How Your Brain Groups Words

When you say or hear a concrete noun, such as “apple”, what happens in your mind? Even without seeing a physical apple in front of you, your brain is drawing up an image of an apple, maybe the last one you ate or saw in the stores or on TV. A team of researchers at Carnegie Mellon used an fMRI (functional magnetic resonance image) machine to find out. Rather than using complex transparent concepts, like “honesty”, the team used simple words that convey physical, everyday objects to see which parts of the brain was activated. The goal was to see how the brain functions when we think of an object, rather than just trying to see an object in our mind. The brain was activated in many different parts for the simplest words, showing a complex, networked effect for even the easiest thoughts.

The fMRI showed that connections between specialized cells in different parts of the brain are used together to exchange information and coordinate simple tasks. However, four activation patterns emerged when 60 commonplace nouns were to be thought of in the mind. The patterns are grouped by how the noun could be sorted: things that are manipulated; things that are eaten; things that represent shelter, or an entryway into shelter; and finally, words that are long. Interestingly, when ‘eating’ nouns were thought of, the brain area associated with eating was activated, which works on coordination and movement of the lower facial muscles. Why these four seemingly simple groupings? It has to do with evolution and the hierarchy of needs.

Maslov’s Hierarchy of Needs pyramid puts human needs in groups based on survival and physiological needs at the bottom with social needs at the top. Humans evolved to survive with the lower needs being met before moving onto higher level needs. The brain works the same way. Things that are manipulated represent concrete physical things, those than exist in reality rather than abstract thought. These words relate to those that are held and used with the hands. Eating and shelter words have to do with physiological and safety needs. So why separate long words into a distinct pattern?

Long words were not useful or needed for much of human history. Human communication grew from meeting the lowest needs on the Maslov pyramid. Eating, shelter, and safety through tools and other object manipulation was needed first and foremost. Culture and civilizations, which came about much later in human history, met the needs of the lowest levels and humans were free to form societies, participate in leisure activities, and think of abstract concepts. Here, longer words emerged that could convey complex, associated and connected things. The long words used in the study represent technological objects that are often compound words from existing simpler words, or modern words (“telephone”, “refrigerators”, “airplane”). These words and word lengths weren’t needed for survival and are grouped different in the brain.

Reference

Just, M., Cherkassky, V., Aryal, S., & Mitchell, T. (2010). A Neurosemantic Theory of Concrete Noun Representation Based on the Underlying Brain Codes PLoS ONE, 5 (1) DOI: 10.1371/journal.pone.0008622