Emotional Processing of Taboo Words in Naturalistic Stimuli
Annette Glotfelty, Sarah Aliko, Bangjie Wang, Steven L. Small, and Jeremy I. Skipper
Abstract
Taboo words (i.e., “expletives,” “curse words,” “obscenities,” “swear words,” etc.) are an evocative subset of words and have been shown to present distinctively in neurological disease and injury. Excessive expletive production may occur in pathologies such as traumatic brain injury. Ictal swearing has been observed in cases of epilepsy. Coprolalia in Tourette syndrome is a well-known phenomenon, and many patients with global aphasia are still capable of cursing. These examples provide evidence that this category of words is somehow encoded and/or accessed differently in the brain than other types of words.
Despite their relevance to neurological conditions, relatively little is known about the neurobiological substrates that underpin taboo word processing. This study examines the nature of expletives as taboo expressions and how this impacts the functional neuroanatomy of their perception in natural contexts. An existing theory is that expletives are imbued with tabooness due to their emotionality (or that their tabooness evokes emotionality), with emotionality defined on a commonly used two-dimensional scale of affective arousal and valence (i.e., positive/negative association).
To explore the relation between emotionality and cursing within real-world contexts, we used the Naturalistic Neuroimaging Database. 56 healthy adult participants watched one of seven films during blood oxygen level dependent (BOLD) MRI acquisition, with each film containing 20+ taboo words. Using a duration-modulated deconvolution, we compared expletives with words matched on frequency, arousal, and valence scores. In a second amplitude-modulated deconvolution, we compared obscenities to words matched solely on frequency, with arousal and valence as modulators, to investigate the contribution of these dimensions to the neurobiological underpinnings of taboo word processing. A linear mixed effects model was used to examine group level effects.
Perceiving expletives – compared to perceiving words matched on arousal, valence, and frequency – led to increased activation in superior and middle temporal gyri, occipital lobe, precuneus, and superior frontal gyri. The second analysis, examining the modulatory role of emotionality, showed that arousal and valence varied with BOLD response of expletive perception in the occipital lobe and precuneus. Additionally, arousal modulated activation in orbitofrontal areas and anterior cingulate gyri, while valence modulated activation in superior frontal gyri and the posterior portion of the cingulate gyrus. In comparison, both modulators varied with BOLD response of matched frequency word processing in the superior and middle temporal gyri.
These results indicate that taboo words in natural contexts may invoke more brain activity than emotionally matched words in auditory and visual processing regions, as well as regions presumed to integrate sensory information. Expletive perception varied with emotionality in areas associated with visual processing, cognitive integration, and emotional regulation, while perceiving words of similar frequency varied with emotionality in putative language regions. These results, based on context-independent ratings of word emotionality, call for further investigation into the role of dynamic pragmatic use cases (e.g., audiovisual context, narrative-based usage) in brain representations of taboo words. By understanding the biological basis of properties associated with cursing, we gain insight into why this class of words is unique in social communication and neurological disease.
Glotfelty, A., Aliko, S., Wang, B., Small, S. L., & Skipper, J. I. (2022). Emotional processing of taboo words in naturalistic stimuli. Paper presented at the 14th Annual Society for the Neurobiology of Language Conference (SNL2022), Philadelphia, Pennsylvania, USA.