Stroop test

• Try it out for yourself 

This one's a true classic: in the test, you're presented with names of colors; the words themselves are printed in different colors, sometimes matching the meaning and sometimes – not (thus, you can see “brown” printed in brown or in blue). The task: to name the color of the ink as fast as possible. Though this is a simple task, it takes significantly longer to say the right answer when the “seen” and “read” colors don't match. 

In experiments or clinical settings, the Stroop test and its variations are used to study or evaluate selective attention and inhibitory control (your ability to focus on the task at hand and ignore distractions).

Go/no-go

• Try it out for yourself

Another popular way to probe task-related attention, is the go/no-go task. In it, participants are given two kinds of stimuli: a target, like a green circle, to which they have to react by pressing a button, and a “no-go” stimulus, a circle with a pattern inside, which they have to ignore. You need to make as few mistakes as you can, as the stimuli are presented to you in quick succession.

Variations of this task can be used as a measure of attention or fatigue within an experiment: for example, the experimental design can involve participants first completing a demanding task like reading a long text with complex terms or watching a monotonous lecture. You can ask your participants to take the go/no-go task before and after their complex task, measure their performance, and see if it changed to suggest either increased or decreased capacity to attend to stimuli.

N-back

• Try it out for yourself

You may have heard that our short-term memory can only hold around 7 things at a time – after all, this was claimed in one of the most widely cited papers in cognitive science. Since then, the number has been contested; experiments show that there are many factors that can affect it – for instance, the length of stimuli and whether a participant is familiar with them. It was also posited that measuring memory in “chunks” (items or blocks you are memorizing) may not be accurate. 

However, there is one method researchers use, if not to measure working memory, then to study it – the N-back task, where N stands for a number. For example, in a 2-back you are presented a list of words in quick succession and need to press a button when you see the word that was presented N words ago. In the “try it out” link above, you can go as high as 9-back to test your memory, but experiments rarely employ any number higher than 3. N-back is a classic task to investigate working memory and related brain structures with fMRI.

Looking for more brain research facts? Check out our stories on music and languages in the brain. For more “brain exercising” games, explore our Quick Fix tag.