The purpose of this study was to examine how language fluency affects processing speed and attention control in the Stroop Effect. The experiment was similar to the J. R Stroop’s experiment two. Stroop (1935) showed that reading words is quickly and automatically than naming colours. The interference happened when color and words are incongruent. There were 41 students in Human Development Program participated in this experiment. Participants were instructed to name the color in which a word is printed. Employed counterbalancing in the design to control order effects- where participants randomly assign to take English first, Spanish second or Spanish first, English second. The finding showed a causal relationship between both conditions. The results indicated that participants complete the Stroop test significantly faster in Spanish than in English. Participant made more errors in English than in Spanish due to color and word are incongruent (“RED” in blue ink). The processing time slowed down because the brain reads words quicker than it recognizes color. The brain also requires extra attention to identify the color. The experiment has proven the Stroop theory and supported the hypotheses. The results from this experiment were useful for further studies concerning the human brain disorders such as schizophrenia, strokes, ADH and etc…
The Link Among Languages, Processing Speed and Cognitive Inhibition
Human mind is one of most sophisticated object. In facts, it’s the combination of logic, intuition, analysis and construction, generally and individually (Fieser, 2008). Cognitive inhibition refers to the mind's ability to ignore disturbing stimuli and focus on relevant tasks. Cognitive ability is worth to investigate because it could give a prediction of future work performance such as solving problems, perform a task more efficiently and accurately (Bostrom, Sandberg, 2009). Many researchers have been used the Stroop effect to measured cognitive abilities and various perceptual.
The Stroop effect (or Stroop test) was first introduced by Ridley Stroop in 1935 and became widely used in a cognitive psychology study, demonstrated that brain’s reaction time is slow down when dealing with irrelevant information (Stroop, 1935); these low down happened due to the interference. Stroop (1935a) found that there was a processing delay when naming the colours that is written in different colour ink. The interference also occurs when individual read faster than recognize the color because reading is automatic for people. In his experiment, participants were informed to name the color of printed words and placed in two different conditions: congruent and incongruent. In the congruent condition, the color name and the color printed words were the same. For instance, the word says “RED” in red ink. Participants responded rapidly without any problems because color and words matched. In the incongruent condition, the color name and the printed words differ, presented with “RED” in blue ink. Participations took longer on this condition because the color and words did not match. In fact, reading words interfere with naming the color (Stroop et al., 1937).
After the experiment, two main theories were developed to explain the Stroop effect. These theories were: In speed of processing and selective attention theory. In the speed of processing theory, the brain read faster than recognize the color. In the selective attention theory, the brain requires extra attention to identify a color than to word encoding, this reason why it took a longer to process (Stroop, 1935b).
Dunbar & McLeod (1984) stated that automatic process could be suppressed through inference. Later, developed the relative speed of processing theory and argued that words reading carried out faster in comparison to color naming, assumed that the faster process inference with the slower process. In the studies of McKeen & Cattell (1886) showed that when look at the objects with colors, it took longer to name the color than to read the word of the color. For example, saying “blue” to a color was slower than saying blue to the word blue. In the case of words and letter, due to the fact that the link between the idea and the name has taken place so often, the process became automatic. On the other hand, in the case of colors and pictures, we must by voluntary pick its own name.
The Stroop effect has been widely used in monolingual and bilingual context in linguistic studies (Preston, Lambert, 1969). According to Dyer (1971) English monolinguals showed the maximal interference when naming colors of words that were written in English. In addition, he also found that declining interference when naming colors of words that were written in language other than English. By using Spanish-English bilinguals in his second experiment, Dyer found maximal interference when naming and diverting languages coexist, but there was also significant interference when the languages did not correspond. Approximately, the different between language conditions showed about 63% of the interference as compare in the same language conditions.
Dyer (1973) The Stroop test also used for diagnostic purpose (e.g. diagnoses brain damage) and used to measure a cognitive processes such as how well a person’s brain processing speed and selective attention are, how well a person can perform in a multi-task, words recognitions vs. color recognitions, languages. Also, look at brain structure and its functions and to test brain disorder such as stroke, ADHD, ADD etc…
The present study also conducted a Stroop Test to study inhibition in language. Since, people read faster than they name colors, they must suppress the inhibition reading to do things they less practical at; like naming colors for example. Indeed, word color-recognition requires extra attention and processing time in comparison to word recognition. This study aimed to prove the Stroop theory and examined how language fluency affects processing speed and attention control in the Stroop Test. Based on previous discussed research, the following hypotheses were proposed:
Hypothesis 1 – Participants will take longer to complete the Stroop test in English than in Spanish because it requires processing time to inhibit the meaning of the words.
Hypothesis 2- Participants will make more errors on a Stroop test in English than in Spanish due to its inhibit control aspect is more complicated.
Method
This was a casual experiment to examine the cause and effect relationships between two variables. Casual within subject designed to investigate how language fluency affects processing speed and inhibitory control in the Stroop Test. Also, employed counterbalancing in the design of experiment to overcome order effects – participants randomly assign to take English first, Spanish second or Spanish first, English second. Half within each order had version 1 vs. 2 of the randomly scrambled card.
