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Drugs and Judgment:Effects of Amphetamineand Secobarbital on Self-EvaluationGene Marshall Smith a & Henry K. Beecher aa Anaesthesia Laboratory of Harvard MedicalSchool at Massachusetts General Hospital ,USAPublished online: 02 Jul 2010.

To cite this article: Gene Marshall Smith & Henry K. Beecher (1964) Drugsand Judgment: Effects of Amphetamine and Secobarbital on Self-Evaluation,The Journal of Psychology: Interdisciplinary and Applied, 58:2, 397-405, DOI:10.1080/00223980.1964.9916761

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Published as a separate and in The Journal of Psychology, 1964, MI 397-405.

DRUGS AND J U D G M E N T : EFFECTS OF AMPHETAMINE A N D SECOBARBITAL ON SELF-EVALUATION.

Anaesthesia Laboratory o f Harvard Medical School at Massachusetts General HosPital

GENE MARSHALL SMITH AND HENRY K. BEECHER~

A. INTRODUCTION Various mood-altering drugs (“pep pills,” “psychic energizers,’] “sedatives,”

“tranquilizers,” etc.) are in widespread use. Many persons make decisions and judgments and engage in potentially dangerous activities, such as driving automobiles, after taking these drugs. T h e effects of such drugs on human decisions] judgments, and activities have merited study in the past and require further study (see references 1 to 18).

In the present investigation] judgment was studied by comparing a subject’s performance on a 60-minute calculus test with his perception of that perform- ance. Performance and subjective evaluation of performance occurred under drug and placebo conditions as described below. In earlier work (14), the method of comparing performance with perceived performance was found to be a highly sensitive indicator of judgment distortion produced in swimmers who had been given secobarbital sodium in a dose of 100 mg per 70 kg of body weight. T h e swimmers reported swimming faster after receiving secobarbital than after receiving placebo, but the fact was that secobarbital impaired per- formance to a highly significant degree.

B. METHOD 1. Nature of the Self-Evaluations

In each of five experimental sessions, after completing a 60-minute, 25- item calculus test, each subject estimated the number of problems he had solved correctly. As explained below, different forms of the test were used for the various sessions. Test scores were not reported to the subjects until the final experimental session was completed. In evaluating a given perform-

* Received in the Editorial Office on June 25, 1964, and published immediately at Provincetown, Massachusetts. Copyright by The Journal Press.

1 Thia work waa supported in part by the United States Public Health Service, Con- tract No. USPH-M-987. in Dart bv the Medical Research and Develooment Com- mand of the United States Army, Contract No. DA-49-007-MD-2136, and in part by Mallinckrodt Chemical Warks.

2 The authors wish to acknowledge the helpful counsel of William G. Cochran. Professor of Statistics, Harvard University.

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ance, a subject had recourse only to such ambiguous and subjective matters as how hard the problems seemed, how well he felt he had been functioning, how hard he had tried, how many answers he had gueyed at, how many problems he had omitted, etc. A subject’s judgmenterror score for each experimental session was determined by subtracting the number of problems he had an- swered correctly from the number he estimated he had solved correctly. T h e subjects appeared challenged by the calculus tests, and their interest is indicated by the fact that all asked to be informed of their scores a t the end of the fifth experimental session. T h e problem of self-assessment also appeared to be approached by the subjects in a spirit of seriousness and cooperation.

2. Subjects

Seventy-eight male graduate and undergraduate students from Massachu- setts Institute of Technology served as subjects. They ranged in age from 18 to 31, with a median of 21 years. Each subject was selected on the basis of his ability to reach a minimum criterion score on a test of intermediate calculus developed by the Educational Testing Service of Princeton, New Jersey.

3. Drugs and Drug Order

Each subject participated in five test sessions. H e took amphetamine sulfate (14 mg per 70 kg of body weight) before two sessions, secobarbital sodium (50 mg per 70 kg of body weight) before one session, and placebo before two sessions. These dosages were selected on the basis of earlier work (14). All medications were oral. O n each experimental day a subject took two capsules: one, two hours and 45 minutes before beginning the experimental session ; the other, one hour and 15 minutes before beginning the session. O n “amphetamine days,” the first capsule contained amphetamine and the second contained a placebo. O n secobarbital days, the first capsule contained a placebo and the second contained secobarbital. O n placebo days both capsules contained placebos. T h e double-capsule technique was used because the peak effective- ness of secobarbital occurs earlier than does that of amphetamine. Subjects were asked to begin fasting one hour before taking the first capsule.

