Understanding Segmentation, Crowding, and Neurodivergence in Sign Language Evolution: Insights from an Experimental Study

Abstract

This thesis investigates the phenomena of segmentation, crowding and neurodivergence in the context of sign language evolution. The study examines how individuals, both neurotypical and neurodivergent (specifically those with ADHD and ASD), perceive and process segmented versus holistic iconic signs. This research project investigates whether there is a relationship between crowding and segmentation as well as what the influence of neurodivergence on language use and evolution is. Two experiments were conducted using different levels of crowding to see how this would affect the two populations’, neurodivergent and neurotypical, preferences for holistic iconic and segmented iconic mappings. Experiment I revealed a strong preference for holistic iconic signs. Experiment II, implementing adjustments to the experimental design to enhance the level of crowding and reduce potential biases, revealed a strong preference for holistic iconic sings. Additionally, it also showed significant interaction effects of holistic iconic and neurotypical and significant main effects of holistic iconic and neurostatus and holistic iconic and stage. The results revealed that there is only a slight effect of crowding on segmentation. This reveals that the current understanding of how crowding and segmentation are connected with each other is not yet fully understood. However, the results did show that there is a difference between the neurotypical and the neurodivergent participants. This shows that neurodivergent and neurotypical individuals use language differently and that neurodiversity impacts communication.