Gummed-up memory: chewing gum impairs short-term recall

Several studies have suggested that short-term memory is generally improved by chewing gum. However, we report the first studies to show that chewing gum impairs short-term memory for both item order and item identity. Experiment 1 showed that chewing gum reduces serial recall of letter lists. Experiment 2 indicated that chewing does not simply disrupt vocal-articulatory planning required for order retention: Chewing equally impairs a matched task that required retention of list item identity. Experiment 3 demonstrated that manual tapping produces a similar pattern of impairment to that of chewing gum. These results clearly qualify the assertion that chewing gum improves short-term memory. They also pose a problem for short-term memory theories asserting that forgetting is based on domain-specific interference given that chewing does not interfere with verbal memory any more than tapping. It is suggested that tapping and chewing reduce the general capacity to process sequences.     

Chewing gum and context‐dependent memory: The independent roles of chewing gum and mint flavour

Two experiments independently investigated the basis of the chewing gum induced context‐dependent memory effect. At learning and/or recall, participants either chewed flavourless gum (Experiment 1) or received mint‐flavoured strips (Experiment 2). No context‐dependent memory effect was found with either flavourless gum or mint‐flavoured strips, indicating that independently the contexts were insufficiently salient to induce the effect. This is found despite participants’ subjective ratings indicating a perceived change in state following administration of flavourless gum or mint‐flavoured strips. Additionally, some preliminary evidence for a non‐additive facilitative effect of receiving gum or flavour at either learning and/or recall is reported. The findings raise further concerns regarding the robustness of the previously reported context‐dependent memory effect with chewing gum.     

运动员咀嚼口香糖行为与竞赛焦虑的关系

为考察运动员咀嚼口香糖行为与竞赛焦虑的关系,本研究采用自编《咀嚼口香糖与竞赛焦虑问卷CGSCA》与《运动竞赛焦虑测验SCAT》,调查了457名运动员。结果发现,SCAT表明,运动员在竞赛情景下普遍处于应激状态并容易体验到焦虑;CGSCA表明,竞赛咀嚼行为与竞赛焦虑存在显著正相关,竞赛焦虑高的个体拥有更多的竞赛咀嚼行为,并更多地采用咀嚼口香糖的方式来缓解竞赛焦虑。本研究表明,咀嚼口香糖可以缓解运动员的竞赛焦虑。     

Cigarette smoking and depressive symptoms: a longitudinal study of adolescents and young adults

Cigarette smoking and depressive symptoms have been shown to be related in previous research. This paper examined the relationship between cigarette smoking and depressive symptoms in a longitudinal sample of 688 adolescents and young adults through surveys conducted over 13 yr. The results indicate that a history of earlier cigarette smoking in adolescence predicts later depressive symptoms in the late twenties. The study also suggests that depressive symptoms during adolescence predict cigarette smoking in the late twenties but not above and beyond prior smoking. These results help clarify and expand current knowledge on the links between cigarette smoking and depression. The results point to several clinical implications for treatment of both cigarette smoking and depressive symptoms among both adolescents and young adults.     

Constructive thinking and coping with laboratory-induced stress.

In a laboratory stress test, poor constructive thinkers produced more negative affective and cognitive responses in all experimental periods and a greater increase in such responses in the stress period than did good constructive thinkers. The groups differed in physiological arousal in the recovery period but not in the stress period. Stressor-instigated negative thoughts and spontaneous negative thoughts produced different patterns of relations with variables measured in the laboratory and with symptoms reported in everyday life. Discriminating patterns of relations were found between measures of cognition and affect in the laboratory and self-reported emotional, physical, and behavioral symptoms in everyday life. The results help explain the relation between maladaptive automatic thinking, on the one hand, and elevated physiological arousal and emotional, physical, and behavioral symptoms, on the other.     

Cigarette smoking intentions and physical fitness: a multivariate study of high school males

This study was conducted to determine the extent to which several measures of physical fitness, treated compositely and individually, vary among adolescent males differentiated according to cigarette smoking status (i.e., strong intenders, mild intenders, and nonintenders). A total of 381 high school males were administered The Physical Performance Test for California to measure six traits of physical fitness, and a written questionnaire to assess smoking intentions and demographic data. As hypothesized, the teenage males who reported no intentions of smoking cigarettes were significantly more physically fit than were mild intenders and strong intenders, especially the latter. Etiological factors mediating the association are discussed within an underlying theme of prevention and cessation of the habit.     

