All posts tagged: brains

Science Journal: Humans’ Big Brains Evolved “For No Particular Reason”?

Science Journal: Humans’ Big Brains Evolved “For No Particular Reason”?

Published by Jenni Sidey

This article by Casey Luskin is republished from Science and Culture Today. Evolutionary biology has lots of problems. But one problem that most folks think the field doesn’t have is coming up with a reason for why humans evolved bigger brains. After all, we’ve heard countless times that bigger brains evolved to allow for higher intelligence in our hominid ancestors, because higher intelligence was selected to help our ancestors to better survive and reproduce. These kinds of arguments are everywhere — here are a few typical examples: Image Credit: Friedbert – Adobe Stock A 2007 chapter titled “The Evolution of Brain Size and Intelligence” in an MIT Press book reads: “It is reasonable to hypothesize that bigger brains evolved based on natural selection for increased intelligence.” (Rushton and Ankney, 2007) A 2025 paper in Philosophical Transactions of the Royal Society B states that “hominin brain expansion underpinned large increases in cognitive abilities.” (González-Forero and Gómez-Robles, 2025) According to a 2011 paper in Frontiers in Human Neuroscience, “An increase in brain size could also result in an increase in …

In VR flight, people’s brains learned to treat wings like limbs

In VR flight, people’s brains learned to treat wings like limbs

Published by skeptic

abstract: Something that exists as an idea or thought but not concrete or tangible (touchable) in the real world. Beauty, love and memory are abstractions; cars, trees and water are concrete and tangible. cognitive: A term that relates to mental activities, such as thinking, learning, remembering and solving puzzles. fiction: (adj. fictional) An idea or a story that is made-up, not a depiction of real events. limb: (in physiology) An arm or leg. motor: A device that converts electricity into mechanical motion. (in biology) A term referring to movement. neuroscientist: Someone who studies the structure or function of the brain and other parts of the nervous system. virtual: Being almost like something. An object or concept that is virtually real would be almost true or real — but not quite. The term often is used to refer to something that has been modeled by (or accomplished by) a computer using numbers, not by using real-world parts. So a virtual motor would be one that could be seen on a computer screen and tested by computer programming …

Human brains may have got bigger for no particular reason

Human brains may have got bigger for no particular reason

Published by skeptic

The skulls of Neanderthals (left) and Homo sapiens were larger than those of earlier hominins PASCAL GOETGHELUCK/SCIENCE PHOTO LIBRARY Our unusually large brains are one of the defining features of our species. But there is no evidence that evolution strongly favoured big brains in the past 2 million years of human evolution, according to a new analysis of fossil skulls. “There is indeed an increase in brain size through time, and there is indeed a reduction of facial size with time,” says Katerina Harvati at the University of Tübingen in Germany. However, this doesn’t appear to have been driven by natural selection. Instead, it seems the evolution of the human brain has been governed by a different evolutionary pressure: one that forced brains to stay the same size. From time to time, this constraint eased for unknown reasons, enabling brains to get larger. With Mark Hubbe at the University of Tennessee, Knoxville, Harvati studied 87 hominin skulls. Of those, 24 belonged to recent members of our species (Homo sapiens), while the remainder were from extinct …

What Are Fish Oil Supplements Good For? Here’s Your Crash Course

What Are Fish Oil Supplements Good For? Here’s Your Crash Course

Published by skeptic

Docosahexaenoic acid (DHA), an omega-3 fatty acid found in abundance in oily fish such as mackerel and sardines, is thought to improve cognitive function by supporting connections between brain cells. However, it has never been conclusively demonstrated that DHA taken as a dietary supplement actually reaches the brain or provides measurable benefits against dementia. Against this backdrop, a research team at the USC School of Medicine has published the results of a large, two-year clinical trial involving older adults at elevated risk of developing Alzheimer’s disease. The study found that while high-dose DHA supplements do indeed reach the brain, they did not improve memory or cognitive function, nor did they slow brain atrophy. “Everyone hopes for a silver bullet to prevent Alzheimer’s disease, but we can’t say that fish oil supplements protect brain health,” said Hussein Naji Yassine, director of the Personalized Brain Health Center at USC. “While omega-3s play an important role in forming brain cell connections needed for cognition, our results do not support fish oil supplements as a preventive measure against Alzheimer’s.” …

Neuroscience can’t tell us the way to govern people’s brains

Neuroscience can’t tell us the way to govern people’s brains

Published by skeptic

K H FUNG/SCIENCE PHOTO LIBRARY Our brains love shortcuts. Decisions are often made via a subconscious muddling through, due to the brain’s desire to minimise energy use. It is perhaps why we value neat categorisations of someone’s brain state, despite these being flawed. Take the age at which you become an adult. Around the world, legal adulthood varies from 16 to 21. This difference matters, as we rightly have different expectations for children versus adults. Some call for this tension to be smoothed by asking policy-makers to consider typical brain maturity levels, ascertained via tools like brain imaging, in matters like criminal sentencing or the right to drive. The idea that our brains don’t fully develop until we are 25 is also becoming popular, but – as we discuss in our special on brain changes – this is wrong. Brains mature at different rates and there are myriad ways to measure their development. This isn’t the only way neuroscience is looked to for informing policy before the science is ready. Take autism, which may come …

