In the classic Stroop effect, conflicting information from color words and the color of the ink they are printed in makes it difficult for the person to focus on just the word or the color of the word. In this case, both of the stimuli are visual. Other people have tried many variations on the original Stroop effect. For instance, a study by Ferstrom (1996) used tried doing a purely auditory Stroop effect with much success. Another study by Cowna and Baron (1987) tested adding an auditory stimulus to the original Stroop by playing a recording of a person saying color words while the participant was reading a list of color words printed in diferent colored inks. With three types of conflicting stimuli, the participants took even longer to list the colors of the words presented than when presented with just the list itself. However, if tested seperately, was ir the visual stimulus of the color word or the auditory stimulus of the recording that was more confusing to the participant? The following experiment was designed to test this.
For the experiment, thirty students from a small college were chosen as participants. The participants were told that the experiment was measuring reaction time, but were not told of the conflicting information that would be present. The main part of the experiment consisted of three seperate video segments, each of which contained twenty trials. Each featured the experimenter presenting the stimuli. To record the keys that were hit by the particiants, a computer program called "Eye-Lines" was used (Beagley, W.K. 1990). Each of four keys represented a box of a certain color; red, yellow, green, or blue. The four keys were in the same order on the keyboard as they were on the television screen. In each of the video segments, there were four colored pieces of contruction paper, one red, one yellow, one green, and one blue. The participants were seated in front of the computer with one finger on each of the "a", "s", "d", and "f" keys, which were the keys chosen to represent the different colors for this experiment.
The participants were told to watch the video. The first video segment opened with the experimenter telling the participants to "Hit the key which corresponds to the color that I instruct you to." Then, the experimenter on the video proceeded to point to and say a color at exactly the same time. For this control video it was the same color. There were twenty of these trials done at a steady rate, with approximately two seconds between each. The second video segment was designed to test conflicting visual stimuli, and is referred to as the visual group. It opened with the experimenter instructing the participants to "Hit the key which corresponds to the color that I tell you to." This video was the same as the control except for that each of the trials the color pointed to and the color said were not the same. In this way errors that were made by the participants could be assumed to have been caused by the confusing visual stimuli. To test conflicting auditory stimuli, the third video opened with the experimenter saying to the participants "Hit the key which corresponds to the color that I point to." As with the previous video segment, errors caused can be assumed to be due to the conflicting stimuli, except in this case it was auditory. But for this difference, it was the same in design as the second video.
As shown on the graph, the auditory group made many more errors than the other two groups (see figure 1). On average, each person made about 1.3 errors in both the control and the visual groups. However, in the Auditory group, the average per person was 7. From these errors, it can be assumed that the conflicting auditroy information is much stronger.
These results may be questioned, but they do show that conflicting auditory stimuli is more confusing to people than visual stimuli. There are some possible explanations. For one, virtually all of the participants were college students. From previous experience, they are probably conditioned to listen to teachers and professors. Thusly, they would pay more attention to what was said on the video. Another possibility is that as most of the participants were female, the results might have been different if there was more equal representation. As was proved in their 1996 experiment, Weekes and Zaidel found that men are more susceptible to the Stroop effect than women. There is also, of course, the chance that auditory stimuli are generally stronger than visual. There are many implications on the findings of this experiment. For instance, advertising should spend more time on catchy jingles than flashy images. On a more serious note, maybe the education system should focus more on in-class lecture than after-school reading.
Beagley, W.K. (1990) Eye-Lines computer program
Cowan, N. & Barron, A. (1987) Cross-modal, auditory-visual Stroop interference and possible implications for speech memory. Perception and Psychophysics, v.41(5), 393-401
Fernstrom, M. (1996). An Experiment on the Stroop Effect and hearing. http://www.ul.ie/~cscw/mikael/stroop.html
Weekes, N.Y. & Zaidel, E. (1996). The Effects of Procedural Variations on Lateralized Stroop Effects. Brain and Cognition, v.31, 308-401