Comparing costs in time-based and event-based prospective memory.

Although much recent research has focused on event-based prospective memory (PM), fewer studies have compared event- and time-based PM. In the current study, two experiments were conducted to directly compare ongoing task costs of focal and non-focal event-based tasks with a time-based task. In the second experiment, an external reminder of the task was present to test whether this reduced the cost of the time-based task.