Summary: A novel study uncovers our physiological response to misused grammar. Researchers identified a direct link between grammatical errors and a change in Heart Rate Variability (HRV).
When confronted with bad grammar, subjects’ HRVs indicated increased stress levels.
This novel discovery highlights the deep-seated connection between our linguistic environment and physiological reactions.
Bad grammar leads to a statistically significant reduction in HRV, indicating stress.
The autonomic nervous system (ANS), responsible for ‘fight or flight’ and ‘rest and digest’ functions, also reacts to cognitive demands such as linguistic irregularities.
HRV offers a new metric to assess implicit linguistic knowledge, useful for evaluating individuals who can’t verbally express their opinions.
Source: University of Birmingham
A new study by professors at the University of Birmingham has revealed for the first time how our bodies go into stress-mode when hearing misused grammar.
The study, “Physiological responses and cognitive behaviours: Measures of heart rate variability index language knowledge” is published in the Journal of Neurolinguistics. The dataset used in the study is available here.
For the research, professors Dagmar Divjak, Professorial Research Fellow in Cognitive Linguistics and Language Cognition at the University of Birmingham, and Professor Petar Milin, Professor of Psychology of Language and Language Learning, discovered a direct correlation between instances of bad grammar and subjects’ Heart Rate Variability (HRV).
HRV captures the time between successive heart beats. The length of the intervals between a person’s successive heart beats tends to be variable when they are relaxed but becomes more regular when they are stressed.
The new study reveals a statistically significant reduction in HRV in response to grammatical violations. This reduction reflects the extent of the grammatical violations, suggesting that the more errors a person hears, the more regular their heartbeat becomes—a sign of stress.
Commenting on the findings, Professor Divjak, principal investigator of the study, said, “The results of this study bring into focus a new dimension of the intricate relationship between physiology and cognition.
“This relationship has been studied using techniques ranging from eye-tracking over electro-encephalography to brain imaging. But the relation between language cognition and the autonomic nervous system (ANS) has so far received less attention.
“The ANS comprises two parts: the sympathetic (SNS) and the parasympathetic (PNS) nervous system. Simply put, the sympathetic nervous system activates the ‘fight or flight’ response during a threat or perceived danger, while the parasympathetic nervous system controls the ‘rest and digest’ or ‘feed and breed’ functions of the body.
“”Our findings show that this system, too, responds to cognitive demands, and this suggests that cognitive effort reverberates through the physiological system in more ways than previously thought.”
The research conducted by Divjak alongside Professor Milin from the University of Birmingham, and Dr. Hui Sun who was working as a postdoctoral researcher on the project at the time, has provided the first evidence to suggest that HRV can be used as an indicator of implicit linguistic knowledge.
Divjak explained, “Your knowledge about your first language is largely implicit, i.e., learning your mother tongue did not require you to sit and study, and using it does not require much, if any, thought.
“This also means that you will find it hard to pin down what exactly is right or wrong about a sentence and, even worse, explain why that is so, especially if you’ve not had formal language training.
“However, accurately 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.
“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.”
Physiological responses and cognitive behaviours: Measures of heart rate variability index language knowledge
Over the past decades, focus has been on developing methods that allow tapping into aspects of cognition that are not directly observable. This includes linguistic knowledge and skills which develop largely without awareness and may therefore be difficult or impossible to articulate.
Building on the relation between language cognition and the nervous system, we examine whether Heart Rate Variability (HRV), a cardiovascular measure that indexes Autonomic Nervous System activity, can be used to assess implicit language knowledge.
We test the potential of HRV to detect whether individuals possess grammatical knowledge and explore how sensitive the cardiovascular response is.
41 healthy, British English-speaking adults listened to 40 English speech samples, half of which contained grammatical errors. Thought Technology’s 5-channel ProComp 5 encoder tracked heart rate via a BVP-Flex/Pro sensor attached to the middle finger of the non-dominant hand, at a rate of 2048 samples per second.
A Generalised Additive Mixed Effects Model confirmed a cardiovascular response to grammatical violations: there is a statistically significant reduction in HRV as indexed by NN50 in response to stimuli that contain errors.
The cardiovascular response reflects the extent of the linguistic violations, and NN50 decreases linearly with an increase in the number of errors, up to a certain level, after which HRV remains constant.
This observation brings into focus a new dimension of the intricate relationship between physiology and cognition.
Being able to use a highly portable and non-intrusive technique with language stimuli also creates exciting possibilities for assessing the language knowledge of individuals from a range of populations in their natural environment and in authentic communicative situations.