Recent studies in cognitive psychology have challenged the traditional view that multitasking enhances productivity. Researchers have found that the human brain is not designed to process multiple complex tasks simultaneously; instead, it rapidly switches attention between tasks, leading to a phenomenon known as 'attention residue.' This residue impairs performance on subsequent tasks because mental resources remain partially engaged with the previous activity. Furthermore, neuroimaging data reveal that heavy multitaskers show reduced activity in brain regions associated with sustained attention and working memory, compared to light multitaskers. These findings suggest that while multitasking may feel efficient, it often results in slower completion times and more errors, particularly for tasks requiring deep concentration.