Workers who excessively use AI agents and tools at work are at increased risk of mental fatigue, according to a recent Harvard Business Review study. In certain industries, more than 25% of hired professionals report increased mental strain due to their role in AI oversight — though these professionals also generally experienced less burnout than peers who aren’t using AI.

This phenomenon — which the researchers refer to as “AI brain fry” — is described as a “‘buzzing’ feeling or a mental fog” that caused study participants to develop headaches and difficulty focusing and making decisions. Individuals pointed to being overwhelmed by large amounts of information and to frequent task switching as the reasons for these feelings.

Studied individuals experienced more brain fry when they utilized AI agents to manage a workload beyond their own cognitive capacity. When participants used AI to replace mundane, repetitive tasks, managing the growing number of tools led to increased mental fatigue. 

Crucially, the study found that fewer individuals who used these AI agents reported workplace burnout.

The researchers predict that this is because burnout testing assesses emotional and physical distress. In contrast, they report, acute mental fatigue “is caused by marshalling attention, working memory and executive control beyond the limited capacity of these systems.” 

These are the processes that are taxed when study participants use multiple AI tools in their workflow, according to the researchers.

The Harvard study identifies several business costs incurred by workers suffering from AI brain fry. The foremost consequence is that these individuals may end up making lower-quality decisions. “Workers in [the] study who endorsed AI brain fry experience 33% more decision fatigue than those who did not,” the study reports. Workers who report AI brain fry were also more likely to self-report making both minor and major errors at their jobs.

Another recent Harvard Business Review study similarly found that employees who use AI tools “worked at a faster pace, took on a broader scope of tasks and extended work into more hours of the day,” but warned that “workload creep can in turn lead to cognitive fatigue, burnout and weakened decision-making.”