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30 Minutes, 3 Exercises: A Routine for an Aging Brain
And you thought you were done with the three Rs
The post 30 Minutes, 3 Exercises: A Routine for an Aging Brain appeared first on Nautilus.

Dogs can tell if you're scared or sad
Any dog owner would tell you that their canine companions are attuned to their humans' emotional state and respond accordingly. Scientists have performed fMRI scans on dogs and identified a specific brain region that processes happy human facial expresses, like a smile, according to a new paper published in the journal iScience. They also found that dogs can tell the difference between negative facial expressions, specifically anger, sadness, and fear.
“Humans are really good at picking up small details on the face, and so are dogs,” said co-author Raúl Hernández-Pérez of the University of Vienna. “This makes dogs very interesting. By studying their brains, we can understand what adaptations have developed to support their remarkable social and emotional understanding of humans.”
Prior behavioral studies have shown that dogs are sensitive to emotion in human faces. Dogs will, for example, choose a box their human has identified with a happy expression over one the human treats with fear or disgust. Past fMRI studies found that an area in the canine left temporal cortex showed a stronger response to human faces compared to dog faces, as well as a greater response in the caudate, hippocampus, and amygdala to human faces showing emotion versus neutral faces.


© Laura V. Cuaya/CC BY-SA
Dogs can tell if you're scared or sad
Any dog owner would tell you that their canine companions are attuned to their humans' emotional state and respond accordingly. Scientists have performed fMRI scans on dogs and identified a specific brain region that processes happy human facial expresses, like a smile, according to a new paper published in the journal iScience. They also found that dogs can tell the difference between negative facial expressions, specifically anger, sadness, and fear.
“Humans are really good at picking up small details on the face, and so are dogs,” said co-author Raúl Hernández-Pérez of the University of Vienna. “This makes dogs very interesting. By studying their brains, we can understand what adaptations have developed to support their remarkable social and emotional understanding of humans.”
Prior behavioral studies have shown that dogs are sensitive to emotion in human faces. Dogs will, for example, choose a box their human has identified with a happy expression over one the human treats with fear or disgust. Past fMRI studies found that an area in the canine left temporal cortex showed a stronger response to human faces compared to dog faces, as well as a greater response in the caudate, hippocampus, and amygdala to human faces showing emotion versus neutral faces.


© Laura V. Cuaya/CC BY-SA
When Dreaming Gets Your Heart Moving
Deep dreaming may be more in tune with the body than we thought
The post When Dreaming Gets Your Heart Moving appeared first on Nautilus.

Breast Cancer May Hijack Nerves To Grow and Resist Treatment
Any Level of Physical Activity May Slow Cognitive Decline, Study Suggests
- Nautilus
- Taxi Drivers Rarely Die of Alzheimer’s—How Complex Mental Maps and Spatial Reasoning Protect Your Brain
Taxi Drivers Rarely Die of Alzheimer’s—How Complex Mental Maps and Spatial Reasoning Protect Your Brain
Working with and living in spatially complex environments may help delay cognitive decline, though more research is needed
The post Taxi Drivers Rarely Die of Alzheimer’s—How Complex Mental Maps and Spatial Reasoning Protect Your Brain appeared first on Nautilus.

Depression Linked to Shrinking Brain Region in Older Adults
The memory center of the brain show signs of decreasing volume
The post Depression Linked to Shrinking Brain Region in Older Adults appeared first on Nautilus.

- The Debrief
- Study Finds Nightmares Connected to PTSD are Reduced or Completely Eliminated by THC from Cannabis
Study Finds Nightmares Connected to PTSD are Reduced or Completely Eliminated by THC from Cannabis
Researchers at Charité – Universitätsmedizin Berlin have demonstrated the potential for using THC, the psychoactive component in cannabis, to treat or even eliminate debilitating nightmares associated with post-traumatic stress disorder (PTSD).
The researchers behind the findings said that THC did not reduce other PTSD symptoms, such as the condition’s severity or depression. However, they plan to further explore its ability to treat nightmares, including the potential safety and efficacy associated with long-term use.
