consistently underestimated in their survey answers indicating their willingness to take risks of being in close proximity to shoppers infected with COVID-19. “If there is a reward in it, people don’t mind taking risks,” said Suresh.

As a result, to program robots to interact with humans, researchers decided to rely on prospect theory, a behavioral economics model developed by Daniel Kahneman, who won the Nobel Prize in economics for his work in 2002. The theory holds that people weigh losses and gains compared to a point of reference. In this framework, people feel losses more than they feel gains. So for example, people will choose to get $450 rather than betting on something that has a 50% chance of winning them $1100. So subjects in the study focused on getting the reward for completing the task quickly, which was certain, instead of weighing the potential risk of contracting COVID.

Researchers also asked people how they would like robots to communicate their intentions. The responses included speech, gestures, and touch screens.

Next, researchers hope to conduct an in-person study with a more diverse group of subjects.

According to new research at the University of Birmingham, in the UK, and Central European University, in Austria and Hungary, babies are not only capable of creative thinking well before starting to speak, but this sort of thinking may be essential for language acquisition.

In the study, published in PNAS, the researchers set out to explore the origins of human creativity and productive thinking to try to find out how people arrive at completely new thoughts and ideas. The basic mechanism for doing this is taking familiar concepts and combining them into new structures, but little is known about how early in life these abilities can be used.

The researchers found that babies were able to very quickly learn new words that describe small quantities — an impressive achievement — and combine these spontaneously with familiar words to fully understand a phrase.

Lead researcher, Dr Barbara Pomiechowska, carried out the research while a postdoctoral fellow at the Central European University (CEU). She is now an assistant professor in the School of Psychology, at the University of Birmingham, in the UK.

Dr Pomiechowska said: “Human creativity has no boundaries: it has taken us to the moon and allowed us to cure deadly diseases — but despite its importance, we don’t yet know when and how this impressive ability to combine ideas and invent new things emerges. This research shows that we must go right back to the beginning of language acquisition to solve this puzzle.”

In the study, the researchers worked with a cohort of 60 babies, all around the age of 12 months. They started by teaching the babies two novel words describing quantity: ‘mize’, to mean ‘one’, and ‘padu’, to mean ‘two’.

Then the babies were asked to combine these new number words with different object names, for example to identify ‘padu ducks’ from among a choice of images. By teaching novel words to represent quantities, the researchers were able to test the babies’ ability to combine concepts in real time, rather than simply recall combinations of words that they already knew from previous experience.

By using eye-tracking technology to monitor where the babies look, the researchers were able to show that the infants could successfully combine the two concepts to understand what they were being asked about.

Dr Agnes Kovacs, from CEU’s Department of Cognitive Science and CEU’s Cognitive Development Center, added: “For babies, this ability to combine different concepts is likely to help not only to interpret the complex language input, but also to learn about different aspects of the physical and social world. For adults, it’s an ability that helps to move past everything that’s already been thought of, opening the mind towards endless possibilities.”

The collaborative research team focused on a specific type of atmospheric wave, known as Convectively Coupled Kelvin Waves, (CCKWs), which are massive waves over 1,000-miles long that travel in Earth’s atmosphere along the equator and significantly influence global rainfall patterns. The study, published June 1, 2024, in the American Geophysical Union’s Journal of Advances in Modeling Earth Systems, provides researchers with a new way to study the behavior and attributes of these Kelvin waves in weather forecast models.

“Our findings suggest that improving the simulation of these Kelvin waves in weather models could enhance the accuracy of predictions for other high-impact weather features,” said Quinton Lawton, a recent graduate of the Rosenstiel School’s Department of Atmospheric Sciences and a lead author of the study. “This has the potential to provide communities, especially those in tropical regions, with more lead time and readiness for destructive weather.”

Utilizing NCAR’s high-performance computing system and cutting-edge weather models including the Model for Prediction Across Scales — Atmosphere (MPAS-A) and ECMWF’s Integrated Forecast System (IFS), the team simulated several Kelvin waves from 2021. One notable Kelvin wave over the Atlantic Ocean was linked to the formation of Tropical Storm Victor.

The study found that current weather forecast models poorly simulated an Atlantic Ocean CCKW, indicating a need for future improvements in weather forecasting systems to better predict these waves and, consequently, other extreme weather events.

The researchers introduced a novel methodology for modifying the strength of Kelvin waves in weather forecast models. With this new tool, researchers will be able to better quantify the characteristics and impacts of Kelvin waves, enhancing our understanding of how these waves are represented in weather forecast models.

Kelvin waves are now recognized for their role in increasing the likelihood of hurricane formation and triggering extreme rainfall events. In a previous study by Rosenstiel School scientists Lawton and Sharan Majumdar published in 2023, they explain how these waves can encourage tropical cyclone formation in the Atlantic.

This study represents the culmination of two years of collaborative research, originating from the lead student author’s PhD dissertation at the University of Miami. The work brings together expertise and resources from UM, NCAR, and ECMWF to push the boundaries of meteorological science.

“The research is a step towards better understanding and predicting the tropical atmosphere,” said study coauthor Sharan Majumdar, a professor of atmospheric sciences at the Rosenstiel School. “The study also highlights the need for further research into why current models struggle with accurately simulating these waves.”