Perceptual and Muto? Skills, 1979, 49, 400-402. @ Perceptual and Motor Skills 1979
EXAMINATION STRESS A N D PERFORMANCE ON A COLOR-WORD INTERFERENCE TEST COLETTE R A Y University College, Cardiff' Summary.-Interference observed in the Stroop color-word task is influenced by various characteristics of the words employed. 38 students in their final year, approaching examinations, were asked to name the colors of words associated with this theme. These words produced greater delay than a control set, and those students who were most anxious about the examinations experienced most interference. This effect might be more generally employed in stress research, providing a performance-based index of reaction to issues or situations which are potential sources of anxiety.
The color-word interference effect refers to the delay in response which occurs when a subjecc is asked to name a series of colors and each stimulus is presented as a word incongruent with the required color name (Stroop, 1935). Theoretical explanations of this phenomenon include perceptual distraction, competition berween encoding strategies, and response conflict at either a covert or overt level (Hock & Egeth, 1970; Windes, 1968; Morton, 1969; Jensen & Rohwer, 1966). Indeed, there is some evidence that interference may occur at several distinct stages of color processing (Ray, 1974). In the original form of the task the irrelevant words were the names of the colors which comprised the focal scimulus dimension. Characteristics of the words may, however, be varied and a study made of the influence of such variations upon their interference potential. For example, Klein (1964) first observed the existence of a 'semantic gradient,' with color names producing more delay than color associates and the latter producing more delay than neutral words. This finding not only had implications for an understanding of the interference effect but also suggested ways in which this might contribute to the investigation of unrelated phenomena. Thus interference tasks have been used co study che relation between different linguistic systems (Preston & Lambert, 1969; Dyer, 1971) and semantic structures within given perceptual domains (Hock & Pecrasek, 1973). In this study the influence of the words' meaning was again investigated, but in this case the characteristic varied was one which may be defined independently of any relationship wich the required response of color naming. Ic was hypochesized that words which elicit anxiety would produce more interference than words which are affectively neutral. Initial support for this hypothesis had been obtained in an unpublished study in which a set of words referring to a variety of stressful themes, e.g., cancer, produced significantly greater interference in color naming than a control word set. The present study 'Now at Brunel University, School of Social Sciences, Department of Psychology, Uxbridge, Middlesex UB8 3PA.
STRESS AND COLOR-WORD INTERFERENCE
401
adopted an alternative approach which permitted the testing of a secondary hypothesis: that the interference potential of such words would vary with their implications for the individual. The subjects were undergraduate students who were tested about four weeks before the beginning of their final examinations. The experimental condition comprised words related to this single theme. It was predicted not only that the latter would produce more interference than the control word set but that this effect would interact with variations between students in the anxiety experienced at this time. Four 6 X 12 color-word matrices were prepared, two for each of the two conditions. The words in the experimental condition were all related to the theme of examinations, e.g., exam, failure, while the words in the control condition, matched for frequency and length, referred to parts of the body. There were nine words in each set, and these were printed in the colors brown, red, green, and blue. Thirty-eight subjects of both sexes were tested; students of psychology were excluded. The subjects were led to believe that the study concerned the relationship between personality and color-naming ability, and the topic of examinations was not mentioned until the conclusion of the session. Before beginning the colornaming task they were asked to complete the State-Trait Anxiety Inventory (Spielberger, e t al., 1970), and to practice color naming under interference conditions but with words different from those employed in the