The Stroop Effect

This blog post deals with The Stroop Test, something we are looking at in our MOOC as an example of experimental intervention as a research design method. I'll briefly touch on what it is, how the experiment is set up and how it works and how this may be useful in practice. 

The Stroop Effect refers to the impact of cognitive interference in the length of time it takes to complete a simple task. The original Stroop Test measured the difference in the time it took to process, identify and name colours, when there was a conflict between the colour being viewed and the colour described in words.  

There are two conditions present in the given example of the Stroop Test (although the original test had three conditions). The first is a list of words describing colours where the text is printed in the colour it denotes. This is the control condition. The experimental condition comprises a list of words where the text is printed in a colour that is different to that which it denotes. 

The experiment requires a participant to note aloud the first set of colours (where the colour of the word and the word itself are the same) and measure the time it takes to do so. They then have to note aloud the second set of colours (where the colour of the word differs from the word itself). Again, the time taken to do this is measured. The times are then compared enabling inferences to be made about the impact that the incongruity has  on the ability of the brain to process information quickly. 

In practice, the Stroop test could theoretically be used to understand how additional variables, such as age, injury, brain damage or dementia etc impact on cognitive processing speed, given that the test provides a benchmark for the impact that interference has on a 'normal' brain.