Michael J. Behe's Blog, page 35

At The Debrief.org: Is Consciousness Really A Memory System For Our Interactions With Reality? New Research Says Maybe.

Tim McMillan writes:

A recent study published in the journal Cognitive and Behavioral Neurology proposes a new theory of consciousness, suggesting subjective awareness is merely a memory system that records our unconscious interactions with reality. 

Unique to other theories on the mystery of consciousness, researchers propose that the majority of the time, humans do not directly make decisions or perceive the outside world. Instead, these activities are performed unconsciously and then milliseconds later we consciously remember doing them. 

“A vast majority, if not all, of human behavior is actually performed unconsciously and consciousness is simply the memory of having performed specific actions,” said Dr. Andrew Budson, a professor of neurology at Boston University, in an email to The Debrief.

Budson, the lead author of the paper titled Consciousness as a Memory System, says that the idea that all our decisions and actions are unconsciously made–and that we simply fool ourselves into believing we consciously made them–may lead to some anxiety-inducing questions about free will. 

However, researchers note that several studies have already demonstrated how conscious awareness of decisions or activities only seems to occur after physiological actions are unconsciously performed. 

“This order is incompatible with the idea that perceptions, decisions, and actions are only possible when conscious awareness and thought are present,” wrote researchers. 

Neurophysiologist Dr. Benjamin Libet, a pioneer in the field of human consciousness, demonstrated the supremacy of unconsciousness over conscious thoughts and actions in a series of groundbreaking experiments in the 1980s.  

Measuring study participants’ neurological electrical activity when asked to carry out a series of simple tasks, Dr. Libet found that regions of the brain responsible for movement become active a few hundred milliseconds before the conscious decision to perform a voluntary act was made. 

Note: An alternate conclusion can be reached based on these observations of neurological activity and consciousness awareness of a decision: according to the biblical model of humans being composed of spirit and body, these results are consistent with the spirit deciding to act, then the consciousness (dependent upon the brain) registering this decision a moment later.

Ostensibly akin to quantum entanglement and Albert Einstein’s “spooky action at a distance,” four decades later, there is still no majority agreement on the interpretation or significance of Libet’s experiments. This is perhaps unsurprising, given the potential implications of Libet’s results on the philosophical concept of free will. 

For his part, Dr. Libet did not believe his results dismissed the notion of free will. Instead, Dr. Libet said he found that research participants still possessed the conscious ability to “veto” an unconsciously made decision through a process sometimes referred to as “free won’t.” 

Speaking with The Debrief, Dr. Budson pointed out that the theory of consciousness as a memory system also does not infringe on the concept of human free will. 

“Just because our decisions and actions are ultimately made unconsciously does not mean that we do not have free will—or, at least, not any more than if we made our decisions and actions consciously,” a portion of Budson’s paper states. “If major life decisions are made slowly, over minutes, hours, days, or longer, these important decisions will almost certainly have input from both our conscious mind and our unconscious brain processes.” 

Modern studies have continued to support and expand on Dr. Libet’s work and the concept that unconscious processes are the true forerunner to conscious behavior. 

A 2008 study by neuroscientists at the Max Planck Institute for Human Cognitive and Brain Sciences in Leipzig, Germany, found that the brain unconsciously makes decisions up to ten seconds before a person is aware of having made a decision.

In the recent study, the neuroscientists highlight additional research showing that conscious processes are too slow to be actively involved in activities requiring split-second decisions, such as playing music or sports. 

In this context, the theory of consciousness as a memory system begins to feel less abstract. For example, it’s widely accepted that professional sports teams regularly practice so that players will be able to unconsciously react to situations that occur during a game. 

“We knew that conscious processes were simply too slow to be actively involved in music, sports, and other activities where split-second reflexes are required. But if consciousness is not involved in such processes, then a better explanation of what consciousness does was needed,” said Dr. Budson. 

