Energy, tiredness, and tension effects of a sugar snack versus moderate exercise

After either eating a candy bar or walking briskly for 10 min on 12 selected days, 18 volunteers made systematic self-ratings of their energy, tiredness, and tension feelings for a fixed 2-hr period each day in the context of their normal daily activities. The snacking or walking activity was randomly selected on each test day after completion of a pretest. Results indicated that walking was associated with higher self-rated energy and lower tension significantly more than was snacking. In the walk condition reliable increases in energy and decreases in tension were observed for 2 hr. The sugar snack condition was associated with significantly higher tension after 1 hr, and a pattern of initially increased energy and reduced tiredness, followed 1 hr later by increased tiredness and reduced energy. The results partially support a general conceptual hypothesis that sugar snacking is often motivated by a low-awareness attempt to raise energy. Additionally, the results clarify an apparent conflict between neurochemical research, which indicates that sugar ingestion increases the tendency to sleep, and popular nutrition theory, which indicates that it increases tension.     

Perception of danger signals: the role of control

How does the perceptual system process stimuli that signal aversive outcomes or dangers? Considering the functional links between perception, attention, and action regulation, we posit that when people can avoid the aversive consequences, sensitivity of the perceptual system to danger signals should be enhanced, whereas it should be reduced when there is no such option. To test this prediction, we used a search task in which tachistoscopically presented conjunctions of features had to be detected. Parameters of sensitivity and response bias were analyzed drawing on procedures from signal detection theory. Although the experimental procedure rewarded correct responses, the predicted asymmetry emerged. For stimuli that were linked to a negative consequence (loss of points in the experimental game), perceptual sensitivity was enhanced when participants had the opportunity to neutralize the loss in a second task; an opposite pattern emerged when they had no such opportunity.     

Modification of escape responding in humans by increasing the magnitude of an aversive event

Escape responding of humans on an avoidance-escape schedule was replaced by avoidance responding by increasing the magnitude of the aversive stimulus. The aversive stimulus consisted of a point loss period. The shift from escape to avoidance responding was effected under a condition of response cost.     

Stress and dietary practices in adolescents.

Baseline data from the Health and Behavior in Teenagers Study (HABITS) were used to investigate associations between stress and dietary practices in a socioeconomically and ethnically diverse sample of 4,320 schoolchildren (mean age = 11.83 years). Male (n = 2,578) and female (n = 1,742) pupils completed questionnaire measures of stress and 4 aspects of dietary practice (fatty food intake, fruit and vegetable intake, snacking, and breakfast consumption) and also provided demographic and anthropometric data. Multivariate analyses revealed that greater stress was associated with more fatty food intake, less fruit and vegetable intake, more snacking, and a reduced likelihood of daily breakfast consumption. These effects were independent of individual (gender, weight) and social (socioeconomic status, ethnicity) factors. Stress may contribute to long-term disease risk by steering the diet in a more unhealthy direction.     

The Effects of Uncontrollable, Unpredictable Aversive and Appetitive Events: Similar Effects Warrant Similar, but not Identical, Explanations?

Exposure to uncontrollable, unpredictable appetitive events produces a variety of cognitive debilitations and vegetative changes, as does exposure to uncontrollable, unpredictable aversive events. Similarities include impaired escape from aversive events, impaired discrimination, finicky consumption, analgesia, and body weight loss. However, in stark contrast, uncontrollable aversive stress causes reduced motor activity where as similar appetitive treatment does not; aversively induced debilitation is causally related to energy regulation, whereas the appetitively induced effects are not. Parallel mechanisms are suggested to explain these effects in terms of a revised anxiety account of the aversive effects, and a frustration account of the appetitive effects. Finally, factors likely to limit important research to resolve the many remaining issues are identified: negative presentation of animal research, political decision making, and ignorance and fear in committees which review the ethics of research.     

Challenging body weight: evidence from a community-based intervention on weight,behaviour and motivation

The objective of this study was to examine the effectiveness of a 12 week weight loss intervention within a commercial fitness centre on body weight, moderate to vigorous physical activity (MVPA), dietary intake, and behavioural regulations for exercise and healthy eating. Using a quasi-experimental design, the intervention group received weekly coaching sessions and bi-weekly seminars designed to increase MVPA and improve dietary intake. Outcome variables were assessed at three time points over a six month period. Results showed a significant interaction for body weight (p = .04) and dietary changes (p < .05) following the weight loss challenge but were not maintained across the six month period. Changes in behavioural regulations favoured the intervention condition. Results imply that a 12 week weight loss challenge within a commercial fitness centre may be effective at prompting short-term weight loss and support the internalization of behavioural regulations specific to healthy eating and exercise.     

