Relationship between food habituation and reinforcing efficacy of food

Reinforcing value and habituation are two processes that have been used to study eating behaviors, but no research has examined their relationship, how they relate to energy intake, and whether they respond in a similar manner to food deprivation. Twenty-two female subjects were randomized to food deprived or non-deprived conditions, and assessed for food reinforcement, habituation to food and ad libitum eating. Results showed food reinforcement and habituation are correlated (r = 0.62, p = 0.002) and both independently predict energy intake. Hierarchical regression showed that the rate of habituation accounted for 30 percent of the variance in eating (p = 0.008), and adding food reinforcement increased the amount of variance accounted for up to 57.5 percent (p < 0.05). This suggests that both processes may influence energy intake in a meal.     

Postural tasks are associated with center of pressure spatial patterns of three-dimensional statokinesigrams in young and elderly healthy subjects

The present study investigated the association between postural tasks and center of pressure spatial patterns of three-dimensional statokinesigrams. Young (n = 35; 27.0 ± 7.7 years) and elderly (n = 38; 67.3 ± 8.7 years) healthy volunteers maintained an undisturbed standing position during postural tasks characterized by combined sensory (vision/no vision) and biomechanical challenges (feet apart/together). A method for the analysis of three-dimensional statokinesigrams based on nonparametric statistics and image-processing analysis was employed. Four patterns of spatial distribution were derived from ankle and hip strategies according to the quantity (single; double; multi) and location (anteroposterior; mediolateral) of high-density regions on three-dimensional statokinesigrams. Significant associations between postural task and spatial pattern were observed (young: gamma = 0.548, p < .001; elderly: gamma = 0.582, p < .001). Robustness analysis revealed small changes related to parameter choices for histogram processing. MANOVA revealed multivariate main effects for postural task [Wilks’ Lambda = 0.245, p < .001] and age [Wilks’ Lambda = 0.308, p < .001], with interaction [Wilks’ Lambda = 0.732, p < .001]. The quantity of high-density regions was positively correlated to stabilogram and statokinesigram variables (p < .05 or lower). In conclusion, postural tasks are associated with center of pressure spatial patterns and are similar in young and elderly healthy volunteers. Single-centered patterns reflected more stable postural conditions and were more frequent with complete visual input and a wide base of support.     

Is your choice my choice? The owners’ effect on pet dogs’ (Canis lupus familiaris) performance in a food choice task

This study investigates the influence of owners on their dogs’ performance in a food choice task using either different or equal quantities of food. Fifty-four pet dogs were tested in three different conditions. In Condition 1 we evaluated their ability to choose between a large and small amount of food (quantity discrimination task). In Condition 2 dogs were again presented with a choice between the large and small food quantity, but only after having witnessed their owner favouring the small quantity. In Condition 3 dogs were given a choice between two equally small quantities of food having witnessed their owner favouring either one or the other. A strong effect of the owner on the dogs’ performance was observed. In Condition 1 dogs as a group chose significantly more often the large food quantity, thus showing their ability to solve the quantity discrimination task. After observing their owner expressing a preference for the small food quantity they chose the large quantity of food significantly less than in the independent choice situation. The tendency to conform to the owner’s choice was higher when the dogs had to choose between equally small quantities of food (Condition 3) rather than between a large and a small one (Condition 2). These results provide evidence that dogs can be influenced by their owners even when their indications are clearly in contrast with direct perceptual information, thus leading dogs to ultimately make counterproductive choices.     

The effect of prenatal androgen exposure on the development of neural reactivity systems: A study of the HEXACO Personality Inventory

The ratio of the lengths of the second and fourth digits of hands (2D:4D) seems to vary as a function of systematic differences in prenatal androgen exposure (Hönekopp & Watson, 2010). The 2D:4D ratio has been shown to be related to a variety of personality attributes. This study predicted that 2D:4D would covary with scores on the emotionality dimension of the six-facet HEXACO personality assessment, due to emotionality’s relationship with neural reactivity systems controlled by the amygdala (Hines, Allen, & Gorski, 1992), but that 2D:4D would relate to no other facet. Consistent with hypotheses, data showed that men had smaller ratios than women on both the right, t(405) = 2.84, p < .05, d = .28, and left hands, t(405) = 4.51, p < .05, d = .45, and the relationship between 2D:4D and emotionality was outside of sampling error of zero, r = .18, p < .001. Additionally, 2D:4D was unrelated to the remaining HEXACO facets. Findings suggest that prenatal testosterone exposure has an organizing effect on personality traits.     

Maternal stress and behavioral adaptation in methadone- or buprenorphine-exposed toddlers

The current study examined the relationship between early interaction, parenting stress, maternal psychological distress symptoms, and behavior problems and health-related quality of life among children born to mothers in opioid maintenance treatment (OMT) in Norway during the period 2005–2007 (N = 36). This group was compared with a normative sample of mothers without substance abuse problems and their children (N = 36). There were significant group differences (p < .01) in perceived child problems in toddlerhood. In a regression model, mothers’ self-reported psychological distress symptoms in terms of depression and anxiety symptoms significantly predicted child behavior problems (p < .01) and health-related quality of life (p < .01) rather than parenting stress. No significant, unique effect of exposure was found after controlling for other factors that could influence developmental outcomes. These findings add to the growing evidence on the importance of maternal psychological well-being for child development, and underscore the need to address opioid-maintained women's personal maladjustment and the constellation of stress experienced by mothers in recovery.     