Dr. Budson and his colleagues caveat their hypothesis by noting that, “Many—perhaps most—creative endeavors, from painters to novelists, likely result from the combination of conscious and unconscious brain processes working together.” 

Offering some speculation, as opposed to a rigid academic argument, researchers postulate that academic or artistic visionaries, such as Albert Einstein, Isaac Newton, Jane Goodall, or Rachel Carson, etc., may have been able to see the world beyond what the conscious mind suggests it is.

“In other words, some of these individuals may have had more access to their unconscious brain processes.” 

Researchers further acknowledge that in support of their hypothesis, they intentionally ignored many of the most significant parts of any complete theory of consciousness, such as the so-called “hard problem” or how a collection of biological material can produce subjective awareness. 

Nevertheless, scientists are hopeful that their new theory of consciousness being essentially and originally a part of explicit memory, or a collective “conscious memory system,” will provide the framework for further research. 

“By careful observation and well-designed experiments, examining this memory theory of consciousness may move us toward a time in the future when such questions will seem quaint, similar to questions about what constitutes the life force that living beings have or how light travels through the ether.” 

Full article at The Debrief.

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At Phys.org: The thinking undead: How dormant bacteria calculate their return to life

Facing starvation and stress conditions, some bacteria enter a dormant state in which life processes stop. Shutting down into a deep dormancy allows these cells, called spores, to withstand punishing extremes of heat, pressure and even the harsh conditions of outer space.

Eventually, when conditions become favorable, spores that may have been dormant for years can wake up in minutes and spring back to life.

A microscopy image reveals several spores with their electrochemical potential color-coded according to the strength of the signal. Credit: Süel Lab—Kaito Kikuchi and Leticia Galera

Spores wake up by re-hydrating and restarting their metabolism and physiology. But until now scientists did not know whether spores can monitor their environment “in their sleep” without waking up. In particular it was not known how spores deal with vague environmental signals that do not indicate clearly favorable conditions. Would spores just ignore such mixed conditions or take note?

University of California San Diego biologists have solved this mystery in a new study published in the journal Science. Researchers in the School of Biological Sciences discovered that spores have an extraordinary ability to evaluate their surrounding environment while remaining in a physiologically dead state. They found that spores use stored electrochemical energy, acting like a capacitor, to determine whether conditions are suitable for a return to normal functioning life.

“This work changes the way we think about spores, which were considered to be inert objects,” said Gürol Süel, a professor in the Department of Molecular Biology. “We show that cells in a deeply dormant state have the ability to process information. We discovered that spores can release their stored electrochemical potential energy to perform a computation about their environment without the need for metabolic activity.”

Many bacterial species form spores—partially dehydrated cells surrounded by a resilient protective coat—as a survival strategy that allows them to remain dormant for thousands of years. Such a remarkable capability makes them a threat in the form of bacterial anthrax as well as a contamination hazard in medicine and the food industry.

Süel and his colleagues tested whether dormant Bacillus subtilis spores could sense short-lived environmental signals that were not strong enough to trigger a return to life. They found that spores were able to count such small inputs and if the sum reached a certain threshold, they would decide to exit the dormant state and resume biological activity.

Developing a mathematical model to help explain the process, the researchers discovered that spores use a mechanism known as integrate-and-fire, based on fluxes of potassium ions for appraising the surrounding environment. They found that spores responded to even short-lived favorable signals that were not enough to trigger an exit from dormancy. Instead of waking up, spores released some of their stored potassium in response to each small input and then summed consecutive favorable signals to determine if conditions were suitable for exiting. Such a cumulative signal processing strategy can reveal whether external conditions are indeed favorable, and prevents spores from “jumping the gun” into a world of unfavorable conditions.

“The way spores process information is similar to how neurons operate in our brain,” said Süel. “In both bacteria and neurons, small and short inputs are added up over time to determine if a threshold is reached. Upon reaching the threshold spores initiate their return to life, while neurons fire an action potential to communicate with other neurons.” Interestingly, spores can perform this signal integration without requiring any metabolic energy, while neurons are among the most energy-dependent cells in our bodies.

