Caffeine Expectancy Questionnaire (CaffEQ): construction, psychometric properties, and associations with caffeine use, caffeine dependence, and other related variables

Expectancies for drug effects predict drug initiation, use, cessation, and relapse, and may play a causal role in drug effects (i.e., placebo effects). Surprisingly little is known about expectancies for caffeine even though it is the most widely used psychoactive drug in the world. In a series of independent studies, the nature and scope of caffeine expectancies among caffeine consumers and nonconsumers were assessed, and a comprehensive and psychometrically sound Caffeine Expectancy Questionnaire (CaffEQ) was developed. After 2 preliminary studies, the CaffEQ was administered to 1,046 individuals from the general population along with other measures of interest (e.g., caffeine use history, anxiety). Exploratory factor analysis of the CaffEQ yielded a 7-factor solution. Subsequently, an independent sample of 665 individuals completed the CaffEQ and other measures, and a subset (n = 440) completed the CaffEQ again approximately 2 weeks later. Confirmatory factor analysis revealed good model fit, and test-retest reliability was very good. The frequency and quantity of caffeine use were associated with greater expectancies for withdrawal/dependence, energy/work enhancement, appetite suppression, social/mood enhancement, and physical performance enhancement and lower expectancies for anxiety/negative physical effects and sleep disturbance. Caffeine expectancies predicted various caffeine- associated features of substance dependence (e.g., use despite harm, withdrawal incidence and severity, perceived difficulty stopping use, tolerance). Expectancies for caffeine consumed via coffee were stronger than for caffeine consumed via soft drinks or tea. The CaffEQ should facilitate the advancement of our knowledge of caffeine and drug use in general.     

Brand Loyalty Is Influenced by the Activation of Political Orientations

Using an experimental design that measures participants’ actual behavior, this study tests the inclusion of a perceived outgroup in an advertisement for a well-established brand to determine if political orientations interact with an advertisement’s content to predict consumption of that product. The results indicate that an advertisement’s activation of one’s political orientation can either change or reinforce brand loyalty. Specifically, more conservative individuals responded to the presence of Muslim and Arab individuals in a Coca-Cola advertisement by selecting Pepsi products despite their initial preference for Coca-Cola; whereas, more liberal individuals maintained their initial brand loyalty to Coca-Cola.     

Smoking, caffeine, and stress: effects on blood pressure and heart rate in male and female college students

This study examined the independent and joint effects of cigarette smoking and caffeine consumption on blood pressure (BP) and heart rate (HR) reactions to stress in male and female college students. Following an initial physiological baseline, participants received one of four experimental treatments (paced smoking, caffeine, smoking plus caffeine, or neither) and had BP and HR measured before, during, and after two stressful tasks. The results revealed that, compared with the control condition, caffeine ingestion enhanced the magnitude of stress-induced systolic BP and HR reactions. Smoking combined additively with stress, and the joint effect of smoking and caffeine was no greater than either taken alone. Males and females were generally similar in their BP and HR responses to smoking, caffeine, and stress. Inconsistencies with previous research and possible physiological mechanisms underlying the observed effects are discussed.     

EFFECTS OF CAFFEINE ON CLASSROOM BEHAVIOR,SUSTAINED ATTENTION,AND A MEMORY TASK IN PRESCHOOL CHILDREN

The effects of caffeine on the behavior of young children is an important issue, as children in our society consume considerable amounts of caffeine, primarily in soft drinks. This study investigated the effects of normative amounts of caffeine on the behavior of 6 normal children in a kindergarten setting. Using a reversal design, counterbalanced for order of conditions, children's behavior was examined during a baseline condition, a caffeinated beverage condition, and a noncaffeinated beverage condition. Measures included direct observation of off-task and gross motor activity, actometer readings of movement, a Continuous Performance Test, a Paired Associates Learning Test, and teacher ratings of classroom behavior. Results suggest that caffeine exerts only small and inconsistent effects on the classroom behavior of kindergarten children. These results cast doubt on the importance of caffeine as a variable controlling the classroom behavior of normal kindergartners.     

