Materials and Apparatus
The aim of this study was to find out if the Stroop (context interference) effect still remains robust. The tested condition only considered the colour naming part of the original Stroop test, examined with a consistent presentation of coloured ink words. 18 participants were selected by using a convenience sampling. The participants’ task was to name words’ ink colours. The times for accomplishing the task were taken in 2 trials, examining 3 lists of coloured ink words on a computer; containing nouns, nonsense, and colour names. It was predicted that there would be an effect of the type of word list on the time taken to name ink colours. Results supported the prediction and demonstrated that the effect on the participants’ ink colour naming time has been bigger for written colour names than for presented nouns or non-sense words. No statistical difference could be found between answering times of the last two groups. It was concluded that contextual effects, here the meaning of a word and its’ relation to the task of ink colour naming, could influence the answering time. In this study words representing colour names were slowing down the ink colour naming time most, as their meaning is closest related to the ink colour. This supports earlier findings about the validity and reliability of the Stroop effect.
Psychological research on attention and interference examined within colour naming (and reading) test has a long tradition, which reaches back to the 19th century (MacLeod, 1991). Stroop wrote one of the most known and cited papers in Cognitive Psychology in the early 20th century (MacLeod, 1991). This paper has shown, within a colour-naming (and reading) test with 3 conditions (black printed colour names, ink coloured colour names, and coloured squares – no words), how information processing (speed) is influenced, especially by contextual information. Participants had to name (and read) presented ink coloured words and their reaction time was measured. For example, the word RED was written in blue letters and participants had to read the word, or name the ink colour of the word.
A strong effect of interference of ink colours differing from the actual word (describing a colour) on naming time was found (Stroop, 1935). Participants were 74% slower in responding when the words were printed in colours, which were differing from the words meaning, than for black words. The ink colour was not reliably influencing the reading time (Stroop, 1935). Stroop (1935) could show that practice on naming the colours correctly (with and without interferences) had an effect, which was presented by an increased answering speed while naming tasks, but decreased speed while reading tasks. The strength of the learning effect decreased over time, which means that the first days learning effects are more impactful than later learning effects (Stroop, 1935). Similar tests are still used on patients with expected impairments or brain damages, to observe their brain functioning within reaction times (MacLeod, 1991).
In conclusion Stroop (1935) was measuring different effects. First, misleading contextual information, as not congruent spelled colour names (e.g. word RED in blue letters) are slowing down the answering time. Second, helpful contextual information (e.g. word RED in red letters) are increasing the reaction speed. And third, practice increases answering speed just for exactly the practiced task, while practice can impair with accomplishing other tasks. Just the inferential (contextual) effect of a meaning of a stimulus on the naming time was later acknowledged as the Stroop Effect. The experiment offers space for errors and misunderstandings, as many variables, like culture, age, expertise/practice level, or personality, etc., may influence the results, which is also a self-critical point about the work of Stroop (1935). This is why the effect has been demonstrated in a number of different ways with a variety of different materials. For example, Mutter, Naylor and Patterson (2005) examined the effects of age and task content and could not find any performance differences between age groups, while Wright and Wanley (2003) looked at differences between adults and children’s performance on the Stroop test.
After hundreds of Stroop-related articles in the literature the question arises, if the effect is still remaining as robust, or not. Appearing problems are how to interpret the different time scores and mistakes of the participants. One reason why this problem appears is because Stroop (1935) measured two different things in his test: first, the speed in reading a (black and coloured ink) word, and second, the speed in naming a colour (of ink or blocks). Even small amounts of practicing word reading can have an interfering effect on the speed of naming colours.
This is why this within-subjects study was examined with 3 sets, with coloured words only (nouns, non-sense, and colour names, as green or red) on 2 trials to establish controllable data. The participants had to name the ink colour of the words and their time was taken with a stopwatch. The aim was to find out if the Stroop effect (here: conflicts between word meanings and naming time of ink colours) remains robust under this more comparable condition of a not combined task of just naming ink colours, not reading the words. For this test the colour name list was expected to be the longest to read, as the written colour names (meanings) are conflicting with the ink colours. The second longest would be the noun set, as the reading time of the words is expected to delay the response. Finally, the shortest answering times should be produced on the nonsense list. The independent variable was the kind of presented words (nouns, non-sense, and colour names), and the dependent variable the time taken to name the ink colours of the words. The data type used was ratio, as time was measured. It is hypothesised there will be an effect of type of word list on time taken to name ink colours.
The test was examined on 18 participants, all second year Psychology students at the Abertay University. All participants were selected by using a convenience sampling. The gender was not taken into account. Every participant was tested on 2 trials in each of the 3 conditions.
Materials and Apparatus
The materials used in the experiment were a manual stopwatch; an instruction-sheet the examiner was reading to the participant (see appendix 1); 3 separate sets of coloured ink words (nouns, nonsense and colour words – see appendix 3), listed one below another, each on a separate PowerPoint slide; a Computer for the test with the programs PowerPoint (for the test) and also IBM’s SPSS (for the data analysis); and a Data collection sheet. The data collection sheet contained a table that recorded the time taken to recall the nouns, nonsense words and colour names in two different trials (see appendix 2).
After the participants received instructions about the task (appendix 1), they were asked to read out the colour of the words on the 3 lists on a computer. The lists were presented on Power Point. The time was taken when the participants started with naming the first word and stopped after the participants named the last word’s ink colour and said stop afterwards. After the participants finished with the last list, they were asked to repeat the same 3 lists to see if there was any noticeable time difference between each of the three lists. The data collection sheet was used to record the times taken with the stopwatch when each list was completed and the participants saying ‘stop’. After the data collection was finished the data was analysed with IBM’s statistic program SPSS. Descriptive and inferential statistics were run, and the data was compared with previous research results and discussed.
illustration not visible in this excerpt
Figure 1. Bar chart showing the mean time taken to name ink colours for nouns, nonsense and colour words with 95% confidence intervals.
The bar chart above shows that nonsense words took participants the shortest amount of time on average for naming the colour (mean = 13.32, CI min=11.49 max=15.89.). The list of coloured words took participants the longest amount of time (mean = 18.51, CI min=16.11 max=20.91), while nouns took the second longest time (mean = 13.54, CI min=11.19 max=15.89; see also appendix).
The parametric assumptions were met. Therefore, a paired samples t test was chosen to test differences between the groups. A t paired samples test was run and shown that there was no significant difference in time taken to read the nouns lists from the nonsense list [t (17) = .334, p = .742]. A paired samples t test was carried out between nouns and colour and was found to be a significant difference when it came to time taken to read the lists [t(17)= -7.14, p < .001]. A paired samples t test was also carried about between nonsense and colour and was also found to be a significant difference in time taken to read the two lists [t(17) = -10.15, p < .001].
- Quote paper
- Max Korbmacher (Author), 2016, Does the Stroop effect remain as robust today? How different kinds of coloured words are influencing the ink-colour naming speed, Munich, GRIN Verlag, https://www.grin.com/document/350510