Using Too Many AI Tools at Once Can Cause 'Brain Fry,' Study Finds

Boston Consulting Group survey reveals productivity boost from AI has limits as workers report mental fatigue from managing multiple AI agents.

Published on Mar. 10, 2026

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Researchers at the Boston Consulting Group found that a small but noticeable number of workers report experiencing mental fog, headaches, and slower decision-making, or what the authors call "AI brain fry," when using multiple AI agents simultaneously. The study surveyed 1,488 full-time U.S.-based workers and found that while AI tools can boost productivity, there are limits, with productivity gains decreasing after using more than two AI tools at once.

Why it matters

As AI becomes more prevalent in the workplace, companies need to be aware of the potential downsides of overusing the technology. The study highlights the risk of "AI brain fry" and the need for companies to manage the adoption of AI tools to avoid burnout and maintain employee well-being.

The details

The study found that employees who go from one to two AI tools simultaneously experience "a significant increase in productivity," but the increase is smaller when they go from two to three tools, and then it decreases from three onward. This illustrates that multitasking with AI tools can have its limits. The authors say businesses should be diligent in crafting their AI policies, including allowing for breaks, to manage the negative impacts of using multiple AI agents.

  • The study was published in the Harvard Business Review on March 10, 2026.

The players

Boston Consulting Group

A global management consulting firm that conducted the study on the impacts of using multiple AI agents in the workplace.

Matthew Kropp

One of the lead authors of the study and a managing director and senior partner at Boston Consulting Group, as well as the chief AI officer of BCG's X, the firm's team of roughly 3,000 engineers that build AI solutions.

Steve Yegge

A veteran software engineer who recently suggested imposing a 3-hour cap on engineers who use AI-assisted coding.

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What they’re saying

“We look at this as kind of the canary in the coal mine. Those engineers that are the early adopters, that are doing the multi-agent orchestration are experiencing this effect, more and more people are trying to move up to that level.”

— Matthew Kropp, Managing Director and Senior Partner, Boston Consulting Group (Business Insider)

“I had one tool helping me weigh technical decisions, another spitting out drafts and summaries, and I kept bouncing between them, double-checking every little thing. But instead of moving faster, my brain just started to feel cluttered. Not physically tired, just… crowded.”

— Senior Engineer Manager (Harvard Business Review)

“If I'm 50 times more productive, maybe I should be 20 times more productive, but have better mental health and not want to quit.”

— Matthew Kropp, Managing Director and Senior Partner, Boston Consulting Group (Business Insider)

What’s next

The study's authors suggest that businesses should be diligent in crafting their AI policies, including allowing for breaks, to manage the negative impacts of using multiple AI agents.

The takeaway

While AI tools can boost productivity, companies need to be mindful of the potential for 'AI brain fry' as workers struggle to manage multiple AI agents simultaneously. Striking the right balance between productivity gains and employee well-being will be crucial as AI becomes more prevalent in the workplace.