Perceptwland Motor Skills, 1990, 71, 99-105. O Perceptual and Motor Skills 1990

EFFECTS O F ALCOHOL O N COGNITIVE PERFORMANCE MEASURED WITH STROOP'S COLOR WORD TEST

"

ROLAND GUSTAFSON AND H

~

KALLMEN N

University of ~ r e b r o Sweden , Summary.-An experiment was performed to test whether alcohol intoxication leads to cognitive disinhibition as measured by the Color Word Test. In psychoanalytic terms, it was hypothesized that alcohol would decrease secondary process functioning leading to disinhibition and so make it easier to perform a primary process function. 24 men and 24 women participated and were randomly assigned co an Alcohol group, a Placebo group or a Control group. The alcohol dose was 1.0 ml of 100% alcohol/kg body weight. No statistically significant differences were found on any of the three dependent measures, number of errors, number of hesitations and total time needed, except that men in the Alcohol group needed significantly longer time to complete the test. These results ind~catethat cognitive disinhibition is not valid as an explanation for alcohol-related changes tn cognitive functioning.

According to a psychoanalytic theoretical frame of reference cognitive processes are either of a primary or a secondary kind. The newborn is fully controlled by primary process, characterized by being irrational and not adjusted to the surrounding physical and social reality. Secondary process develops during the first years of life and slowly comes to dominate the cognitive style of the mature individual. Secondary process develops as a product of the individual's interactions with the environment and is characterized by being rational and adjusted to conditions dictated by reality. An important aspect of the secondary process is its regulatory function. Cultural values and social norms are said to be introjected into the Superego of the individual, and these standards are used by secondary process to adjust the behavioral and cognitive style to reality to minimize conflicts. While primary process refers to immediate gratification of drive impulses, secondary process refers to inhibition of such internal demands as in either postponing gatification or adjusting gratification to reality. This internal confict is a constant fight between dynamic forces. Psychological disinhibition is often referred to as an explanation of alcohol-related effects. In the sober state secondary process dominates over primary process. It is assumed that alcohol intoxication reduces the inhibiting forces of secondary process which gives more room for primary process

'This study was supported by rants from The Swedish Delegation for Social Research (DSF), $tockholm, and from ~ysrembofa~et's Foundation for Alcohol Research (SFA), Stockholm. Address requests for reprints yo Dr. Roland Gustafson, Department of Psychology, University of Orebro, Box 923, S-701 30 Orebro, Sweden.

functioning. The individual's behavioral and cognitive styles are transformed into more primitive expressions (Room & Collins, 1983). Experiments designed to test the validity of alcohol-induced psychological disinhibition yield equivocal data. A symbiotic conflict can be conceptualized as a conflict between primary and secondary processes. An unconscious wish, developed by primary process, to be close to a mother figure is in conflict with a conscious striving, developed by secondary process, towards independence and individuality (Silverman & Weinberg, 1985). If disinhibition occurs under intoxication, the symbiotic conflict should be reduced and the need for oneness at least partially satisfied. However, alcohol intoxication does not seem to reduce such conflicts and the disinhibition hypothesis is not supported (Gustafson & K h C n , 1990). On the other hand, the ability to reproduce unstructured pictures, a cognitive ability highly dependent on secondary process, is significantly decreased under alcohol (Gustafson & KdmCn, 1989a, 1989b). This latter result can be interpreted as supportive of the disinhibition hypothesis. The purpose of the present study was to test the validity of the disinhibition hypothesis further by studying the effect of alcohol intoxication on a primary process abihty. The rationale is that, if alcohol reduces secondary process functioning and so relaxes psychological inhibitions directed towards primary process function, an ability dependent upon primary process should be easier to perform. The Color Word Test offers a test situation for this. The individual is instructed to tell the colors of a series of printed words printed in discrepant colors, for instance, report "Red" when the word "Yellow" is printed in red. To read the word as it is printed is a secondary process function highly overlearned, and if alcohol reduces secondary process, it should be easier to distract oneself from reading and instead report the color of the text. The hypothesis tested states that alcohol has the described effect.

Subjects, Design, and Alcohol In all, 24 men (M age = 27.4 yr.; SD = 6.4) and 24 women (M age = 32.5 yr.; SD = 9.3) participated as voluntary paid subjects in the experiment. They were all recruited from a regional hospital in the middle part of Sweden. The subjects were randomly assigned to three experimental groups, namely, a Control group, a Placebo group, and an Alcohol group, with 8 men and 8 women in each group. The Alcohol group received an alcohol drink containing 1.0 ml of 100% alcohol/kg body weight in the form of Swedish commercial Absolut Vodka containing 40% alcohol by volume. The drink was mixed with an equal

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amount of tonic water (Schweppes). The Placebo group received a drink containing 5 ml/kg body weight of tonic flavored by 10 ml of vodka essence (Simpson) to give it a taste and smell of alcohol. The Control group received 5 rnl/kg body weight of tonic. All drinks were chilled with an ice cube and a slice of lemon floated on top.

