Yes, You Can? A Speaker’s Potency to Act upon His Words Orchestrates Early Neural Responses to Message-Level Meaning

Evidence is accruing that, in comprehending language, the human brain rapidly integrates a wealth of information sources–including the reader or hearer’s knowledge about the world and even his/her current mood. However, little is known to date about how language processing in the brain is affected by the hearer’s knowledge about the speaker. Here, we investigated the impact of social attributions to the speaker by measuring event-related brain potentials while participants watched videos of three speakers uttering true or false statements pertaining to politics or general knowledge: a top political decision maker (the German Federal Minister of Finance at the time of the experiment), a well-known media personality and an unidentifiable control speaker. False versus true statements engendered an N400 - late positivity response, with the N400 (150–450 ms) constituting the earliest observable response to message-level meaning. Crucially, however, the N400 was modulated by the combination of speaker and message: for false versus true political statements, an N400 effect was only observable for the politician, but not for either of the other two speakers; for false versus true general knowledge statements, an N400 was engendered by all three speakers. We interpret this result as demonstrating that the neurophysiological response to message-level meaning is immediately influenced by the social status of the speaker and whether he/she has the power to bring about the state of affairs described.

Early brain responses to words predict developmental outcomes in children with autism

The pattern of brain responses to words in 2-year-old children with autism spectrum disorder predicted the youngsters’ linguistic, cognitive and adaptive skills at ages 4 and 6, according to a new study.

The findings, published May 29 in PLOS ONE, are among the first to demonstrate that a brain marker can predict future abilities in children with autism.

“We’ve shown that the brain’s indicator of word learning in 2-year-olds already diagnosed with autism predicts their eventual skills on a broad set of cognitive and linguistic abilities and adaptive behaviors,” said lead author Patricia Kuhl, co-director of the University of Washington’s Institute for Learning & Brain Sciences.

“This is true four years after the initial test, and regardless of the type of autism treatment the children received,” she said.

In the study, 2-year-olds – 24 with autism and 20 without – listened to a mix of familiar and unfamiliar words while wearing an elastic cap that held sensors in place. The sensors measured brain responses to hearing words, known as event-related potentials.

The research team then divided the children with autism into two groups based on the severity of their social impairments and took a closer look at the brain responses. Youngsters with less severe symptoms had brain responses that were similar to the typically developing children, in that both groups exhibited a strong response to known words in a language area located in the temporal parietal region on the left side of the brain.

This suggests that the brains of children with less severe symptoms can process words in ways that are similar to children without the disorder.

In contrast, children with more severe social impairments showed brain responses more broadly over the right hemisphere, which is not seen in typically developing children of any age.

“We think this measure signals that the 2-year-old’s brain has reorganized itself to process words. This reorganization depends on the child’s ability to learn from social experiences,” Kuhl said. She cautioned that identifying a neural marker that predicts future autism diagnoses with assurance is still a ways off.

The researchers also tested the children’s language skills, cognitive abilities, and social and emotional development, beginning at age 2, then again at ages 4 and 6.

The children with autism received intensive treatment and, as a group, they improved on the behavioral tests over time. But the outcome for individual children varied widely and the more their brain responses to words at age 2 were like those of typically developing children, the more improvement in skills they showed by age 6.

In other studies, Kuhl has found that social interactions accelerate language learning in babies. Infants use social cues, such as tracking adults’ eye movements to learn the names of things, and must be interested in people to learn in this way. Paying attention to people is a way for babies to sort through all that is happening around them and serves as a gate to know what is important.

But with autism, social impairments impede children’s interest in, and ability to pick up on, social cues. They find themselves paying attention to many other things, especially objects as opposed to people.

“Social learning is what most humans are about,” Kuhl said. “If your brain can learn from other people in a social context you have the capability to learn just about anything.”

She hopes that the new findings will lead to brain measures that can be used much earlier in development – at 12 months or younger – to help identify children at risk for autism.

“This line of work may lead to new interventions applied early in development, when the brain shows its highest level of neural plasticity,” Kuhl said.