subsequent task. The four color-word macrices were then presented in balanced order, with the examination-related word matrices appearing either in the first and fourth or second and third positions. Subjects were instructed to name the colors of the stimuli row by row and to do this as accurately and as quickly as possible. Response times for the two trials within each condition were averaged, and subjects were divided into three groups on the basis of their state-anxiety scores. Color-naming times were then submitted to a repeated-measures analysis of variance in which word list, state-anxiety, gender, and order of presentation were the four factors, with trait anxiety as a covariate. The only significant effects were word list (F = 15.54, df = 1/26, p < .001) and the interaction between word list and state anxiety ( F = 3.42, df = 2/26, p < .05). The mean response times in each word-list condition broken down by state anxiety are presented in Table 1. Both hypotheses were supported; the words related to TABLE 1 MEANCOLOR RESPONSETIMES( I N SECONDS)FOR EXAMINATION AND NEUTRAL WORDLISTS word ~ i s r low ( n = 1 2 ) M SD
Neutral Examination
46.95 48.09
4.71 5.06
Stace anxiery moderate (n = 1 4 )
high ( n = 1 2 )
M
SD
M
SD
49.23 50.56
5.01 6.22
51.49 56.28
8.64 9.46
402
C RAY
the stressful theme of examinations produced more interference than neutral words and this effect was enhanced for those subjects who were experiencing most anxiety during this period. It should be noted that other studies of the effects of stress or arousal on color-word response times have produced inconsistent results. For example, Callaway and Stone ( 1960) and Agnew and Agnew ( 1963) found decreased response times associated with the influence of a stimulant drug and threat of electric shock, while Hochman found that stress elicited by a reduced inter-stimulus interval affected performance adversely (1967). The present study indicates that the effects of arousal on performance will depend not only on the source of the arousal but also upon the relationship between this and the nature of the stimuli presented. Here state anxiety was not significantly related to performance in a neutral word condition, but a significant decrement in performance was observed where the stimuli were relevant to the presumed source of the anxiety. This finding suggests a possible application of the color-word interference task in research on stress, with color response times being considered alongside self-report and physiological measures as an index of stress. Such an application would, of course, be appropriate only for those contexts in which the stressor may be specifically identified and represented thematically in the word component of the color-word stimuli. REFERENCES AGNEW, N., & AGNEW, M. Drive level effects on tasks of narrow and broad attention. I. exp. Psychol., 1963, 15, 58-62. CALLAWAY, E., & STONE, G. Pre-evaluating focus of attention. In L. Uhr & J. G . Miller (Eds.), Drugs and behavior. New York: Wiley Interscience, 1960. Pp. 11-27. DYER,F. N. Color naming interference in monolinguals and bilinguals. I , verb. Learn. verb. Behav., 1971, 10, 297-302. HOCHMAN, S. H. The effects of stress on Stroop color-word performance. Psychon. Sci., 1967, 9, 475-476. HOCK,H., & EGETH, H. Verbal interference with encoding in a perceptual comparison task. 1. exp. Prychol., 1970, 83, 299-303. HOCK,H., 8r PETRASEK. J. Verbal interference with perceptual classification: the effect of semantic structure. Percept. Psychophys.. 1973. 13. 116-120. JENSBN. A. R., & ROHWER, W. D. The Stroop color-word test: a review. Acta Psychol., 1966, 25, 36-93. KLEIN,G. J. Semantic power measured through the interference of words with color naming. Amer. J . Psychol., 1964, 77, 576-588. MORTON.J. Interaction of information in word recognition. Psychol. Rev., 1969, 76, 165-178. PRESTON. M. S.. & LAMBERT. W. E. Interlingual interference in a bilingual version of the Stroop color-word test. I. verb. Learn. uerb. Behav., 1969, 8, 295-301. RAY, C. Some components of color-word interference and their relationship with field dependence. Acta Psychol., 1974, 38, 323-330. SPIELBERGER.C. D., GORSUCH, L., & LUSHBNE, R. E. Manual f o r the State-Trait Anxiety Inventory. Palo Alto: Consulting Psychologists Press, 1970. STROOP,J. R. Studies of interference in serial verbal reactions. J. exp. Pjychol., 1935, 18, 643-662. WINDES.J. D. Reaction time for numerical coding and naming of numerals. 1. exp. P~ychol.,1968. 78. 318-322.
