I have never read this story, so take my answer with a grain of salt, but by process of elimination and a little bit of logic I can safely rule out options A and B given the general definition of a clearing. I hope this helps, if you can give me more information I might be able to give you a better answer. I wish to help you as much as possible. If this is sufficient, then have a nice day! :)
Answer:
The answer to the question: What is the author´s purpose for including this statement, would be: To show the greatness, and yet the simplicity, of the innovations and discoveries that this researcher, Terry Sejnowski accomplished, regarding learning, on many fields, including language mastering. This neuroscientist, better known as Terrence Joseph Sejnowki, has been known around the world for his work on neural circuits, and other things regarding how the brain works, especially when it comes to learning, and mastering different fields of knowledge. What he showed through his multiple research is that learning is much simpler than it was used to believe, and it required the correct work of a neural circuit. He found that this neural circuit was the only thing necessary to ensure proper learning, and that is what the author in "Talking Robots" wanted to express through this excerpt.
The author could be referring to a cage to describe the feelings of the person's life. using the word cage to identify the emotions from the person. Maybe the person, the author is writing about feels like he or she is stuck in the circumstances of everyday life referring to a cage. He or she could be dealing with tough situations and they could be feeling trapped like in a cage. The author could be describing the patterns of the person's way of making decisions. which hinders them and causes them to make wrong choices That keeps them stuck in a cage emotionally.