Anger arousal,deindividuation, and aggression

We tested the notion that angered persons' aggression would be increased through a process of excitation transfer when they are deindividuated, but that individuated subjects would be most aggressive in circumstances under which they could use the information that they had ingested an arousing drug as a pretext for their aggression. Sixty-two male undergraduates participated under either deindividuated or individuated conditions, ingested either 350 mg of caffeine or a placebo, were informed that they had either taken a stimulant or a nonarousing drug, and were all angered by a confederate. According to prediction, when deindividuated and aroused by caffeine the amount of noxious stimulation subjects delivered to the provocateur was greater if they believed that the drug they had taken was nonarousing than if they thought it was a stimulant; in contrast, individuated subjects' aggression was greater when aroused subjects believed the drug was a stimulant. The results are discussed in terms of excitation transfer and the effect of aggression inhibition on the use of information about one's arousal.     

Depression, anxiety, hostility, and physical health

This study assessed the relationship of depression, anxiety, and hostility to physical health in a multicultural student population (N=106). When controlling for a variety of demographic and health risk factors (viz., age, sex, body mass, smoking, alcohol, salt, caffeine, and exercise), hostility, depression, and anxiety were related to higher reported incidences of physical symptoms and somatic illness. Depression and hostility had the strongest relationships with physical health, although the most striking single relationship was between depression and illness. Results suggest that it may be premature to focus our attention on hostility in research on the personality-illness relationship. They also suggest that the health behavior model of the relationship between personality and disease does not provide an adequate explanation, since negative affect was significantly associated with illness even when controlling for a variety of health risk factors. This work was supported, in part, by an intramural grant from the University of Hawaii, #R511.     

Reinforcing effects of caffeine in coffee and capsules.

In a residential research ward the reinforcing and subjective effects of caffeine were studied under double-blind conditions in volunteer subjects with histories of heavy coffee drinking. In Experiment 1, 6 subjects had 13 opportunities each day to self-administer either a caffeine (100 mg) or a placebo capsule for periods of 14 to 61 days. All subjects developed a clear preference for caffeine, with intake of caffeine becoming relatively stable after preference had been attained. Preference for caffeine was demonstrated whether or not preference testing was preceded by a period of 10 to 37 days of caffeine abstinence, suggesting that a recent history of heavy caffeine intake (tolerance/dependence) was not a necessary condition for caffeine to function as a reinforcer. In Experiment 2, 6 subjects had 10 opportunities each day to self-administer a cup of coffee or (on different days) a capsule, dependent upon completing a work requirement that progressively increased and then decreased over days. Each day, one of four conditions was studied: caffeinated coffee (100 mg/cup), decaffeinated coffee, caffeine capsules (100 mg/capsule), or placebo capsules. Caffeinated coffee maintained the most self-administration, significantly higher than decaffeinated coffee and placebo capsules but not different from caffeine capsules. Both decaffeinated coffee and caffeine capsules were significantly higher than placebo capsules but not different from each other. In both experiments, subject ratings of "linking" of coffee or capsules covaried with the self-administration measures. These experiments provide the clearest demonstrations to date of the reinforcing effects of caffeine in capsules and in coffee.     

Caffeine, fatigue, and cognition

Effects of caffeine and fatigue are discussed with special attention to adenosine-dopamine interactions. Effects of caffeine on human cognition are diverse. Behavioural measurements indicate a general improvement in the efficiency of information processing after caffeine, while the EEG data support the general belief that caffeine acts as a stimulant. Studies using ERP measures indicate that caffeine has an effect on attention, which is independent of specific stimulus characteristics. Behavioural effects on response related processes turned out to be mainly related to more peripheral motor processes. Recent insights in adenosine and dopamine physiology and functionality and their relationships with fatigue point to a possible modulation by caffeine of mechanisms involved in the regulation of behavioural energy expenditure.     

Depression,anxiety, hostility,and physical health

This study assessed the relationship of depression, anxiety, and hostility to physical health in a multicultural student population (N=106). When controlling for a variety of demographic and health risk factors (viz., age, sex, body mass, smoking, alcohol, salt, caffeine, and exercise), hostility, depression, and anxiety were related to higher reported incidences of physical symptoms and somatic illness. Depression and hostility had the strongest relationships with physical health, although the most striking single relationship was between depression and illness. Results suggest that it may be premature to focus our attention on hostility in research on the personality-illness relationship. They also suggest that the health behavior model of the relationship between personality and disease does not provide an adequate explanation, since negative affect was significantly associated with illness even when controlling for a variety of health risk factors. This work was supported, in part, by an intramural grant from the University of Hawaii, #R511.     