With respect to drug order, the subjects were divided into 12 groups with approximately seven subjects per group. Each group received medications in one of the following 12 orders: APSAP, APSPA, ASPAP, ASPPA, PSAAP, PSAPA, PASAP, PASPA, SAPAP, SAPPA, SPAAP, SPAPA ( A = am- phetamine, P = placebo, S = secobarbital). In all orders, A and P occur

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GENE MARSHALL SMITH AND HENRY K. BEECHER 399

among the first three medications and occur again among the last two.8 The first A and P are designated A1 and PI ; the second A and P are designated A2 and Pz. Secobarbital occurs only among the first three medications in each order. T h e secobarbital results reported are based on comparisons of S and PI. T h e drugs were distributed by a person not involved in collecting and evaluating the data; thus i t was possible to maintain the double-blind pro- cedure even though drug order was counterbalanced. Subjects were told that “pep pills” and placebos were being used. They were not told that a “sedative” was also being used.

4. Testing

During each experimental session the testing was done on a group basis, in an auditorium, with vacant seats separating subjects. All testing sessions began a t 5:45 p.m. Each evening the subjects took a different 60-minute calculus test. Six calculus tests’ were prepared by Educational Testing Service. One, the screening test mentioned above, was designed to be slightly harder than the five that were used for the experiment proper. Three of the remaining five were designed to parallel each other in difficulty and content; they were used for the first three sessions. T h e other two tests, which were used for the last two sessions, were designed to parallel each other and were similar to the first three, but were not necessarily parallel to the first three. Each of the six calculus tests contained 25 items and each item had five multiple-choice answers. T h e time limit was 60 minutes for each test, a time selected to be insufficient for completion of all items. All subjects received Form No. 1 of the calculus test in the first test session, Form No. 2 in the second test session, etc. Thus, test form and drug were balanced with respect to each other, while test form and session were not.

C. RESULTS A subject’s judgment-error score for each session was determined by sub-

tracting the number of problems he had solved correctly from the number he estimated he had solved correctly. T h e placebo and amphetamine judgment-

8 A and P were repeated a recood time to permit an examination of the test-retest reproducibility of the amphetamine efects. Data concerning reproducibility (from several separate iovertigationr) will be prerented and dimmed in a subsequent report.

4 Some problems in each calculus teat required knowledge of elementary algebra, trigonometry and analytic geometry. More advanced problems dealt with the differ- entiation and integration of elementary functions and with the application of these techniques to the computation of areas and volumes and to the aolution of minimum and maximum problems. Some problemr dealt with multiple integrals and the change of order of integration.

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error scores of the 78 subjects are plotted as dots in Figure 1. T h e average of a subject’s two placebo judgment-error scores [ (PI + P2) + 21 is plotted on the ordinate, and the average of his two amphetamine judgment-error scores [ (A1 + A2) + 21 is plotted on the absc i~sa .~ T h e horizontal line intercepting

I

I I I I I // .. * .

roo 0. ..

+ I 0

c 0 a - 0 w L 0 V c 3

. 8 7 %

f * - - - - _.

9%

I -5 +5 +I0

A M PHE T A M /NE /no. of Probhms ) FIGURE 1

JUDCMENT ERROR UNDER AMPHETAMINE A N D PLACEBO CONDITIONS Dots above the broken horizontal line indicate overvaluation with placebo. Dots to

the right of the broken vertical line indicate overvaluation with amphetamine. Dots below the diagonal line indicate subjects who overvalued their calculus performance relatively more with amphetamine than with placebo. The eight open dots indicate scores based on a single amphetamine WJ. placebo comparison rather than a mean of two such comparisons. See Footnote No. 5 .

6 Eight of the scores in the figure appear as open rather than solid dots. These are the scores of eight subjects who failed to give a performance estimate on one of the eessions. The position of each of these subjects in the figure is determined either by PI and A, or by P, and A,, rather than by [(PI + P2) + 21 and [(A1 + A,) + 21. T h e per cents reported in the figure, and the chi-square analyses reported in the text, are based on the entire group of 78 subjects represented in the figure.

