Stroop Effect


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Stroop Effect

  1. 1. Name of Student: Mak Koon Wing Kenneth Student number: 209310608 Module: 06PSC2220A Instructor: Walter Lam Experimental Project: Automaticity – Stroop Effect 1
  2. 2. Introduction Automaticity, conventionally known as habit formation, takes place from controlled processing to automatic processing. In controlled processing, an unpractised and unfamiliar task requires more focused attention. Effortful and conscious control of thought and behaviour with high mental concentration is needed. In controlled processing, the person can usually perform one task at a time and is slow, flexible and open to change. However, in automatic processing, practice and familiarity with a task decrease the required mental effort and attention. Processing of information automatically with minimal effort and conscious awareness. The person can perform several different activities at the same time and one’s performance is rapid and inflexible. According to E. Bruce Goldstein (2005), automatic processing can be demonstrated by the Stroop effect, in which the names of words interfere with the ability to name the colour of ink used to print the words. The reason the Stroop effect shows automatic processing is that reading the words occurs automatically, without the person’s intention to do so. Although reading the words uses few cognitive resources, it does use enough resources to slow down the speed of saying the colours. In other words, according to the tutor’s lecture note, literate adult participants have had so much practice reading meanings of words that the task requires little attention and is performed rapidly. However, when a task is automatized and habitualised, it is hard to inhibit and may interfere with other unfamiliar task on the same stimulus which requires much attention. In short, when a word is presented to a participant, the participant need perform simultaneously two tasks, namely reading the meaning of words and recognising their colour. Reading the meaning of words is automatic processing whereas recognising the colour of these words is controlled processing. According to Robert L. Solso etc (2005), an automatic process occurs without intention. In the case of Stroop Test, participants normally experience conflict between these two tasks and frequently read the words when asked to name the colours. Reading, a more powerful automatic process, takes some precedence over colour naming and occurs without the intention of participants. Besides, automatic processes are concealed from consciousness and consume few or no conscious resources. Participants are told to not pay any attention to the word names and simply to report the colour of the ink. The predictions/ hypothesis of the Stroop test are stated as follows: 1. Participants are slower to properly identify the colour of ink when the ink is used to produce colour names different from the colour of the ink. That is, participants are slower to identify red ink when it spells the word blue. 2. Native English speakers experience a greater interference of saying the colour of the ink when the words are written in English than English-as-a-second- language Chinese speakers do. 3. Chinese illiterate in English experience no interference of saying the colour of the ink when the words are written in English instead of Chinese. 2
  3. 3. Methodology What methods are used in this experiment? The software, CogLab 2.0, will be used. On each trial, the participant will be shown a word (RED, GREEN, or BLUE) that is printed in either red, green, or blue font colour. The participant’s task is to classify, as quickly as possible, the font colour, regardless of the word name. The independent variable in this experiment is whether the font colour and word name are the same or different. The dependent variable was the reaction time between the appearance of the stimulus and the participant’s response. Experimental design is within-subject design as the same experimental participant is exposed to more than one condition. (i.e. font colour and word name) What are the procedures of the experiment? 1. Start a trial by pressing the space bar. Stare at the fixation dot in the middle of the window. 2. A short time later, a word (RED, GREEN, or BLUE) will appear on the screen, and the word will be displayed in either a red, green, or blue colour. Your task is to classify, as quickly as possible, the font colour, regardless of the word name. 3. If the font colour is red, press the h key; for green, press the j key; for blue, press the k key. It may take some practice to remember which key corresponds to which font colour. 4. After pressing a key to identify the font colour, you will receive feedback on whether your answer is correct. If you are incorrect, the trial will be repeated later in the experiment. 5. If you find yourself making lots of mistakes, you should slow down or make sure you understand which key corresponds to which font colour. Press the space bar to start the next trial. 6. There are at least 45 trials, 30 in which the font colours and word names are different, and 15 in which the font colours and colour names are the same. You can also discard a trial by pressing the t key instead of identifying the font colour. 7. Discarding is appropriate if, after starting a trial, you get distracted. Discarded trials will be repeated later. Your data will be displayed as a table and a plot. What is the background of participants? 23 participants are invited to participate in Stroop Test. All participants aged below 40 received education of at least Form 5. 20 participants are divided into two age groups: 20-29 and 30-39. Within each age group, 5 male participants and 5 female participants took the test. The last three include a young native English speaker and two old native Chinese illiterate in English. 3
  4. 4. Result and analysis The details of participants are tabulated as follows: Age Sex Reaction time Reaction time Difference in Remark (name and font (name and font RT (See code same) different) below.) 24 F 806.5 869.5 63 ESL 25 F 910.7 1034.8 124.1 ESL 26 F 830.5 1058.7 228.2 ESL 28 F 755.8 869.9 114.1 ESL 29 F 863.5 1012.5 149 ESL 20 M 950.3 1015.6 65.3 ESL 21 M 735.4 796.5 61.1 ESL 26 M 735.5 793.5 58 ESL 27 M 746.5 790.5 44 ESL 29 M 946.2 1103.5 157.3 ESL 30 M 869.5 946.5 77 ESL 33 M 765.5 795.6 30.1 ESL 34 M 900.5 1010.5 110 ESL 34 M 867.5 965.4 97.9 ESL 38 M 1110.5 1335.5 225 ESL 30 F 958.3 1010.4 52.1 ESL 34 F 890.6 1105.5 214.9 ESL 35 F 821.5 998.6 177.1 ESL 35 F 1108.5 1306.5 198 ESL 37 F 1144.6 1333.3 188.7 ESL *23 F 890.3 1198.8 308.5 NES *65 F 1430.5 1435.6 5.1 EIC *70 M 1411.9 1406.8 -5.1 EIC Note: * these three data are excluded from calculation into the following table. (Code: ESL : English-as-a-second-language Chinese ; NES: Native English speaker; EIC: English-illiterate Chinese) The following table shows the averages of various variables. Age group Average RT (name Average RT (name Average & font same) & font different) different in RT All age groups 885.9 1007.6 121.7 20-39 20-29 828.09 934.5 106.41 30-39 943.7 1080.78 137.08 20-29 male only 822.78 899.92 77.14 20-29 female only 833.4 969.08 135.68 30-39 male only 902.7 1010.7 108 30-39 female only 984.7 1150.86 166.16 From my data, the following findings are observed: Generally speaking, the average reaction time (name & font different) is larger than the average reaction time (name & font same) in both age groups (20-39). This result is in line with the prediction 1 that participants are slower to properly identify the colour of ink when the ink is used to produce colour names different from the colour of the ink. 4
