Slide Slam P16 Sandbox Series
Unique features of brain processing of expletives in naturalistic context
Annette Glotfelty1, Jeremy I. Skipper2, Sarah Aliko2, Steven L. Small1; 1The University of Texas at Dallas, 2University College London
Expletives (“curse words”, “swear words”, “profanity”, “obscenities”, “taboo words”) have been shown to have unique properties in individuals with neurological disease. Profanity can be a manifestation of vocal tics in Tourette’s syndrome, used as a compensatory technique during stuttering blocks, and preserved in cases of aphasia. Further, uttering such words can increase some people’s pain tolerance. The observed conservation of cursing ability in the presence of even global aphasias with lesions to areas considered critical for language processing (e.g., posterior superior temporal gyrus, posterior inferior frontal gyrus) provides evidence that these words are somehow encoded and/or accessed differently than other types of words in the brain. One explanation for the distinctiveness of such words is that obscenities are emotionally charged, possibly to such an extent that their use in context may approximate non-word emotional utterances such as laughing, groaning, or screaming. However, relatively little neuroimaging evidence is available to inform the neural processes that underpin cursing. This study in its preliminary stages seeks to explore brain dynamic functional connectivity during profanity perception in a rich contextual environment, using fMRI recordings of participants watching full length films from the Naturalistic Neuroimaging Database. By understanding the biological basis of the differential comprehension of this class of utterances, we seek to gain further insights into embodied brain representations of language in healthy individuals and those with neurological disease. Network architecture will be examined for a continuum of emotional vocalizations, from those assumed to be more deliberate to those thought more visceral: words matched by arousal scores, curse words, and non-word emotional vocalizations. Patterns of functional brain activation and connectivity over time will be examined for commonalities and distinctiveness across the conditions. Nascent hypotheses are that network organization along the continuum will begin with putative language regions serving as hubs of high connectivity for matched arousal words, moving toward a model where hubs are based in areas recognized as critical to emotional perception (e.g., limbic regions such as the thalamus and amygdala, limbic-related areas such as the insular cortex) for non-word emotional utterances. We hypothesize that swear words will demonstrate connectivity in voxels that bridge these hubs. A pilot duration-modulated regression was run on 86 participants watching 10 movies. Individual analyses and group t-tests indicated that perceiving an initial subset of expletives in natural context, compared to perceiving words matched on arousal score, showed significantly increased activation in the precuneus, posterior middle temporal gyrus, insular cortex, fusiform gyrus, and periaqueductal gray. ‘Decoding’ resulting regions with Neurosynth indicates that these areas are associated with terms related to social and emotional cognition. We will aim to further improve this model of natural processing of profanity by extending the list of expletives and controls and by performing dynamic functional connectivity analysis. Additionally, findings will be analyzed to determine how semantic context affects the neural processing of obscenities (e.g., swearing during a highly emotional scene vs. cursing as a character’s trait) or how individual differences in participant emotional health (assessed by NIH Toolbox affective batteries) modulate the findings.