The Stroop Phenomenon Essays - Neuropsychology, Perception

The Stroop Phenomenon Introduction The stroop phenomenon is a way of measuring how automatic or intentional some well practised tasks are and how we respond in conflict situations. This phenomenon also measures individual distinctions, originality and cognitive flexibility. The two aspects of cognitive development that are demonstrated by the stroop task are naming response and counting response. When two responses compete or are in conflict, the time required to make the correct decision is dependent on speed and accuracy. In the article "Tracing The Time Course of Picture Word Processing", by M.C. Smith and L.E. Magee; these two researchers found that picture naming was affected by the presence of incongruent words (Experiment 1). Also naming a picture was faster than when a congruent word was present. Therefore pictures activate the name code. Another experiment (Experiment 2) indicated that memory for pictures and words, whether they were initially named or categorized had an effect on memory. Memory was better for words if they have been categorized and for pictures if they have been named. Experiment 3 showed the same results as the previous two experiments. The fourth experiment, with the introduction of less common objects, subjects could name the words faster than generating a category name for the words. Naming pictures are prone to interference when incongruent words are presented simultaneously. Word naming is not as much influenced by distracting pictures. Pictures and words differ in the amount of information to be filtered out, to get the correct response. The design of this experiment is a within subject experiment as the number of choices to be made after viewing the stimulus on the screen are same for everybody (2,3,4). Also the meaning versus number choices (same, different, conflicting) are used by everyone. The dependent variables in this experiment are average accuracy (%) and average time/response (msec). the independent variable is the random stimulus which appeared on the screen, whether it was the same, different or conflicting. In this experiment we were shown 2, 3, or 4 items on the screen in a randomized form and had to select the right number of items using 2,3,4 on the keyboard as quickly and accurately as possible. In this experiment, the stroop task will be demonstrated. When there is no conflict between the stimulus and response to be chosen, responses will be quick and accurate. When there is a conflict between the stimulus and response to be made, interference will exist and responding will be slower and less accurate. Results & Discussion Figure 1 The average accuracy in percent for subject 1, was good for the 'same' condition. Then they started to decrease when the stimulus was 'different'. This score for subject 1 at the 'different' condition was the lowest among all 3 conditions. When the stimulus was 'conflicting', subject 1 was losing accuracy again and so was not as high as in the 'same' condition. Subject 1 was less accurate in the 'different' and 'conflicting' situations. The average accuracy in percent for subject 2, was quite consistent, being one hundred percent in all conditions. So this subject had a higher accuracy rate than subject 1. Figure 2 In relation to average time/response in milliseconds, subject 1 was quicker than subject 2. Then condition where subject 1 slowed down the most was in the 'different' condition. In the 'conflicting' condition, subject 1 increased their speed more than in any other condition. Subject 2 was quite consistent in all 3 conditions in relation to average time/response, with the milliseconds being only 3 or 4 different from the other conditions. For subject 2 the highest responding rate was in the 'conflicting' condition, followed by 'same', then the 'different' condition. This shows that in the 'conflicting' condition, the subjects response rate increased. In the 'different' condition the response decreased. Also if one subject has a higher accuracy rate than another subject, then the average time/response will be lower. The stroop task demonstrates that the naming response (same) is faster than the response used while counting (different) and that when 2 responses conflict (conflicting), the time to make a correct decision increases. Since people find the 'conflict' condition difficult, they will make more errors and take more time to determine the correct response. So the accuracy and response rate decreases in the 'conflict' situation. The difference in speed and accuracy in the 3 conditions (same, different, and conflicting) was the result of the experience with each specific condition. The more practice with each condition, the smaller the differences in speed and accuracy among the three conditions. When there