Stroop Effect Automaticity is and important behaviour that allows frequent behaviours to be carried out unconsciously, while attention is diverted towards other, less familiar tasks. (Wheatley and Wegner, 2001). According to Goldenstein (2005), automatic response can be demonstrates b the Stroop effect, discovered by John Riddley Stroop, an American psychologist who illustrated autonomic processing and conscious visual control by demonstrating the effect of interferences in the reaction time of a task.
This demonstrates reading as an automatic processing. As automaticity is the result of learning and repetitive behaviour, for those who have had enough practice, reading words does not require the use of many cognitive resources and therefore can be performed quickly without much attention (Goldenstein 2005). However, by habitualising it through the presentation of a new stimulus, it can interfere with the automaticity of reading and hence becomes a more difficult task, requiring more attention.
In the Stroop task participants were presentednames of colours, in various colours of ink and asked to either read the word of the same colour (colour congruent), or state the color ink it was printed in (colour incongruent). (Stroop, 1935). Where normally an automatic process occurs without intention, participants experience conflict in this task. The results found that subjects had a slower reaction time to colour incongruent words (Stroop, 1935). This study has been repeated many times, all with similar results, and has led psychologists to conclude hat in such cases, readings an automated process, one that interferes with the ability of participants to state only the colour of the text. The purpose of this study was to investigate the Stroop effect through a computerized task by an application that creates and presents stimuli similar to those found in the original study by Stroop (1935). The methodology is laid in a way that similar to that used by Stroop presented with stimuli consisting of the names of colours in varying font colours
It was hypothesised, from knowledge built on the results of previous experiments and studies on the Stroop effect, that the participants would take the shortest amount of time to respond to stimuli when the words are colour congruent, longer when the words are colour incongruent and an intermediate speed with non colour words. Method Participants The participants for this experiment were 357 undergraduates from a first year psychology class at QUT chosen at random. No selection criterion was applied. Design
The independent variables in this experiment were the colour congruent, colour incongruent and non-colour words. The dependant variable was the reaction time from when the stimulus appeared to when the participant made a response. Using this information, means and standard deviations were calculated for the reaction times in each condition of the experiment. Apparatus and Procedure A Laboratory task called Stroop Effect was used for this experiment, where Participants completed the task on computers in a computer lab.
The task was accessed through a CD named PYB102 Experiments and accessed from a file named Lab 2 Stroop Effect. The task window was empty apart from the stimuli used in the tasks, The stimuli were 48 non-colour words (12 times for each of the 4 words), 48 colour words (12 times for each colour name) and printed colour of the words, which were manipulated so that each word appeared in each colour equally often, all presented in comfortably readable font. Participants used the keyboards provided to select their responses during the experiment.
They first read the instructions for the task displayed at the top of the screen informing them about which keys on the keyboard to select depending on which colour the font. Participants pushed the space bar when they were ready to begin the first trial. For each of the 96 trials, participants were presented with a word and prompted to clicked appropriate colour button to identify the colour the word was printed in, as rapidly as possible. Once their response was entered, the next stimulus appeared.
Once a trial had finished, participants clicked the space bar button to present the next trial. If the participant had selected the incorrect colour, the word “incorrect” appeared on the screen. . They were also warned if they gave the wrong response or if they took more than 2 seconds to respond. Both incorrect and slow (>2s) responses were excluded from calculation of average reaction times Results For colour congruent words, the average response time was 716 ms with a standard deviation (SD) of 71. 52 ms, whereas the average time for colour incongruent words is 784. 6 ms with a SD of 108. 50ms.
The response time for non-colour words on the other hand fall between these 2 figures with an average response time of 736. 13ms, with a SD of 78. 18ms. The difference between the variable are displayed by Figure 1 along with the standard error of each variable. Calculation of the t-test for reach variable were as follows: All three variables show that there were significant differences (p<. 001) in reactions times between the three conditions.
Discussion The results of the current study support the hypothesis. It was ypothesised that reaction times would be least rapid when the colour of the font differed from the name of the word presented as the stimulus, most rapid when the colour of the font was the same and intermediate when presented with non-colour words. . This prediction is supported by the obtained results because a significant difference was found to exist between the reaction times in the two conditions. Close examination of Figure 1 shows that the average reaction time when the font colour differed from the word name was, on average, over 80 ms longer than when the colour and word were the same.
The present study supports to the ideas proposed by Stroop (1935). There were, however, some limitations to this study, as the experiment did not taken into account is the participant were all native English speakers or spoke English as a second language, as the latte on the reaction time. An implication of this study might be to fuel more support to the theory that accepts reading as an automatic process, capable of interfering g with conscious process such as shown in the Stroop task.
Other than that, there is limited usefulness of this study, as this experiment has been replicated many times before. Nevertheless, future research on this would benefit from adding another variable to the experiment, preferably one unexamined in detail in relation to the Stroop effect. Such as one mentioned as a limitation, comparing the effect of subjects that do and do not English as their first language. Also, the impact of other factors such as gender, age etc. that were also unaccounted for in this study could be examined in future studies.
