For those who find themselves wincing whenever they hear a “could of” instead of a “could have”, or a “less” when it should be “fewer”, it may not just be a passing annoyance. A new study has revealed that our bodies can show physical signs of stress upon hearing grammatical violations.
As Dagmar Divjak, principal investigator of the study, explained in a statement, the relationship between language cognition and physiological responses has previously been explored in the form of studying brain activity and eye tracking, “but the relation between language cognition and the autonomic nervous system (ANS) has so far received less attention.”
It’s the ANS that controls our heart rate, so the researchers looked to measure the heart rate variability (HRV) of people listening to incorrect grammar to find out more about the cognition-physiology relationship. As it tells us the length of time between successive heartbeats, HRV can be a useful indicator of stress – those intervals between beats tend to be a more regular duration when someone is stressed, versus more variable when relaxed.
With a heart rate sensor attached to their middle fingers, 41 British English-speaking adults listened to 40 English speech samples. Half of these contained grammatical errors in the form of articles, such as adding an “a/an” where it was not required or omitting a “the” when it was.
The results showed that there was a statistically significant reduction in HRV in response to incorrect grammar, to the point where the more errors a person heard, the more regular their heartbeat – and the higher their stress levels – became.
"The results of this study bring into focus a new dimension of the intricate relationship between physiology and cognition… Our findings show that [the ANS], too, responds to cognitive demands, and this suggests that cognitive effort reverberates through the physiological system in more ways than previously thought,” said Divjak.
The researchers also believe that the results demonstrate that HRV could be used as an indicator of someone’s implicit linguistic knowledge; this is the knowledge of a language, often our first, that we pick up without really thinking about it. If someone’s heartbeat suggests they’re stressed out by poor grammar, it might also indicate that they know the language well. But why does knowing about this matter?
“[A]ccurately assessing someone’s linguistic abilities, regardless of age and physical or cognitive abilities, is important for many questions pertaining to core areas of life relating to cognition, including brain health,” explained Divjak.
“This study provides us with a new method for tapping into aspects of cognition that are not directly observable. This is particularly valuable in work with language users who are unable to verbally express their opinion due to young or old age, or ill health.”
The study is published in the Journal of Neurolinguistics.