Mind Your Brain
Recent discoveries about the brain and the mind reveal the wonders inside our skulls and pose deep philosophical questions.
Switchboard operator: How does your brain keep track of the constant stream of input coming in from the senses without getting lost in the stimuli? Science Daily says you have a switchboard operator called the pulvinar. It “regulates communication between clusters of brain cells as our brain focuses on the people and objects that need our attention.” For instance, when crossing a street, you need to be able to focus on the oncoming bus without worrying about all the other sights and sounds. An orchestra musician needs to focus on his or her part amidst all the rest of the players. A mother wants to hear her daughter’s voice coming off the train amidst all the other voices. “The transmission of behaviorally relevant information between various parts of the brain is tightly synchronized,” the article said. “When we pay attention to important visual information, the pulvinar makes sure that information passing between clusters of neurons is consistent and relevant to our behavior.” This makes it sound like attention is a choice, and the pulvinar is a servant of our choices.
Cleaning crew: A whole plumbing system in the brain has been overlooked till now. Like other organs, brains generate garbage that needs to be taken out, but the blood-brain barrier isolates the brain from the rest of the circulatory system, thus protecting it from viruses and microbes. The mystery has been solved, according to National Geographic News. A pump and plumbing system that circulates cerebrospinal fluid was undiscovered before now because opening the skull makes it stop. For this reason, neuroscientists thought cerebrospinal fluid moved by passive diffusion throughout the brain. Now, researchers at University of Rochester Medical Center have found a system that is “on the order of a thousand times faster than diffusion” – a “glymphatic system” as named by Maiken Nedergard. The article describes how it works:
Glial cells do this by growing their “feet” around vessels and veins that carry blood, forming a sort of pipe around a pipe. Tiny pores in this outer pipe then suck nutrient-rich cerebrospinal fluid from the blood vessels into channels dense with nerve cells, and pores at other locations pump the fluid out. The process simultaneously carries away the brain’s waste while feeding its cells.
Another neuroscientist not involved in the study said this discovery “made his heart sing.” The finding may have implications for brain abnormalities such as Alzheimer’s disease.
Memory champs: Speaking of Alzheimer’s disease, why do some people maintain superb memories even to old age? A new study is trying to figure that out, reported Live Science. One initial finding is that the cerebral cortex of these seniors looks just like those of young people. Maybe that’s what should be considered normal. Researchers tend to focus on abnormalities, but “perhaps we could learn just as much by looking at what goes right with the brain.”
Brain’s timekeeper: More continues to be learned about the body clock, also known as circadian rhythms. Science Magazine (7 August 2012: Vol. 337 no. 6096 pp. 805-806, DOI: 10.1126/science.1227203) reported how the clock involves proteins, genes and electrical activity in neurons working in a feedback loop. Here’s an excerpt about how the brain clock interacts with the rest of the body:
Circadian rhythms pervade all aspects of our physiology and behavior. For example, at night we sleep and our metabolic activity is low, while during the day, we are awake and active, and our metabolism is high. Genes and proteins that underpin the molecular timekeeper of these rhythms have been modeled as a transcription-translation feedback loop (TTFL). This TTflclock is present in cells, tissues, and organs of eurkaryotes, and some of its molecular components are conserved across animal species. In mammals, the master circadian clock is in the brain’s suprachiasmatic nuclei (SCN) of the hypothalamus. Individual neurons of the SCN contain the TTflclock, and the coordinated activity of these cell-autonomous oscillators conveys timekeeping signals to the rest of the brain and body.
Nutrient supply lines: Before the brain is ready to use, networks of blood vessels need to set up the supply lines. Announcing a new finding, PhysOrg posed the scientific problem:
How the intricate network of blood vessels forms within the brain has long fascinated biologists. Though the human brain comprises only 2 percent of body weight it receives up to 15 percent of the cardiac output through this network, or vessel vasculature. The vasculature in the human brain consists of a complex branching network of blood vessels, in total some several hundred miles in length. The network is formed so as to distribute blood efficiently to all brain regions, and abnormalities can lead to various neurological disorders, including strokes, learning difficulties and neurodegeneration. Yet our knowledge of just how the brain vasculature develops remains relatively limited.
Using zebrafish embryos, researchers at the Chinese Academy of Sciences were able to observe neurons and blood vessels undergoing a complex interplay involving growing and pruning, “with some 45 percent of early-formed vessel segments pruned during the course of brain development.” The pruning process is “mainly mediated by the expression of Rac1, a protein known to drive migration of the EC cells concerned,” they said.
