Researchers at Massachusetts General Hospital have discovered a microscopic “thesaurus” within the brain, revealing how neurons process and derive meanings from spoken words. This groundbreaking study utilized novel technology to record the activities of single neurons, providing a detailed map of how the human brain represents word meanings and comprehends language. 

By recording neuronal activity as individuals listened to sentences and stories, the scientists found that different neurons are responsible for processing various types of word meanings: for instance, some neurons activated in response to action-related words like “ran” or “jumped”, while others responded to emotional words such as “happy” or “sad”. This neuronal mapping led to the understanding of how the brain distinguishes between different concepts and meanings. 

Additionally, the study revealed that certain neurons could reliably differentiate between words that sound alike but have different meanings based on the context of sentences – this enables people to quickly and accurately comprehend language, understanding words like “sun” and “son” or “see” and “sea” within their respective contexts. The researchers discovered that these neurons continuously anticipate the most likely meanings of words as they are heard. 

Perhaps most excitingly, the scientists demonstrated that by recording the activity of a small number of neurons, they could predict the meanings of words in real time during speech. This ability to decode word meanings from neuronal activity opens possibilities for developing brain-machine interfaces, which could help people with speech-related conditions, such as motor paralysis or stroke, to communicate more effectively. 

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Source: Massachusetts General Hospital