Addictive Behaviors, Vol. 14, pp. 89-93, 1990 Printed in the USA. All rights reserved.

0306-4603/90 $3.00 + .OO Copyright o 1990 Pergamon Press plc

BRIEF REPORT

IDENTIFICATION OF NONALCOHOLIC AND ALCOHOLIC BEERS: EFFECTS OF CONSUMPTION PRACTICES AND BEER BRAND

CHRISTOPHER S. MARTIN, MITCHELL EARLEYWINE, and RICHARD DAVID YOUNG

Department of Psychology, Indiana University, Bloomington

Abstract - Because nonalcoholic beer provides sensory cues that simulate alcoholic beer, this beverage may be more effective than other placebos in contributing to a credible manipulation of expectancy to receive alcohol. The present experiment assessed the sensory identification of nonalcoholic and alcoholic beers. Subjects with higher beer consumption practices were more accurate than subjects with lower beer consumption practices in the identification of nonalcoholic beers. Brand of nonalcoholic beer affected the identification performance of subjects with lower beer consumption practices.

To understand the effects of alcohol on behavior, researchers must differentiate contributions of pharmacological effects and subjects’ expectancies. Several research designs attempt to control for or assess expectancy effects by testing subjects who are deceived about the alcohol content of beverages. Manipulations concerning the presence or absence of alcohol in beverages must be credible to subjects to control or assess expectancy. Beverages employed in placebo-controlled alcohol research usually disguise the presence or absence of alcohol in beverages (Rohsenow & Marlatt, 1981) so that subjects will not be able to determine beverage type on the basis of sensory cues. Alcoholic beverages usually contain ratios of alcohol to mixer that subjects cannot discriminate from mixer alone (Marlatt, Demming, & Reid, 1973) and strong tasting additives are often added to beverages.

Such manipulations may detract from an expectancy manipulation when subjects receive a placebo beverage but are told that they are receiving alcohol. Sensory cues inconsistent with experimental instructions may lead subjects to pay more attention to internal sensations after drinking, making a manipulation of expectancy to receive alcohol more difficult to achieve. The credibility of strategies to simulate sensory cues for alcohol in placebo beverages, such as floating a small amount of alcohol on the top of the beverage, have not been adequately assessed.

Nonalcoholic beer simulates the sensory cues provided by alcoholic beer, and research suggests that it is a relatively effective placebo beverage. Keane, Lisman, and Kreutzer (1980) found that subjects rated nonalcoholic beer higher in alcoholic content than all other placebo beverages investigated, including those with a small amount of alcohol added to the top of the beverage. Nonalcoholic beer may be a useful placebo beverage for subjects or situations for which beer is the alcoholic beverage of choice (Cox & Klinger, 1983). The

The first and second authors dedicate this article to the memory of the late Dr. Richard David Young. The authors thank James Craig and John Logan for their advice on experimental design and statistical analysis, Cara Wellman and two anonymous reviewers for their comments on an earlier draft of this manuscript, and Jordan Greenberg and Michelle Morey for their work as research assistants. This research was supported, in part, by NIMH grants PHS T32 MH 14588-11 and PHS T32 MH 17146-05 to Indiana University.

Requests for reprints should be sent to Christopher S. Martin, Psychology Department, Indiana University, Bloomington, IN 47405.

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90 C.S. MARTIN, M. EARLEYWINE, and R.D. YOUNG

sensory cues simulated by nonalcoholic beer may make it a useful beverage for evaluating conditioned responses to alcohol cues (Pomerleau, Fertig, Baker, & Cooney, 1983).

Subjects should not be able to accurately identify the absence of alcohol in nonalcoholic beer in order for this beverage to serve as an effective placebo. Cox and Klinger (1983) used a paired-comparison procedure to determine that subjects could discriminate alcoholic beer from nonalcoholic beer but could not accurately discriminate between nonalcoholic beer and nonalcoholic beer with ethanol added. An absolute identification paradigm, in which subjects make a judgment for one beer type on each trial, serves as a closer analogue to typical placebo conditions in which subjects may attempt to identify the presence or absence of alcohol in a single beverage type on the basis of sensory cues.

The present experiment employed an absolute identification paradigm to investigate the ability of subjects to identify a variety of nonalcoholic and alcoholic beers. Beer consumption practices of subjects were assessed in order to determine the effects of such practices on the identification of the beers. A “sip-spit” procedure was used (Green, 1985) to control for effects of alcohol.