Accepted August 1 , 1979.
EXAMINATION STRESS A N D PERFORMANCE ON A COLOR-WORD INTERFERENCE TEST COLETTE R A Y University College, Cardiff' Summary.-Interference observed in the Stroop color-word task is influenced by various characteristics of the words employed. 38 students in their final year, approaching examinations, were asked to name the colors of words associated with this theme. These words produced greater delay than a control set, and those students who were most anxious about the examinations experienced most interference. This effect might be more generally employed in stress research, providing a performance-based index of reaction to issues or situations which are potential sources of anxiety.
The color-word interference effect refers to the delay in response which occurs when a subjecc is asked to name a series of colors and each stimulus is presented as a word incongruent with the required color name (Stroop, 1935). Theoretical explanations of this phenomenon include perceptual distraction, competition berween encoding strategies, and response conflict at either a covert or overt level (Hock & Egeth, 1970; Windes, 1968; Morton, 1969; Jensen & Rohwer, 1966). Indeed, there is some evidence that interference may occur at several distinct stages of color processing (Ray, 1974). In the original form of the task the irrelevant words were the names of the colors which comprised the focal scimulus dimension. Characteristics of the words may, however, be varied and a study made of the influence of such variations upon their interference potential. For example, Klein (1964) first observed the existence of a 'semantic gradient,' with color names producing more delay than color associates and the latter producing more delay than neutral words. This finding not only had implications for an understanding of the interference effect but also suggested ways in which this might contribute to the investigation of unrelated phenomena. Thus interference tasks have been used co study che relation between different linguistic systems (Preston & Lambert, 1969; Dyer, 1971) and semantic structures within given perceptual domains (Hock & Pecrasek, 1973). In this study the influence of the words' meaning was again investigated, but in this case the characteristic varied was one which may be defined independently of any relationship wich the required response of color naming. Ic was hypochesized that words which elicit anxiety would produce more interference than words which are affectively neutral. Initial support for this hypothesis had been obtained in an unpublished study in which a set of words referring to a variety of stressful themes, e.g., cancer, produced significantly greater interference in color naming than a control word set. The present study 'Now at Brunel University, School of Social Sciences, Department of Psychology, Uxbridge, Middlesex UB8 3PA.
STRESS AND COLOR-WORD INTERFERENCE
401
adopted an alternative approach which permitted the testing of a secondary hypothesis: that the interference potential of such words would vary with their implications for the individual. The subjects were undergraduate students who were tested about four weeks before the beginning of their final examinations. The experimental condition comprised words related to this single theme. It was predicted not only that the latter would produce more interference than the control word set but that this effect would interact with variations between students in the anxiety experienced at this time. Four 6 X 12 color-word matrices were prepared, two for each of the two conditions. The words in the experimental condition were all related to the theme of examinations, e.g., exam, failure, while the words in the control condition, matched for frequency and length, referred to parts of the body. There were nine words in each set, and these were printed in the colors brown, red, green, and blue. Thirty-eight subjects of both sexes were tested; students of psychology were excluded. The subjects were led to believe that the study concerned the relationship between personality and color-naming ability, and the topic of examinations was not mentioned until the conclusion of the session. Before beginning the colornaming task they were asked to complete the State-Trait Anxiety Inventory (Spielberger, e t al., 1970), and to practice color naming under interference conditions but with words different from those employed in the subsequent task. The four color-word