Built-in Brain Designs that Amaze Scientists
Here’s a quick run-down of brain news that should make us stand in awe of the 3-pound mass inside our skulls.
The amazing adaptability of brain’s vision center (Science Daily): Children born blind can use their visual center to recognize sound, especially language. This runs contrary to evolutionary expectations.
“The traditional view is that cortical function is rigidly constrained by evolution. We found in childhood, the human cortex is remarkably flexible,” said Johns Hopkins cognitive neuroscientist Marina Bedny, who conducted the research while at Massachusetts Institute of Technology. “And experience has a much bigger role in shaping the brain than we thought.“
Our elegant brain: Motor learning in the fast lane (Medical Xpress): A photo of a tennis player introduces findings from McGill University. Researchers there “have discovered that to learn new motor skills, neurons within the cerebellum engage in elegant, virtually mathematical, computations to quickly compare expected and actual sensory feedback. They then quickly readjust, changing the strength of connections between other neurons to form new patterns in the brain in order to accomplish the task at hand.”
Human hippocampus represents space and time during retrieval of real-world memories (PNAS): Studies with rats about space-time recognition are confirmed for humans at even greater scales:
The rodent hippocampus contains neurons that code for space on the scale of meters, a discovery that was recently awarded a Nobel Prize. However, it remains unclear whether humans harness similar representations for memory at the scale of their lives. Our results reveal that the human hippocampus represents the spatial and temporal location of memories for real-life events at scales of up to 30 km and a month of time.
Another paper in PNAS about the hippocampus finds that “a substantial proportion of human hippocampal neurons encode specific memories that support the discrimination of overlapping representations.”
Newly discovered brain network recognizes what’s new, what’s familiar (Medical Xpress): The brain, when not suffering from dementia, has a remarkable ability to compare things: “new research from Washington University in St. Louis has identified a novel learning and memory brain network that processes incoming information based on whether it’s something we’ve experienced previously or is deemed to be altogether new and unknown, helping us recognize, for instance, whether the face before us is that of a familiar friend or a complete stranger.”
Receptor that helps protect brain cells has important role in support cells for the retina (Science Daily): Remember Müller cells, the waveguides that transfer photons directly to the photoreceptors (see 2/27/15)? They rely on a receptor also known to protect brain neurons from oxidative stress. “While the ubiquitous receptor was known to help protect neurons in the brain and eye, its impact on Müller cell function was previously unknown.” The receptor, named Sigma 1, releases antioxidant genes.
Category Learning: Top-Down Effects Are Not Unique to Humans (Current Biology): “Human infants use top-down information to learn the sound category of their language,” Emmanuel Dupoux writes. “A new study using an artificial language containing species-specific vocalizations shows that songbirds may rely on a similar mechanism.” But wait; songbirds are not related to humans. Could this be an example of top-down design in both cases? Dupoux says nothing about evolution. Those interested in starling murmurations should note that the songbirds mentioned in the article are none other than the well-known formation flyers: “European starlings use complex vocalizations consisting of sequences of motifs,” he says.
Fly brains filter out visual information caused by their own movements, like humans (Medical Xpress): “That’s thanks to a complex process in our brain that tell us when and how to pay attention to sensory input. Specifically, we ignore visual input caused by our own eye movements.” Research at Rockefeller University shows that flies have this ability as well. But wait; flies are not related to humans. Could this be an example of top-down design in both cases? The article says nothing about evolution. Researcher Gaby Maimon apparently doesn’t feel that evolutionary theory is necessary for understanding this ability: “Since fly brains contain 100,000 times fewer neurons than human brains, we should be able to develop a much deeper understanding of this process, and build a blueprint for how to think about sensory silencing across all animals, and, ultimately, even humans.”
Rapid eye movements in sleep reset dream ‘snapshots’ (Science Daily): Your brain is processing images while you sleep. “When we move our eyes in REM sleep, according to the study, specific brain regions show sudden surges of activity that resemble the pattern that occurs when we are introduced to a new image — suggesting that eye movements during REM sleep are responsible for resetting our dream ‘snapshots.’”
Embodied cognition: A grasp on human thinking (two book reviews by Elsbeth Stern in Nature): Lead question: “How has Homo sapiens uncovered the laws of nature, invented technology and established culture and institutions?” She decides that the authors of two new books on the human mind fight straw men when they try to reduce the brain to evolutionary pressures.
Computational abstraction towards a theory of the brain (book review by John Tsotsos in Current Biology): While favorable to a new book on the evolution of the brain, Tsotsos admits reservations:
Who in their right mind would take on the task of trying to convey the state of current thought regarding how the human brain functions, as well as put forward a proposal for how to tie it all together, to both a non-specialist and specialist audience, in a single volume? I cannot think of more than a few people on the planet who might have any chance at all of pulling it off without the hyperbole and sensationalism one often sees. Dana Ballard is one of those, and he does indeed pull it off. With any such attempt there are bound to be many points of contention — after all, as the author repeats throughout his book, there is still so much we do not understand about the brain, its structure, function, and behavior.
Surprise: there is no mention of evolution in the book review. Much of the article is about understanding mechanisms, not inquiring how they emerged from animal brains. At points, the reviewer seems to acknowledge human exceptionalism when it comes to awareness, goals and conscious purposeful action. He even uses metaphors suggesting intelligent design:
Ballard roots his development in the language of computation, the only tool available with which we can express the full breadth of necessary concepts, from mathematics to logic, representations, input and output, algorithms, control, systems, memory, interaction, and more…. He uses this full breadth of computational methodologies far more effectively than seen previously and thus makes a more powerful statement for their utility than David Marr or others.
It would be hard to make an evolutionary tale stick, anyway: “It is not an exaggeration to say that one can find peer-reviewed results to support almost any theory or interpretation of results.”
How Neuroscience Is Helping Answer the Question ‘Who Am I?’ (National Geographic): Simon Worrall interviews Anil Ananthaswamy, author of a book on the “Science of the self.” His evolutionary explanation is brief and simple. Worrall asks, “You say that self-awareness gave humans an evolutionary advantage. How?”
When we developed memory and an awareness of ourselves as entities spanning time, it would have made it easier to plan—knowing how things would unfold in the future, or how things had happened in the past. All of these would have been survival advantages.
This, however, is not an evolutionary explanation. Ananthasway makes no mention of what mutation could have led to awareness; he never answers the question, “How?” If anything, he makes this sound like intelligent design, as if humans “developed” memory and awareness for the purpose of planning and surviving. That, of course, is totally contrary to Darwin’s theory.
We see again in the field of neuroscience that Darwinian theory is useless. It’s not only useless, but wrong. There’s no way that capabilities seen in the human brain can have counterparts in birds or flies by blind, unguided processes of material nature. The evidence points to know-how in the design of creatures that allows them to function in their environments. The evidence also suggests that humans are exceptional among creatures. No other animal is writing scientific papers or book reviews about abstract concepts like philosophy. No other creature has “uncovered the laws of nature, invented technology and established culture and institutions.” Your brain is a fantastic resource, given to you by your Maker. Use it wisely.