METHOD

Subjects Subjects were 21 male volunteers from the Bloomington, IN, area who responded to an

advertisement in the student newspaper for a “beer taste test” experiment. Subjects were 21-38 years old (mean = 24.9, SD = 5.1). Only one subject reported ever trying

nonalcoholic beer.

Stimuli The stimuli were four alcoholic beers (Miller Lite, Blatz, Old Milwaukee, and Burger) and

four nonalcoholic beers (Kingsbury, Clausthaler, Barbican, and Kalibar) containing less than 0.5% alcohol, which were served to subjects at 4°C.

Procedure Subjects presented proof of age, filled out a measure of alcohol consumption adapted from

Hull, Young, and Jouriles (1986), and were asked if they had ever tasted nonalcoholic beer. Subjects were told that they would be sampling beers that did and did not contain alcohol, but were provided with no other information.

All subjects were tested individually at 3:00 p.m. Subjects were seated behind a partition so that they could not identify beverage containers. On each trial, a male graduate student experimenter poured a one-ounce sample of beer into a clear plastic cup. An undergraduate experimenter (male or female), who did not know the alcohol content of the sample, gave it to the subject. Subjects sipped the beer sample, tasted it, and expectorated. After each trial, subjects rinsed thoroughly with tap water. Subjects judged each beer sample as nonalcoholic or alcoholic and provided a confidence rating for each of their judgments on a five point scale. The four nonalcoholic and four alcoholic beers were presented six times each, for a total of 48 trials. The order of presentation was completely randomized.

RESULTS

Subjects were assigned to low (N = 10) and high (N = 11) beer consumption groups on the basis of a median split of self-reported beer consumption practices. Four subjects reported the median (12 beers per month) beer consumption value and were assigned to the low and high beer consumption groups on the basis of their overall alcohol consumption practices. The percentage of samples correctly identified for the different nonalcoholic and alcoholic

Identification of beers 91

Table I. Percentage of correct identifications for each beer for all subjects, and subjects in the high and low beer consumption groups

All Ss:

Claust

Nonalcoholic

Kings Kal

Beer

Alcoholic

Barb Lite Old M Blatz Bur

Mean 60.3% 65.9% 67.5% 70.6% 77.8% 58.7% 61.1% 65.1%

High beer consumption Ss:

Mean 69.7% 80.3% 74.2% 78.8% 72.7% 45.5% 68.2% 71.2% SD 21.6 26.7 20.1 24.8 21.4 29.9 27.3 18.4 p value < ,001 i ,001 < ,001 < ,001 < .OOl > .l < ,001 < .002

Low beer consumption Ss:

Mean 50% 50% 60% 61.7% 83.3% 73.3% 53.3% 58.3% SD 33.3 34.4 34.4 23.4 17.6 20.5 20.5 29.7 p value >.l >.l <.07 c.04 <.ool <.OOl >.l >.I

P values for tests of proportions against chance performance are given for the identification data for each subject group. (Claust = Clausthaler; Kings = Kingsbury; Kal = Kalibar; Barb = Barbican; Lite = Miller Lite; Old M = Old Milwaukke; Bur = Burger)

beers is shown in Table 1 for all subjects, and for the high and low beer consumption groups. A test of proportions was performed for each beer brand within each subject group to

examine if identification was different from chance (50%). Pooled variance estimates were employed and alpha levels were set at .05 to reduce the probability of type II errors. Table 1 shows the p values for these tests. The high beer consumption group identified all four nonalcoholic and three of the four alcoholic beers beyond a chance level. The low beer consumption group identified one of the nonalcoholic and two of the alcoholic beers beyond a chance level.

The mean accuracy score collapsed across all subjects and beers was 65.9% (SD = 13.9). Mean accuracy across all beers was 70.1% (SD = 13.2) for the high beer consumption group, and 61.2% (SD = 13.8) for the low beer consumption group. A hierarchical log-linear analysis (SPSS Inc., 1983) of the beer type ratings was conducted for the factors of beer consumption group, beer type (alcoholic vs. nonalcoholic), and trial. Main effects of beer consumption group, beer type, and trial were not obtained. The interaction of beer consumption group and trial, beer type and trial, and the three-way interaction were all nonsignificant. A significant interaction of beer consumption group and beer type was obtained, partial chi-square = 13.9, p < .Ol. Chi-square tests revealed that the groups did not differ in the identification of alcoholic beers, but that the high beer consumption group was significantly better in identifying nonalcoholic beers, chi-square = 22.3, p < .Ol .

