Remco C. Havermans

Impulsivity in obese women

In our obesogenic environment, self-control might be necessary in order to prevent overeating. Impulsivity is supposed to make it more difficult to resist the temptation to eat too much and can thereby contribute to overweight. In the present study, the hypotheses is tested that obese individuals are more impulsive. Thirty-one obese and 28 lean women, sampled from the normal population, are tested on a behavioural measure and three self-report measures of impulsivity. The obese women appeared more impulsive on the last part of the behavioural task, but not on the self-report measures. Implications of the results are discussed.

The interactive effect of hunger and impulsivity on food intake and purchase in a virtual supermarket

Objective:It has been shown repeatedly that impulsivity, obesity and food intake are related; obese people are more impulsive than lean people and impulsive people eat more than less impulsive people. The relation between impulsivity and food intake might be state dependent; hunger motivates food seeking behaviour and food consumption, especially of high caloric food. Difficulties to overrule automatic behavioural tendencies might make impulsive people more susceptible to the effects of hunger on food selection. Therefore, they are expected to increase their intake more than low impulsive people when feeling hungry.Study 1:Fifty-seven female participants were randomly assigned to a hunger or sated condition. Response inhibition (a measure of impulsivity) and food intake were measured. Results show that impulsive participants ate significantly more, but only when feeling hungry.Study 2:Ninety-four undergraduate students participated. Hunger, response inhibition and the purchase of food in a virtual supermarket were measured. The same interaction was found: impulsive participants bought most calories, especially from snack food, but only when feeling hungry.Conclusion:Hunger and impulsivity interact in their influence on consumption. These data suggest that reducing hunger during calorie restricting diets is important for successful weight loss, particularly for the impulsive dieters.

High-restrained eaters only overeat when they are also impulsive

Recent work shows that the inability to inhibit basic motor responses (like pressing a button) is related to overeating, weight gain and overweight. In the present study it was tested whether this inability to inhibit motor responses--or impulsivity--can differentiate between successful and unsuccessful restrained eaters. A typical preload and food exposure paradigm was used and it was hypothesized that only the high-restrained eaters that are simultaneously inefficient inhibitors of prepotent motor responses would overeat when confronted with tempting foods. In line with the hypothesis, the data show that overeating follows from an interaction between restraint and impulsivity; high-restrained eaters only overate when they were also impulsive. It is concluded that being restrained per se is not a determinant of overeating. Being a restrained eater only bears the risk of overeating in case of coexisting impulsivity.

Beer à no-go: learning to stop responding to alcohol cues reduces alcohol intake via reduced affective associations rather than increased response inhibition

AIMS   Previous research has shown that consistently not responding to alcohol-related stimuli in a go/no-go training procedure reduces drinking behaviour. This study aimed to examine further the mechanisms underlying this go/no-go training effect. DESIGN, SETTING AND PARTICIPANTS   Fifty-seven heavy drinkers were assigned randomly to two training conditions: in the beer/no-go condition, alcohol-related stimuli were always paired with a stopping response, while in the beer/go condition participants always responded to alcohol-related stimuli. Participants were tested individually in a laboratory at Maastricht University. MEASUREMENTS   Weekly alcohol intake, implicit attitudes towards beer, approach-avoidance action tendencies towards beer and response inhibition were measured before and after the training. FINDINGS   Results showed a significant reduction in both implicit attitudes (P = 0.03) and alcohol intake (P = 0.02) in the beer/no-go condition, but not in the beer/go condition. There were no significant training effects on action tendencies or response inhibition. CONCLUSIONS   Repeatedly stopping pre-potent responses towards alcohol-related stimuli reduces excessive alcohol use via a devaluation of alcohol-related stimuli rather than via increased inhibitory control over alcohol-related responses.

Increasing children's liking of vegetables through flavour-flavour learning

Positive flavour-flavour learning refers to a form of Pavlovian conditioning in which a neutral flavour is paired with an already preferred flavour. Due to this pairing one acquires an association between the neutral flavour and the liked flavour, resulting in a positive shift in liking and hence preference for the initially neutral flavour. In the present study, it was investigated whether a flavour-flavour learning procedure increases childrens preference for a specific vegetable taste. Twenty one children were recruited and received six pairs of conditioning trials comprising the tasting of a sweetened vegetable and another unsweetened vegetable taste. At test the children had to evaluate the tastes unsweetened. Results show an increase in preference for the previously sweetened vegetable taste. It is concluded that flavour-flavour learning may be beneficial in increasing childrens liking and acceptance of vegetables.

Learning to dislike alcohol: conditioning negative implicit attitudes toward alcohol and its effect on drinking behavior.

RationaleSince implicit attitudes toward alcohol play an important role in drinking behavior, a possible way to obtain a behavioral change is changing these implicit attitudes.ObjectivesThis study examined whether a change in implicit attitudes and in drinking behavior can be achieved via evaluative conditioning.MethodsParticipants were randomly assigned to an experimental condition and a control condition. In the experimental condition, participants were subjected to an evaluative conditioning procedure that consistently pairs alcohol-related cues with negative stimuli. In the control condition, alcohol-related cues were consistently paired with neutral stimuli during the evaluative conditioning phase. Implicit attitudes, explicit attitudes, and drinking behavior were measured before and after the evaluative conditioning phase.ResultsFollowing the evaluative conditioning procedure, participants in the experimental condition showed stronger negative implicit attitudes toward alcohol and consumed less alcohol compared to participants in the control condition. However, this effect was only found when the evaluative conditioning task paired alcohol-related cues with general negative pictures, but not when using pictures of frowning faces.ConclusionsThese results demonstrate that evaluative conditioning can effectively change implicit attitudes toward alcohol and also suggest that this procedure can be used to change drinking behavior. Hence, evaluative conditioning may be a useful new intervention tool to combat alcohol misuse.

