The primary purposes of the lab are to replicate and investigate the Stroop Effect. Along the way, though, you will hopefully learn about the related topics of automatic mental processes and response times as a dependent variable.
The Stroop effect was first described in 1935 by the scientist whose name it now bears. Generally, the Stroop effect refers to the difficulty observers have in eliminating meaningful but conflicting information from a task, even when that information is irrelevant or counterproductive in that task. The Stroop effect can be manifest as ³interference,² that is, when one mental operation degrades the performance of another.
The Stroop Effect can also be manifest as ³facilitation,² that is, when one mental operation enhances the performance of another. The classic demonstration of the Stroop effect is produced when one tries to name the color of the ink in which a word is printed when the word itself is the name of a color other than that of the ink (Reed, 1988). Typically, one is slower in this situation than if the word is not a color term. This form of Stroop interference is thought to be evidence for the automatic nature of reading. ³Automatic² in this context refers to an activity, such as reading, that is so well learned that it is occurs even when one attempts to suppress it (Reed, 1988). The interference probably arises when different words in the mental lexicon representing the color terms are activated by both the words and the ink color and ³compete² with one another, slowing the overt response.
In this lab, we will try to do the following:
As in some of the previous experiments, students in a lab should first pair off into different pairs, and the members of each pair should take turns acting as subject and experimenter. The stimuli are three lists of words printed in different colors. Each list represents three different experimental conditions that vary in the relationship between the words themselves and the color of the ink. Each list is labeled, indicating which experimental condition it represents:
In order to conduct the experiment, a program called ³stroop² should be started by double-clicking on it¹s icon. Once it starts, it will show the instructions in a window. After reading through the instructions, the experimenter and participant should follow them. That is, the experimenter should determine a randomized list of experimental conditions, preceeded by practice, and write these conditions on the left margin of a piece of paper. On each trial, the experimenter should tell the participant the condition, so that the participant can selec tthe condition from the list of buttons on the screen. The experimenter should also check the particpant¹s accuracy of color naming, and make sure the particpant corrects themselves before proceeding. Finally, the experimenter should record the color naming times on the piece of paper after each trial.
In the experiment, each participant will be presented with each stimulus on two occasions, once in their in their normal orientation, such that the words are ³right side up,² and once ³inverted,² such that the words are upside down. On each trial, the participant should name the colors of the ³ink² of each item, naming from top to bbottom, and left column first. They should name the ink colors as rapidly and as accurately as possible, and try to ignore the written words. A random ordering for an entire experiment, to be used on a single subject, might be the following:
Trial Condition Practice Practice
After all students have been tested, the data for the entire lab group should be entered on a summary sheet on each computer. Then complete the following data analysis steps (the last three correspond to the questions/issues proposed above):
The Present Lab Report.
You should write a complete lab report, from title page to figure. The following tips and ideas should help you. You should elaborate on items listed below.
Refer to Reed article
Insert the one made with the Excel spreadsheet