macrices were then presented in balanced order, with the examination-related word matrices appearing either in the first and fourth or second and third positions. Subjects were instructed to name the colors of the stimuli row by row and to do this as accurately and as quickly as possible. Response times for the two trials within each condition were averaged, and subjects were divided into three groups on the basis of their state-anxiety scores. Color-naming times were then submitted to a repeated-measures analysis of variance in which word list, state-anxiety, gender, and order of presentation were the four factors, with trait anxiety as a covariate. The only significant effects were word list (F = 15.54, df = 1/26, p < .001) and the interaction between word list and state anxiety ( F = 3.42, df = 2/26, p < .05). The mean response times in each word-list condition broken down by state anxiety are presented in Table 1. Both hypotheses were supported; the words related to TABLE 1 MEANCOLOR RESPONSETIMES( I N SECONDS)FOR EXAMINATION AND NEUTRAL WORDLISTS word ~ i s r low ( n = 1 2 ) M SD
Neutral Examination
46.95 48.09
4.71 5.06
Stace anxiery moderate (n = 1 4 )
high ( n = 1 2 )
M
SD
M
SD
49.23 50.56
5.01 6.22
51.49 56.28
8.64 9.46
402
C RAY
the stressful theme of examinations produced more interference than neutral words and this effect was enhanced for those subjects who were experiencing most anxiety during this period. It should be noted that other studies of the effects of stress or arousal on color-word response times have produced inconsistent results. For example, Callaway and Stone ( 1960) and Agnew and Agnew ( 1963) found decreased response times associated with the influence of a stimulant drug and threat of electric shock, while Hochman found that stress elicited by a reduced inter-stimulus interval affected performance adversely (1967). The present study indicates that the effects of arousal on performance will depend not only on the source of the arousal but also upon the relationship between this and the nature of the stimuli presented. Here state anxiety was not significantly related to performance in a neutral word condition, but a significant decrement in performance was observed where the stimuli were relevant to the presumed source of the anxiety. This finding suggests a possible application of the color-word interference task in research on stress, with color response times being considered alongside self-report and physiological measures as an index of stress. Such an application would, of course, be appropriate only for those contexts in which the stressor may be specifically identified and represented thematically in the word component of the color-word stimuli. REFERENCES AGNEW, N., & AGNEW, M. Drive level effects on tasks of narrow and broad attention. I. exp. Psychol., 1963, 15, 58-62. CALLAWAY, E., & STONE, G. Pre-evaluating focus of attention. In L. Uhr & J. G . Miller (Eds.), Drugs and behavior. New York: Wiley Interscience, 1960. Pp. 11-27. DYER,F. N. Color naming interference in monolinguals and bilinguals. I , verb. Learn. verb. Behav., 1971, 10, 297-302. HOCHMAN, S. H. The effects of stress on Stroop color-word performance. Psychon. Sci., 1967, 9, 475-476. HOCK,H., & EGETH, H. Verbal interference with encoding in a perceptual comparison task. 1. exp. Prychol., 1970, 83, 299-303. HOCK,H., 8r PETRASEK. J. Verbal interference with perceptual classification: the effect of semantic structure. Percept. Psychophys.. 1973. 13. 116-120. JENSBN. A. R., & ROHWER, W. D. The Stroop color-word test: a review. Acta Psychol., 1966, 25, 36-93. KLEIN,G. J. Semantic power measured through the interference of words with color naming. Amer. J . Psychol., 1964, 77, 576-588. MORTON.J. Interaction of information in word recognition. Psychol. Rev., 1969, 76, 165-178. PRESTON. M. S.. & LAMBERT. W. E. Interlingual interference in a bilingual version of the Stroop color-word test. I. verb. Learn. uerb. Behav., 1969, 8, 295-301. RAY, C. Some components of color-word interference and their relationship with field dependence. Acta Psychol., 1974, 38, 323-330. SPIELBERGER.C. D., GORSUCH, L., & LUSHBNE, R. E. Manual f o r the State-Trait Anxiety Inventory. Palo Alto: Consulting Psychologists Press, 1970. STROOP,J. R. Studies of interference in serial verbal reactions. J. exp. Pjychol., 1935, 18, 643-662. WINDES.J. D. Reaction time for numerical coding and naming of numerals. 1. exp. P~ychol.,1968. 78. 318-322.
Accepted August 1 , 1979.