Caffeine effects on mood and memory.

The purpose of the present research was to assess whether a psychoactive dose of caffeine would have differential affects on the mood dimensions of arousal versus feelings of pleasantness and whether these mood alterations would influence memory either by (1) the experience of arousal at learning and/or (2) altered and congruent mood states at learning and recall. To address these questions, the administration of 5 mg/kg caffeine or placebo at learning and retrieval sessions was manipulated and subjects' mood was evaluated by several different self-report measures. Sixteen words were incidentally studied during the learning session and memory was evaluated by the number of words correctly recalled at the retrieval session two days later. Results revealed that caffeine reliably increased arousal, but did not affect any emotion dimensions related to feelings of pleasure. Subjects who received caffeine at learning and retrieval were also in equivalent mood states at both sessions. Moreover, caffeine did not produce any effects on memory; thus, neither hypothesis concerning the influence of arousal on memory was supported. These data show that caffeine is a useful method for manipulating arousal in the laboratory without influencing feelings of pleasantness or learning and memory performance.     

The Attraction of Africanized Honey Bees (Apis mellifera L.) to Soft Drinks and Perfumes

The attraction of Africanized bees to soft drinks and perfumes was investigated. In the first experiment, the ability of bees to discriminate between two perfumes (Realm for Men and Realm for Women) was assessed. The results indicated that the scents could be used as conditioned stimuli. In the second experiment, bees were divided into individual groups and confined to small metal tubes. Groups were fed either Diet Pepsi, spring water (control), Diet Guaraná, Diet Coca-Cola, Coca-Cola, Sprite, Pepsi, Guaraná, Sukita Orange, Fanta Orange, Fanta Grape, or sucrose (control). The dependent variable was the amount of time the bee's proboscis was in contact with a strip of filter paper saturated with the substance. The results indicated little or no contact with the diet soft drinks and spring water, 45–65 s of contact with Coca-Cola, Sprite, Pepsi, Guaraná, and Sukita Orange, and 75–140 s of contact with Fanta Orange, Fanta Grape, and sucrose (sucrose elicited the most contact of the substances tested). In a third experiment, the ability of bees to associate an odor with a soft drink was assessed in a discrimination task. With Citral and Geraniol as conditioned stimuli, conditioning was best to sucrose, Guaraná, and Fanta Orange. Little conditioning was observed with Pepsi, and no conditioning was observed with Diet Pepsi.     

LETA STETTER HOLLINGWORTH SPEAKS ON "COLUMBIA'S LEGACY"

At the 1983 APA convention in Anaheim, CA, Divisions 1 and 26 co-sponsored a lecture series to commemorate the 50th anniversary of the publication of Edna Heidbreder's Seven Psychologies. Aimed at the general audience, Heidbreder's book described the roots of American psychology and the seven schools of thought most representative of the discipline in this country: structuralism, the psychology of William James, functionalism, behaviorism, Gestalt psychology, Freud and the psychoanalytic movement, and the dynamic psychology of Columbia's Robert Woodworth. At the 1983 APA meetings five scholars with backgrounds in one of the seven psychologies lectured as a figure from the past on the legacy of that school of thought. Stephanie Shields represented Leta Hollingworth (1886–1939), the only woman in the group. Hollingworth was charged with discussing the legacy of Columbia University for contemporary psychology. Her lecture reviews psychological research at Teachers College and Columbia University from 1911 through the 1920s and then evaluates the lasting contribution made by that research to present-day psychology. This paper is the text of that talk, with a few modifications tailored for an audience of feminist psychologists. As an historical fiction the material for this talk is drawn primarily from Hollingworth's own writings, and, insofar as it is possible, it tries to represent accurately the theoretical and ideological concerns she expressed during her career. It attempts to bring her concerns as a psychologist, as an educator, and as a feminist, to bear on the state of present-day psychology, particularly from the perspective of the testing movement between the two world wars. All of the events described here did happen or could have happened. Those that are fictional or represent inference are clearly indicated. Direct quotes from her published work appear within quotation marks.     

