MIT actually has a paper on how ChatGPT use impacted cognitive skills for essay writing.

> Your Brain on ChatGPT: Accumulation of Cognitive Debt when Using an AI Assistant for Essay Writing Task

> https://arxiv.org/abs/2506.08872

> Cognitive activity scaled down in relation to external tool use. …

> Self-reported ownership of essays was the lowest in the LLM group and the highest in the Brain-only group. LLM users also struggled to accurately quote their own work. While LLMs offer immediate convenience, our findings highlight potential cognitive costs. Over four months, LLM users consistently underperformed at neural, linguistic, and behavioral levels.