PERSON
Sophie Leroy
The French-American organizational psychologist whose 2009 discovery of attention residue identified the hidden cognitive tax of every task switch—and who unwittingly became the load-bearing theorist of the AI-augmented workplace’s most urgent and least measured problem.
Sophie Leroy did not set out to describe the AI age. She studied meetings and email in conventional office settings and measured what happens when a person is pulled from one task to another before completion. The phenomenon she isolated—
attention residue—is the persistence of cognitive engagement with a prior task after the switch to a new one: the unresolved elements of the first task continue to occupy working memory resources that the second task requires, producing measurable decrements in the speed, accuracy, and quality of performance on the task that follows. The finding was robust, replicated across experimental conditions, and invisible from the inside: the person carrying residue does not feel impaired, she feels busy. What Leroy could not have predicted was that her narrow empirical result would become the key to understanding why the AI productivity boom is generating, simultaneously, the most capable and the most cognitively depleted knowledge workers in history. The AI tool eliminates the production bottleneck