Behavioral effects of caffeine, methamphetamine, and methylphenidate in the rat

It was possible to distinguish three closely-related psychomotor stimulants, caffeine, methamphetamine, and methylphenidate, by means of two operant behavior procedures, fixed interval and fixed number. Under the fixed interval procedure, the percentage change in the number of R_Bs per reinforcement was significantly smaller with caffeine than with methamphetamine or methylphenidate (p < .001). Under the fixed number procedure, the percentage change was significantly smaller with methamphetamine than with caffeine or methylphenidate (p < .001). Thus, methylphenidate had a methamphetamine-like effect under fixed interval and a caffeine-like effect under fixed number.     

Human coffee drinking: manipulation of concentration and caffeine dose.

In a residential research ward coffee drinking was studied in 9 volunteer human subjects with histories of heavy coffee drinking. A series of five experiments was undertaken to characterize adlibitum coffee consumption and to investigate the effects of manipulating coffee concentration, caffeine dose per cup, and caffeine preloads prior to coffee drinking. Manipulations were double-blind and scheduled in randomized sequences across days. When cups of coffee were freely available, coffee drinking tended to be rather regularly spaced during the day with intercup intervals becoming progressively longer throughout the day; experimental manipulations showed that this lengthening of intercup intervals was not due to accumulating caffeine levels. Number of cups of coffee consumed was an inverted U-shaped function of both coffee concentration and caffeine dose per cup; however, coffee-concentration and dose-per-cup manipulations did not produce similar effects on other measures of coffee drinking (intercup interval, time to drink a cup, within-day distribution of cups). Caffeine preload produced dose-related decreases in number of cups consumed. As a whole, these experiments provide some limited evidence for both the suppressive and the reinforcing effects of caffeine on coffee consumption. Examination of total daily coffee and caffeine intake across experiments, however, provides no evidence for precise regulation (i.e., titration) of coffee or caffeine intake.     

Caffeine, Cognition, and Persuasion: Evidence for Caffeine Increasing the Systematic Processing of Persuasive Messages

Caffeine is known to increase arousal, attention, and information processing–all factors implicated in facilitating persuasion. In a standard attitude-change paradigm, participants consumed an orange-juice drink that either contained caffeine (3.5 mg/kg body weight) or did not (placebo) prior to reading a counterattitudinal communication (anti-voluntary euthanasia). Participants then completed a thought-listing task and a number of attitude scales. The first experiment showed that those who consumed caffeine showed greater agreement with the communication (direct attitude: voluntary euthanasia) and on an issue related to, but not contained in, the communication (indirect attitude: abortion). The order in which direct and indirect attitudes were measured did not affect the results. A second experiment manipulated the quality of the arguments in the message (strong vs. weak) to determine whether systematic processing had occurred. There was evidence that systematic processing occurred in both drink conditions, but was greater for those who had consumed caffeine. In both experiments, the amount of message-congruent thinking mediated persuasion. These results show that caffeine can increase the extent to which people systematically process and arc influenced by a persuasive communication.     

Dishabituation and spontaneous recovery of the electrodermal orienting response: Effects of extraversion,impulsivity, sociability,and caffeine

The relationship between extraversion and psychophysiological indices of arousal is not yet fully understood. The present study attempted to further clarify this relationship by using caffeine to systematically manipulate arousal. Subjects pretested on the Eysenck Personality Inventory were given caffeine or a placebo, then underwent habituation, dishabituation, and spontaneous recovery of the electrodermal OR. Separate analyses examined the main and interactive effects of extraversion, impulsivity, and sociability with caffeine. Several tonic and phasic measures showed group reversal effects, with introverts having higher tonic levels and larger phasic responses under placebo conditions and extraverts having larger phasic responses and higher tonic levels under caffeine. Although both tonic and phasic responses were differentially affected, the group reversal effects occurred at different points in time on tonic than they did on phasic measures relative to the theoretical buildup of inhibition. The findings for impulsivity were quite consistent with those for extraversion, and both sets of results were generally supportive of the Eysenck hypothesis.     