PTSD Nightmares Cause Sleep Deprivation and Fear of Going to Sleep
According to a statement from the Charité team, people who survive or witness extreme experiences such as abuse, war, disasters, or other acts of violence can become overwhelmed and unable to consciously process their experience. As a result, many experience what researchers term an “echo,” where the subconscious tries to process the trauma. The more common term for the experience is post-traumatic stress disorder, or PTSD.
People suffering from this condition often report nightmares as one of the most persistent and debilitating symptoms. Along with the horror associated with continuously reliving their traumas, sometimes on a nightly basis, sufferers also experience severe sleep deprivation. These problems are then compounded by a fear of going to sleep and experiencing nightmares repeatedly.
Attempts to treat PTSD related nightmares have found mixed results. For example, some doctors have prescribed antidepressants or blood pressure-lowering medications to treat the symptoms. However, the research team notes that pharmacological treatments are only partially effective, and “often fail to adequately relieve” PTSD-related nightmares.
There is one medication specifically approved for treating PTSD-induced nightmares. However, the team notes, it is not yet widely available, including in Germany where the study was performed.
Exploring Alternative Treatments
To explore alternative treatment solutions, Prof. Stefan Röpke, who conducts research on trauma-related disorders at the Department of Psychiatry and Neurosciences on the Benjamin Franklin Campus of Charité, and colleagues designed experiments around tetrahydrocannabinol, or THC.
Although widely used for recreational purposes, cannabis has shown some promise for treating a wide variety of medical and psychological conditions. Still, until recently, the drug’s legal status has limited its medical applications, offering researchers a potentially untapped source of PTSD nightmare relief.
For this study, Professor Röpke and colleagues were interested in THC’s established interactions with the human body’s endocannabinoid system. That’s because this system plays a role in sleep regulation, stress, and the processing of emotional memories.
For example, the professor explained, some evidence suggests that THC reduces activity during REM sleep. Known as the dream state, REM sleep is an intense dream phase during which “the brain processes experiences and regulates emotions.
“THC reduces dream activity and thereby alleviates nocturnal stress responses,” the professor explained.
More Than a Third Report Complete Elimination of Nightmares
To start, the team enlisted more than 170 study participants. Critically, all participants suffered from PTSD and intense nightmares, resulting in sleep deprivation and a fear of going to sleep. Instead of smoking cannabis, the researchers administered a form of cannabis-derived THC drops called Dronabinol. As a legal medication, this form of THC is considered clinically safe.
During the ten-week study period, each participant was instructed to take the drops before bedtime. Half of the participants received THC drops, while the others received cannabis-flavored placebo drops. To maintain double-blind study integrity, neither the participants nor the researchers knew who received which treatment.
After the trial period finished, the researchers discovered several positive results. Most notably, the THC group reported a significant decrease in nightmares compared to the placebo group.
According to the study authors, when ranking a participant’s “nightmare burden” on a scale of zero to eight points, participants’ scores dropped by an average of 3.7 points. For comparison, the placebo group experienced an average drop of 2.2 points.
Perhaps even more significant, Professor Röpke said that “more than a third” of the THC patients reported a complete absence of nightmares after the ten-week period concluded. The professor also noted that 21 percent of the study participants reported that their nightmare burden had been at least cut in half. Finally, the professor said that five out of six study participants in the THC group “felt their health had markedly improved.”
Exploring the Safety and Efficacy of Long-Term THC Use
Although the study results offer some possible hope for relief from nightmares and improved sleep, the researchers said the THC treatments did not affect all PTSD symptoms. For example, they observed that a participant’s PTSD severity and any accompanying depression “did not change conclusively.”
No severe side effects were reported by the THC group. However, the researchers did observe some minor complaints, such as headaches, dizziness, or increased appetite. Participants did not report any withdrawal symptoms after the cessation of the treatment period.
Moving forward, the team will explore the safety and effectiveness of long-term nightly THC treatments. They also hope to explore whether patients develop a tolerance to THC’s nightmare-abating effects over time.
The study “Dronabinol for nightmares in post-traumatic stress disorder: a randomized controlled trial” was published in Nature Medicine.
