Plain English Meaning

Trying to do several thinking tasks at once. The brain can't really do that — it just jumps back and forth quickly, and things get missed.

Full Definition

The attempt to perform two or more cognitively demanding tasks at the same time. In practice, the brain does not handle these tasks simultaneously but rapidly switches attention between them, which reduces performance and increases the chance of errors on each task.

Context Anchor

Seen in aviation training discussions about cockpit workload, student performance, and why instructors should avoid overloading a learner with too many tasks at once.

Derivation

From 'multi' (many) and 'tasking' (assigning tasks), originally a 1960s computing term describing how a single processor handled several jobs by switching quickly between them. The aviation use borrows the same idea: a single brain switching between tasks, not actually doing them in parallel.