Cognitive debt is the term an MIT Media Lab group used in 2025 for the pattern their EEG study found in essay writers: the people who wrote with ChatGPT showed the weakest brain connectivity of three groups, struggled to quote a sentence from the essay they had just produced, and reported the lowest sense of ownership over it. The convenience is taken at the moment of writing. The cost arrives when the person has to do the same work without the tool.
The analogy is to technical debt. Borrowing against the future is sometimes the right call, and the debt is only a problem when it is invisible and unmanaged. What makes cognitive debt hard to manage is that every ordinary measure improves while it accumulates: the essay is finished faster, the practice score is higher, the code compiles. The loss only shows when the tool is removed and unassisted performance is measured, and most organisations never take that measurement.
The term is a label for an observation, not an established construct, and the study behind it is a preprint with 54 participants. It is useful because it names the timing of the cost. The repayment schedule is set by whether the person keeps practising the skill without the tool, which is a decision a school, an employer or an individual can make.