Age-related changes in cardiovascular response as a function of a chronic stressor and social support.

The effects of aging, chronic stress, and social support on cardiovascular functioning were examined using a cross-sectional design. Thirty-six family caregivers of Alzheimer's disease victims and 34 control Ss performed 2 active coping tasks while continuous noninvasive measures of cardiovascular activity were monitored. Results revealed that caregivers high in social support displayed typical age-related decreases in heart-rate reactivity, whereas caregivers low in social support displayed age-related increases in heart-rate reactivity. Analyses further indicated that only Ss with low social support were characterized by age-related increases in systolic blood pressure. These results suggest that social support can moderate age-related changes in cardiovascular functioning, particularly in Ss exposed to a chronic stressor.     

Acute exposure to a novel stressor further reduces the habituated corticosterone response to restraint in rats

The present study sought to identify dishabituation of the hypothalamic-pituitary-adrenal(HPA) axis response to different psychological stressors. Young adult male Sprague Dawley rats were exposed to five, 1 h sessions of restraint stress on five consecutive days. On the sixth day, and 2 h before additional exposure to restraint, animals were subjected to 30 min of a small (27cm square), elevated open field stressor (pedestal), which served as the dishabituating stimulus. We predicted HPA axis response dishabituation in chronically restrained rats exposed to the novel pedestal. Rats which underwent five days of restraint stress showed significantly blunted plasma corticosterone levels to restraint (habituation) as compared to restraint-nai've rats. However, rats which underwent five sessions of restraint responded with an enhanced habituation response when confronted with restraint shortly after exposure to the novel pedestal. Instead of HPA axis response dishabituation, we observed enhanced habituation. Subsequent experiments determined that a 1.25 mgkg corticosterone injection could substitute for pedestal exposure to produce enhanced restraint habituation.Combined treatment with both the glucocorticoid receptor antagonist RU40555 (30 mgkg)and the mineralocorticoid receptor antagonist RU283 18 (50 mgkg) blocked the expression of enhanced habituation after pedestal exposure. Thus, the delayed corticosterone negative feedback produced by novel stress led to enhanced expression of corticosterone response habituation.     

Habituation to a stressor predicts adolescents' adiposity

Background and Objectives: Stress is associated with gains in adiposity. One factor that determines how much stress is experienced is how quickly an adolescent reduces responding (habituates) across repeated stressors. The purpose of this study was to determine the association of body mass index (BMI) percentile and the rate of habituation to a stressor. Design: Thirty-four adolescents completed anthropometric measures and a habituation protocol using a within study design. Methods: The habituation protocol measured the rate of decline in perceived stress and heart rate (HR) across four, two-minute serial subtraction trials. Results: Multivariate linear regression revealed the habituation rate of the HR predicted BMI percentile after adjusting for gender, socioeconomic status, and initial HR (β?=?17.2, p?Conclusions: Slower habituation to a laboratory stressor was associated with greater BMI percentiles in adolescents.     

Some effects of exposure to a heat stressor upon the rat's subsequent reactions to that stressor

In six experiments, rats were placed on a heated plate on two occasions (test and retest), and the latencies with which they licked their paws were taken as an index of their sensitivity to nociceptive stimulation. Experiment 1 provided evidence that rats were selectively analgesic on retest depending upon the intensity of the heat experienced on the initial test. Experiment 2 showed that this analgesia was recruited rapidly and was long-lasting, as it was observed when retest was scheduled as early as 0.2 and as late as 48 h after the initial exposure to the hot-plate. Experiment 3 documented a role for conditioning processes, as this analgesia was removed by an extinction-like procedure conducted between test and retest. Experiments 4 and 5 provided evidence for a non-opioid mechanism of pain control, because the analgesia was not diminished by the opioid antagonist, naloxone, nor by a history of morphine injections. These experiments also revealed that the analgesia observed on retest was enhanced and reduced when rats were given naloxone and morphine, respectively, on the initial test. Finally, Experiment 6 showed that the analgesia on retest summated with that produced by morphine. The results were taken to mean that the hot-plate assay for analgesia can itself activate endogenous mechanisms of pain control, and some speculations were offered as to how this occurred.     