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GENE MARSHALL SMITH A N D HENRY K. BEBCHBR 401

zero on the ordinate separates the 68 subjects who overvalued their placebo performances from the seven who undervalued them. T h e vertical line inter- cepting zero on the abscissa separates the subjects who overvalued their am- phetamine performances from those who undervalued them. As is shown in Figure 1, 87 per cent of the subjects overvalued their performance under the placebo condition and 91 per cent did so under the amphetamine condition.

Notwithstanding the highly significant tendency to overvalue placebo per- formances, a significant majority of the subjects had a relatively grruter overvaluation score for their amphetamine performances than for their placebo performances. T h e 50 subjects below the diagonal line in Figure 1 over- valued their amphetamine performances relatively more than their placebo performances. T h e 20 subjects above that line overvalued their placebo performances relatively more. T h e deviation of 50/20 from 35/35 yields a

TABLE 1 CALCULUS PERFORMANCE, ESTIMATE OF PERFORMANCE, AND JUDGMENT ERROR FOR

FIVE EXPERIMENTAL SESSIONS: MEANS FOR 70. SUBJECTS

Variable A,** P, S A2 p2

Calculus performance (Number of problems right) 14.10 14.43 13.51 13.81 13.97

Estimate of performance (Number of problems thought right) 17.44 17.04 16.72 16.57 16.16

Judgment Error*- (Number thought right minus number right) 3.34 2.61 3.21 2.76 2.19

Only the data of the 70 subjects having scores for all five sessions were used in

4* A, = first amphetamine session, PI = first placebo session, S = secobarbital

*** All five judgment-error means are significantly different from zero (p < 0.0001).

chi-square value of 12.01 which, with a two-tailed test, is significant a t the 0.001 level. Within the group of 58 subjects whose scores were in the direc- tion of overvaluation for both the amphetamine and placebo conditions (and who did not fall on the diagonal line), 41 overvalued the amphetamine per- formances relatively more, and 17 overvalued the placebo performances rela- tively more. T h e deviation of 41/17 from 29/29 yields a chi-square of 9.12, which is significant a t the 0.01 level. It is concluded that amphetamine pro- duced an overvaluation tendency that is significantly greater than the highly significant placebo overvaluation tendency.

Table 1 reports the PI, Ax, S, Pz and A2 means for each of three variables: number of problems solved correctly, number of problems the subjects thought

computing the I5 means.

lession, A, = second amphetamine session, P, = second placebo session.

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they solved correctly, and judgment error. Under the placebo condition the subjects, considered as a group, overestimated the number of correct solutions by about two and one-half problems. Under each of the two active drug con- ditions, the judgment error was approximately 30 per cent greater than that found with placebo.6

Table 2 shows the results of t-test evaluations of the effects of amphetamine and of secobarbital on judgment error. T h e [ (A, - PI) + (A? - P2)] -+ 2 comparison was analyzed two ways: ( u ) For subjects missing either an A,- P1 or an A2-P2 score, the available difference score was used as an estimate of the average of the two difference scores. There are 78 subjects in that analysis. ( b ) Subjects with missing data in either the A1 - PI or the A 2 - p ~ comparison were deleted. There ate 70 subjects in that analysis. Both analyses yielded results consistent with those based on the chi-square

TABLE 2 EFFECT OF A M P H E T A M I N E A N D SECOBARBITAL, RELATIVE 'TU PLACEBO, O N JUDGMENT ERROR

ludement e r ror Statistic -

N X SD I fl

r (Al-pP1) + (A~---P~)I + 2 78 0.77 2.28 2.96 0.01 C(A,-PP,) + ( '42-P2)1 + z 70 0.65 2.29 2.39 0.02 s-P, 76 0.64 3.36 1.68 0.10

-.

Legend: A, = first amphetamine session, P, = first placebo session, S = secobarbital session, A, = second amphetamine session, P2 = second placebo session, N = sample sire, X = mean effect, SD = standard deviation, t = t value, $ = two-tailed probahility value.