The researchers believe the new information about spores reframes popular ideas about cells in extremely dormant states that seem dead. Such findings hold implications for evaluating life on objects such as meteors as well as space missions seeking evidence of life.

“This work suggests alternate ways to cope with the potential threat posed by pathogenic spores and has implications for what to expect from extraterrestrial life,” said Süel, who holds affiliations with the San Diego Center for Systems Biology, BioCircuits Institute and Center for Microbiome Innovation. “If scientists find life on Mars or Venus, it is likely to be in a dormant state and we now know that a life form that appears to be completely inert may still be capable of thinking about its next steps.”

Phys.org

This fascinating research presents yet another remarkable example of biochemical complexity with a functionality dependent upon environmental sensing, signal evaluation, operational feedback, managing stored resources, and survivability–all within a supposedly inert “spore.” I’ll call that evidence of intelligent design. Anyone else want to suggest that the origin of this mechanism seems more consistent with an unguided natural process?

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At EOS.org: What Can Zircons Tell Us About the Evolution of Plants?

Alka Tripathy-Lang writes:

Geologists love zircon for its ability to tell time. They’ve also used these robust, tiny time capsules in a variety of studies ranging from estimating when water first appeared on Earth to exploring the origin of plate tectonics.

Scientists led by Chris Spencer, an assistant professor of tectonics and geochemistry at Queen’s University in Kingston, Ont., Canada, combed through data from hundreds of thousands of zircons culled from numerous studies. In a recent Nature Geoscience paper, they compiled only single crystals with three kinds of analyses—the age of the zircon and two additional measurements that serve as proxies for what the melt that birthed each crystal was like.

With this data set, the authors posit that zircons—perhaps known best for recording magmatic and metamorphic events deep within Earth—might chronicle the radiation of plants with roots, leaves, and stems, a development that occurred about 430 million years ago.

Zircons may record the evolution of vegetation like that lining the Swiss river Kander. Credit: Adrian Michael/Wikimedia, CC-BY-3.0Elements and Isotopes

Zircon contains zirconium, silicon, and oxygen. Other elements, like uranium and hafnium, can also sneak into its structure; uranium isotopes are radioactive and decay to lead, providing geochronologists with a way to date nearly every zircon crystal.

Oxygen—part of zircon’s backbone—has only stable, naturally occurring isotopes. Low-temperature surface processes preferentially sort these isotopes, divvying heavy from light. For example, water with light oxygen tends to evaporate first. Water with heavy oxygen will precipitate more readily as rain. And when water interacts with rock, weathering processes partially separate heavy oxygen from its lighter counterparts, explained Brenhin Keller, an assistant professor and geochronologist at Dartmouth who was not involved with this study.

In particular, as rocks erode, they disintegrate into sands and eventually muds made from clays. Clays tend to incorporate more heavy oxygen, explained Annie Bauer, an assistant professor and geochronologist at the University of Wisconsin–Madison who was also not involved in this study. Subducting mud and mixing it into the mantle would result in melt—and likely zircon—featuring heavier oxygen than a melt that incorporates no crustal material or crust that experienced less weathering.

Therefore, oxygen isotopes can be used as a proxy for whether a zircon crystal’s precursor melt contained rocks that spent time at the surface, explained Spencer.

Zircons also contain plenty of hafnium, some of which is produced by the radioactive decay of lutetium. “To a first order, the lutetium-hafnium system will tell you about the source of a magma and therefore also the source of a zircon…crystallizing from that magma,” said Keller.

If the magma contains melt fresh from the mantle, its hafnium signature will look very different from a melt signature containing old crust that’s been recycled via subduction. In Hawaii, for instance, freshly erupted basalts weather into sediments easily identified as being “from magmas that were extracted from the mantle very, very recently,” said Spencer. The hafnium isotope signatures of these sediments will indicate their youth. Sediments in the Amazon River delta, in contrast, come from several-billion-year-old cratons. “The rocks from which those sediments are derived have a very different [hafnium isotope signature] that goes back billions of years,” he explained.