Dependent Variables The task was the Stroop Color Word Test (Stroop, 1935), which consists of a sheet of paper on which are printed 100 words. The words are ordered in 10 lines with 10 words on each line. Each word is a color name red, blue, green or which name is printed in an incongruent color. That is, the word "Blue" may be printed in green, red, or yellow. The order of both colors and printed words is random. The test contains one text dimension and one color dimension, and the task of the subjects is to separate the two dimensions from each other and only report one, the printed color of the word. The dependent variables are (a) total time needed to complete the test, (b) number of incorrect reports, and (c) number of hesitations. Total time is defined as the time taken by the subject to report all the colors of the 100 words. Number of incorrect reports is defined as the total number of times the subject reports an incorrect color by being influenced by the actual letters, and number of hesitations is defined as the total number of times the subject deviates from his individual reading rhythm with more than 1 sec. before reporting the color. In addition the subject had to answer two questionnaires, namely, the Manifest Anxiety Scale (Taylor, 1953), indicating the subject's state of anxiety, and a modified version of the Internal-External Scale (Rotter, 1966), which in its present form measures the subject's here-and-now feeling of whether his locus of control is experienced inside or outside himself. Procedure Upon arriving at the laboratory, the subject filled out a questionnaire containing a number of background questions after which a first blood alcohol sample was taken using an alcometer (Lion SD2). Then the subject received the appropriate drink which he was instructed to drink slowly over a 15-min, period. During this time the subject completed the Taylor Anxiety Scale and the Internal-External questionnaire. After the 15 min. of drinking time, the subject had to wait an additional 15 min., during which time he was allowed to read newspapers. After the total of 30 rnin. from starting to drink, a second breath sample was secured followed by the Color Word Test. Finally, a last blood sample was registered followed by a thorough debriefing interview. The subject was paid a nominal fee and sent home after due precautions.

Blood Alcohol Levels (BALs) All subjects came sober to the laboratory. After the initial 30 min. the women had a mean BAL of 0.082% (SD = 0.037), and after completion of the Color Word Test the mean BAL was 0.074% (SD = 0.031). The corresponding values for the men were 0.075% (SD = 0.025) and 0.068% (SD = 0.019%). All subjects were on a declining blood alcohol curve during the test session according to a t test for dependent samples (t,,= 2.95, p < .01). Measures of Performance Separate 3 (Alcohol group) x 2 (Sex) analyses of variance applied to the different dependent variables indicated no significant main effects or interactions on either of the three dependent measures-total time needed to complete the test, total number of errors, and total number of hesitations. The respective F ratios (df = 1/42 or 2/42) were in the range of 0.03 to 2.13 (p>.13). However, a post hoc test according to the least significant difference technique (Keppel, 1982), yielded a significant difference among the Alcohol and the Placebo groups for total time needed to complete the test ( p < .04), with the Alcohol group needing more time than the Placebo group. The same type of test also showed that this difference was restricted to men ( p < .03), while the difference for women did not even approach significance ( p > .43). For means and standard deviations of total time needed, see Table 1. Since the Manifest Anxiety Scale yielded a significant pattern (see below), also separate analyses of covariance for the three dependent measures with the anxiety scores as a covariate were performed. The analysis indicated no other significant differences than those of the primary analysis of variance. TABLE 1

MEANTOTALTJMENEEDEDTO COMPLETE COLORWORDTESTAS A FUNCTION OF SEXAND ALCOHOL DOSE(SEC.) Total

Group

Control Placebo Alcohol

Men

M

SD

107.37 99.87' 113.75'

19.99 12.04 22.64

M 103.75 96.37b 118.00~

Women

SD

M

SD

20.73 6.14 24.37

111.00 103.37 109.50

19.96 15.66 21.53

Measures of Anxiety and Locus of Control A 3 x 2 analysis of variance applied to the manifest anxiety scores indicated only a significant interaction of alcohol group by sex (F,,,, = 5.07, p< .01). Post hoc tests according to the least significant difference method (Keppel, 1982) showed that the men in the Alcohol group were significantly

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103

more anxious than the men in the Placebo group (PC .05). With respect to the women, the same type of analysis showed that the women in the Alcohol group were significantly less anxious than the women in the ControI group (PC .O3). For means and standard deviations, see Table 2. TABLE 2 ANXIETY SCORES AS ~ ~ E A S U RBY E DTAYLOR'S MANXEST ANxrEn SCNE AS A FUNCTION OF SF.X AND ~%LCOHOLDOSE Group

Total

M Control 5.88 4.38 Placebo Alcohol 5.19 Nofe.-See text for p values.