Christopher Plain is a Science Fiction and Fantasy novelist and has spent the last six years as Associate News Editor and Head Science Writer at The Debrief. Follow and connect with him on X, learn about his books at plainfiction.com, or email him at christopher@thedebrief.org
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Inflammation may trigger persistent 'out-of-body' experiences, emerging research hints
Inflammation may be behind a mysterious phenomenon known as dissociation, a mental state that includes "out-of-body" experiences and the feeling that the world is "unreal," emerging research suggests.
Scientists have long known that this altered state of consciousness is often triggered by trauma. But new research hints at how: Trauma triggers a stress response, which dials up chronic inflammation. The findings are part of a broader shift in psychiatric research as experts increasingly examine how the immune system may play a role in mental health conditions.
The research, which has been accepted for publication and is currently under peer review, is still preliminary, and it is based on correlations between blood markers and symptoms, which cannot prove inflammation causes dissociation. But if follow-up work shows inflammation fuels dissociation, that raises the possibility that anti-inflammatory drugs could treat disorders in which people spend much of their time feeling detached from themselves or reality, experts told Live Science. Interventions that broadly target reducing inflammation could also be beneficial, the study suggests.
Research in this area could provide a "whole new avenue for potential treatment options," study lead author Evelyn Dilkes, a psychology researcher at the University of Essex in England, told Live Science.
A common experience, a rare disorder
Dissociation encompasses both out-of-body experiences, known as depersonalization, and the feeling that everything around you is unreal, called derealization, said Dr. Ruth Lanius, a psychiatry professor and Harris-Woodman chair of mind-body medicine at Western University in Ontario. Both of these experiences are related to a person's sense of self and embodiment.
As a short-term phenomenon, it is common; between a quarter and three-quarters of the population may experience dissociation at some point in their lives. It can also be a symptom of many conditions, such as schizophrenia, depression, anxiety, panic disorders and epilepsy.
In around 1% of the population, people may experience prolonged dissociation, in what's known as depersonalization-derealization disorder (DPDR). People with this condition may frequently feel detached from their body or from reality for hours, weeks, months or years at a stretch.
Research suggests DPDR is often associated with past trauma, such as a life-threatening event or childhood abuse. During a traumatic event, dissociation may be helpful because it may offer "a psychological escape when a physical escape is not possible," Lanius told Live Science. It may also help a person stay calm and focused on the threat at hand.
The problem arises when dissociation continues after the threat has passed.
"[Dissociation] helps you to survive, but in the aftermath of trauma, it leaves you detached from all of your emotions, positive and negative, and so often individuals lose the capacity to feel fully alive," Lanius said.
So why does dissociation linger long past the immediate trauma for some people?
From stress to inflammation and then dissociation
Past research showed that inflammation, which can be the immune system's response to infection or injury, seems to be dysregulated in individuals with dissociative conditions. So Dilkes wondered whether the link between trauma and prolonged dissociation runs through the body's response to stress as a kind of "biological embedding," in which life experiences alter a person's physiology. That hypothesis proposes that trauma initially triggers a stress response. When that stress response doesn't subside, the body's stress system stays activated, continually releasing the hormone cortisol from the adrenal glands.
Cortisol is typically anti-inflammatory in short exposures, but when it remains elevated over long periods, it can contribute to chronic inflammation. This can show up in blood levels of interleukin-6 and C-reactive protein.
So Dilkes' lab looked for those inflammatory markers in the blood of children in the U.K. who were followed, starting in the 1990s, as part of the Avon Longitudinal Study of Parents and Children. The study collected samples at age 9 and 12 and again at age 17 and 24. The study asked participants when they were adults whether they “ever felt that they were not a real person, not part of the living world,” or if they “ever felt that the world was unreal, that things around them were like a stage set.”
Early results suggest that high interleukin-6 levels at age 9 seem to be correlated with people experiencing depersonalization in adulthood, while elevated C-reactive protein levels in earlier childhood, but lower ones in adulthood, are linked with experiencing derealization as an adult.
In the latter case, the study authors suggest that chronic stressors could dampen the immune response, leading C-reactive protein levels to drop over time even as symptoms linger.
