The Stroop Effect In the Field of Experimental Psychology

The Stroop effect is a phenomenon that studies how distractions affect the reaction time while doing a particular task. The Stroop effect is an occurrence in the field of experimental psychology which was first noted by John Ridley Stroop in 1935.It was further researched on by other scientists in Germany and even published. It is used to demonstrate the reaction time of a task and is frequently used to show how our brain processes different information either via automatic or controlled processing.

The Stroop effect is a simple procedure that involves subjecting the human trials with two tasks whereby one is related to the direct aim of the task i.e. correctly naming the color provided together with its word which is the congruent task while the other (incongruent) is a repeat of the first but the color and name of the color do not necessarily match. This poses a challenge in focusing on the word rather than the color. The difference between the two times is known as the Stoop effect and the aim of this research is to minimize the stroop effect as the bigger it is the poorer the selective attention of a person which reflects in insufficient execution of tasks that come up in our daily lives which is full of interferences whether from the surrounding or in our cognitive make up. Different sensory stimuli is taken up by the brain differently and this is seen in the horse race model. Congruent stroop items are processed faster by the brain and they reach the finish line at the same time and there is no response competition in this case however for incongruent items, the word reaches the finish line sooner than the color then the brain starts another competition which is answer verification and the color in this case wins. This extra time of response verification results to a longer stroop effect. An investigation is done to whether there can be manipulation that will minimize the stroop effect using the horse race experiment to predict the outcome and how accurate it is.

IntroductionEvery day we are faced and bombarded with lots of information that needs brain processing all at once. We are therefore faced with the challenge of separating relevant information from irrelevant information as well as scheduling which task should be handled first and which last. Our brains have developed mechanisms of scheduling and processing data.

Use a random discrete-trial version of the Stroop color-word test to test hypothesis that the conflicting response is directly suppressed to allow the appropriate color response. (Neill, 1977, pg. 12). This data is relevant to our study as it reveals how our brains work through selective attention. Selective attention is required in our day to day activities. However, our brains prioritize specific activities above others which can become a challenge when the prioritized data is not relevant at that particular time. For example, our brains register words before color. Therefore, in a situation that requires us to identify color before words, the processing time in our brains is elongated. This phenomena is referred to as the Stroop effect. The difference in time for reading the words printed in colors and the same words printed in time for reading words printed in black is the measure of the interference of color stimuli upon reading colored words. (Stroop, 1935, pg. 643.). This information is relevant to the study as it offers that color information is processed slower than word information. This create the basis of our study which is to analyze the different response speeds during different tasks.

The Stroop effected was first noted in 1935 by one J.R Stroop in the field of experimental psychology. The original Stroop experiment involved color naming of word stimuli that was written in different ink colors. Some of the word stimuli was congruent meaning that the color name was written in its ink. For example; blue written in blue ink. The rest of the word stimuli was incongruent meaning that the color name was written in a different ink color. For example; BLUE written in red ink. When stimuli was presented to test subjects it took an averagely longer time to identify incongruent stimuli from congruent stimuli. The difference in time was then referred to as the Stroop effect.

The horse race model arose to seek to predict what happens when two stimuli are presented to the brain. In a horse race, both horses run towards the finishing line and just like the horses both stimuli; word and color, race to the finish line. Since the word information is processed faster than the color information it is likened to the faster horse which wins the race. The color stimuli on the other hand, arrives last at the finishing line in the model. Once information gets to the finishing line, that information starts to compete for the control of responding. In the case of the word blue in color red, the word information arrives first, urging the response to be blue which is incorrect. So that one can make the right choice, one must subdue the impulse to give blue as the answer and wait for the slower horse; color information, in order to give the appropriate reply.

In case of RED printed in blue ink, red arrives at the output buffer before blue does, even when the required response is blue. Although processed in parallel up to the output buffer, the buffer is single channel and the two responses must compete for entry (Kelly & Colin, 1984, pg. 624.). This information is relevant to the study as it reveals that word and color information must compete for final control of output which is the measure of our experiment.

In the case that the word blue is written in blue; the same race between word and color information will still occur. However, because the name and color of the stimuli is blue, there is no need to fight the urge to present the answer as blue. This is because, although the word information is the incorrect response, it is similar to the color and the answer will therefore still be accurate. This speed difference is seen as particularly critical when two potential responses (one from a word and one from an ink color) compete to be the response actually produced (Macleod, 1991, pg.188).This data is relevant to the study as we apply the theory that information wrestles to control the final output.

The horse race model however makes two fundamental assumptions. One; information is processed at different rates; that is word information is processed faster than color information. The second assumption is that information competes for control over responding. Responses are slower when response competition occurs than wen response competition does not occur. The specific aim of the experiment is to figure out if different tasks can lower or completely eliminate the Stroop effect. The experiment further seeks to prove the horse model as per its prediction of the outcome of the experiment. My hypothesis is that the Stroop effect will be greatly reduced or completely eliminated in the task factor as compared to the congruency factor in which the Stroop effect will still remain. This will therefore prove the horse race model to be an accurate one.

Methods Participants 19 students from Brooklyn colleges experimental psychology class had participated in an experiment which their reaction time to congruent items compared to incongruent items. Materials The study was conducted on a 15inch monitor, using METACARD software. The experiment included 8 possible target stimulus which was 4 possible word (red, green, blue, yellow) and 4 possible words (red, green, blue, yellow). Students used the keyboard to type in the possible answers.

Procedure

All students will respond to the task(IV), Congruency(IV), and Reaction time(DV). This experiment was a within subject design because all of the participants were given the same treatment. Task 1 and task 2 both consisted of 48 trials equally, equaling 96 trials all together, with each subject being 50/50. Task 1 required students to name the word while task 2 required students to name the color. A number of two participants were place in a cubical room with two desktops. Each student had their own desktop where they completed both task quietly so that the task can be done in the most accurate way. Participants was required to type in the word or color they see as quickly and accurate as they can while every trial was randomly selected by the computer. Participants were required to type in one of the four possible responses which were red, yellow, blue, and green.

At the beginning of the experiment the instructions were presented on the screen and next required participants type in their initials before beginning. Every trial had clear instructions, aside from the instructions given in the beginning of the experiment. In caps, it had what the participants was required to do, as well as what they needed to ignore in low case. For example, TYPE COLOR ignore word. Each trial began the task which was presented across the screen for 500ms followed by the stimulus which was the colored word. The colored word remained on the screen until the participant responded and moved on to the next stimulus by hitting the spacebar. When the experiment was done, the results were divided into two categories, color identification task and word identification with those having sub categories congruent and incongruent.

Results Many statistical test were ran through SPSS. In which it converted the average reaction time for all participants for congruent and incongruent items. In table 1, the reaction time for color congruency was (M= 1034.6842, SD= 235.82127) while word congruency was (M=798.5263, 149.82040). Included in table 1 were incongruent items as well resulting in color incongruent being (M=1293.3684, SD= 268.92899) and word incongruent being (M= 809.4211, SD= 167.16802). Based on these results, The Stroop Test says that congruent items resulted in a faster reaction time than incongruent items however, when we refer to word identification the reaction time is extremely faster than color identification. The results in table 2 for task is F(1,18) 150.561=P