Large language model linguistic perplexity in childhood onset psychosis: unique features and developmental trends

The study examined language changes in children and young adults with childhood onset psychosis (COP) using large language models. The research included 23 COP patients (mean age 12.78 years) and 15 controls (mean age 11.67 years), whose extensive interviews were analyzed (total 10,408 words). Researchers measured perplexity, which indicates how difficult it is for a model to predict words based on context. They found that perplexity from the LLaMA model decreased with age in COP patients but not in controls. The difference between groups was statistically significant. The results suggest that individuals with COP have an altered developmental trajectory in real-time semantic and syntactic planning during speech production.