Men

Women

SD

M

SD

M

SD

3.99 2.22 3.21

4.25 3.87 6.87

3.01 1.88 3.13

7.50 4.87 3.50

4.37 2.83 2.39

As to locus of control (I-E scale) an analysis of variance indicated no significant main effects or interactions; F ratios (df = 1/42 or 2/42) varied from 0.25 to 1.97 ( p > .14).

Alcohol has a minor effect on the ability to report only the colors of words instead of reading the words when the words are printed in incongruent colors. Neither number of errors nor number of hesitations differentiated the groups. The only significant effect was that intoxicated men needed more time than sober men in the Placebo group to report all the words. Provided the dependent measures mirror to what extent secondary processes are in operation, these results indicate that secondary process is not affected by alcohol, and so it must be concluded that alcohol does not lead to disinhibition in terms of cognitive style. On the contrary, the fact that intoxicated men needed more time to complete the whole series of words rather indicate that secondary process is reinforced by alcohol leading to increased interference with primary process and more difficulties to perform a cognitive primary process task. The results require a few comments. First, with respect to the disinhibition hypothesis (Room & Collins, 1983) it must be kept in mind that the present data only can be interpreted in terms of cognitive style. It is quite possible that the disinhibition hypothesis might be valid for some social behaviors. Steele and his coworkers have shown that alcohol seems to disinhibit social behaviors like helpfulness, given that the individual is in a "response inhibitory conflict" also before starting to drink (Steele, Critchlow, & Liu, 1985). However, an hypothesis causing general disinhibition must obviously be discarded. Second, the fact that men need more time when intoxicated to complete the test while women do not could maybe be understood in terms of com-

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R. GUSTAFSON & H.

ULLMEN

pensation for the effect of alcohol. Compensation refers to an active and conscious effort to stay alert and concentrated and focus on the task. It has been reported that subjects sometimes are successful in compensating for the detrimental effects of alcohol (Williams, Golman, & Williams, 1983). If that is so, all subjects believing that they have consumed alcohol should try to do so, that is, the subjects in the Placebo and the Alcohol groups. It can further be assumed that this tendency to compensate varies with the strength of the social disapproval of behaving intoxicated. In our culture, women can be expected to compensate more than men. The tendency is in the predicted duection with respect to total time needed. It can be argued that women tend to compensate successfully for the detrimental effects of alcohol both in the Placebo and the Alcohol group, while men tend to do so to a much lesser extent and actually perform significantly worse under alcohol. The compensation hypothesis is attractive and can explain many otherwise unexplained results. However, the hypothesis has never been put to a direct test but has only been used as a post hoc explanation. An experimental test is therefore required before leaning coo heavily on the compensation hypothesis. Third, it has been demonstrated previously that alcohol has almost no significant effects during the first minutes of testing when simple reaction time is used as dependent variable (Gustafson, 1986). If the test is prolonged with high demands on concentration and frequent reactions, the detrimental effects of alcohol are significant after about 10 min. of testing. This effect might apply not only to psychomotor performance but also to cognitive performance. If this is so, one should anticipate no effects of alcohol on a brief test like the present one. It would be of interest to prolong the Color Word Test to check whether the effect of alcohol is different after the initial minutes of testing. Since the ability to compensate is a function of concentration and alertness, the compensation hypothesis certainly predicts that the detrimental effects of alcohol will be more pronounced as the ability to compensate declines. REFERENCES

GUSTAFSON, R. Effects of moderace doses of alcohol on simple audtory reaction time in a vigilance setting. Perceptual and Motor Skills, 1986, 62, 683-690. GUSTAFSON, R., & K ; ~ L L M ~ H. N , Alcohol effects on cognitive and personality style in wornen,with special reference to primary and secondary process. ALCOHOLISM: Clinical and Experimental Research, 1989, 1 3 , 644-648. (a) GUSTAFSON, R., & KXLLM~N,H. The effect of alcohol intoxication on primary and secondary processes in male social drinkers. Britirh Journal of Addiction, 1989, 84, 1507-1513.(b) GUSTAFSON, R., & KjiLLhlg~,H. Alcohol, subliminal scimulacion and disinhibitory processes. Psychological Reports, 1990, 70, 495-502. KEPPEL, G. Design and analysis: a researcher's handbook. Englewood Cliffs, NJ: Prentice-Hall, 1982. ROOM, R., & COLLINS,G. Alcohol and disinhibition: nature and meaning of the link. U.S. Department of Health and Human Services, NIAAA, 1983.

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ROT~ER, J. B. Generalized ex ectancies for internal versus external control of reinforcement. Psychological ~onograpls,1966, 80, No. 1 [Whole No. 6091. SILVERMAN, L. H., & WUNBERGER, J. Mommy and I are one. American Psychologist, 1985, 40, 1296-1308.

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Accepted June 14, 1990.

Effects of alcohol on cognitive performance measured with Stroop's Color Word Test.

An experiment was performed to test whether alcohol intoxication leads to cognitive disinhibition as measured by the Color Word Test. In psychoanalyti...
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