Chemical Correlation

“At first blush…it just looks like shotgun blasts of data,” said Spencer, referring to the relationship between oxygen and hafnium signatures. There is a general lack of correlation for pre-Paleozoic zircons older than about 540 million years, but hafnium signatures do correlate with oxygen isotopes in younger zircons.

Taken together, these data point to zircons coming from a mantle source containing old crust (from hafnium) that was exposed to liquid water (from oxygen), said Keller.

This relationship is surprising, said Bauer, because “there’s no reason to expect hafnium and oxygen to correlate [in zircons].” Sediments incorporated into a mantle melt might contain heavier oxygen, indicating more weathering, but they need not have a distinct hafnium signature because “it’s just random sedimentary material.”

Pinning down just when the two signatures began to correlate took some statistical sleuthing. Nevertheless, Spencer found a shift between 450 million and 430 million years ago that suggests some rapid, irreversible change in zircon chemistry, he said.

Biological Causation

Around 430 million years ago, few mountains were being built, said Spencer, which led him to surmise that something else must have caused the peculiar correlation.

Prior to about 450 million years ago, river deposits tended to have very low proportions of mud, whereas after that, muddy river deposits increased. The cause of this shift to muddy rivers, said Spencer, “is the advent of land plants.” Roots, he explained, help hold mud and other sediment on river banks, which in turn helps rivers meander. Therefore, roots control what sediment eventually arrives in subduction zones to be carried down to the mantle, melted, and returned to the surface, perhaps with zircons transcribing the tale.

Just how land plants changed the sediment cycle, however, is still being debated, Keller pointed out. For instance, plants stabilize banks, but they can also increase the extent of weathering. “It’s a reasonable hypothesis that [plants] should maybe do something to the global cycling of sediments,” he said, “and if so, then maybe you can see it in the geochemical record.”

Ultimately, there are only about 5,000 zircons in Spencer’s database, which he described as “paltry” compared to other zircon data repositories that reach into the hundreds of thousands of analyses. The small sample size is a result of few studies obtaining both oxygen and hafnium information from a single zircon, in addition to age.

“The main challenges are always representativeness,” said Keller, “and preservation bias.”

“I anxiously await the time when we have 10,000 [analyses],” said Spencer. 

EOS.org

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At Evolution News: Michael Behe in World Magazine — “Game Over” for Darwinism

David Klinghoffer writes:

Image: A scene from “Molecular Machines — ATP Synthase: The Power Plant of the Cell,” via Discovery Institute.

Professor Behe was present at a “semi-secret” scientific gathering “whose theme was a specific controversial question: Did Darwinian evolution have any limitations?” ATP synthase (pictured above) is a fearfully and wonderfully made molecular machine, the “power plant of the cell.” John Walker [a British scientist who has studied ATP synthase for over 40 years] had the floor and was discussing his area of expertise. Behe explains:

ATP synthase is not simple. Comprising thousands of amino acid building blocks in about 10 kinds of protein chains, its intricate structure carefully directs a flow of acid particles, beginning from outside the cell, through deep channels in the machine’s organization, into the cell’s interior. Somehow, like the cascade of water over a hydroelectric dam that turns a turbine, the flow of acid through the channels rotates a central camshaft. The cams push against multiple discrete areas of a stationary region of the synthase, distorting their shapes. The distortion forces together two bound feed-chemicals, ADP and phosphate, provoking them to react to yield the energy-rich-yet-stable molecule ATP. As the camshaft completes a turn, the ATP is released into the cell, and the machine begins another cycle. Incredibly, the many copies of the machine in each person produce about 150 pounds of ATP molecules every day, but each is used rapidly as energy — in effect, recharging each cell like a reusable battery.