The effects of uncontrollable, unpredictable aversive and appetitive events: Similar effects warrant similar, but not identical, explanations?

Exposure to uncontrollable, unpredictable appetitive events produces a variety of cognitive debilitations and vegetative changes as does exposure to uncontrollable, unpredictable aversive events. Similarities include impaired escape from aversive events, impaired discrimination, finicky consumption, analgesia, and body weight loss. However, in stark contrast, uncontrollable aversive stress causes reduced motor activity where as similar appetitive treatment does not; aversively induced debilitation is causally related to energy regulation, whereas the appetitively induced effects are not. Parallel mechanisms are suggested to explain these effects in terms of a revised anxiety account of the aversive effects, and a frustration account of the appetitive effects. Finally, factors likely to limit important research to resolve the many remaining issues are identified: negative presentation of animal research, political decision making, and ignorance and fear in committees which review the ethics of research. The research reported here was supported by a Sydney University Special Project Grant and Australian Research Council Grants to R.F.S. Job. The paper was completed while the author was supported by a Special Study Leave Grant from the University of Sydney.     

Identifying the ‘if’ for ‘if-then’ plans: Combining implementation intentions with cue-monitoring targeting unhealthy snacking behaviour

Implementation intentions aimed at changing unwanted habits require the identification of personally relevant cues triggering the habitual response in order to be effective. To facilitate successful implementation intention formation, in the present study, planning was combined with cue-monitoring, a novel way to gain insight into triggers for unhealthy snacking. It was tested whether keeping a cue-monitoring diary and tailoring implementation intentions accordingly improves plan effectiveness. A 2 Monitoring (cue-monitoring, control)?×?2 Planning (implementation intention, goal intention) between subjects design was adopted. Participants (N = 161) monitored their unhealthy snacking behaviour for a week using either a cue-monitoring or a control diary. Participants then formulated a goal intention or an implementation intention tailored to their personal cue. Snacking frequency and caloric intake from unhealthy snacks were examined using a seven-day snack diary. The results did not indicate an interaction but yielded a main effect of Monitoring. Cue-monitoring either or not combined with implementation intentions reduced unhealthy snacking behaviour compared with control. Findings emphasise the effectiveness of cue-monitoring, suggesting that on the short term, cue-monitoring suffices to decrease unhealthy snacking, without additional benefit from planning. Future research should examine whether supplementing cue-monitoring with implementation intentions is required to establish long-term behaviour change maintenance.     

Behavioral approaches to weight control: An updated review

Recent developments in the behavioral treatment of obesity were surveyed. Since the earlier review (Abramson, 1973) no studies of aversive therapy have been published. Three studies of covert sensitization have yielded discouraging results. Any positive effects of this technique appear to be the result of non-specific demand characteristics rather than aversive conditioning. Several demonstrations of the effects of therapist controlled reinforcement indicate that this technique can promote weight loss while the contingencies are in effect. The weight is rapidly regained, however, after the contingencies are withdrawn. It is concluded that self-control treatments, especially complex self-control, are the most consistently successful treatment approaches. Several methodological problems are presented and unresolved issues are discussed.     

Concurrent schedules of positive and negative reinforcement: differential-impact and differential-outcomes hypotheses

Considerable evidence from outside of operant psychology suggests that aversive events exert greater influence over behavior than equal-sized positive-reinforcement events. Operant theory is largely moot on this point, and most operant research is uninformative because of a scaling problem that prevents aversive events and those based on positive reinforcement from being directly compared. In the present investigation, humans' mouse-click responses were maintained on similarly structured, concurrent schedules of positive (money gain) and negative (avoidance of money loss) reinforcement. Because gains and losses were of equal magnitude, according to the analytical conventions of the generalized matching law, bias (log b (double dagger) 0) would indicate differential impact by one type of consequence; however, no systematic bias was observed. Further research is needed to reconcile this outcome with apparently robust findings in other literatures of superior behavior control by aversive events. In an incidental finding, the linear function relating log behavior ratio and log reinforcement ratio was steeper for concurrent negative and positive reinforcement than for control conditions involving concurrent positive reinforcement. This may represent the first empirical confirmation of a free-operant differential-outcomes effect predicted by contingency-discriminability theories of choice.     

