Additionally, the original paper uses the term “cognitive debt“ not cognitive decline, which may have an important ramifications for interpretation and conclusions.
I wouldn’t be surprised to see similar results in other similar types of studies, but it does feel a bit premature to broadly conclude that all LLM/AI use is harmful to your brain. In a less alarmist take: this could also be read to show that AI use effectively simplifies the essay writing process by reducing cognitive load, therefore making essays easier and more accessible to a broader audience but that would require a different study to see how well the participants scored on their work.