Increasing the efficacy of cue exposure treatment in preventing relapse of addictive behavior

Theoretically, cue exposure treatment should be able to prevent relapse by extinguishing conditioned drug responding (e.g. cue-elicited craving). According to contemporary learning theory, though, extinction does not eliminate conditioned responding. Analogous cue exposure with response prevention (CERP) as a treatment of addictive behavior might not eliminate the learned relation between drug-related cues and drug use. This does not necessarily mean that cue exposure cannot successfully prevent relapse. Various suggestions for increasing the efficacy of cue exposure treatment are being discussed from a contemporary learning theory perspective. It is suggested that cue exposure treatment incorporating retrieval cues can be a beneficial treatment in preventing relapse of addictive behavior.

Can’t stop the craving: The effect of impulsivity on cue-elicited craving for alcohol in heavy and light social drinkers

RationaleA robust finding in the alcohol literature is that heavy and alcohol-dependent drinkers show stronger reactions to alcohol-related cues than light drinkers. However, there are individual differences in the degree of cue-elicited craving. Personality factors appear to be involved in cue reactivity and impulsivity is a possible candidate.ObjectivesThe aim of the present study was to examine the role of different aspects of impulsivity in heavy drinking and alcohol cue reactivity in social drinkers.MethodsParticipants were heavy (n = 13) and light (n = 29) social drinkers who were exposed to neutral and alcohol-related stimuli during a single laboratory session. Trait impulsivity, response inhibition, and sensitivity to reward were assessed with the Barratt Impulsiveness Scale (BIS-11), the Stop Signal Task, and the Card-Arranging Reward Responsivity Objective Test, respectively.ResultsHeavy drinkers scored higher on trait impulsivity (BIS-11) than light drinkers. In addition, heavy drinkers reported elevated levels of craving for alcohol, but both in light and heavy drinkers, craving increased equally after exposure to alcohol cues. Impulsivity appeared to moderate this relation: heavy drinkers with ineffective response inhibition showed more craving to alcohol cues, compared to heavy drinkers with adequate response inhibition. In light drinkers, response inhibition did not influence craving to alcohol cues.ConclusionsDifferent aspects of impulsivity are involved in heavy drinking and perhaps motivate alcohol consumption in a variety of ways. Having a deficient response inhibition appears to be a risk factor for heavy drinkers because it is associated with increased craving to alcohol cues.

Fighting food temptations: The modulating effects of short-term cognitive reappraisal, suppression and up-regulation on mesocorticolimbic activity related to appetitive motivation

The premise of cognitive therapy is that one can overcome the irresistible temptation of highly palatable foods by actively restructuring the way one thinks about food. Testing this idea, participants in the present study were instructed to passively view foods, up-regulate food palatability thoughts, apply cognitive reappraisal (e.g., thinking about health consequences), or suppress food palatability thoughts and cravings. We examined whether these strategies affect self-reported food craving and mesocorticolimbic activity as assessed by functional magnetic resonance imaging. It was hypothesized that cognitive reappraisal would most effectively inhibit the mesocorticolimbic activity and associated food craving as compared to suppression. In addition, it was hypothesized that suppression would lead to more prefrontal cortex activity, reflecting the use of more control resources, as compared to cognitive reappraisal. Self-report results indicated that up-regulation increased food craving compared to the other two conditions, but that there was no difference in craving between the suppression and cognitive reappraisal strategy. Corroborating self-report results, the neuroimaging results showed that up-regulation increased activity in important regions of the mesocorticolimbic circuitry, including the ventral tegmental area, ventral striatum, operculum, posterior insular gyrus, medial orbitofrontal cortex and ventromedial prefrontal cortex. Contrary to our hypothesis, suppression more effectively decreased activity in the core of the mesocorticolimbic circuitry (i.e., ventral tegmental area and ventral striatum) compared to cognitive reappraisal. Overall, the results support the contention that appetitive motivation can be modulated by the application of short-term cognitive control strategies.

Food liking, food wanting, and sensory-specific satiety

Sensory-specific satiety refers to a temporary decline in pleasure derived from consuming a certain food in comparison to other unconsumed foods. It has been argued that such a reduction may not be limited to food liking but extends to food wanting as well. Animal research suggests that sensory-specific satiety reflects a reduction in both food liking and food wanting and in the present study it was investigated whether this also holds true for humans. Participants had to consume a certain amount of chocolate milk and afterwards approximately half of the participants played a game to obtain more chocolate milk, whereas the other half played a game to obtain crisps. Participants showed a decline in subjective liking of taste and smell of the chocolate milk in comparison to crisps. Furthermore, they showed less motivation (i.e. wanting) to obtain more chocolate milk. It is concluded that sensory-specific satiety in humans reflects a decrease in both food liking and food wanting.