Raising levels of dopamine and noradrenaline allows the brain to untangle ambiguous grammatical structures faster, researchers at the Max Planck Institute for Psycholinguistics in Nijmegen have found, according to infohub.kz.
To understand how people reinterpret confusing sentences, the scientists ran an experiment with 30 healthy volunteers. Participants were asked to read ambiguous sentences in which a single word at the end completely changes the meaning of what has been said.
During the tests, the volunteers took part in two sessions: one after taking a placebo and another after taking methylphenidate, which raises levels of the neurotransmitters dopamine and noradrenaline. Brain activity was recorded using electroencephalography (EEG), a method of registering the brain's electrical signals.
The study found that after taking the drug, participants showed a stronger P600 signal at the moment they read the key word that reveals the true meaning of the sentence. This signal is linked to extra mental effort in processing complex grammar. Notably, the strongest effect was seen in participants who initially had a lower working memory capacity.
According to co-author Peter Hagoort, the finding proves that the brain's chemicals play a role in allocating resources when building grammatical connections.