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Science & Medicine: Veterans write new endings for their nightmares

Kristi Pruiksma, PhD is a clinical psychologist and researcher who develops treatments for sleep disorders, nightmares, and post-traumatic stress disorder, which are often — but not always — experienced together.“Insomnia and nightmares are symptoms of PTSD,” she said, “but sometimes people who experience trauma may or may not have PTSD, but they have insomnia and nightmares.”Up to 70% of people who have PTSD also have nightmares, according to Pruiksma, who is an associate professor in the Department of Psychiatry and Behavioral Sciences at UT Health San Antonio.“They’re having these dreams that are so disturbing that they’re causing them to wake up, usually, and they can remember the dreams. They’re very vivid. They’re very disturbing,” Pruiksma explained.

Brandie Jenkins

Kristi Pruiksma, PhDLicensed clinical psychologistAssociate professorDepartment of Psychiatry and Behavioral SciencesThe University of Texas Health Science Center at San Antonio

Pruiksma’s patients are mostly members of the military or veterans, and she uses a kind of talk therapy called cognitive behavioral therapy to help reduce the frequency and intensity of their nightmares. One technique involves a kind of exposure therapy, where the patient writes their nightmare down in as much detail as they can remember, then reads it aloud to their therapist.“This is done in a very supportive, collaborative way, and it can be really difficult,” Pruiksma said, “but people also often feel very empowered after doing that.”An alternative technique is called “rescripting.”“The idea is to write a new dream with a lot of detail and really change the scenario so that they have some power and control,” she said.Pruiskma recalled a patient who had a terrifying recurring nightmare in which he was in a convoy that was driving down a road where a roadside bomb exploded. Pruiksma says he rewrote the dream to include one of his and his battle buddies’ favorite singers, Katy Perry.“In his rescription, he had this Katy Perry angel coming in and distracting them, and then they go down a different road, and things happen a different way,” she said.The idea, Pruiksma said, is to give the brain a different path to travel.“People don’t usually dream the rescription, but their dreams tend to change,” she said. “So either they don’t wake up, or if they do wake up, it’s not as disturbing, and they can go back to sleep faster.”Pruiksma has created free, online training modules for practitioners who treat civilians experiencing nightmares. She is also developing a study that would examine a treatment for PTSD and nightmares that would, at the same time, also try to tackle insomnia that goes beyond nightmares.Science & Medicine is a collaboration between TPR and The University of Texas Health Science Center at San Antonio that explores how scientific discovery in San Antonio advances the way medicine is practiced everywhere.

How tall was Goliath? Scientists reveal the surprising height of the Biblical giant

By WILIAM HUNTER Published: 10:08 EST, 26 January 2025 | Updated: 10:08 EST, 26 January 2025

Caltech Scientists Discover the Surprising Speed Limit of Human Thought – Just 10 Bits per Second

Artistic rendering of the brain’s “speed limit” — we think, process, and decide at the slow pace of 10 bits per second. Credit: J. Zheng
Scientists at Caltech have uncovered a surprising limit to human thought speed—just 10 bits per second—despite our senses absorbing data at a billion bits per second.
This discovery raises fascinating questions about how our brains filter information and why we process one thought at a time. The study suggests evolutionary factors may play a role, with early brains designed for simple navigation rather than multitasking.
Quantifying the Speed of Thought
Caltech researchers have quantified the speed of human thought and found it to be just 10 bits per second. In contrast, our sensory systems process information at an astonishing rate of a billion bits per second—100 million times faster than our thinking speed. This discovery opens up intriguing questions for neuroscientists, particularly why the brain can focus on only one thought at a time while simultaneously handling vast amounts of sensory input.
The study was conducted in the lab of Markus Meister (PhD ’87), the Anne P. and Benjamin F. Biaggini Professor of Biological Sciences, with graduate student Jieyu Zheng leading the research. Their findings were recently published in the journal Neuron.
Markus Meister. Credit: Lance Hayashida/Caltech
Understanding Bits and Human Cognition
A bit is a basic unit of information in computing. A typical Wi-Fi connection, for example, can process 50 million bits per second. In the new study, Zheng applied techniques from the field of information theory to a vast amount of scientific literature on human behaviors such as reading and writing, playing video games, and solving Rubik’s Cubes, to calculate that humans think at a speed of 10 bits per second.
The Paradox of Brain Efficiency
“This is an extremely low number,” Meister says. “Every moment, we are extracting just 10 bits from the trillion that our senses are taking in and using those 10 to perceive the world around us and make decisions. This raises a paradox: What is the brain doing to filter all of this information?”
There are over 85 billion neurons in the brain, with one-third of these dedicated to high-level thinking and located in the cortex. Individual neurons are powerful information processors and can easily transmit more than 10 bits per second of information. But why don’t they? And why do we have so many if we’re thinking so slowly? Meister suggests that, given the discovery of this “speed limit” in the brain, neuroscience research ought to consider these paradoxes in future studies.
Another conundrum that the new study raises is: Why does the brain process one thought at a time rather than many in parallel the way our sensory systems do? For example, a chess player envisioning a set of future moves can only explore one possible sequence at a time rather than several at once. The study suggests that this is perhaps due to how our brains evolved.
Jieyu Zheng. Credit: J. Zheng
Evolutionary Origins of Thought Processing
Research suggests that the earliest creatures with a nervous system used their brains primarily for navigation, to move toward food, and away from predators. If our brains evolved from these simple systems to follow paths, it would make sense that we can only follow one “path” of thought at a time. “Human thinking can be seen as a form of navigation through a space of abstract concepts,” Zheng and Meister write. The team emphasizes the need for future research into how this constraint—one train of thought at a time—is encoded in the architecture of the brain.
“Our ancestors have chosen an ecological niche where the world is slow enough to make survival possible,” Zheng and Meister write. “In fact, the 10 bits per second are needed only in worst-case situations, and most of the time our environment changes at a much more leisurely pace.”
Rethinking Brain-Computer Interfaces
The new quantification of the rate of human thought may quash some science-fiction futuristic scenarios. Within the last decade, tech moguls have suggested creating a direct interface between human brains and computers in order for humans to communicate faster than the normal pace of conversation or typing. The new study, however, suggests that our brains would communicate through a neural interface at the same speed of 10 bits per second.
Reference: “The unbearable slowness of being: Why do we live at 10 bits/s?” by Jieyu Zheng and Markus Meister, 17 December 2024, Neuron.DOI: 10.1016/j.neuron.2024.11.008
Funding was provided by the Simons Collaboration on the Global Brain and the National Institutes of Health. Markus Meister is an affiliated faculty member with the Tianqiao and Chrissy Chen Institute for Neuroscience at Caltech.

