Introduction

There are two Discovery Labs related to dual-task interference. It is best to complete Dual-Task Interference: The Perceptual Refractory Period Paradigm first.

You have seen in the perceptual refractory period paradigm that when a person has to complete two tasks that require a quick response, performance on the second task has to wait until performance of the first task is complete. What about when the first task doesn’t require you to do anything except enter information into short-term memory? Will the second task still be affected?

At the core of dual-task interference is the phenomenon of attention—that capacity-limited cognitive mechanism that we rely on for everything from identifying objects to understanding words to completing all but a very few number of highly-learned tasks. Whenever any two tasks both require attention, you run the risk of encountering dual-task interference. It doesn’t matter if both tasks require quick responses, or even if both tasks require responses at all! What matters is whether or not the tasks both require attention. This is an important point to make because it shows that you can be distracted and unable to make quick responses just by thinking, if that thinking takes up too much of your attention! To demonstrate this, you will now complete a dual-task experiment where the first task is an encoding task and the second task is a timed response to a tone.