The Stroop task was discontinued on 01/20/2020. Participant OSA5025 was the last participant that underwent Stroop testing. It should be noted, that some participants also got Stroop tested in the MRI scanner under slightly different conditions. Instead of reading out loud, they would press a color-coded button on a button box. Note that this is cognitively a different process than reading or speaking out loud.
The Stroop task is a color-word naming task consists of 3 separate parts:
Naming colors of non-word stimuli (rectangles)
Reading color words (congruent)
Naming the color of a word that describes a color but is printed in a different color. This condition is an incongruent set of stimuli and requires inhibition of our automatic mental reading abilities. Therefore, it requires more time (i.e. response time) to name the colors.
Each block had a maximum duration of 270 seconds or 4.5 minutes.
A Stroop effect or score can be computed from the accuracy (number of mistakes) and time to read through the list. Thereby, timing and accuracy of all 3 conditions are considered.
Recording of the exact timing and accuracy of each word, however, is difficult in the laboratory. The instructions are to name the colors as fast as possible without making mistakes. Different people will use different strategies and trade off one vs. the other. They also self-correct a lot when they say the wrong color. In our case, there was a set time for each block. If participants finished the list before the block ended, they could manually discontinue by pressing a button. The block will then be shown as ended in Acqknowledge. However, if the participant took longer than the provided time, they were cut off in the middle of the naming list. We are not interested in the exact cognitive performance (i.e. time and accuracy), but the physiological reactions to this task, as it is cognitively demanding and therefore more “stressful”.
