Biomedical subjects

Suzanne Higgs

Publications and source records attributed to Suzanne Higgs.

8 recordsLinked to original sources

PubMed2006

Associations between dieting and smoking-related behaviors in young women.

Many young women report smoking due to weight concerns, but little is known about the relationship between weight concerns and current smoking behavior. The present study examined smoking topography and the acute sensory and physiological responses to smoking in dieting and non-dieting young women. In addition, the effect of presentation of food cues on these responses was examined. Self-reported female current dieters (n=15) and non-dieters (n=15) attended two laboratory sessions (food cues present/food cues absent). Physiological and subjective responses were recorded pre- and post-cigarette at each session. Smoking topography was assessed by video analysis. Dieters scored higher than non-dieters on measures of weight control smoking, dietary restraint, and disinhibition. At both sessions, they smoked less of the cigarette, had shorter inhalation durations, longer inter-puff intervals, experienced smaller physiological effects and gave lower ratings of the sensory aspects of smoking than non-dieters. The presence of food cues did not alter smoking topography or sensory/physiological responses but the dieters reported a greater desire to smoke in the presence of food cues. These data suggest that sensory factors may be less important influences on smoking for weight control smokers than non-weight control smokers and that further investigation of the role of food cues in maintaining smoking behavior in weight control smokers is warranted.

Adolescent↗

PubMed2006

Acute psychomotor, subjective and physiological responses to smoking in depressed outpatient smokers and matched controls.

RATIONALE: Cigarette smoking is highly prevalent in people diagnosed with depression, and depressed smokers are less likely to quit. Examining depressed smokers' responses to smoking will help determine the role of depression in maintaining cigarette smoking. OBJECTIVES: To determine the psychomotor, subjective and physiological effects of cigarette smoking in currently depressed smokers versus matched controls. MATERIALS AND METHODS: Fourteen currently depressed smokers and 14 never-depressed smokers, matched in age, gender, nicotine dependence and daily cigarette consumption, smoked three cigarettes at half-hourly intervals. All smokers were non-deprived. Self-reported mood and craving for cigarettes, performance on a simple reaction time task, expired-air carbon monoxide, heart rate and blood pressure were assessed before and after smoking each cigarette. Smoking topography was also assessed. RESULTS: Depressives and controls did not differ in terms of dependence on cigarettes or expired-air carbon monoxide. Topographic and cardiovascular measures were similar in depressed and control participants, suggesting that they smoke cigarettes in a similar manner. However, depressives displayed enhanced reaction time performance after the first cigarette. Positively reinforced craving was reduced after smoking each cigarette but returned to baseline levels within 30 min in depressed but not in control smokers. Depressed smokers also displayed higher levels of negatively reinforced craving. Both depressives and controls reported improved positive mood after smoking. CONCLUSIONS: Cigarette smoking in non-deprived depressed smokers enhances psychomotor performance and the reduction of positively reinforced craving in depressed smokers after smoking is transient, suggesting that enhanced craving may play a role in the maintenance of smoking in depression.

Adaptation, Physiological↗

PubMed2005

Dietary restraint and US devaluation predict evaluative learning.

Previous research has indicated that flavor-flavor learning is impaired in restrained eaters. In Experiment 1 we sought to extend this finding using a larger sample and a more comprehensive assessment of dietary behavior. Participants (N=90, including 30 current dieters) sampled three novel flavors (CSs), each on 10 separate occasions, in a randomized order. Each flavor was paired with chocolate (US) either 10%, 50%, or 90% of the time. We then assessed liking for the three CSs and asked participants to complete the DEBQ-restraint and TFEQ-disinhibition sub-scales. After these CS-US parings, restrained eaters tended to prefer the 10% paired flavor whereas unrestrained eaters tended to prefer the 90% paired flavor. Differential CS liking was not evident in dieters and it was not predicted by disinhibition. Using a similar methodology, in Experiment 2 (N=76) we assessed evaluative change following picture-sweet pairings. Relative to the other CSs, the restrained eaters reported a greater increase in their liking for the 10% paired CS and the unrestrained eaters reported a greater increase in their liking for the 90% paired CS. We also discovered that evaluative change is related to the level of US devaluation that takes place during conditioning. Evidence that a sweet US can bring about a decrease in liking has not been reported previously. One interpretation is that negative beliefs and attitudes can contaminate the representation of the US during training.

Adult↗

PubMed2005

Benzodiazepine effects on licking responses for sodium chloride solutions in water-deprived male rats.