The researchers also speculated that interleukin-6 and C-reactive protein may differentially act on the different brain regions affected in depersonalization and derealization, respectively. These findings may reflect differences in how stress and immune activity shift across the lifespan following trauma. "It's suggestive of a very intricate system," Dilkes said.
Affected brain regions and networks
Dilkes' research can't answer which brain regions and networks are likely affected, but past research suggests dissociation involves emotional blunting in the brain. In this response, the prefrontal cortex, which is involved in planning and decision-making, acts as a brake on the limbic system, which helps people experience emotions, Lanius said.
According to this theory, dissociation occurs because circuits in the amygdala, the fear-processing part of the brain, hyperactivate the prefrontal cortex. The overactive prefrontal cortex then disrupts normal signaling to the limbic system. The overall result is a dampening of emotions, which may enable people to stay focused and rational during a scary event.
This brain activation pattern, which is characteristic of DPDR, is the opposite of that classically found in post-traumatic stress disorder (PTSD), in which the amygdala is hyperactive, while parts of the prefrontal cortex are underactive. (There is, however, a subtype of PTSD associated with dissociation.)
Some early research hints that the default mode network and the temporoparietal junction, which are thought to be involved in maintaining a sense of self, may be affected in dissociation.
In the new study, the researchers speculate that interleukin-6 exposure in youth may influence the development of the default mode network, which could result in depersonalization symptoms later in life.
Many unanswered questions
While Dilkes' findings are intriguing, outside experts cautioned against overinterpreting early results.
Extrapolating results from studies that investigate dissociative disorders is difficult because patient groups with different diagnoses differ a lot from each other, said Judith K. Daniels, a professor of clinical psychology at the University of Groningen in the Netherlands. What's more, many symptoms can overlap between different dissociative disorders. Dissociation fueled by childhood abuse may differ biologically from dissociation found in a panic disorder, but current research isn't able to distinguish these groups.
What's more, biomarkers of inflammation like C-reactive protein and interleukin-6 are often elevated in other inflammatory and autoimmune conditions — such as rheumatoid arthritis, lupus and multiple sclerosis, while, most people who experience trauma do not develop a dissociative disorder, which suggests that additional genetic or environmental factors are likely involved, Lanius said.
The nonspecific nature of these blood markers would also make it challenging to use them to diagnose DPDR, though in the future they could potentially be used alongside traditional DPDR screening tools, experts told Live Science.
One big limitation is that scientists do not yet fully understand how the brain constructs conscious reality in the first place.
"In my opinion, if we don't understand altered states of consciousness and dissociation, we can't understand psychopathology fully," Lanius said.
For now, more research is needed to determine whether therapies targeting inflammation would benefit people with dissociative disorders. Conditions like DPDR are thought to be rare, but symptoms are often overlooked, which can make it hard to both determine how common it is and to find study participants. But Dilkes thinks dissociation is underdiagnosed.
"So many people experience this, but no one has the words or knowledge of what it is," Dilkes said.
Editor's Note: This article was produced as part of the Dalla Lana Fellowship in Journalism and Health Impact program at the University of Toronto.
See how much you know about the most complex organ in the human body with our brain quiz!
- The Debrief
- The Brain Has a Flexible Sense of Time That Can Split Across Regions, New Research Reveals
The Brain Has a Flexible Sense of Time That Can Split Across Regions, New Research Reveals
When the brain tracks time, it must decide whether its regions should rely on a shared timing signal or tack time separately. A recent study in Nature Communications provides evidence that the brain uses both approaches, switching between them depending on the situation.
A group at the Institute of Science Tokyo simultaneously measured the activity of thousands of neurons in two mouse brain regions and found that the areas sometimes shared timing information but maintained more independent representations at other times. The researchers, led by Associate Professor Riichiro Hira, maintained that this flexibility enables the brain to remain stable as it adapts to changing requirements.
A Task Built to Catch the Brain Switching Modes
Hira’s team created a task to highlight this timing mystery. They trained mice to expect rewards at intervals that switched between 6 and 12 seconds, without any break to mark the end of one trial and the start of the next. Since there was no pause, the mice had to keep updating their internal sense of time throughout the experiment, instead of resetting their mental stopwatch for each new trial.