Neural diversity: Not all neurons in the brain are the interchangeable. In Nature, 488 16 Aug 2012, pp. 289–290, doi:10.1038/488289a), Nathaniel Urban and Shreejoy Tripathy commented a new study that shows a lot of specialization between neurons. “Neurons of the same type can show functional differences,” the subtitle said. “It turns out that this diversity is in part the result of the cells’ adaptation to their specific neural networks.” It means that neurons cannot be treated like “interchangeable parts” on a Ford assembly line. “However, neuroanatomists have long marvelled at the snowflake-like diversity apparent in the shapes of individual neurons, even within a cell type,” announcing that “recent analyses have demonstrated that same-class neurons show substantial heterogeneity in their intrinsic properties, although the origin of such diversity is poorly understood.” The new study in by Angelo et al. in the same issue of Nature (488, 16 Aug 2012, pp. 375–378, doi:10.1038/nature11291) provides one example: “physiological variability among mitral cells (a type of neuron in the olfactory system) is at least partly caused by differences in the inputs that they receive.” Imagine what this means if each of your 100 billion neurons is as unique as a snowflake.
MRIrony: In an effort to plumb the question of mind-brain coordination, researchers in France used MRI to study subjects faced with statements of irony: “as each key sentence was read, the network activity was greater when the statement was ironic.” They are performing experiments on Theory of Mind (ToM) to examine the physical aspects of known mental activities. “This shows that this network is directly involved in the processes of understanding irony, and, more generally, in the comprehension of language,” they believe. Other possibilities could explain the increased activity, though: by analogy, a TV display might light up more during an action scene, without having any cause-effect relationship with the content of the action. That interpretation might be ironic for the researchers.
Baby morals: Do infants have a moral compass? The debate heats up, reported Live Science. New experiments in New Zealand raise questions about a previous Yale study that suggested babies have an innate sense of right and wrong. The Yale researchers dispute the new study, however, while both sides claim flaws in each others’ experimental methods. One thing seems clear, though; apes don’t care much for morality. “When it comes to food, chimps only think of themselves,” PhysOrg reported.
Science of the soul: Giulio Tononi has written a historical scientific novel, Phi: A Voyage from the Brain to the Soul, that claims the mind is composed in the neurons of the brain. Christoph Koch, reviewing the book in Nature, “marvels at a journey that explains mind–body theory through a fantastical lens,” but is not sure he buys its materialism. Is consciousness a mere epiphenomenon of the physical brain and its interactions? That’s the deep question that “scholars, scientists, doctors and artists from the Enlightenment to the modern era” including “Descartes, Nicolaus Copernicus, Charles Darwin, Sigmund Freud, Marcel Proust and … Alan Turing,” actors in Tononi’s story, wrestled with. Claude Shannon, Leibniz, Spinoza and Thomas Nagel (the only living person featured in the book) interact with protagonist Galileo in the plot. In the end, Tononi puts hell in the mind, along with everything else that tugs at human consciousness. “I believe that in the fullness of time, the quantitative framework outlined in Phi will prove to be correct,” Koch states; “Consciousness is tightly linked to complexity and to information, with profound consequences for understanding our place in the evolving Universe.” Koch and Tononi failed to specify whether their own thoughts and opinions could be reduced to a quantitative framework, or whether “understanding our place in the evolving Universe” has any hope of being true given the premises of materialist neuroscience. A little thought (with one’s mind) would suggest that Galileo, Leibniz, and any number of other non-materialist scientists and philosophers would have different opinions about that.
Big brain by mutation: Science Daily bombastically announced, “Evolutionary Increase in Size of the Human Brain Explained: Part of a Protein Linked to Rapid Change in Cognitive Ability. Researchers have found what they believe is the key to understanding why the human brain is larger and more complex than that of other animals” Wow, this would almost encourage readers to drink more protein shakes. “Researchers have found what they believe is the key to understanding why the human brain is larger and more complex than that of other animals,” the article continued. Could it be that modifications to a protein named DUF1220 made us what we are today, knowing that “The size and cognitive capacity of the human brain sets us apart”? The researchers at University of Colorado think their magic protein “points to a new way to study the human brain and its dramatic increase in size and ability over what, in evolutionary terms, is a short amount of time.” In short, “The take home message was that brain size may be to a large degree a matter of protein domain dosage.” Funny that no other animal ever hit on that formula.
Free will: Early experiments that supposedly showed free will is an illusion (because the brain acts before our consciousness does) have been called into question. New Scientist announced, “Advocates of free will can rest easy, for now. A 30-year-old classic experiment that is often used to argue against free will might have been misinterpreted.” Anil Ananthaswamy wrote that the Libet experiment, that showed electrical potentials 550 milliseconds prior to a subject’s action, has flaws: “Libet argued that our brain has already decided to move well before we have a conscious intention to move.” Aaron Schurger responds, “We argue that what looks like a pre-conscious decision process may not in fact reflect a decision at all. It only looks that way because of the nature of spontaneous brain activity.” Ananthaswamy left the debate open, begging the question whether any of the contestants used their free will to argue their propositions.
The wonders of the brain stand in sharp contrast to the simplistic folly of evolutionists who think a mutation to a protein turned Bonzo into Einstein, or who use their minds to say minds don’t really exist. We’ve already shown how this kind of thinking is self-refuting (see 8/15/2012) so no need to belabor the point here. Use your mind rightly to contemplate the gifts you have from your Designer – and resolve to use them wisely. (Pondering the “evolution of wisdom” would not be a good example.)