It’s well known that the tools we use can change how we think. With the advent of the internet for instance, tasks that once required deep research could be found by plugging a simple query into a search box. As the use of search engines increased, research found we became less likely to remember details, something dubbed “the Google effect”. (Some argue, however, the internet also serves as an external memory system that frees up our brain to do other tasks.)
But there is now growing alarm that as we offload even more of our thinking to LLMs and other forms of AI, the effects on our memories and ability to solve problems could get worse. Artificial intelligence tools can write convincing poetry, give financial advice and provide companionship. Students are increasingly outsourcing their own work to AI tools as well.
Studies have already shown that young people might be particularly vulnerable to the negative effects that using AI can have on key cognitive skills like critical thinking. Kosmyna, however, wanted to dig deeper into the potential effects.
Reduced mental effort
She and her colleagues at MIT Media Lab recruited 54 students to write short essays and split them into three groups. One was instructed to use ChatGPT. A second could use Google search, with AI-generated summaries turned off. The third didn’t use technology. Each student’s brainwaves were measured while they worked.
The essay topics were deliberately open-ended, meaning little research was needed for the task, with prompts including questions around loyalty, happiness or our daily life choices.
The results haven’t been published in a scientific journal yet, but they were none-the-less eye-opening, according to Kosmyna. Those who used their own minds had a brain that was “on fire”, showing widespread activity across many parts of the brain, she says. The search engine-only group still showed strong activity in the visual parts of the brain, but the ChatGPT group showed notably less brain activity – it was reduced by up to 55%.
“The brain didn’t fall asleep, but there was much less activation in the areas corresponding to creativity and to processing information,” says Kosmyna.
ChatGPT also affected people’s memories. After submitting their essays, people in the AI group were unable to quote from their essays, and several felt they had no ownership over the work. Other studies have also shown that people become less able to retain and recall information when they use AI tools such as ChatGPT.
While the findings are still undergoing peer review, they echo those from other studies. One study by researchers at the University of Pennsylvania suggests that some people undergo something they term “cognitive surrender” when using generative AI chatbots. This means they tend to accept what the AI tells them with minimal scrutiny and even allow it to override their own intuition.
Similar effects can be found outside the world of AI chatbots too – even in life-or-death situations. A recent multinational study team found that medical professionals who used an AI tool to screen for colon cancer for three months were subsequently worse at spotting the tumours without it.