1. The first hypothesis on the speed of processing- the independent variable was language (English=fluent vs. Spanish=familiar). The dependent variable was processing speed, operationally defined as time to complete test in second.
2. The second hypothesis on the attention control- the independent variable was language (English=fluent vs. Spanish=familiar). The dependent variable was inhibitory control, the operation defined as number of mistakes made out of possible 100.
Extraneous Variables:
Null Hypothesis: There will be no difference results when taking both English and Spanish.
Alternative Hypothesis: There will be a relationship between the results – English will take longer.
Participants
A total of 41 students in Human Development Program participated in this experiment. Everyone was an English fluent speaker and no one was colorblind. The experiment excluded all fluent Spanish speakers, people who incorrectly identified English color words and those who didn’t understand the Stroop Effect test. Initially, 41 participants excluded five students who reported they’re fluent in Spanish, and three who incorrectly identified English color words, final sample consisting of 33 individuals.
Materials
Four-color cards were designed: English words (define: red, blue, green, gray) – there are 100 words total, approximately ¼ congruent colors (e.g. the words RED in red ink), ¾ incongruent color (the words RED in blue ink). Spanish words (define: rojo, azul, verde, gris) – there are 100 words total, approximately ¼ congruent colors (e.g. the words ROJO in red ink), ¾ incongruent color (e.g. the words ROJO in blue ink). These 2 versions are randomly scrambled. Also, a survey that asked to match colors, monolingual or bilingual or fluent in Spanish.
Procedure
In class, participants were asked to participate in an investigation of experimenting the Stroop Effect. For the Stroop test, card English and card Spanish were given out. Employed counterbalancing methods, students were split into two groups. The first half of the group did the English card and other half did the Spanish card. In this experiment, students were instructed to name the color of the word, but not what the word says. For instance, for the word that say “RED” but in blue ink, student should say "Blue”. For each test, students recorded down the speed of time, accuracy and errors. Next, compared half class to another half class to find the number of errors; it showed that people who took English first tend to make more errors by saying the incorrect words of color than Spanish second. The last surveys were asked to match the color with the definition of the word by writing the number corresponding to the color that matches the printed word. If student does not know the matching color, students can take a guess. This survey was designed to see if students are monolingual or bilingual and fluent in Spanish. Finally, excluded all fluent Spanish speakers and people who incorrectly identified English color words for accurate results.
Data Analytic Plan
Time processing speed was converted into seconds. Recorded all errors as numbers of mistakes. Excluded Yes (as people who reported that they're fluent) for fluent in Spanish. Mean and Standard Deviation for both tests is calculated. Error bars represented standard deviations. Used dependent sample T-test to analyze both hypothesis.
Result
Hypothesis 1: Participants will take longer to complete the Stroop test in English than in Spanish because it requires processing time to inhibit the meaning of the word.
On average, participants performed faster in Spanish than in English (see Table 1). The results indicated that participants complete the Stroop test significantly faster in Spanish than in English t (33) = -8.98, p < 0.005 (see Table 1/Figure 1).
Hypothesis 2: Participants will make more errors on a Stroop test in English than in Spanish due to its inhibit control aspect is more complicated. The results showed that participants made more errors in English than in Spanish (see Table 1). The number of errors made on the Stroop test was also significant. Overall, participants made more errors in English than in Spanish t (33) = -2.97, p <0.005 (see Table 1/Figure 2)
Discussion
The goal of this study was to examine how language fluency affects processing speed and inhibitory control in the Stroop Test. The results of this experiment showed that the processing time performed on the Stroop test in Spanish was significantly faster than in English, as seen in figure 1. After the average and Standard Deviation for errors were calculated, it can be seen that English significantly made more errors than Spanish (see Figure 2). English was harder due to the color and meanings of the word are incongruent; it takes longer to identify the color due to the conflicting messages being received by the brain. The results supported both hypotheses and rejected the null hypothesis. Also, consistent with previous researched; the Stroop Effect (1935) where participants were placed in two different conditions: the congruent condition and incongruent condition. It was found that participants in the incongruent condition have significantly fewer reaction times compared to those in congruent condition, the brain took longer to resolve the conflicts between word-recognition and color-recognition. The theory of Dunbar & McLeod (1984) can also be applied to the results. Their researches have proven that controlled process was slower than automatic. Automatic process can be suppressed through inference since reading is automatic for people, word reading carried out faster than naming. Less interference when words and color were similar and more interference when words and color were different. In contrast to previous research, this study revealed greater knowledge and greater experience can increases the chance of inhibition effect.
Limitations and Further studies
Extraneous variables such as a limited number of words and very small printed words; making participants difficult to read the words, this could mean that printed words didn’t interfere as much, so the colour naming is quicker in both conditions. Confounding variables -were those participants who have poor reading skills but able to distinguish their colors. Also, uncontrolled variables like interfering noise could have affected the processing time and number of errors. Different people stop the stopwatch differently so maybe future studies can use one automated timekeeper. To increase the validity of the Stroop test, a more diverse gender should be taken into consideration. According to Kumar (2015) males may have faster reaction times as compared to female. Overall, the results from this experiment were useful for further studies concerning the human brain’s structure and it functions as well as further research on the brain disorders such as schizophrenia, strokes, ADH, ADD and other brain diseases.