How We Think Before We Speak: Making Sense of Sentences

We engage in numerous discussions throughout the day, about a variety of topics, from work assignments to the Super Bowl to what we are having for dinner that evening. We effortlessly move from conversation to conversation, probably not thinking twice about our brain’s ability to understand everything that is being said to us.  How does the brain turn seemingly random sounds and letters into sentences with clear meaning? In a new report in Current Directions in Psychological Science, a journal of the Association for Psychological Science, psychologist Jos J.A. Van Berkum from the Max Planck Institute in The Netherlands describes recent experiments using brain waves to understand how we are able to make sense of sentences.

In these experiments, Van Berkum and his colleagues examined Event Related Potentials (or ERPs) as people read or heard critical sentences as part of a longer text, or placed in some other type of context. ERPs are changes in brain activity that occur when we hear a certain stimulus, such as a tone or a word. Due to their speed, ERPs are useful for detecting the incredibly fast processes involved in understanding language.

Analysis of the ERPs has consistently indicated just how quickly the brain is able to relate unfolding sentences to earlier ones. For example, Van Berkum and colleagues have shown that listeners only need a fraction of a second to determine that a word is out of place, given what the wider story is about. As soon as listeners hear an unexpected word, their brain generates a specific ERP, the N400 effect (so named because it is a negative deflection peaking around 400 milliseconds). And even more interesting, this ERP will usually occur before the word is even finished being spoken.

In addition to the words themselves, the person speaking them is a crucial component in understanding what is being said. Van Berkum also saw an N400 effect occurring very rapidly when the content of a statement being spoken did not match with the voice of the speaker (e.g. “I have a large tattoo on my back” in an upper-class accent or “I like olives” in a young child’s voice).  These findings suggest that the brain very quickly classifies someone based on what their voice sounds like and also makes use of social stereotypes to interpret the meaning of what is being said. Van Berkum speculates that “the linguistic brain seems much more ‘messy’ and opportunistic than originally believed, taking any partial cue that seems to bear on interpretation into account as soon as it can.”

But how does the language brain act so fast? Recent findings suggest that, as we read or have a conversation, our brains are continuously trying to predict upcoming information. Van Berkum suggests that this anticipation is a combination of a detailed analysis about what has been said before with taking ‘quick-and-dirty’ shortcuts to figure out what, most likely, the next bit of information will be.

One important element in keeping up with a conversation is knowing what or whom speakers are actually referring to. For example, when we hear the statement, “David praised Linda because. . .,” we expect to find out more about Linda, not David. Van Berkum and colleagues showed that when listeners heard “David praised Linda because he. . .,” there was a very strong ERP effect occurring with the word “he”, of the type that is also elicited by grammatical errors. Although the pronoun is grammatically correct in this statement, the ERP occurred because the brain was just not expecting it. This suggests that the brain will sometimes ignore the rules of grammar when trying to comprehend sentences.

These findings reveal that, as we make sense of an unfolding sentence, our brains very rapidly draw upon a wide range of information, including what was stated previously and who the speaker is, in helping us understand what is being said to us. Sentence understanding is not just about diligently combining stored word meanings. The brain rapidly throws in everything it knows, and it is always looking ahead.


Interesting that no one commented. I find the topic endlessly fascinating and you article in particular provides food for thought. Thank you.

I have had seizures for 3 years in December. For the past year off and on I have had language problems. Have not got a diagnosis of Epilepsy or PNES (Psychological Seizures.) Physical or Mental I do not know. Any ways when this language problem first came on it was very mild and I felt like words were “translating.” I could not tell at that time. Very mild and felt the change in conscious very mildly. It went away and came back a little stronger months later. See thing again went away came back months later stronger. Not sure if it went away after that, or came back again but this time it hasn’t went away. It starts a little after I wake up. Only last 15 seconds at the most. Usually only 10 at the most. When it happens I feel a slight change in my conscious. Basically what happens is I can’t understand the real words and my mind seems to generate everytime the same thing. However I cannot say it’s always the same as I can never remember what my mind generates. I feel like my mind is generating that the seizures arent real or they are because of something I did. The something I’m not going to discuss, but I will say Binaural beats. Words heard or read always “feel” like whatever my mind generates when this happens. And it just “feels” like it makes sense. Like “natural no sugar added” on my drink container when it happened (just happened before the stuff after this but I had happened type out and all the stuff to the left made sense as whatever my mind generates I guess it’s a psychological thing like this is going to fix me) anyways when it happened the “natural no sugar added” made sense of whatever was in my mind. Also my seizures are grand mal one every two weeks and they are nocturnal. This year they have got down to 1 a month for the most part. No change in the only seizure medicine I take. Levitiracetam. I need someone

When I lay in bed at night I always notice that my subconscious thoughts seem to beat my concious mind in forming a sentence. I find it incredible that, when thinking of a sentence,I already know how that sentence will end. And I can stop trying to form it in my mind because I already know how it will come out. It keeps me up but amazes me. I was trying to learn more about that when I stumbled on this article.

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