More to Thank God for in Your Brain

first_img(Visited 56 times, 1 visits today)FacebookTwitterPinterestSave分享0 News about the most complex arrangement of matter in the known universe.Hit that curveball: The apparent sudden drop in a well-executed curveball pitch is a matter of output from an algorithm in your brain. If you understand how your body’s GPS works, Science Daily explains, you can avoid being fooled. Did you know you have a GPS system? Yes. Even though it can be tricked by a curveball, its algorithm is quite robust. “This study shows that the solutions that the brain finds for dealing with imperfect information often match optimal solutions that engineers have come up with for similar problems, like your phone’s GPS,” the article concludes.Smell that GPS: Speaking of GPS, the analogy came up in another Science Daily article. The long title sums it up: “Humans’ built-in GPS is our 3-D sense of smell: Like homing pigeons, humans have a nose for navigation because our brains are wired to convert smells into spatial information.” A dramatic animation of the sense of smell, along with other amazing stories of animal navigation, are featured in Illustra Media’s new film, Living Waters: Intelligent Design in the Oceans of the Earth.Social GPS: A “social map” of sorts has been found in the hippocampus, Science Daily says. Researchers at Mt. Sinai School of Medicine found activity in that brain region that “tracks relationships, intimacy and hierarchy within a kind of ‘social map’,” the article says. This capability to map people to  places is apparently shared with other mammals, Science Magazine says, although no research work on this subject has yet been done by fat, big-mouthed river horses on the Hippo Campus.Value computation: PLoS Biology has a technical paper about “neuroeconomics”— the way perceptions of value are represented in the brain. It’s an “embarrassment of riches,” the title suggests. The two authors discuss another recent paper that evaluates the role of two brain areas in this function that underlies how we make rational choices.  That work “provides valuable insight into the complexity of value computation, and helps set the agenda for future work in this area.”Facial recognition: “How does the brain recognize faces from minimal information?” Science Daily asks. Your fast computing system is part of the answer. “Our brain recognizes objects within milliseconds, even if it only receives rudimentary visual information,” the article begins. “Researchers believe that reliable and fast recognition works because the brain is constantly making predictions about objects in the field of view and is comparing these with incoming information.” The article describes how “predictive coding” works.Sorting illusions from reality: The brain can be fooled, as shown by optical illusions. To make sense of the world, the brain has to solve problems “by inferring what is the most likely cause of any given image on your retina, based on knowledge or experience,” Science Daily says. This ability is shared by other mammals, as experiments on nonhuman primates show. Chimpanzees, however, have never been observed to perform experiments on humans to uncover the workings of their neural circuits for the sheer pleasure of understanding how something works.Complexity of thought:  A controversial new theory of thought by Swedish neuroscientists was announced on Science Daily. They question the “prevailing doctrine” that thinking is simple. Known as “sparse coding,” the orthodoxy has been that “the brain has a system to maintain brain activity at the lowest possible level while retaining function.” The number of neurons involved in thinking, and the complexity of their interconnections when we take in information from sensations, is much more widespread than currently believed.Memory locus: Neuroscientists continue to try to understand where memories are stored. Research reported on Science Daily is focusing on neurons in the medial temporal lobe as the location where changes take place in response to learning.  But since no one can “see” a memory by looking at neurons firing, “the underpinnings of episodic memory formation is a central problem in neuroscience” that is bound to remain challenging.Calcium memory: We encountered calcium in yesterday’s entry about the “fight or flight” response. Another article, this one in PLoS Biology, introduces calcium as a key component in memory.Every fact or task that we remember—the shape of the utensil we call a fork, the appropriate hand-motion needed to beat egg whites until fluffy, or the sequential steps involved in baking a cake—must be encoded by long-lasting changes in the way that our neurons function and in the strength with which they connect and communicate to each other. Current experimental evidence has led neuroscientists to propose that learning elicits a particular pattern of electrical activity in neurons, which can in turn induce changes in their morphology, their responsiveness to incoming signals, the expression of their genes, and the strength of their connection to other neurons.These changes are the cellular counterpart of what we think of as memory. However, neuroscientists have not found many mechanisms by which a neuron can store information relative to its previous activity. In a study just published in PLOS Biology, Friedrich Johenning, Anne-Kathrin Theis, Dietmar Schmitz, Sten Rüdiger, and colleagues provide evidence that specific electrical activity within neurons induces a long-lasting change in the