And Walker’s more recent studies — using the ­newest, most powerful iteration of microscopy, called “cryo-electron” microscopy — would reveal its mechanism in unprecedented detail.

A Snipe Hunt

But there was an obvious problem:

By now, the scientists assembled before Dr. John Walker had run out of patience. The man had just held forth for nearly an hour on this miracle of biological architecture. Elegant and complex, precision-engineered, multiplied daily in the billions across the biosphere and on which the entirety of life depends. Finally, during the Q&A period, a questioner asked him directly: How could a mindless Darwinian process produce such a stunning piece of work?

Walker’s entire reply (paraphrasing): “Slowly, through some sort of intermediate or other.”

Far out of earshot I muttered two simple words: “Game over.”

If a Nobel laureate who has worked on one of life’s most fundamental systems for four decades can’t give an account of how it supposedly arose through a series of lucky mutations and natural selection — despite knowing its innermost workings in spectacular detail — then it’s reasonable to conclude no such account exists, and the effort to find one is a snipe hunt. [Emphasis added.]

A snipe hunt is a “fool’s errand” because the so-called snipe in the metaphor is an imaginary animal. And indeed the game is over for Darwinian evolutionary theory: an unguided evolutionary explanation for what Behe calls irreducibly complex structures, including ATP synthase, will not be found. It remains for Darwin’s apologists, some of them rather vicious, to recognize this and permit the public to hear it, too. Read the rest of Behe’s essay for World here.

Full article at Evolution News.

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At SciTech Daily: Dinosaur-Killing Asteroid Triggered Monstrous Global Tsunami With Mile-High Waves

Sixty-six million years ago a miles-wide asteroid struck Earth, wiping out nearly all the dinosaurs and around three-quarters of the planet’s plant and animal species.

It also triggered a monstrous tsunami with mile-high waves that scoured the ocean floor thousands of miles from the impact site on Mexico’s Yucatan Peninsula, according to a new University of Michigan-led study that was published online on October 4 in the journal AGU Advances.

The research study presents the first global simulation of the Chicxulub impact tsunami to be published in a peer-reviewed scientific journal. Additionally, U-M scientists reviewed the geological record at more than 100 sites worldwide and discovered evidence that supports their models’ predictions about the tsunami’s path and power.

“This tsunami was strong enough to disturb and erode sediments in ocean basins halfway around the globe, leaving either a gap in the sedimentary records or a jumble of older sediments,” said lead author Molly Range.

Maximum tsunami wave amplitude following the asteroid impact 66 million years ago. Credit: From Range et al. in AGU Advances, 2022Energy impact

According to the study’s calculations, the initial energy in the impact tsunami was up to 30,000 times larger than the energy in the December 2004 Indian Ocean earthquake tsunami. That one is one of the largest tsunamis in the modern record and killed more than 230,000 people.

The researcher’s simulations show that the impact tsunami radiated mainly to the east and northeast into the North Atlantic Ocean, and to the southwest into the South Pacific Ocean through the Central American Seaway (which used to separate North America and South America).

Geological corroboration

U-M’s Moore analyzed published records of 165 marine boundary sections for the review of the geological record. He was able to obtain usable information from 120 of them. Most of the sediments came from cores collected during scientific ocean-drilling projects.

“We found corroboration in the geological record for the predicted areas of maximal impact in the open ocean,” said Arbic. He is a professor of earth and environmental sciences and oversaw the project. “The geological evidence definitely strengthens the paper.”

Comparing models

The modeling portion of the study used a two-stage strategy. First, a large computer program called a hydrocode simulated the chaotic first 10 minutes of the event. This included the asteroid impact, crater formation, and initiation of the tsunami. That work was conducted by co-author Brandon Johnson of Purdue University.