The pearson product-moment correlation between the five confidence rating categories and percent accuracy was .144 for the high beer consumption group and .175 for the low beer consumption group. These correlations are significantly different from 0, p < .Ol, but confidence ratings accounted for very little of the variance in accuracy scores, suggesting that subjects were not very accurate in their ability to judge their identification performance.

A signal detection analysis was performed to assess discrimination performance indepen- dent of response biases. Mean beta and d ’ values for the two groups were calculated from the proportion of hits (correctly identifying an alcoholic beer) and false alarms (identifying

92 C.S. MARTIN, M. EARLEYWINE, and R.D. YOUNG

ROC space for High and Low Beer Consumption l-

0.9.. + 0

SS

Hit Rate o.s--

0.4--

0 Low Consumption

+ High Consuqtion

0 0.1 0.2 0.3 0.4 03 0.6 0.7 0.9 0.9 i

False Alarn Rate

Fig. 1. ROC space for subjects in the high and low beer consumption groups.

a nonalcoholic beer as alcoholic). The mean beta values were 2.14 (SD = 3.3) for the high beer consumption group and 0.877 (SD = .29) for the low beer consumption group. This difference was not significant (t = 1.14, p > .2), suggesting that the two groups did not differ reliably in terms of their response biases. The high beer consumption group was better at discriminating the two types of beers (d’ = 1.305, SD = .82) than the low beer consumption group (d’ = 0.5447, SD = .88), t = 4.13, p < .06). The proportion of hits and false alarms for subjects in the two groups is plotted in an ROC space in Figure 1. d’

is represented by the distance from the diagonal line to a subject’s point in the space.

DISCUSSION

Subjects with higher beer consumption practices were more accurate in identifying nonalcoholic beers in terms of percent accuracy and the discriminability index d'. Researchers who study populations with higher beer consumption practices should be cautious in employing nonalcoholic beer as a placebo. Subject populations with relatively little beer drinking experience, however, are less likely to accurately identify nonalcoholic beer on the basis of sensory cues. The effects of an alcohol expectancy manipulation on the behavior of these subjects may be different than the effects of such a manipulation on the behavior of more experienced subjects. Brand of nonalcoholic beer affected the identification performance of subjects with lower beer consumption practices. Researchers who employ nonalcoholic beer should use this type of identification data to select an effective placebo.

This experiment provided a strict test of identification performance for nonalcoholic beers, as subjects were informed that some of the beers were nonalcoholic. In contrast, subjects in placebo conditions are usually informed that they will be consuming alcohol, and may be less likely to accurately identify the alcoholic content of their beverages. It must be emphasized, however, that research should distinguish the ability to identify beverage type on the basis of sensory cues from the ability to accurately monitor internal sensations regarding alcohol effects.

Evidence suggesting that alcohol and expectancy are difficult to manipulate orthogonally (Knight, Barabee, & Boland, 1986) raises important questions about the effectiveness of deception procedures in alcohol research. Beverages that simulate sensory cues for alcohol may contribute to a credible manipulation of expectancy to receive alcohol. Research should

Identification of beers 93

identify variables that increase the effectiveness of expectancy manipulations, such as beverage type, the amount of beverage consumed, deployment of attention, and alcohol consumption practices.

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Cox, W.M., & Klinger, E. (1983). Discriminability of regular, light, and alcoholic and nonalcoholic near beer. Journal of Studies on Alcohol, 44, 494-498.

Green, B.G. (1985). Menthol modulates oral sensations of warmth and cold. Physiology and Behavior, 35, 427-434.

Hull, J.G., Young, R.D., & Jouriles, E. (1986). Applications of the self-awareness model of alcohol consumption: Predicting patterns of use and abuse. Journal of Personality and Social Psychology, 51, 790-796.

Keane, T.M., Lisman, S.A., & Kreutzer, J. (1980). Alcoholic beverages and their placebos: An empirical evaluation of expectancies. Addictive Behaviors, 5, 313-328.

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