Research published March 3 in Nature Communications challenges long-held assumptions about how our brains extract meaning from speech. A study led by Northwestern University and the University of Pittsburgh found that Heschl’s gyrus, a brain region previously thought to handle basic sound processing, plays a sophisticated role in interpreting the melody of speech.
The discovery highlights the specialized nature of human communication, where subtle variations in pitch convey specific meanings. The researchers used electrodes implanted in 11 adolescent patients’ brains to record neural activity while they listened to an audiobook. This unique setup allowed scientists to collect high-quality recordings of brain activity that would not have been possible otherwise.
Heschl’s gyrus was found to create abstract representations of pitch patterns, transforming subtle acoustic variations into meaningful linguistic categories. The region handles prosody as a discrete, phonological entity separate from the processing of actual words being spoken. This challenges previous theories that suggested this level of speech processing happened primarily in the superior temporal gyrus.
The study’s findings also suggest that humans may have a unique ability to categorize and interpret pitch patterns. When tested with non-human primates, their brains didn’t create the same abstract representations as human brains did. This highlights the specialized nature of human language experience.
Understanding how the brain processes prosody could have wide-ranging implications, including improved speech rehabilitation, AI-powered voice assistants, and a better understanding of what makes human communication unique. The research provides scientific evidence for the adage that it’s not just what you say, but how you say it – and that our brains have specialized neural circuits to extract meaning from vocal melodies.
Source: https://scienceblog.com/your-brain-decodes-hidden-messages-in-speech-melody