-

analyses reported above. Although the S - PI analysis did not reach the 0.05 level of significance, it should be mentioned that the magnitude of the seco- barbital effect was as great as that found with amphetamine. Because ampheta- mine was given twice, its effect was assessed with greater precision ( a smaller standard error) than was the effect of secobarbital. Thus , although the two effects were the same in magnitude, the amphetamine effect may be con- sidered conclusive while the secobarbital effect must be considered only suggestive.

6 T h e judgment error found during the later phase of the experiment ( A 2 + P,) was significantly smaller ( j < 0.05) than that found earlier ( A , + P,), but the meaning of this reduction is uncertain. As already stated, a subject was not told the number of problems h e had solved correctly on any test until the fifth experimental session w a s concluded. Some subjects were observed working together on problems af ter each experimental session and this might have provided corrective feedhack which con- tributed to the reduction in judgment error a s the experiment progressed. Available da ta do not, however, permit a test of that possibility.

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GENE MARSHALL SMITH A N D H E N R Y K. BEECHER 403

D. DISCUSSION W h i l e it is of interest that a large per cent of subjects (87 per cent) over-

valued their calculus performance under the placebo condition, our main concern in the present discussion is with the effect of amphetamine on judg- ment and with the implications of that effect. A subsequent report will concern the overvaluation tendency found under placebo and nondrug conditions in this and other studies.

T h e fact that the effect of amphetamine on judgment was in the direction of impairment rather than improvement is of interest for three reasons.

First, considerable evidence is available demonstrating improvement in per- formance on various mental and physical tasks after administration of ampheta- mine, but its potential impairment effects are not well documented. I n con- cluding their review of 112 publications concerning effects of caffeine and the amphetamines on human performance, Weiss and Laties (18, p. 32) say:

Except for reports of insomnia, the subjective effects of the ampheta- mines in normal doses are usually favorable. Moreover, no one has ever presented convincing evidence that they impair judgment.

Second, amphetamines are widely used by ambulant patients and by indi- viduals who take them without prescription; hence indication of any type of judgment impairment produced by such agents has important practical im- plications. T h e potential significance of this matter in regard to juvenile delinquency and crime has been discussed elsewhere (13).

Finally, the impairment of judgment shown above is not paralleled by the effects of amphetamine on the performance of the same group of 78 subjects tested with respect to two other aspects of mental functioning. I n a n earlier report, amphetamine was shown to facilitate the performance of these subjects on a clerical test of digit-letter coding to a highly significant degree ( p < 0.0001 ) and to have no effect on their calculus performance ( 15). T h u s , when we examine the effects of amphetamine on the same group of 78 subjects evaluated with regard to three different types of mental performance (judg- ment, coding, and calculus), we find one type of performance significantly impaired, one type significantly improved, and one type not affected. These results stress the need for cautious generalization concerning drug-induced changes in mental performance.

O u r analyses suggest that secobarbital might also be capable of elevating the overvaluation tendency beyond that found under the placebo condition. T h a t a small dose of secoharbital (50 m g is one-half the standard sedative dose) might produce certain mental effects similar to those produced by amphetamine

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( a “stimulant”) is of interest and is consistent with earlier findings. Smith and Beecher (13) administered amphetamine and secobarbital to athletes in the same dosages as those employed in the present study and found that both agents produced significant increases in reports of mental and physical activa- tion, elation, and intoxication. T h e activation effects, however, were more definite in the case of amphetamine than in the case of secobarbital.

T h e nature of the drug-induced judgment error found in the amphetamine results (and suggested in the secobarbital results) is not well understood at present. Both agents produce significant mood changes which might play a role in this matter. In addition to the activation, elation, and intoxication effects just mentioned, amphetamine (in the 14 mg per 70 kg body-weight dosage) has been found to produce significant increases in reports of boldness, friendliness, and impulsiveness, both in athletes (13) and in the 78 subjects of the current study (15). Further work is needed to elaborate the meaning and significance of the observed association between drug-induced changes in mood and judgment.

E. SUMMARY Each of 78 graduate and undergraduate college students attempted to solve

25 calculus problems and afterward estimated the number of his correct solutions. Subjects did this on each of five occasions: twice after taking amphetamine sulfate (14 mg per 70 kg of body weight), once after taking secobarbital sodium (50 mg per 70 kg of body weight), and twice after taking a placebo. After taking placebo the subjects overestimated, to a significant degree, the number of problems solved correctly. After taking amphetamine or secobarbital the overestimation tendency, or judgment error, was still greater. T h e increase in judgment error was statistically significant with amphetamine but only suggestive with secobarbital. Implications of the find- ings concerning the effect of amphetamine on judgment were discussed.