Scientists Strapped QR Codes Onto Thousands of Bees to Learn How Far They Actually Fly

We say hard workers are “busy as a bee,” but in a recent study, honey bees seemed more like employees in an office building.
Entomologists and engineers in the U.S. glued tiny QR codes to the backs of tens of thousands of honey bees in rural areas of Pennsylvania and New York. The unprecedented application of this technology, as detailed in a paper published in November in the journal HardwareX, will help scientists and beekeepers study how far the insects travel to collect food. Excitingly, the experiment has already shed new light on this crucial pollinator’s mysterious behaviors.
Previous studies suggest that honey bees can forage up to 6.2 miles (10 kilometers) from their hives, but the entomologists hypothesize that this rarely occurs. “The goal is to understand if that 10-kilometer estimation is biologically accurate. Can we determine exactly how far honey bees travel from their hives?” Margarita López-Uribe, an entomologist at Pennsylvania State University (Penn State) and co-author on the study, said in a university statement.

The QR codes, called fiduciary tags, essentially work like badges in an office building. The team developed an automatic imaging system with a sensor at the hive entrance to register each time a tagged bee enters or exits, allowing the entomologists to track their individual foraging times. The sensor records the individual bee ID, date, time, temperature, and whether the bee is entering or exiting.
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Traditional entomology field work is usually less hands-on, but this approach is providing unprecedented insight into honey bee behavior.
“This technology is opening up opportunities for biologists to study systems in ways that weren’t previously possible, especially in relation to organic beekeeping,” said López-Uribe. Organic beekeeping includes, among other things, maintaining sufficient space from industrial regions to prevent bees from collecting pollen in polluted areas. However, since common bee foraging distances remain elusive, the U.S. Department of Agriculture’s recommendations for organic certification might be inaccurate in this regard.

“In field biology, we usually just look at things with our eyes, but the number of observations we can make as humans will never scale up to what a machine can do,” she added. In total, the team tagged over 32,000 bees across six apiaries with QR codes smaller than human pinky nails that don’t harm the bees or restrict their movement.
“We targeted young bees so we could track their age more accurately, especially when they start to fly and when they stop,” said Robyn Underwood of Penn State, who also participated in the study. Younger individuals are easier to handle because they don’t sting yet.
So, what are bees up to?

The researchers observed that most trips from the hive usually lasted between one and four minutes—potentially potty breaks or a quick weather check—and some longer excursions were still less than 20 minutes. However, 34% of the tagged bees ventured out of the hive for over two hours.
This longer absence could be due to longer foraging excursions. Some longer trips, for example, corresponded to time periods with less flowers, during which bees likely had to travel farther to collect their due. However, the scientists also admitted that the data could have been skewed by bees that simply never returned or entered the hive upside down, effectively hiding the QR code from the sensor.

Additionally, “we also found that bees are foraging for a lot longer over their lifetimes than initially thought,” said Underwood. Entomologists previously suggested that honey bees lived approximately 28 days, she explained. However, “we’re seeing bees foraging for six weeks, and they don’t start foraging until they are already about two weeks old, so they live a lot longer than we thought.”
When they do start foraging, bees within the same hive share information about food sources with each other through the so-called “waggle dance.” Now, the team is working with researchers from Virginia Tech to align their foraging time data with this behavior to continue investigating how far bees travel from their hive.
Maybe the next step will be gluing tiny AirTags to their backs.