Stroop effect
...vidual’s attention skills can be determined by external considerations (gain) and or internal considerations (enthusiasm), or whether they have had practice at the task presented to them or on a similar task. The nature of automatic and attentional processing styles was investigated by Shiffrin and Schneider (Anderson, 1995) and from these they developed the criteria that automatic processing allows tasks (normally simple or repetitive tasks) to be performed with virtually no conscious effort and these types of tasks are known to improve with practice (e.g. reading). On the other hand tasks which require attentional processing require fixed attention but, it can be difficult to decipher whether some processing is fully one or the other and there are suggestions that a degree of both is involved. (Eysenck & Keane, 1995). It is hoped that the processes involved in this particular presentation of the Stroop effect will show clearly whether automatic or attentional processing is to the forefront in this experiment. Method Design The experiment had a within subject and a repeated measures design. The independent variable was the reaction time of correct responses from each participant. The dependent variable was the cards. The subjects were split into groups of two and given 8 tests cards, 2 for each of the four conditions, plus 1 practice card which was of colour names printed in black ink, an experimenter’s key and a stop watch. Subjects 137 students from Psychology 2 tutorial groups at Edinburgh University were persuaded to undertake the task. The subjects were run in groups of two and given their materials to take to closed cubicles. Apparatus/Materials 17 laminated cards to each group Cards were broken down as follows:- 2 cards with asterisks in groups of four printed in 4 colours (****, ****, ****, ****) 2 cards printed with common words in four colours (not associated with colours) 2 cards printed with words (e.g. Grass) printed in incongruent colours (e.g. Grass) 2 cards printed with colour names (e.g. Red) printed in incongruent colours (e.g. Red) 1 card with practice words printed in black ink 8 cards with correct responses printed in black ink for each of the test cards Procedure Each group was asked to read experiment guide lines before entering cubicles these were. Participants were not allowed to point at the words they are reading. Participants are not allowed to touch the cards during the experiment. Participants are not allowed to squint, defocus their eyes, or adopt similar strategies which make it easier to ignore the text on the card. Participants must be reminded at the start of the experiment not to sacrifice accuracy for speed. If more than 3 errors per card made then card must be redone at the end of the experiment. Practice card presented first. Participant asked to simply read the colour names as fast as possible, reading from left to right and starting from top left hand corner of the page. At the beginning of each row the participant reports the row number, this enables the experimenter to check that rows are not read twice or missed out. For the 8 test cards, the participant reports aloud the colour of ink in which each word or block of asterisks are printed, reading from left to right, top to bottom and is timed from the point that the cover sheet is removed. Again the participant should read out the identity of each row to enable the experimenter to keep track. The experimenter must keep track of the error for these cards using the colour key for the particular card. Two to three errors per card can be tolerated, as participants will typically correct themselves anyway, anymore than this must be reported to the demonstrator. Once a participant had completed all 8 test cards the response time for the 2 cards of each type were added to provide an overall (summed) time for each of the four conditions, and data was enter on to the top row of a blank table. Roles were now reversed and data collected from the second half of the group. Data was collected from all subjects for analysis. Results After all 137 subjects had completed the task of naming the colours as quickly and accurately as possible, the data for each subject was collated and analysed by SPSS. The source of variation between subjects was calculated and is presented in Table 1. Table 1: Source of Variation between subjects. Source of variation Sum of squares Degrees of freedom Mean Square F-ratio Between people 10496.347 1.36 738.944 Between conditions 84294.474 2.549 33067.558 571.829 Error 20048.043 346.686 57.828 Totals F value Significance level df 4748.696 P=0.000 1 An ANOVA test gave the following statistics F-ratio = between people ÷33067.558 57.828 Significance between conditions is 3 and between people 2. p› 19.2 t...