REFERENCES 1. GOOONOW, R. E., BEECHEK, H. K, BMZIEK, M. A. B., MOSIXLLEK, F. C., 0

TACIUU, R. Phyriological performance following a hypnotic dose of a barbi- turate. J . Phornacof., 1951, 102, 55-61.

2. HAUTY, G. T., k PAYNE, R B. Effectr of dextro-amphetamine upon judgment. J . Pharnacol.. 1957, 140, 33-37.

3. KELLY, E. L, MILLER, J. G., MAROUIS, D. G., Grum, R. W., k UHR, L Continued meprobamate and prochlorpcrazine administration and behavior. A N A . Arch. Nrrrol. I Psychiat., 1958, So, 247-252.

4. K~NS~SKY, C. Effcetr of meprobam8te. phenobarbital and dextro-amphetamine on reaction time and learning in man. J . Phamacol., 1958, UU, 216-219.

5. KORNCmrr, C, k HWMPHRIKS, 0. Psychological effcm of centrally acting d r u p

Dow

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ded

by [

New

Yor

k U

nive

rsity

] at

00:

18 0

6 O

ctob

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014

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6.

7.

8.

9.

10.

11.

12.

13.

14.

15.

16.

17.

18.

in man: Effects of chlorpromazine and secobarbital on visual and motor beha- vior. J . Ment. Sci., 1958, 104, 1093-1099.

KORNETSRY, C., HUMPHRIES, O., & EVARTS, E. V. Comparison of psychological effects of certain centrally acting drugs in man. A.M.A. Arch. Neurol W Psychiat., 1957, 77, 318-324.

LEHMANN, H. E., & CSANK, J. Differential screening of phrenotropic agents in man: Psychophysiologic test data. J. Clin. U Exper. Psychopath., 1957, 18, 222-235.

LOOMIS, T. A., & WEST, T. C. Comparative sedative effects of barbiturate and some tranquilizer drugs on normal subjects. J. Pharmacol., 1958, I.!&?, 525-531.

MARQUIS, D. G., KELLY, E. L., MILLER, J. G., GERARD, R. W., dr RAPOPORT, A. Experimental studies of behavioral effects of meprobamate on normal subjects. Ann. N . Y . Acad. Sci., 1957, 67, 701-711.

REITAN, R. M. Comparative effects of placebo, ultran, meprobamate on psychologic test performances. Antibiot. M d . , 1957, 4, 158-165.

SEASHORE, R. H., & IVY, A. C. Effects of analeptic drugs in relieving fatigue. Psychol. Monog., 1953, 67, 1-16.

SMITH, G. M., & BEECHER, H. K. Amphetamine sulfate and athletic performance: I. Objective effects. J.A.M.A., 1959, 170, 542-557.

. Amphetamine, secobarbital, and athletic performance: I1 Subjective evaluations of performances, mood states, and physical states. J.A.M.A., 1960,

-. Amphetamine, secobarbital, and athletic performance: 111. Quantitative effects on judgment. J.A.M.A., 1960, 172, 1623-1629.

SMITH, G. M., WEITZNER, M., LEVENSON, S. R., & BEECHER, H. K. Effects of amphetamine and secobarbital on coding and mathematical performance. J. Pharmacol., 1963, 141, 100-104.

STEINBERG, H. Selective effects of an anaesthetic drug on cognitive behaviour. Quart. J . Expcr. Psychol., 1954, 6, 170-180.

vON FELSINCER, J. M., LASAGNA, L., & BEECHER, H. K. T h e persistence of mental impairment following a hypnotic dose of a barbiturate. J. Pharmacof., 1953,

WEIS, B., & LATIES, V. G. Enhancement of human performance by caffeine and the amphetamines. Pharmacol. Rev., 1962, 14, 1-36.

172, 1502-1514.

109, 284-291.

Department of Anaesthesia Massachusetts General Hospital Boston 14, Massachusetts

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