Self-experimentation as a source of new ideas: ten examples about sleep, mood, health, and weight

Little is known about how to generate plausible new scientific ideas. So it is noteworthy that 12 years of self-experimentation led to the discovery of several surprising cause-effect relationships and suggested a new theory of weight control, an unusually high rate of new ideas. The cause-effect relationships were: (1) Seeing faces in the morning on television decreased mood in the evening (> 10 hrs later) and improved mood the next day (> 24 hrs later), yet had no detectable effect before that (0-10 hrs later). The effect was strongest if the faces were life-sized and at a conversational distance. Travel across time zones reduced the effect for a few weeks. (2) Standing 8 hours per day reduced early awakening and made sleep more restorative, even though more standing was associated with less sleep. (3) Morning light (1 hr/day) reduced early awakening and made sleep more restorative. (4) Breakfast increased early awakening. (5) Standing and morning light together eliminated colds (upper respiratory tract infections) for more than 5 years. (6) Drinking lots of water, eating low-glycemic-index foods, and eating sushi each caused a modest weight loss. (7) Drinking unflavored fructose water caused a large weight loss that has lasted more than 1 year. While losing weight, hunger was much less than usual. Unflavored sucrose water had a similar effect. The new theory of weight control, which helped discover this effect, assumes that flavors associated with calories raise the body-fat set point: The stronger the association, the greater the increase. Between meals the set point declines. Self-experimentation lasting months or years seems to be a good way to generate plausible new ideas.     

Effects of response requirement and alcohol on human aggressive responding.

Nine men participated in two experiments to determine the effects of increased response requirement and alcohol administration on free-operant aggressive responding. Two response buttons (A and B) were available. Pressing Button A was maintained by a fixed-ratio 100 schedule of point presentation. Subjects were instructed that completion of each fixed-ratio 10 on Button B resulted in the subtraction of a point from a fictitious second subject. Button B presses were defined as aggressive because they ostensibly resulted in the presentation of an aversive stimulus to another person. Aggressive responses were engendered by a random-time schedule of point loss and were maintained by initiation of intervals free of point loss. Instructions attributed these point losses to Button B presses of the fictitious other subject. In Experiment 1, increasing the ratio requirement on Button B decreased the number of ratios completed in 4 of 5 subjects. In Experiment 2, the effects of placebo and three alcohol doses (0.125, 0.25, and 0.375 g/kg) were determined when Button B presses were maintained at ratio values of 20, 40 and 80. Three subjects who reduced aggressive responding with increasing fixed-ratio values reduced aggressive responding further at higher alcohol doses. One subject who did not reduce aggressive responding with increasing fixed-ratio values increased aggressive responding at the highest alcohol dose. The results of this study support suggestions that alcohol alters aggressive behavior by reducing the control of competing contingencies.     

Continuity and discontinuity in memory for threat

Using a paradigm that allows a quasi-continuous tracking of memory performance over time, two experiments were designed to test the hypotheses that (a) persons with a cognitively avoidant style of coping with threat manifest a dissociation between (intact) short-term and (reduced) long-term retrieval of aversive information and (b) persons with a vigilant coping style recall aversive information particularly well after long retention intervals, provided they are free to think about aversive events. Study 1 (N?=?75) showed that avoiders manifest a poor memory for aversive pictures after long retention intervals only. Study 2 (N?=?95) replicated this finding. In addition, manipulation of the cognitive load during the retention interval influenced vigilants’ recall of aversive information in the predicted way. Results indicate that processes occurring during the retention interval are essential for individual difference in memory for aversive information and require similar attention as encoding, appraisal, and retrieval processes.     

When competition breeds equality: Effects of appetitive versus aversive competition in negotiation

Competitive motivation is prevalent in negotiation but systematic insight into its effects is missing. We introduce the distinction between appetitive competition, in which negotiators seek relative gain, and aversive competition, in which negotiators seek to prevent relative loss. Two experiments tested the predictions that (i) appetitive competitors are less vigilant and more confident than aversive competitors, and are (ii) therefore more likely to reach an agreement. However, we further hypothesized that (iii) information about one's opponent undermines appetitive competitors' confidence, yet enables trust in aversive competitors. Results supported these predictions. Appetitive competitors more often reached an impasse than aversive competitors when information was provided about the opponent, whereas aversive competitors more often reached an impasse without this information.     

The effects of outcome expectations and satisfaction on weight loss and maintenance: correlational and experimental analyses--a randomized trial.

