In this study, 54 people, mostly students, were assigned at random to 3 groups of 18 and wrote 3 texts of 20 minutes while an electroencephalogram (EEG) recorded their brain activity. The signals recorded were most closely linked to one another with no tool and least with ChatGPT. In session 1, 15 of the 18 participants in the ChatGPT group could not quote a sentence from their text, against 2 of 18 in each of the other 2 groups; in the next 2 sessions, 4 then 6 of 18 did not provide an exact quotation, against 2. This study, posted online in June 2025, has not yet appeared in a peer-reviewed journal, and a commentary by 4 researchers judges its sample too small.
Read the source article: AI impact on the brain: what 3 studies show, and their limits