Based on the findings of previous studies, the scientists modeled an asteroid that was 8.7 miles (14 kilometers) in diameter, moving at 27,000 mph (12 kilometers per second). It struck granitic crust overlain by thick sediments and shallow ocean waters, blasting an approximately 62-mile-wide (100-kilometer-wide) crater and ejecting dense clouds of soot and dust into the atmosphere.

Two and a half minutes after the asteroid struck, a curtain of ejected material pushed a wall of water outward from the impact site, briefly forming a 2.8-mile-high (4.5-kilometer-high) wave that subsided as the ejecta fell back to Earth.

According to the U-M simulation, 10 minutes after the projectile hit the Yucatan, and 137 miles (220 kilometers) from the point of impact, a 0.93-mile-high (1.5-kilometer-high) tsunami wave—ring-shaped and outward-propagating—began sweeping across the ocean in all directions.

According to the team’s simulation:

One hour after impact, the tsunami had spread outside the Gulf of Mexico and into the North Atlantic.Four hours after impact, the waves had passed through the Central American Seaway and into the Pacific.Twenty-four hours after impact, the waves had crossed most of the Pacific from the east and most of the Atlantic from the west and entered the Indian Ocean from both sides.By 48 hours after impact, significant tsunami waves had reached most of the world’s coastlines.Dramatic wave heights

For the current study, the research team did not attempt to estimate the extent of coastal flooding caused by the tsunami.

However, their models indicate that open-ocean wave heights in the Gulf of Mexico would have exceeded 328 feet (100 meters), with wave heights of more than 32.8 feet (10 meters) as the tsunami approached North Atlantic coastal regions and parts of South America’s Pacific coast.

As the tsunami neared those shorelines and encountered shallow bottom waters, wave heights would have increased dramatically through a process called shoaling. Current speeds would have exceeded the 0.4 mph (20 centimeters per second) threshold for most coastal areas worldwide.

“Depending on the geometries of the coast and the advancing waves, most coastal regions would be inundated and eroded to some extent,” according to the researchers. “Any historically documented tsunamis pale in comparison with such global impact.”

Full article at SciTech Daily.

We can be thankful that no such large impacts (extinction events) have occurred in human history.

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At Evolution News: The Multiverse: From Epicurus to Comic Books and Beyond

On a new episode of ID the Future, Discovery Institute Senior Fellow Andrew McDiarmid explores the roots of the idea that our universe is just one of many universes, an idea stretching back to the ancient atomists and given new life in the modern era, first by physicist Hugh Everett. McDiarmid looks at how the idea percolated into comic books and from there into other areas of popular culture. He caps off the episode with a reading of a recent article about the multiverse hypothesis by Stephen Meyer, author of the bestseller, Return of the God Hypothesis: Three Scientific Discoveries That Reveal the Mind Behind the Universe.

Image source: Wikimedia Commons.

Meyer shows why some atheist scientists are attracted to the multiverse. As he explains, there is little if any good evidence for the idea, but atheists need it to explain away the fact that the laws and constants of the universe are exquisitely fined-tuned to allow for life. The fine-tuning smacks of intelligent design, and physicist Leonard Susskind has frankly remarked that the multiverse is needed to answer the arguments of design proponents. But as Meyer explains, not only does the multiverse hypothesis lack evidence, it doesn’t even remove the need for a fine-tuner, a point that the makers of recent comic book movies from Marvel and DC seem to grasp. Download the podcast or listen to it here.

Evolution News

By definition, the “universe” is everything that exists in the physical realm. By definition, anything that might exist beyond our universe is “metaphysical.” By appealing to the metaphysical realm to explain fine-tuning or life itself, is akin to acknowledging God as the creator. A profound difference between appealing to the multiverse and appealing to God, is that the historical and personal evidence for God throughout human history is multilayered and pervasive, whereas the evidence for the multiverse remains firmly at zero.

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At Phys.org: Discovery of new microscopic species expands the tree of life

Scientists have discovered several very rare species of microorganisms, some of which have never been seen before and others which have escaped the curious eyes of scientists for over a hundred years.