amplitude of transitory increases of calcium ion concentration (Ca2+ transients) inside dendritic spines—the specialized protrusions of the dendrites of a neuron, which receive input from other neurons via synapses.The Ca2+ ion is a fundamental player in the transformation of electrical to biochemical activity within neurons.Synthesizing the senses: How does the brain combine information from different senses? That’s what PhysOrg wants to know. We take in visual information from two eyes, and auditory information from two ears. That information needs to be combined into a meaningful whole. For vision, that presents a problem called binocular rivalry. “Musicians are ideal subjects for studying the congruence between abstract visual representations because they are familiar with symbolic musical notation, and can therefore experience melodic structure through both sound and vision,” Korean researchers say, so they used musicians in experiments on perception with audiovisual information. “Taken together, these results demonstrate robust audiovisual interaction based on high-level, symbolic representations and its predictive influence on perceptual dynamics during binocular rivalry,” they found.Update 7/07/15: Researchers at Northwestern University have found “the organization of the human brain to be nearly ideal” for information processing. Dmitri Krioukov explains the optimal organization, considering the tradeoffs involved:“An optimal net­work in the brain would have the smallest number of con­nec­tions pos­sible, to min­i­mize cost, and at the same time it would have max­imum navigability—that is, the most direct path­ways for routing sig­nals from any pos­sible source to any pos­sible des­ti­na­tion,” says Kri­oukov. It’s a bal­ance, he explains, raising and low­ering his hands to indi­cate a scale. The study presents a new strategy to find the con­nec­tions that achieve that bal­ance or, as he puts it, “the sweet spot.”The press release repeatedly gives evolution the credit: “Have you ever won­dered why the human brain evolved the way it did?” the article begins. It also gives a historically debunked orthogenetic view of evolution: “The find­ings rep­re­sent more than a con­fir­ma­tion of our evo­lu­tionary progress.” Krioukov ascribes the match between actual brain and theoretical ideal as an evolutionary product: “That means the brain was evo­lu­tion­arily designed to be very, very close to what our algo­rithm shows.” No clarification is provided on how blind, unguided processes correlate to the oxymoron “evolutionarily designed.”Most of these articles had any use for Darwinian thinking (how’s that for an oxymoron: “Darwinian thinking”). Only the last (Update) article spoke nonsense about “evolutionary design”—one of the worst oxymorons possible (see sophoxymoroniac).Science has barely scratched the surface toward understanding the workings of the brain. Think about memory: how many terabytes, exabytes or yottabytes of information are packed inside your skull?I used to be in a marching band and took a liking to band music. Recently, I was listening to Pandora and heard a Sousa march I had not heard for probably thirty years or more. As I listened, I was amazed at how quickly it all flooded back to my mind; I was able to predict most of the next lines even before they played. In fact, had I turned off the radio, I could probably have played back most of the rest of it in my head. It would play in high fidelity, too, not like an old scratchy vinyl record. Somehow, all that information was still encoded in my brain after decades, and could be recalled instantly. Multiply that ability by all the songs you know, all the quotes you can remember, and all the audiovisual experiences you could relive from childhood as if they happened yesterday. Is it not astonishing what our brains can do?We know something about encoding information like this. Samples are taken of a complex, moving waveform, passed through an analog-to-digital converter, and represented alphanumerically on a storage medium. If the medium is not damaged, the information can be converted back into sound for playback. Our brains, though, are not hard surfaces like CD’s or computer memory. They are made up of dynamic, soft tissues—living cells—with electrical and chemical signals whizzing constantly in every direction. How can that kind of living tissue store complex experiences for instant recall decades later?And that’s just memory. Think of the predictive coding, sensory integration, abstract thinking and motor control we take for granted every day.  You may have noticed that your brain has a search engine. Can’t recall a name? You struggle for a moment to recall it, but then get distracted onto some other matter. Moments later, while you’re not even thinking about it, the name pops into your consciousness. How does that happen? How does a piano player control her fingers so fast they become a blur on the keyboard? or better yet, an organist with 10 fingers on 3 ranks of keys, and two feet on the pedals? How did Leonhard Euler perform complex mathematical derivations in his head while blind?It’s a shame we complain about the littlest trifles in life. We have been given outstanding audiovisual and computer processing equipment freely by our Creator. The design in nature, in our bodies and in our own heads is so abundantly clear, the only proper response should be gratitude, wonder, and worship.—DClast_img

Recommended Reading


Your email address will not be published. Required fields are marked *