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CogLab
explanation

Stroop Effect

What methods did we employ in this experiment?

On each trial you were shown a word (RED, GREEN, or BLUE) that was printed in either red, green, or blue font color. Your task was to classify, as quickly as possible, the font color, regardless of the word name.

The independent variable in this experiment was whether the word name and font color were the same or different. The dependent variable was the reaction time between the appearance of the stimulus and your response. Only trials in which you made the correct classification were kept. If a trial was incorrect, it was repeated later in the experiment.

What do we predict participants will do? Why?

The Stroop effect is that people tend to be faster at identifying the font color when the word name and font color are the same and are slower when they are different.

How robust is this effect? Are there limits to this effect?

Although not large in terms of absolute time, the Stroop effect is very robust. A common explanation for the Stroop effect is that observers (especially college undergraduates) have automatized the process of reading. Thus, the color names of the words are always processed very quickly, regardless of the color of the ink. On the other hand, identifying colors is not a task that observers have to report on very often, and, because it is not automatized, it is slower. The fast, and automatic, processing of the color name of the word interferes with the reporting of the ink color.

Average experiment results for class: cogusa05

Stroop Effect

Average reaction times (ms) for same or different word names and font colors. The expected finding is that RT for name and font same will be smaller than RT for name and font different.


Data summary:

Statistics are based on 39 participants.

Averages across participants

Condition RT (ms)
Name and font same: 907.6735
Name and font different: 1025.4957

Standard deviations across participants

Condition RT (ms)
Name and font same: 309.216
Name and font different: 319.774

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