Legendrea loyezae with trailing tentacles. Credit: Bournemouth University

Microorganisms are made up of only one cell and are at the bottom of the food chain. They live all around us and can be found in any habitat, from small puddles to vast oceans; there is still a great deal to discover about them.

“Biodiversity at a microscopic level is not as widely understood as other areas of nature, despite the fact that whole ecosystems depend on it,” explained Professor Esteban.

“Some of these species are completely new and others have not been seen for over a century. We documented many curious behaviours on them and carried out DNA analysis of them for the first time.

“This means we can understand more about their relationships with other microbes and find new branches for them on the tree of life,” Professor Esteban continued.

“Most organisms on the tree of life are microscopic. In fact, most life on Earth has always been microscopic. Microorganisms were the first predators on Earth, their greedy appetites were one of the leading factors of the evolution of more complex life in the early ages of Earth,” Weiss explained.

“As prey developed better defences, predators needed to develop better ways of catching them. After the evolution of multicellular, complex life they became the main food source for others such as krill and plankton, which in turn are food for larger species. If the organisms at the very bottom were removed, all other parts of the food chain above them would collapse too,” he added.

“As with all forms of wildlife spotting, the more you look, the more you find. By taking so many samples, almost every day, we knew we could find something new. The more we know about the microscopic world, the more we can learn about the rest of their habitats where all other forms of life survive.”

Complete article at Phys.org.

The just-so evolutionary bedtime story rattled off in this article is presented without scientific evidence, and one could say, in spite of the evidence. The complex, information-rich biochemistry of complex life cannot arise just because a microbe has a “greedy appetite.”

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At Medical Xpress: Pupil dilation: A window to perception

Graciela Gutierrez of Baylor College of Medicine writes:

The eyes are often referred to as the “windows to the soul.” In fact, there is a grain of neurobiological truth to this. An international research team from the Universities of Göttingen and Tübingen, Germany, and Baylor College of Medicine in Houston, are now able to provide answers as to why pupil size is influenced by not only sensory stimuli like light, but also by our internal state such as fear, excitement or attention.

Credit: Pixabay/CC0 Public Domain

The findings, appearing in the current edition of Nature, help to explain whether these rapid, state-dependent changes in pupil size found not only in humans but also in other vertebrates, affect the way we perceive our surroundings.

Researchers started their work by investigating how state-dependent changes in pupil size affected the vision of mice.

“While the eyes convert light to neural activity, it is the brain which is crucial for the interpretation of visual scenes,” said Dr. Katrin Franke, research group leader at the Institute for Ophthalmology Research at the University of Tübingen and first author of the study.

In their experiments, the researchers showed mice different colored images and recorded the activity of thousands of individual neurons within the visual cortex, a particularly relevant brain area for visual perception. Based on these recordings, they used deep neural networks to create a computer model as a digital twin of the cortex, simulating the responses of large numbers of neurons in the brain. They then used this computer model to identify the optimal visual light stimulus for each neuron, meaning each neuron’s “favorite image.”

Effects on visual perception

This model revealed something quite interesting: When the mice dilated their pupils due to an alert state of mind, the color sensitivity of the neurons changed from green to blue light within seconds, meaning neurons were more green sensitive in a quiet state and became more UV sensitive in an active state.

This was particularly true for neurons that sample stimuli from the upper hemisphere used to observe the sky. In subsequent experiments they were able to verify that this also happens in the real biological neurons.

With the help of eye drops that dilate the pupil, researchers were then able to simulate the higher sensitivity to blue light even for a quiet brain state.

“These results clearly demonstrate that pupil dilation due to an alert brain state can directly affect visual sensitivity and probably visual perception as well. The mechanism here is that a larger pupil lets more light into the eye, recruiting different types of photoreceptors in our retina and thus indirectly changing the color sensitivity in the visual cortex,” Franke said.

