The brain is, perhaps, the most intriguing and least understood part of the human anatomy.  There are many aspects of brain function that scientists still do not completely understand, such as how does the brain select what to focus on when a person is learning new things?  Researchers at Stanford University may have recently discovered an answer.  

How Learning Occurs

Every species must learn which sights, sounds and sensations are important to survival.  Over time, an animal (and humans) must learn how the importance of those details may change.  Exactly how humans and animals track these details has long been a mystery.

But, Stanford biologists, Professor Xiaoke Chen, and researcher Greg Nachtrab may have just cracked the code, in a recent study they conducted.  The scientists discovered that a part of the brain called the paraventricular thalamus (PVT) may serve as a gatekeeper of sorts, ensuring that the brain tracks and identifies significant, details of a situation.

The study was published in an October issue of Science.  The results were very surprising to the scientists, because they did not previously suspect that the thalamus could perform such a complex job.  “We showed thalamic cells play a very important role in keeping track of the behavioral significance of stimuli, which nobody had done before,” said Chen.

How Does the Brain Decide What to Learn?

In essence, learning is linked with feedback.  For example, if you experienced pain resulting from stubbing your toe because you didn’t wear shoes, subsequently, you deliberately wore shoes–which was effective in preventing pain; you will wear shoes in the future to prevent stubbing your toe.  If it doesn’t work, because, for example, you wore toeless sandals, you might use a different approach the next time.  Scientists have extensively studied this method of learning. They’ve traced it to some specific areas of the brain that perform feedback and drive in the learning process.  

The discovery of how animals and humans figure out what is important to learn, and what is not, has not been given very much attention in the world of research… until recently. 

The Study

Chen and his team performed mice studies, teaching mice to associate specific odors with good or bad outcomes.  For example, one odor signaled to the mice that they would receive a food or water, another meant that a puff of air to the face—unpleasant experience—would occur.
Later, the experiment involved electric shocks, taking the place of the puff of air—for the bad experience.  When this occurred, the researchers discovered that an additional 30% of the nerve cells in the PVT tracked signaling of the electric shock, compared to the nerves that tracked the puff of air.

Study Conclusion

The data indicated a place for researchers to look in the future—the PVT—when studying how focus and attention impacts how we learn. The results point to several broader conclusions, Chen said. In addition, neuroscientists have found an innovative way to control learning in a lab setting, which may eventually lead to being able to influence patterns in drug addiction.  Chen commented that the research data may be able to help people, such as those with addictions unlearn their association between taking a substance and feeling high.


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