We speak in metaphors all the time. Yes, I mean "we" as in everyone, not just the poets and creative writers out there. In fact, much of what we understand about the world is understood in metaphorical terms. George Lakoff and Mark Johnson explain in their work "Metaphors We Live By" that "...metaphor is pervasive in everyday life, not just in language but in thought and action". If we take the time to think about it, they're right - metaphors certainly are. the foundation to our house of knowledge (see what I did there?).
Until recently, it was assumed that metaphors were interpreted in the part of our brain that deals with language comprehension. The textbook calls this "Wernicke's Area", located in the superior temporal gyrus, usually in the left cerebral hemisphere. However, MD, PhD Krish Sathian of Emory University, has just released the results of several studies that show that metaphors can activate the sensory portions of our brains as well. So, when someone says they've had a "rough day", do you feel sandpaper beneath your fingers? Perhaps not, though the same parts of your brain are working in response to both these stimuli.
I was able to experience this concept firsthand: a friend of mine was recently involved in a longboarding accident, in which his Wernicke's Area was put at high risk. However, he is now able to tell me that, while in the hospital, doctors asked him questions concerning sense-related language (like metaphors), and that he was able to understand the concepts behind these messages. This highlights the role of neural networks in our brains, and can help scientists better understand the importance of these neural networks. So, truthfully, this newfound information may simply be the "tip of the iceberg", the "knock at the door of opportunity", the "window to the truth" behind the complex structure we call the human brain. Exciting, right? I think so too.
Article and information: Quinn Eastwood, "Hearing Metaphors Activates Brain Regions Involved in Sensory Experience" 3 Feb 2012. Medical Xpress; medicalxpress.com
Elleni Paulson; 4256521