But what are the benefits of this change in visual sensitivity? Konstantin Willeke, co-first author of the study and member of the research group led by adjunct professor of neuroscience at Baylor Dr. Fabian Sinz, said, “We were able to show that the higher neuronal sensitivity to blue light probably helps the mice to better recognize predators against a blue sky.”

Dr. Andreas Tolias, also principal investigator on the study and professor and director of the Center for Neuroscience and Artificial Intelligence at Baylor, said, “The finding that brain state-related changes in pupil size affect visual sensitivity has implications for our understanding of vision well beyond predator detection in mice. Further research questions now arise as to how perception in numerous other animals is influenced by this effect. The pupils in our eyes could thus not only be a window into the soul, but also change the way we perceive the world from moment to moment depending on our inner state of mind.”

Full article at Medical Xpress.

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From Sci Tech Daily: Drinking Two to Three Cups of Coffee Daily Is Linked With a Longer Lifespan

Good news for coffee lovers!

Drinking two to three cups of coffee a day is associated with a longer lifespan and a lower risk of cardiovascular disease compared with avoiding coffee. This is according to new research published on September 27 in the European Journal of Preventive Cardiology, a journal of the European Society of Cardiology (ESC). The findings of increased longevity applied to ground, instant, and decaffeinated varieties of coffee.

According to a new study, drinking two to three cups of coffee a day is linked with a longer lifespan and a lower risk of cardiovascular disease.

All types of coffee were linked with a reduction in death from any cause in the study. The greatest risk reduction was seen with two to three cups per day, with ground coffee providing the most benefit. Drinking two to three cups of ground coffee a day was associated with a 27% lower likelihood of death and a 20% reduced likelihood of cardiovascular disease.

“In this large, observational study, ground, instant, and decaffeinated coffee were associated with equivalent reductions in the incidence of cardiovascular disease and death from cardiovascular disease or any cause,” said study author Professor Peter Kistler. He is an international leader in cardiac arrhythmia research from the Baker Heart and Diabetes Research Institute, Melbourne, Australia. “The results suggest that mild to moderate intake of ground, instant, and decaffeinated coffee should be considered part of a healthy lifestyle.”

Included in the study were 449,563 participants free of arrhythmias or other cardiovascular diseases at baseline. The median age of participants was 58 years and 55.3% were women. A questionnaire was completed by participants, which asked how many cups of coffee they drank each day and whether they usually drank instant, ground (such as cappuccino or filtered coffee), or decaffeinated coffee. Additionally, they were grouped into six daily intake categories, consisting of none, less than one, one, two to three, four to five, and more than five cups per day. The usual coffee type was instant in 198,062 (44.1%) participants, ground in 82,575 (18.4%), and decaffeinated in 68,416 (15.2%). Non-coffee drinkers, who served as the comparator group, made up 100,510 (22.4%) of the participants.

Professor Kistler said: “Caffeine is the most well-known constituent in coffee, but the beverage contains more than 100 biologically active components. It is likely that the non-caffeinated compounds were responsible for the positive relationships observed between coffee drinking, cardiovascular disease, and survival. Our findings indicate that drinking modest amounts of coffee of all types should not be discouraged but can be enjoyed as a heart-healthy behavior.”

Full article at Sci Tech Daily.

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L&FP, 60: Illustrating an all too common atheistical attitude

The below is taken from a typical Internet Atheist trollish rhetorical stunt, illustrating all too familiar patterns of fallacious reasoning that are here seen in an attempt to bully and stereotype Christians as ignorant, stupid, insane or wicked. For first level responses see here [Jesus], here [worldviews], here [evil Christians].

This sort of polarising snide stunt is what we need to recognise as a real problem (and no, turnabout projection is not an acceptable response), acknowledging that it is unacceptable bigotry and intellectual irresponsibility, and then set such aside, there are fate of civilisation issues on the table:

Now, let us ponder:

Where we do not need to go. END

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