The interactive effect of personality, time of day, and caffeine: a test of the arousal model

The personality dimension of introversion/extraversion is one of the few personality dimensions that can be reliably identified from study to study and investigator to investigator. The importance of this demension within personality theory is due both to the stability of the trait and the influential theory of H. J. Eysenck. The basic assumption in Eysenck's theory of introversion/extraversion is that the personality differences between introverts and extraverts reflect some basic difference in the resting level of cortical arousal or activation. Assuming that there is a curvilinear relationship (an inverted U) between levels of stress and performance leads to a test of this arousal theory. That is, moderate increases in stress should hinder the performance of introverts who are presumably already highly aroused. However, the same moderate increase in stress might help the performance of the presumably underaroused extraverts. Revelle, Amaral, and Turriff reported that the administration of moderate doses of caffeine hindered the performance of introverts and helped the performance of extraverts on a cognitive task similar to the verbal test of the Graduate Record Examination. Assuming that caffeine increases arousal, this interaction between introversion/extraversion and drug condition supports Eysenck's theory. This interaction was explored in a series of experiments designed to replicate, extend, and test the generality of the original finding. The interaction between personality and drug condition was replicated and extended to additional cognitive performance tasks. However, these interactions were affected by time of day and stage of practice, and the subscales of introversion/extraversion, impulsivity, and sociability, were differentially affected. In the morning of the first day, low impulsives were hindered and high impulsives helped by caffeine. This pattern reversed in the evening of the first day, and it reversed again in the evening of Day 2. We concluded that the results from the first day of testing require a revision of Eysenck's theory. Instead of a stable difference in arousal between low and high impulsives, it appeared that these groups differed in the phase of their diurnal arousal rhythms. The result is that low impulsives are more aroused in the morning and less aroused in the evening than are the high impulsives. A variety of peripheral or strategic explanations (differences in caffeine consumption, guessing strategies, distraction, etc.) for the observed performance increments and decrements were proposed and tentatively rejected. It seems probable that some fundamental change in the efficiency with which information is processes is responsible for these performance changes.     

Effects of slow-release caffeine and a nap on driving simulator performance after partial sleep deprivation

A driving simulator was used to evaluate the effectiveness of a 30-min. nap and 300-mg slow-release caffeine as countermeasures to drivers' sleepiness induced by partial sleep deprivation. 12 participants were allowed 45 hr. time in bed at the laboratory. Driving performance then was measured twice--at 9 a.m. and at 1 p.m.--by a 45-min. driving task on a simulator. Subjective sleepiness/alertness and mood were assessed four times on the Stanford Sleepiness Scale and the Profile of Mood States. Driving performance was assessed as Lane Drifting, Speed Deviation, and Accident Liability. A 30-min. nap opportunity and 300 mg of slow-release caffeine both were successful in counteracting drivers' sleepiness. The remedial effect of slow-release caffeine lasted longer than that of the nap, that is, it was also effective in the afternoon session. This suggests that slow-release caffeine represents a valuable countermeasure that, in the case of partial sleep deprivation, is preferred to a nap when sleepiness has to be counteracted for a longer time.     

Cardiovascular reactivity, mood, and task performance in deprived and nondeprived coffee drinkers

Forty habitual, heavy coffee drinkers (M = 5.7 cups/day) participated in two experimental sessions. Participants were deprived of their morning coffee for one of the laboratory sessions, not deprived the other. During each session, subjects consumed 12 oz of caffeinated coffee, decaffeinated coffee, or caffeine-free herbal tea. Measurements of heart rate, blood pressure, mood, and catecholamine response to deprivation and consumption of the beverage, alone and in combination with challenging tasks, were made. This study found that caffeine continues to cause blood pressure increases with chronic, heavy consumption and that these effects do not appear to habituate with regular use. Subjects reacted to behavioral challenge with fewer negative mood effects if they had consumed caffeine or coffee. Mild caffeine deprivation was associated with symptoms of stress.     

Diet, exercise, and physical discomfort in college students

778 students in a 4-yr. urban commuter college were tested to determine the effects of exercise and diet on self-reported discomfort. High exercisers reported significantly less physical discomfort than moderate or low exercisers. Greater consumption of sweets and fast food were significantly related to reported physical discomfort regardless of levels of exercise. High levels of fruit and vegetable consumption were associated with less discomfort in high exercisers. High dairy consumption was significantly related to fewer symptoms for high exercisers. Men who reported high ingestion of caffeine had significantly more discomfort than those who reported moderate to lower ingestion of caffeine.