The brain “talks over” a monotonous speaker to make their quotes more vivid, researchers from the University of Glasgow have reported in the journal NeuroImage.
The scientists studied 18 participants and scanned their brains using functional magnetic resonance imaging (fMRI) while they listened to audio clips of short stories containing direct or indirect speech quotations.
The direct speech quotations were either spoken “vividly” or “monotonously” and the results showed that listening to monotonous quotations increased brain activity.
Dr Bo Yao, the principal investigator, said: “You may think the brain need not produce its own speech while listening to one that is already available. But, apparently, the brain is very picky on the speech it hears.
“When the brain hears monotonously-spoken direct speech quotations which it expects to be more vivid, the brain simply ‘talks over’ the speech it hears with more vivid speech utterances of its own.
“By doing so, the brain attempts to optimise the processing of the incoming speech, ensuring more speedy and accurate responses.”