New research shows brain’s predictive nature when listening to others
Our brain activity is more similar to that of speakers we are listening to when we can predict what they are going to say, a team of neuroscientists has found. The study, which appears in the Journal of Neuroscience, provides fresh evidence on the brain’s role in communication. Dr Suzanne Dikker (New York University and Utrecht University) is the study’s lead author.
“Our findings show that the brains of both speakers and listeners take language predictability into account, resulting in more similar brain activity patterns between the two,” says Suzanne Dikker (New York University, Department of Psychology / Utrecht University, Utrecht Institute of Linguistics OTS). “Crucially, this happens even before a sentence is spoken and heard.”
Brain as prediction machine
In recent years, many neuroscientists have come to see the brain as a ‘prediction machine’: we are constantly anticipating events in the world around us so that we can respond to them quickly and accurately. Rather than processing sounds, putting them into words and then words into sentences, we can predict words and sounds based on context—and our brain takes advantage of this. For instance, when we hear “Grass is…” we can easily predict “green.” What’s less understood is how this predictability might affect the speaker’s brain, or even the interaction between speakers and listeners.
Experiment: describing images
In the Journal of Neuroscience study, the researchers collected brain responses from a speaker while she described images that she had viewed. These images varied in terms of likely predictability for a specific description. Then, another group of subjects listened to those descriptions while viewing the same images. During this period, the researchers monitored the subjects’ brain activity. When listeners can predict what a speaker is going to say, the authors suggest, their brains take advantage of this by sending a signal to their auditory cortex that it can expect sound patterns corresponding to predicted words (e.g., “green” while hearing “grass is...”). Interestingly, they add, the speaker's brain is showing a similar effect as she is planning what she will say: brain activity in her auditory language areas is affected by how predictable her utterance will be for her listeners.
Impact of predictive power of the brain on communication
“In addition to facilitating rapid and accurate processing of the world around us, the predictive power of our brains might play an important role in human communication,” notes Dikker. “During conversation, we adapt our speech rate and word choices to each other—for example, when explaining science to a child as opposed to a fellow scientist—and these processes are governed by our brains, which correspondingly align to each other.” Dikker conducted this study as part of her research funded by a Netherlands Organisation for Scientific Research Innovation Scheme Veni Grant.