Question Your World: How Does the Brain Make Decisions? | Community Idea Stations


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Question Your World: How Does the Brain Make Decisions?

Decisions, decisions, decisions! Our lives are basically a series of decisions, on after the other. The big and small decisions we make shape and guide everything in our lives. So, the big question right now is, how does the brain make decisions? Learn more in this Question Your World radio report produced by the Science Museum of Virginia.

What's for lunch? A Greek salad or a hot dog? Where should you buy your house? In the downtown area overlooking the river or away from it all? What should you wear to the weekend party? A suit and hat or your best seasonal accessory? All of these things ultimately make your life what it is. Decisions play an important role in basically everything that's happened to human beings for the last 200,000 years. Recently scientists made a pretty big decision, to try to understand how the brain makes decisions.  

Deep in the central part of the brain there's a little neural component called the lateral habenula. This part of the brain was in the spotlight as scientists examined its role in the process of assessing cost and benefit, or making decisions. The study was conducted on rats, but that's not a strange distant comparison. The brain is an ever evolving power house here on Earth and a lot of its evolutionary growth can be found in our brains. We have a brain that's a result of millions upon millions of years of evolution. The part of the brain that scientists were questioning is not just in the human brain, but in most mammals. The rats that were the subjects for this research have the lateral habitual just like we do. In these tests some remarkable discoveries were made which would apply to humans just as well.  

A small electrical pulse was sent as a deep brain signal targeted to the lateral habenula. In human studies we've seen how a slight electrical pulse can inactivate the lateral habenula temporarily. What's remarkable is that in this slight period of non-activity the brain seems to be incapable of making a decision. This is not just a behavioral study; this is rooted in some pretty intense neuroscience. The later habenula was also linked with avoidance and depression in previous studies. So, how do depression and decisions go hand in hand? Well, in testing they observed that depressed subjects' ability to make a decision was greatly impacted with an inactive lateral habenula. The same exact process also showed that their depression was lowered as well. Not because they were happier, but because with an inactive lateral habenula subjects just didn't seem to care as much about what decisions lay in front of them. This study is still in very early stages, but these preliminary findings connect the brain's decision making ability to the effects of mental conditions. Further research could yield some amazing information regarding these mental conditions like depression and schizophrenia.  

Biologists and neuroscientists are celebrating this discovery as a major accomplishment in better understanding the incredibly complex and bizarrely wired mystery that we call the brain. The beauty of science is that no answer is left alone. Every answer to each question propagates more questions. Now that there is an established link between the decision making part of the brain and mental conditions we can ask new questions to further expand on our recently acquired knowledge. These questions will produce answers which will in turn create more questions. So, the understanding of the lateral habenula could lead to a pretty wide variety of scientific breakthroughs in the future ranging from treating mental conditions a lot more efficiently to perhaps enhancing the rate at which we make decisions. Imagine a world of quick thinking humans, would make for a few less accidents hopefully. 

As we move forward in time we continue to make more and more of these decisions to continue to take humanity further along on our journey. The decisions these scientists made will likely have a profound impact down the road and hopefully make a positive impact on how we write our human history. Keep that in mind though, literally every single thing that has involved human interaction with the natural world is rooted in a series of decisions. Everything from living together, the advent of fire, clothing, agriculture, technology, societal changes, wars, peace marches, TV shows, Beethoven's 5th, and so much more are all a result of decisions, remarkably possible due to something that's a little bit larger than a jelly bean. Consider that the next time you have to make a decision. 

Article by Prabir MehtaScience Museum of Virginia