  5. 5. From the two age groups, the elder age group (30-39) has a larger reaction time than the younger age group (20-29) in both reaction times. This implies that younger adults response faster than elder adults do. Within the age group (20-29), male participants responded faster than female counterparts. Within the age group (30-39), male participants also responded faster than female counterparts. From the data, the average difference in reaction time is larger in: • age group 30-39 than 20-29 • female than male in age group (20-29) • female than male in age group (30-39) • age group (30-39) than (20-29) in male participants • age group (30-39) than (20-29) in female participants Discussion Hypothesis (1) is true for English-as-a-second-language Chinese in both age groups and both sexes. All 20 data support this hypothesis, as shown from the greater reaction time for name and font different than that for name and font same. However, hypotheses (2) and (3) need more data for further confirmation, as not many native English speakers or old adults can be located in my vicinity to participate in the test. The reaction time generally increases when the age increases and when the participant is female instead of male. Whether a maturer adult takes more time to inhibit the automatic processing (learning the meaning of words quite well) or to learn the controlled processing, or both to different extent remains my further exploration and justification. One may argue that an older adult is more well-trained and familiar with the automatic processing whose interference facing him/her is larger. On the contrary, one may also argue that it is more difficult for an older person to learn a new trick than younger ones. There are some interesting points to note from the three anomaly data. The native English speaker seems to get most interfered by the meaning of the words while deciding on the colour of the fonts, as shown from her greatest difference in reaction time in comparison to all other participants. Probably, no translation is needed from second language to mother tongue and she faces greater interference than English-as-a-second-language Chinese participants do. Unfortunately, only one native English participant is insufficient in number to support this hypothesis. More data are needed to show and compare the trend in different groups. For all Chinese participants who studied English as a second language, the interference from meaning of English words might not instantly affect the font colour recognition process as a translation process from English to Chinese is needed. The meaning making process of English words takes more steps for Chinese. Whether the English-to-Chinese translation process further complicates and interferes the font colour recognition process, or the participants translate and make sense of the meaning of the English words after the font colour recognition process takes place, depends very much on how the participants process a second language (maybe, English-to-Chinese translation is not 5
  6. 6. needed!) and make sense of the second language. Certainly, this requires further exploration! Both Chinese participants illiterate in English reported very little difference in reaction time. This indicates that the meaning of the English words is irrelevant to them, as they do not know English at all, not even as simple as ABC. They simply reported the colour of the English words without being interfered by the words’ meaning. Taking all these data into consideration, I think that Stroop effect is supposed to be more prominent for native English speakers than English-as-a-second-language Chinese do, as the test is conducted in English words. However, English-as-a-second- language Chinese also report Stroop effect but to a different extent. Another variable (how the Chinese participants who studied English as a second language make sense of the English words) may be operating. The proficiency of English, the presence of translation effect and whether the meaning of the English words can directly invoke their meaning in the perceiver without resorting to translation do affect, to a certain extent, the reaction time, but all these factors are beyond the scope of my experiment and surely need my further exploration. Maybe, I also need inquire their HKCEE or HKALE English grades in comprehension to testify or falsify the correlation between their English examination grade and the extent of the Stroop effect! To get a more accurate prediction from the Stroop effect for local Chinese, mother-tongue (Chinese characters) should be used instead of English words (a second language), so that the automatic processing of the meaning of Chinese characters would instantly interfere with the controlled processing of stating the colour of Chinese characters by native Chinese, without the need to take translation into meaning-making process. Another prediction is that the more the participants practise the controlled processing (stating the colour of the font), the more such a process approximates automatic. Some participants even reported that on a few practices, they managed to press the appropriate keys on keyboard corresponding to the colour of the words without the same degree of thinking as they initially did. Some even develop the shortcut or expert knowledge to perform the task, simply by focusing on one letter at either end of the whole words so that they need not read the whole words to grasp the meaning of the words before they can state just the colour of the last letter. According to what they claimed, they reported smaller interference by the automatic processing while performing the controlled processing, which may approximate automatic upon more repetitions. In other words, the extent to which controlled processing approximates automatic depends on participants’ intelligence in acquiring the knowledge or skill sets to perform the once unfamiliar task (controlled processing). Similarly, is the reaction time related to the cognitive style or other mental ability of the participants? This question remains to be answered! 6
  7. 7. Conclusion Stroop effect is observed in native English speakers and native Chinese who studied English as a second language. However, for native Chinese illiterate in English, the Stroop effect is not found! Reference 1. Goldstein, E. B. (2005). Cognitive Psychology: Connecting Mind, Research and Everyday Experience. Belmont, Calif.: Wadsworth; London : Thomson Learning. 2. Robert L. Solso, M. Kimberly MacLin, Otto H. MacLin (2005). Cognitive Psychology (7th ed) Boston, MA : Pearson/Allynand Bacon. 7