Eureka Moments - Visual Illusions - Diet & Brain - Estrogens & Learning
Breedlove, S
https://www.nature.com/articles/d41586-025-01963-7
Eureka! The brain science behind lightbulb moments
Humberto Basilio
Mindia Wichert has taken part in plenty of brain experiments as a cognitive-neuroscience graduate student at the Humboldt University of Berlin, but none was as challenging as one he faced in 2023. Inside a stark white room, he stared at a flickering screen that flashed a different image every 10 seconds. His task was to determine what familiar object appeared in each image. But, at least at first, the images looked like nothing more than a jumble of black and white patches.
“I’m very competitive with myself,” says Wichert. “I felt really frustrated.”
Cognitive neuroscientist Maxi Becker, now at Duke University in Durham, North Carolina, chose the images in an attempt to spark a fleeting mental phenomenon that people often experience but can’t control or fully explain. Study participants puzzling out what is depicted in the images — known as Mooney images, after a researcher who published a set of them in the 1950s1 — can’t rely on analytical thinking. Instead, the answer must arrive all at once, like a flash of lightning in the dark (take Nature’s Mooney-images quiz below).
Becker asked some of the participants to view the images while lying inside a functional magnetic resonance imaging (fMRI) scanner, so she could track tiny shifts in blood flow corresponding to brain activity. She hoped to determine which regions produce ‘aha!’ moments.
Over the past two decades, scientists studying such moments of insight — also known as eureka moments — have used the tools of neuroscience to reveal which regions of the brain are active and how they interact when discovery strikes. They’ve refined the puzzles they use to trigger insight and the measurements they take, in an attempt to turn a self-reported, subjective experience into something that can be documented and rigorously studied. This foundational work has led to new questions, including why some people are more insightful than others, what mental states could encourage insight and how insight might boost memory.
© 2025 Springer Nature Limited
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https://www.nytimes.com/2025/06/26/science/neuroscience-brain-illusions.html
How Two Neuroscientists View Optical Illusions
By Katrina Miller
Take a look at this video of a waiting room. Do you see anything strange?
Perhaps you saw the rug disappear, or the couch pillows transform, or a few ceiling panels evaporate. Or maybe you didn’t. In fact, dozens of objects change in this video, which won second place in the Best Illusion of the Year Contest in 2021. Voting for the latest version of the contest opened on Monday.
Illusions “are the phenomena in which the physical reality is divorced from perception,” said Stephen Macknik, a neuroscientist at SUNY Downstate Health Sciences University in Brooklyn. He runs the contest with his colleague and spouse, Susana Martinez-Conde.
By studying the disconnect between perception and reality, scientists can better understand which brain regions and processes help us interpret the world around us. The illusion above highlights change blindness, the brain’s failure to notice shifts in the environment, especially when they occur gradually.
To some extent, all sensory experience is illusory, Dr. Martinez-Conde asserts.
“We are always constructing a simulation of reality,” she said. “We don’t have direct access to that reality. We live inside the simulation that we create.”
She and Dr. Macknik have run the illusion contest since 2005. What began as a public outreach event at an academic conference has since blossomed into an annual competition open to anyone in the world.
They initially worried that people would run out of illusions to submit. “But that actually never happened,” Dr. Martinez-Conde said. “What ended up happening instead is that people started developing illusions, actually, with an eye to competing in the contest.”
© 2025 The New York Times Company
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https://undark.org/2025/06/24/mental-illness-ketogenic-diet/
Possible Connection Between Mental Illness and Diet
By Gordy Slack, MindSite News
Lauren Kennedy West was still a teenager when she began to smell and hear things that weren’t there. Then to see things, too, that were invisible to others. Meanwhile, her moods began to intensify, sometimes turning very, very dark. “It was confusing, disturbing, and depressing,” she recalls.
She had periods of elation, too. But when she came down from these, she’d keep descending until she hit emotional bottom. It got so bad that in her early 20s, at college, Kennedy West tried to end her life twice. Finally, when she was 25, she was diagnosed with schizoaffective disorder, a form of schizophrenia with powerful mood swings. The medications she was prescribed eased her worst symptoms, she said, but they also had troubling side effects that ranged from extreme weight gain and “dry mouth” to feeling lethargic and an episodic condition called oculogyric crisis which causes people to continually, involuntarily, gaze upward. Worst of all, she said, was the feeling of being “emotionally blunted.”
Learning that she’d likely be taking those medications for the rest of her life was a blow, but the diagnosis gave Kennedy West a meaningful framework for her struggle. To be as stable, happy, and engaged as possible she would have to cultivate acceptance of her condition and the limitations it imposed, she was told.
Driven by a hope that others might be spared the disabling confusion and depression she suffered before her diagnosis, Kennedy West and her partner started a YouTube Channel, which they called “Living Well with Mental Illness” (now “Living Well with Schizophrenia“) In frequent posts, Kennedy West recounted her own struggles and triumphs and interviewed experts on mental illness and related subjects. In early 2023, Christopher Palmer was a guest on the channel.
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Spatial learning circuitry fluctuates in step with estrous cycle in mice
By Sydney Wyatt
The shape and density of dendritic spines fluctuate in step with the estrous cycle in the hippocampus of living mice, a new study shows. And these structural changes coincide with shifts in the stability of place fields encoded by place cells.
“You can literally see these oscillations in hippocampal spines, and they keep time with the endocrine rhythms being produced by the ovaries,” says study investigator Emily Jacobs, associate professor of psychological and brain sciences at the University of California, Santa Barbara. She and her colleagues used calcium imaging and surgically implanted microperiscopes to view the dynamics of the dendritic spines in real time.
The findings, published in Neuron in May, replicate and expand upon a series of cross-sectional studies of rat brain tissue in the early 1990s that documented sex hormone receptors in the hippocampus and showed that changes in estradiol levels across the estrous cycle track with differences in dendritic spine density.
“The field of neuroendocrinology was really changed in the early ’90s because of this discovery,” Jacobs says.
The new work is a “very important advancement,” says John Morrison, professor of neurology at the University of California, Davis, who was not involved in the research. It shows that spines change across the natural cycle of living mice, supporting estradiol’s role in this process, and it links these changes to electrophysiological differences, he says.
“The most surprising part of this study is that everything seems to follow each other. Usually biology doesn’t cooperate like this,” Morrison says.
Before the early 1990s, estrogens were viewed only as reproductive hormones, and their effects in the brain were thought to be limited to the hypothalamus, says Catherine Woolley, professor of neurobiology at Northwestern University, who worked on the classic rat hippocampus studies when she was a graduate student in the lab of the late Bruce McEwen. For that reason, her rat hippocampus results were initially met with “resistance,” she adds. A leader in the field once told her to “get some better advice” from her adviser “because estrogens are reproductive hormones, and they don’t have effects in the hippocampus,” she recalls.
© 2025 Simons Foundation
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