The mice eventually figured out the pattern. At first they expected a reward every six seconds even if the time they had to wait was longer than this, but by the end of the training session, their behavior indicated that they had learned to anticipate both reward intervals. This showed that the mice were capable of keeping track of both durations and of predicting which one would come next.
While the mice performed the task, the researchers recorded activity in their secondary motor cortex and the posterior parietal cortex using wide-field two-photon calcium imaging. Both regions play key roles in planning, prediction, and working memory.
Two Regions, Two Kinds of Mistakes
The neurons fired in sequence in each brain area, with different cells becoming active at different times. This sequence showed that each region was monitoring the passage of time.
The researchers also identified two kinds of errors in the neural activity. In some cases, both areas made the same mistake when assessing the passage of time. These coherent errors suggested that both regions sometimes shared the same timing drift. In other instances, only one region was inaccurate while the other remained correct. These independent errors suggested that one region could temporarily maintain a different timing representation from the other. Independent errors were more frequent than coherent ones, and this ratio remained the same in all the mice examined.
If the brain regions were just randomly out of sync, you’d expect the ratio to change. However, it didn’t, which suggests that the brain has a built-in way to balance working together and working independently.
Modeling the Switch Between Coherence and Independence
To identify this mechanism, the team built a computational model with two recurrent neural networks linked by sparse, long-range connections and exposed to the same background noise. The model produced the same 2-to-1 ratio of independent to coherent errors seen in the mice.
The model also discovered that the limited connections between the networks tended to cause them to become synchronized, while the common noise caused them to move in separate directions. Hira provided an explanation of the interaction saying, “We found sparse inter-regional connectivity promotes synchronization between the two regions, whereas widespread fluctuations prevent complete synchronization, allowing each region to preserve its own temporal representation.” Neither force takes precedence; instead, a compromise is reached which allows communication between the regions.
The findings challenge the idea that brain regions rely on a single synchronized timing system. It indicates that the brain can adjust how different parts are coordinated, rather than just turning that coordination on or off.
What a Flexible Clock Could Mean for the Brain
Hira’s team believes that there are implications beyond simple timing circuits. “In the future, our results may contribute to a better understanding of cognition, neurological disorders involving disrupted inter-regional coordination, and the development of brain-inspired artificial intelligence and robotic control systems that combine stability with flexibility,” said Hira.
This last idea may prove most important in the years ahead. Engineers building AI and robotic systems face a similar challenge: how to let separate parts work on their own when needed, yet still come back into sync. The mouse brain shows that sparse connections and shared background fluctuations can achieve this balance. This could point to a design principle that even applies to systems with no biological components.
Austin Burgess is a writer and researcher with a background in sales, marketing, and data analytics. He holds an MBA, a Bachelor of Science in Business Administration, and a data analytics certification. His work focuses on breaking scientific developments, with an emphasis on emerging biology, cognitive neuroscience, and archaeological discoveries.
Decades of Financial Hardship Linked to Faster Brain Aging
A large British study spanning more than 70 years has found that people who experience chronic money struggles over their working lives show measurable declines in memory and processing speed by their 50s, along with signs of accelerated brain shrinkage decades later.
The post Decades of Financial Hardship Linked to Faster Brain Aging appeared first on Sci.News: Breaking Science News.
- Live Science
- Diagnostic dilemma: Rare 'spinal stroke' struck an 8-year-old and temporarily paralyzed her
Diagnostic dilemma: Rare 'spinal stroke' struck an 8-year-old and temporarily paralyzed her
The patient: An 8-year-old girl in the U.S.
The symptoms: The girl arrived at an emergency department after waking up with sudden, severe pain in her upper back. Within hours of the pain emerging, she developed rapidly worsening weakness in all four limbs, making it impossible for her to stand or walk.
She also reported painful tingling and loss of sensation in her hands, and doctors discovered that she had diminished reflexes and sensory changes beginning at her upper chest and moving down her body. In multiple instances at the hospital, she lost control of her bladder and bowels.
The combination of acute paralysis, severe back pain and incontinence suggested damage to the spinal cord, but the cause wasn't immediately clear, her doctors wrote in a report of the case.