Fluctuating oestrogen levels may alter how drugs enter women’s brains

Fluctuating oestrogen levels may alter how drugs enter women’s brains

Published by skeptic

The effectiveness of an intranasal drug that failed in a late-stage trial may be influenced by oestrogen Sergei Babenko/Alamy The experimental drug davunetide was showing promise for degenerative brain conditions until, more than 10 years ago, a pivotal late-stage trial fell flat. Allon Therapeutics, the company behind davunetide, subsequently halted its development. But upon closer inspection, scientists found the drug may actually be effective in women. Digging deeper, they have now revealed that fluctuating oestrogen levels may influence how much of the drug reaches the brain, raising the possibility that its effectiveness – and those of other treatments – varies depending on our levels of hormones like oestrogen, which fluctuate throughout the menstrual cycle. “It’s very common that brain disease is regulated by steroid hormones [such as oestrogen, progesterone and testosterone] and that’s not taken into consideration very often, which is a massive, massive problem,” says Jens Pahnke at the University of Oslo, Norway, who wasn’t involved in the research. More than 20 years ago, Illana Gozes at Tel Aviv University in Israel derived davunetide …

A scientist says he can scan prisoners’ brains for signs of evil. Did his disputed science put a man on death row? | US news

A scientist says he can scan prisoners’ brains for signs of evil. Did his disputed science put a man on death row? | US news

Published by Sam Flores

Kent Kiehl loves to talk about the criminal defendant who first put his controversial brain research on the map, the serial killer Brian Dugan. “He was just utterly and completely psychopathic. A perfect – I mean, I hate to say this word – specimen.” In 2009, Dugan’s lawyers asked Kiehl to testify about Dugan’s inclination for killing. At the time, a jury in Chicago was deciding whether to sentence Dugan to death for the rape and murder of a 10-year-old girl. Dugan had already confessed to the murder in 1985, while he was serving a life sentence in state prison for the rape and murder of two other women. DNA evidence later established that Dugan had been at the crime scene. In the words of one of Dugan’s attorneys, the case was “a slam dunk for the prosecution”. Out of desperation, they summoned Kiehl, a researcher at the University of New Mexico who has made it his specialty to study the brains of the incarcerated, as their star witness. Dugan was certain to be found …

How some people’s brains make an extraordinary recovery from stroke

How some people’s brains make an extraordinary recovery from stroke

Published by skeptic

Scientists are working to enhance stroke recovery Craig Boylan A well-known actor who had experienced a stroke was treated by stroke specialist Sandor Nardai. The actor had been left with aphasia, or an impaired ability to speak – brutal for anyone, but “probably the most devastating thing that could happen to an actor”, says Nardai. After three months of recovery, though, the actor was able to say some words. After a year, he voiced a commercial. Remarkably, he eventually got well enough to return to live theatre, says Nardai, who is at Semmelweis University in Hungary. For every happy story like this, though, there are many people who survive stroke but have less encouraging ones. Strokes send the brain into freefall, damaging areas that control cognitive and physical functions. Only an estimated 35 per cent of survivors make a full recovery or live with only minor impairments. The majority have profoundly life-altering issues, like aphasia, paralysis, behavioural changes or cognitive and sensory challenges. The numbers are dizzying: almost 100 million live with the after-effects of …

3 People Have Gotten Cancer-Detecting Implants in Their Brains

3 People Have Gotten Cancer-Detecting Implants in Their Brains

Published by skeptic

A San Francisco startup with ties to Elon Musk’s Neuralink has started testing its brain implant to detect and treat cancer in humans. Coherence Neuro says it temporarily placed its coin-sized implant in the brains of three people undergoing surgery to have brain tumors removed at the Royal Melbourne Hospital in Australia. The implant was in place for roughly 30 minutes before being removed, providing an important safety check before the device can be implanted long-term in patients with brain cancer. Known as a brain-computer interface, the Coherence Neuro device is designed to sense the unique electrical signals of tumors and deliver mild electrical stimulation to prevent their growth. In the time the implant was in the patients’ brains, the company was able to see how it performed for a short period. (The patients had consented prior to surgery.) Matthew MacDougall, Neuralink’s head neurosurgeon, is an adviser and investor in Coherence. Rory Murphy, a neurosurgeon at the Barrow Neurological Institute in Arizona who is an investigator in one of Neuralink’s trials, is also slated to …

Faecal transplant makes the brains of old mice act young again

Faecal transplant makes the brains of old mice act young again

Published by skeptic

A scanning electron micrograph of the intestinal lining of a mouse, with several bacteria (green) and one red blood cell (red) CJC Copyright: IKELOS GmbH/Dr. Christopher B. Jackson/Science Photo Library A faecal microbiome transplant (FMT) could make an aged brain as adaptable as a young one. Our gut microbiome has been linked to our risk of depression and may even play a role in shaping our personality. But for the first time, a study has shown that older mice given the gut microbiomes of younger animals via an FMT experience improved brain plasticity. This meant they could overcome a condition similar to amblyopia, also known as lazy eye, which is typically only successfully treated in childhood. “This study suggests that microbial communities may help regulate critical periods of brain development by defining when developmental windows of heightened plasticity open and close,” says Parisa Gazerani at Oslo Metropolitan University in Norway, who wasn’t involved in the work. “It suggests that the gut microbiome may be an active developmental partner that helps shape neural circuit maturation alongside sensory …