Each participant was presented with a three-word starting sentence that flashed up for 300ms, followed by a second sentence that was either identical or differed by one word. Participants were asked to indicate whether the sentences matched, with the experiment repeated using different starting sentences.
The results reveal participants made faster and more accurate judgments on whether the sentences matched when they contained a subject, verb and object – such as “nurses clean wounds” – than when they contained a list of nouns such as “hearts lungs livers”.
What’s more, participants’ brain activity rapidly increased in response to a starting sentence with a subject, verb and object, with activity detected in the left-middle temporal cortex within 130ms – about 50ms quicker than for a list of nouns.
A similar rapid response was noted when starting sentences with a subject, verb and object were altered so that they contained an agreement error – for example “nurses cleans wounds” – or became implausible, for example “wounds clean nurses”.
But the effect disappeared when the sentences were given less typical structures, for example “wounds nurses clean” or “wounds cleans nurses”. Pylkkanen said that suggests these sequences do not trigger the same sentence-recognition system.