What happened next: The medical team launched an extensive search for the underlying cause. An MRI of her neck and torso showed evidence of extensive inflammation or injury that stretched from her lower neck to the middle of her back. The scan also showed a small tear in one of the disks in her lower neck, with a small amount of disk material pushing outward.
However, the girl and her parents did not report any recent falls or injuries, and the MRI alone couldn't determine what had caused this apparent damage.
The girl's medical team then performed blood tests, a spinal fluid analysis and more imaging to look for signs of infections, autoimmune diseases or other inflammatory conditions that can trigger acute paralysis in children. These tests all came back negative.
While clinicians continued investigating, the girl was treated with intravenous steroids and underwent a procedure called plasmapheresis, during which blood is drawn from the patient into a machine which separates blood plasma (the liquid portion of blood) from blood cells and then returns the blood cells to the patient mixed with fresh plasma from donors. This process helps to filter out harmful antibodies and abnormal proteins that can be present in people with autoimmune or blood disorders.
Over the following days, the girl gradually regained her ability to feel, walk and control her bladder. However, repeat MRI scans showed worsening inflammation, which didn't seem to match the girl's improving condition.
The diagnosis: Throughout her hospital stay, the medical team suspected a diagnosis of transverse myelitis, which is a rare neurological disorder that involves swelling in the spinal cord. However, as infectious and autoimmune causes became increasingly unlikely, the physicians changed their minds.
They instead concluded that the girl had experienced a spinal cord infarction, or essentially a stroke affecting the spinal cord. This blood-flow blockage was most likely caused by an exceptionally rare condition called fibrocartilaginous embolism (FCE).
In FCE, a small piece of jelly-like material from the soft center of an intervertebral disk breaks off, enters the bloodstream and blocks one of the arteries supplying the spinal cord. The resulting loss of blood flow can cause sudden paralysis, sensory loss and bowel and bladder dysfunction.
It's unknown exactly how many people experience FCE, as it's difficult to diagnose and frequently underreported. One literature review found only 30 suspected cases and 41 confirmed cases of FCE that had been documented in the U.S.
The case study notes that FCE is most common in children and young adults ages 10 to 20, and that rate also jumps up later in adulthood, around ages 40 to 60. It is slightly more common among female patients than male. While slightly younger than the most commonly affected demographic, the 8-year-old patient in this case otherwise fit this description.
FCE is difficult to diagnose because there is no definitive laboratory or imaging test for it. Instead, physicians must rule out more common causes of spinal cord injury while looking for imaging findings and clinical signs and symptoms that might fit the diagnosis of FCE.
The treatment: There isn't a specific treatment for FCE; instead, care focuses on managing the symptoms caused by the spinal stroke.
The patient was treated with corticosteroids to reduce inflammation, medications to manage pain and plasmapheresis. After a few weeks, and with extensive rehabilitation therapy, the girl regained nearly all of her strength and functional abilities. Her only lingering symptom was weakness in her hands.
What makes the case unique: The case study notes that FCE is often linked to minor trauma to the spine, such as that caused by heavy lifting or other activities that briefly increase pressure inside the spinal disks. In this case, however, the medical team was unable to identify a clear triggering event, and the girl was otherwise healthy and had no reported history of physical trauma. The girl simply woke up with symptoms, which made the diagnosis even more unexpected.
The case also highlights that, although FCE is rare and often carries a poor prognosis — as many patients experience long-term disability and some may even die from complications — meaningful recovery is also possible. The case report authors concluded that, with early recognition and supportive treatment, patients with FCE may achieve improved outcomes and a return to their normal activities.
For more intriguing medical cases, check out our Diagnostic Dilemma archives.
This article is for informational purposes only and is not meant to offer medical advice.
Kakadiya, J., Lakhani, D. A., Gaddamanugu, S., Goncalves, F. G., & Mullen, A. J. (2026). Presumed fibrocartilaginous embolism causing spinal cord infarct in 8-year-old female: A case report. Radiology Case Reports. https://doi.org/10.1016/j.radcr.2026.03.047
Can you guess the diagnosis in these strange medical cases? Find out with our diagnostic dilemma quiz!