AI does rot the brain

While I have written about AI before (here), there is research showing that regular use of LLM apps - such as Claude.ai and ChatGPT - appears to reduce our brainpower. In a small experiment designed to see if we 'lose it' if we don't 'use it', participants were divided into three groups of 18, tasked with writing a piece "with[out] digital assistance, or with the help of an internet search engine, or [with] ChatGPT" (Kosmyna et al., 2025; McBain, 2025). There have been previous studies (Kosmyna et al., 2025, citing Stadler et al., 2024), and this paper had a limited number of student participants - a group of 54; we probably need to do a few more studies to firm things up.

Regardless of participant numbers, the findings seem relatively unambiguous. Using EEG to track cognitive engagement and load (Kosmyna et al., 2025), results indicate "that the more external help participants had [for their writing task], the lower their level of brain connectivity, so those who used ChatGPT to write showed significantly less activity in the brain networks associated with cognitive processing, attention and creativity" (McBain, 2025). Through a a process known as "cognitive offloading", results indicate that increased use of "AI systems [...] lead[s] to diminished prospects for independent problem-solving and critical thinking", which in turn "raises concerns about the long-term implications for human intellectual development and autonomy" (Kosmyna et al., 2025, p. 10).

The findings are worrying, especially as secondary school students seem to use AI/LLMs a LOT. Tertiary institutes are still trying to hold back the tide on AI use... for now. With these research results, this strategy seems imminently sensible, as "excessive reliance on AI-driven solutions" seems to "inadvertently contribute to cognitive atrophy" (Kosmyna et al., 2025, p. 10). Ouch. That is pretty damning.

I know of people who regularly use LLMs for work tasks. They outsource their emails to an LLM; the text to frame their quotes; their first draft contracts; policy; procedure; and other writing. But, as I have mentioned before (here), writing, composition, clarity of thought and expression of argument are learned expertises, or "time skills" (Canning, 1975), “where the ticking away of the unforgiving seconds plays a dominant part in both learning and application of the skill” (p. 277). Like driving, we cannot contract it out to others and expect our skills to improve without that continuous practice. Our old skills will grow rusty from disuse, and we will have to retrain to some level to reclaim what has evaporated through atrophy.

Of course, these results may be a knee-jerk reaction to the 'new'; over-blown drama that will evaporate like dew as the field progresses. We may simply be replacing one skill for another. 

Only time will tell.

Sam

References:

Canning, B. W. (1975). Keyboard skill-a useful business accompaniment. Education + Training, 17(10), 277-278. https://doi.org/10.1108/eb016409

Kosmyna, N., Hauptmann, E., Yuan, Y. T., Situ, J., Liao, X. H., Beresnitzky, A. V., ... & Maes, P. (2025). Your brain on ChatGPT: Accumulation of cognitive debt when using an AI assistant for essay writing task. arXiv. Advance online publication. https://arxiv.org/abs/2506.08872

McBain, S. (2025, October 18). Are we living in a golden age of stupidity?. The Guardian. https://www.theguardian.com/technology/2025/oct/18/are-we-living-in-a-golden-age-of-stupidity-technology