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Scientists pour a lot of brainpower into understanding how their experimental equipment works.
You don’t want to be fooled into thinking you’ve made a great discovery because of some quirk in the apparatus you didn’t know about. Just the other day, a new paper published online suggested that the instruments used to detect gravitational waves exhibited such a quirk, tricking scientists into claiming the detection of waves that maybe weren’t really there.
It appears that gravity wave fans can relax, though. A response to the challenge pretty much establishes that the new criticism doesn’t undermine the wave discoveries. Of course, you never know — supposedly well-established results sometimes do fade away. Often that’s because scientists have neglected to understand the most important part of the entire experimental apparatus — their own brains.
It’s the brain, after all, that devises experiments and interprets their results. How the brain perceives, how it makes decisions and judgments, and how those judgments can go awry are at least as important to science as knowing the intricacies of nonbiotic experimental machinery. And as any brain scientist will tell you, there’s still a long way to go before understanding the brain will get crossed off science’s to-do list. But there has been progress. A recent special issue of the journal Neuron offers a convenient set of “perspective” papers exploring the current state of understanding of the brain’s inner workings. Those papers show that a lot is known. But at the same time they emphasize that there’s a lot we don’t know.
Glancing at the table of contents reveals the first lesson about understanding the brain: It’s a complex problem that needs to be approached from multiple perspectives.
On one level, there’s the dynamics of electrical currents that constitute the main signaling method of the brain’s nerve cells. Then on a higher level there’s the need to figure out the rules by which nerve cells make connections (synapses) and create the neural circuitry for processing sensory input, learning and behaving. Another challenge is understanding how nerve cell networks represent memories and how you recall what you’ve learned. And it’s essential to understand how neurobiological processing conducted by molecules and cells and electrical signaling gets translated into behaviors, from simple bodily movements to complex social interactions.
Nerve cells in the brain, or neurons, are known to communicate among themselves by transmitting electrical signals, aided by chemical signaling at the synapses connecting the neurons. But there are gaps in understanding how that process takes the brain from perceptions to thoughts to actions. Each of Neuron’s perspective papers both describes what’s already known about how the brain works and offers speculations where scientists lack full knowledge about how the brain does it jobs.
Much of the effort to explain the brain involves mapping the electrical signaling throughout the entire network of nerve cell connections. Per Roland of the University of Copenhagen, for instance, discusses how those signals vary in space and time. He emphasizes the important balance between signaling that incites neurons to send signals and the messaging that inhibits signaling, keeping some neurons quiet.
Sophie Denève and colleagues of the Ecole Normale Supérieure in Paris also emphasize the balance between excitation and inhibition in neural circuitry. That balance is important, they say, for understanding how the whole brain can learn to do things based on changes in the connections between individual neurons. Somehow the rules governing synaptic connections between cells enable such “local” activity to modify the “global” neural circuitry that carries out the brain’s many functions. Excitation-inhibition balance, plus feedback from the global network influencing synapse strength, “can ensure that global functions can be learned with local learnin
Explanation:
Brain is responsible for the control and coordination of our body