Cigarette smoking and personality change across adulthood: Findings from five longitudinal samples

Personality traits are related to cigarette smoking. However, little is known about the link between smoking and change in personality. Therefore, the present study examined whether current cigarette smoking and smoking cessation are associated with personality change across adulthood. Participants (n = 15,572) aged from 20 to 92 years were drawn from five longitudinal cohorts with follow-ups that ranged from 4 to 20 years. Compared to non-smokers, current smokers were more likely to increase on neuroticism and to decline on extraversion, openness, agreeableness and conscientiousness over time. Compared to the persistent smokers, those who quit had a steeper decline in agreeableness. Cigarette smoking is related to detrimental personality changes across adulthood, and the pattern was not improved by smoking cessation.     

The activity of the hypothalamo-neurohypophysial system in response to acute stressor exposure: neuroendocrine and electrophysiological observations

The present mini review focuses on stress-induced alterations of the electrical and secretory activity of vasopressin (AVP) and oxytocin (OXT) neurones originating within the supraoptic nucleus (SON) and constituting the hypothalamo-neurohypophysial system (HNS) in the male rat. Previously, it was thought that SON neurones are predominantly activated by osmotic and reproductive stimuli. However, recent findings also suggest a selective activation of AVP and/or OXT neurones in response to specific stressors. Inhibitory amino acids seem to participate at the level of the SON in the control of HNS activity during stress. Taurine, probably of glial origin, selectively inhibits the secretory activity of AVP neurones. In contrast, GABA, probably of neuronal origin, interferes with the release of OXT both from axon terminals into blood and from somata/dendrites into the extracellular fluid of the SON. Depending upon whether a defined stressor triggers taurine and/or GABA release within the SON the secretion of AVP and/or OXT from HNS neurones will be inhibited. These observations shed new light on the neurone-neurone and glial-neurone interactions that ensure an appropriate neuroendocrine stress response.     

Relations between plasma oxytocin,depressive symptoms and coping strategies in response to a stressor: the impact of social support

Background: Social support can serve as a protective factor against the negative impacts of stressors and may thereby promote well-being. As well, exogenous administration of oxytocin has been tied to diminished stress responses and might also enhance the effects of social support.

Methods/Results: In the current study, conducted among female undergraduate students (N?=?67), higher depressive symptoms were related to lower endorsements of problem-focused coping in response to a psychosocial stressor comprising the Trier Social Stress test (TSST). However, the relation between depressive symptoms and problem-focused coping was absent among participants who had a close female friend present serving as social support prior to the stressor experience. Additionally, endogenous plasma oxytocin levels were related to certain coping strategies being favored (e.g., problem-solving, humor, cognitive distraction, self-blame and support seeking) in response to the psychosocial stressor. However, the strength of these relations varied as a function of whether individuals had social support present or not.

Conclusion: These findings confirm the positive impact of social support in attenuating the relation between depressive symptoms and specific coping methods. The results of this study are consistent with view that oxytocin levels are accompanied by particular stress responses, possibly through the promotion of coping methods endorsed.     

Coping with a major stressor: differences between habitual short- and longer-sleepers.

We compared the coping strategies of 39 short-sleepers and 33 longer-sleepers to the stresses associated with the October 17, 1989 San Francisco Bay Area earthquake using their responses to the eight scales of the Ways of Coping Questionnaire. Over-all, the short-sleepers scored significantly higher on this questionnaire and in general, the pattern of their responses was consistent with inferences that could be drawn from a 1972 paper by Hartmann, Baekeland, and Zwilling.     

Movie exposure to smoking cues and adolescent smoking onset: a test for mediation through peer affiliations.

OBJECTIVE: To determine whether the effect of movie exposure to smoking on adolescent smoking onset is mediated through increased affiliation with peers who smoke. DESIGN: A longitudinal study was conducted with a sample of 5th- 8th graders; persons who were nonsmokers at the baseline assessment (N = 2,614) were followed up 18 months later. Movie exposure to smoking cues was assessed at baseline with a rigorous coding procedure. MAIN OUTCOME MEASURE: A school-based survey and follow-up telephone interview determined whether the participant smoked cigarettes. RESULTS: Longitudinal structural modeling analysis indicated movie-smoking exposure was related to smoking onset both through an indirect effect involving increased affiliation with peer smokers and through a direct effect. The analysis controlled for demographics, parenting style, rebelliousness and sensation seeking, school performance, parental smoking, and sibling smoking; several of these variables also had mediated or direct effects to smoking onset. CONCLUSION: The effect of movie exposure on adolescent smoking onset is attributable in part to a social mechanism. Implications of media effects for prevention are discussed.