The aim of this study was to investigate, for the first time, the effects of a centrally active benzodiazepine receptor agonist, midazolam maleate, on the microstructure of licking responses for a range of sodium chloride (NaCl) solutions in mildly water-deprived male rats. Doses of midazolam were chosen (0.3-3.0 mg/kg. i.p.) which have been characterised in studies of licking responses for several different kinds of nutrients. NaCl concentrations (0.075 M-0.45 M) were chosen to cover a range of taste preferences and acceptability. A brief-contact testing session was employed to focus on the initial determinants of licking responses (i.e. taste palatability), and to minimise any contribution of post-ingestional effects. The results indicate the midazolam significantly increased the total number of licks recorded across all salt concentrations, but that it had no effect on the number of bouts of licking. Instead, midazolam specifically enhanced the mean duration of licking bouts, an effect that was most evident at the weaker but more acceptable NaCl concentrations (0.075 M and 0.15 M). In addition, midazolam diminished the intrabout rate of licking across all salt concentrations. These results confirm that benzodiazepines can exert a specific pattern of effects on the microstructure of licking for salt solutions. They are discussed in terms of the oropharyngeal stimulation controlling intake and the palatability or "liking" hypothesis for the effects of benzodiazepines on taste stimuli, and indicate that the hypothesis is applicable to salt solution ingestive behaviour.

Analysis of Variance↗

PubMed2005

Memory and its role in appetite regulation.

The importance of memory processes for the formation and expression of conditioned food preferences and satieties has long been appreciated. Recently, based on the eating of multiple meals in amnesic patients, it has been suggested that information about a recent eating episode may be factored into decisions about how much to consume at the next meal. In support of this, it has been shown that enhancing memory for a recent meal, by cueing neurologically intact participants to recall items eaten at lunch, suppresses intake at a taste test later in the afternoon. This effect is specific to recalling food eaten that day, since asking participants to think about lunch consumed the previous day had no effect on intake. These studies suggest that memory for recent eating has a role to play in controlling everyday eating. However, the involvement of memory and cognition does not exclude learnt control by physiological after effects of the recent meal; indeed, this seems likely from the known functions of the hippocampal system that is damaged in amnesic patients.

Animals↗

PubMed2004

Effects of baclofen on feeding behaviour examined in the runway.

The motivational mechanisms underlying the effects of systemic administration of the GABA-B agonist baclofen on feeding were examined using a runway. Food-deprived male hooded Lister rats were trained to traverse a runway for food reinforcement. Baclofen (1 mg/kg i.p.) significantly increased food intake and this was most evident on the final two blocks of testing. The 2 mg/kg dose of baclofen increased running speed without significantly altering intake. At the highest dose tested (4 mg/kg), no significant effects on either consummatory or appetitive measures were observed. These data suggest that low doses of baclofen enhance the consummatory phase of ingestion by attenuating the natural signals associated with onset of satiation. The data also suggest that baclofen has complex effects on appetitive behaviour that may interfere with its effects on consumption.

Analysis of Variance↗

PubMed2002

Cannabinoid influences on palatability: microstructural analysis of sucrose drinking after delta(9)-tetrahydrocannabinol, anandamide, 2-arachidonoyl glycerol and SR141716.

RATIONALE: Central cannabinoid systems have been implicated in appetite control through the respective hyperphagic and anorectic actions of CB1 agonists and antagonists. The motivational changes underlying these actions remain to be determined, but may involve alterations to food palatability. OBJECTIVES: The mode of action of cannabinoids on ingestion was investigated by examining the effects of exogenous and endogenous agonists, and a selective CB1 receptor antagonist, on licking microstructure in rats ingesting a palatable sucrose solution. METHODS: Microstructural analyses of licking for a 10% sucrose solution was performed over a range of agonist and antagonist doses administered to non-deprived, male Lister hooded rats. RESULTS: Delta(9)-tetrahydrocannabinol (0.5, 1 and 3 mg/kg) and anandamide (1 mg/kg and 3 mg/kg) significantly increased total number of licks. This was primarily due to an increase in bout duration rather than bout number. There was a non-significant increase in total licks following administration of 2-arachidonoyl glycerol (0.2, 1.0 and 2.0 mg/kg), whereas administration of the CB1 antagonist SR141716 (1 mg/kg and 3 mg/kg) significantly decreased total licks. All drugs, with the exception of anandamide, significantly decreased the intra-bout lick rate. An exponential function fitted to the cumulative lick rate curves for each drug revealed that all compounds altered the asymptote of this function without having any marked effects on the exponent. CONCLUSIONS: These data are consistent with endocannabinoid involvement in the mediation of food palatability.

Animals↗

PubMed2002

Memory for recent eating and its influence on subsequent food intake.

The effect of being reminded of a recent eating episode on subsequent food intake was examined in unrestrained eaters. In Experiment 1, female participants were exposed to a "lunch cue" (in which they were asked to think about what they had eaten for lunch), or "no cue" (free thought condition), for 5 min prior to eating. Participants ate less following exposure to the "lunch cue" than the "no cue" condition. In Experiment 2, food intake was measured following exposure to either a "lunch today" cue, "lunch yesterday" cue or "no cue" condition. Intake in the "lunch today" condition was suppressed relative to both the "lunch yesterday" and "no cue" condition. Subjective ratings of hunger, fullness, and desire to eat did not vary as a function of cue type in either Experiment 1 or Experiment 2. These results are consistent with the suggestion that memory of recent eating is an important cognitive factor influencing food intake.

Cognition↗