This study examines the hypothesis that highly favorable outcome expectations promote weight loss and hinder weight maintenance. To investigate the effects of outcome expectations and satisfaction with treatment outcomes on weight loss, 349 adults were randomly assigned to 1 of 2 weight loss programs that emphasize either (a) an "optimistic" message, focusing exclusively on the positive aspects of weight loss, or (b) a "balanced" message, giving equal time to positive and negative aspects of weight loss. Participants changed their weight loss cognitions in response to the intervention, but there was no significant difference between the intervention treatment groups in short-term or long-term (18-month) weight loss. Independent of treatment message, positive outcome expectations and satisfaction were both associated with weight loss.     

Emotionally Based Expectancies and Willingness To Use Aversive Therapy

Intellectually based expectancies are beliefs about the world that are subjectively perceived as true. Emotionally based expectancies are beliefs that have an "as if" quality to them. The two types of expectancies derive from different sources and are influenced by different variables. This study examined the relationship between these two types of expectancies and willingness to use aversive therapy. Forty-seven undergraduate subjects were first given a brief lecture on childhood autism and the treatment of self-injurious behavior by aversive therapy. Afterwards, they indicated on a brief questionnaire their intellectually and emotionally based expectancies about how effective aversive therapy would be. Finally, they indicated their willingness to use aversive therapy themselves with autistic children. The partial correlation of emotionally based expectancies with stated intentions was .48, that of intellectually based expectancies with stated intentions was .10. As predicted, the emotionally based expectancy correlation was significantly higher.     

Distinguishing BIS-mediated and BAS-mediated disinhibition mechanisms: a comparison of disinhibition models of Gray (1981, 1987) and of Patterson and Newman (1993)

The theoretical framework developed by J. A. Gray (1981, 1987a, 1987b) was used to study disinhibitory behavior. Using a point-scoring reaction time procedure, 4 different experiments were conducted to differentiate 2 disinhibitory mechanisms associated with the behavioral activation system (BAS) and the behavioral inhibition system (BIS). Consistent with the work of C. M. Patterson and J. P. Newman (1993), the BAS-mediated mechanism was related to a lack of inhibition in reward-directed behavior after introducing an occasional aversive contingency and to deficits in learning from aversive cues when responding for reward (Experiments 1-3). The BIS-mediated mechanism was related to a higher ability to extinguish aversive associations (Experiment 1), a lower aversive generalization gradient (Experiment 3), and a lower interference with appetitive behavior in the presence of aversive stimuli (Experiment 4).     

Suppression of behavior by timeout punishment when suppression results in loss of positive reinforcement

This investigation, using rats as subjects and punishment by timeout for responses maintained on a ratio schedule, sought to determine whether behavior would be suppressed by timeout punishment when such suppression also reduced reinforcement density or frequency. A series of experiments indicated that timeout punishment suppressed responding, with the degree of suppression increasing as a function of the duration of the timeout period. Suppressive effects were found to decrease as a function of increases in deprivation (body weight) and were eliminated when the punished response also was reinforced. It was concluded that timeout can produce aversive effects even when loss of reinforcement results. An alternative interpretation of the findings, based on the effects of extinction periods and delay of reinforcement on chained behavior, was discussed.     

Response-outcome contingency: Behavioral and judgmental effects of appetitive and aversive outcomes with college students

In two experiments, positive, negative, and zero response-outcome contingencies were responded to and rated by college students under a free-operant procedure. In Experiment 1, outcomes were either neutral or were associated with point gain. In Experiment 2, subjects were administered different outcome treatments: neutral outcomes, outcomes associated with money gain, or outcomes associated with money loss. In both experiments, subjects' judgments of response-outcome contingency and their operant responses were each strong linear functions of ΔP, the difference between the probability of an outcome given a response and the probability of an outcome given no response. Appetitive and aversive outcomes produced opposite and symmetrical response patterns. In Experiment 1, no differences in ratings occurred with neutral or appetitive outcomes; however, in Experiment 2, more potent appetitve outcomes led to somewhat more extreme ratings than either neutral or aversive outcomes. Increasing outcome probability produced only a slight bias in ratings of noncontingent problems in Experiment 1 and no bias in Experiment 2. Contrary to predictions derived from an analysis of superstitious behavior, increasing outcome probability in noncontingent problems decreased operant responding when outcomes were appetitive and increased operant responding when outcomes were aversive. Trend analyses revealed that Δ P was superior to several other metrics in predicting subjects' estimates of contingency and the behavioral effects of contingency. Operant responding was in closer accord with matching predictions than with maximizing predictions.