The harmful and beneficial impacts of weight bias on well-being: the moderating influence of weight status

Weight bias is evident among normal weight and obese individuals. This weight bias may be associated with comparisons to others, which may enhance feelings of self-worth. However, the ego-enhancing versus ego-diminishing influence of these evaluations may be moderated by the individual's weight status, and the strength of these effects may be moderated by gender. Eight-five participants completed the Implicit Associations Test, questionnaires assessing explicit weight bias, body image, and self-esteem, and height and weight assessments. Implicit weight bias was prevalent among all individuals, p < .001, and was associated with a more positive body image, ps < .05, and higher self-esteem, ps < .01, for thinner individuals but a more negative body image and lower self-esteem for heavier individuals. Gender moderation effects were not observed. It is arguably problematic that the positive benefits to normal weight individuals’ self-esteem and body image appear to come via negative comparisons with overweight individuals.     

Development and validation of a measure of an individual’s lateness attitude

The authors developed and validated a measure of employees’ attitudes toward lateness at work. Analyses provided clear evidence of the reliability and validity of the new measure. Specifically, high reliabilities were observed in both student (α = .82) and employee (α = .84) samples. Using objective lateness data from organizations, the measure significantly predicted two lateness behaviors, lateness frequency (r = .25, p < .01) and duration (r = .24, p. < .01), over a six-month period. Most importantly, lateness attitude improved prediction of lateness behavior above and beyond prediction made with only general job attitudes and conscientiousness.     

Gender differences in rumination: A meta-analysis

Starting in adolescence and continuing through adulthood, women are twice as likely as men to experience depression. According to the response styles theory (RST), gender differences in depression result, in part, from women’s tendency to ruminate more than men. A meta-analysis was performed to evaluate gender differences in rumination in adults (k = 59; N = 14,321); additionally, an analysis of subtypes of rumination – brooding and reflection – was conducted (k = 23). Fixed effects analyses indicated that women scored higher than men in rumination (d = .24, p < .01, SEd = .02), brooding (d = .19, p < .01, SEd = .03) and reflection (d = .17, p < .01, SEd = .03); there was no evidence of heterogeneity or publication bias across studies for these effect sizes. Although statistically significant, the effect sizes for gender differences in rumination were small in magnitude. Results are discussed with respect to the RST and gender differences in depression.     

Individual differences and propensity to engage with in-vehicle distractions - A self-report survey

Ratings of severity and frequency of engagement with distracting driver behaviours are reported in this paper. Survey data were collected using an anonymous online questionnaire. Four hundred eighty-two respondents contributed to the survey during a 2 month data collection period. Results indicate that the three behaviours rated as most distracting when driving were (i) writing text messages (41%), (ii) reading text messages (62%), and (iii) using a cellular telephone hand-held (52%). The three most frequently reported distracting behaviours that resulted in accidents were (i) ‘interaction with child passengers’ 2.1% (near misses = 7.5%), (ii) both, route guidance destination entry with 2% (near misses = 2.8%) and use of an ‘… add-on media device, e.g., an iPod’ with 2% (near misses = 3.9%), and (iii) the three items ‘reading a text message’, ‘following advice from a route guidance system’, and ‘interaction with pets’, all with 1.7% of respondents reporting an accident when undertaking the activity (with 6.5%, 3%, and 2.2% respectively for near misses). Two hierarchical regression models were explored. The first introducing personal factors, i.e., age, extraversion, agreeableness, conscientiousness, emotional stability and intellect (R² = 0.131, p < 0.001). The second controlled for variables in the first model and introduced driver-related variables, mileage, penalty points, and frequency of accidents with assumed responsibility (R² = 0.253, p < 0.001). This model identified age, extraversion, mileage, penalty points and accidents all to be significant predictors of engagement with unnecessary distractions. The data presents a picture of widespread awareness of, and engagement with, distracting behaviours by drivers in the United Kingdom. Findings from the hierarchical regressions suggest scope may exist to mediate the levels of distracting behaviours by exploring individual differences and driving styles.     

Energy expenditure and enjoyment of small-sided soccer games in overweight boys

When space is limited, it would be preferable to play multiple small-sided soccer games (SSG) simultaneously on small courts, rather than a single game, to maximise participation. Given that the layouts of most gymnasiums incorporate several badminton courts, we examined whether energy expenditure and enjoyment of SSG on a badminton court (6.1 × 13.4 m) were comparable to larger court dimensions (volleyball and basketball courts; 9 × 18 m and 14.2 × 26.5 m, respectively). Twelve overweight boys played 30 min three-a-side SSG on each court in a counterbalanced design. During SSG, energy expenditure was estimated via accelerometry, heart rate was monitored and ratings of perceived exertion (RPE) and enjoyment were obtained. Energy expenditure was similar between badminton and volleyball courts, but lower than the basketball court (p < .05). Mean% HR_max was significantly lower on the badminton court than the volleyball and basketball courts (p < .05). There was no effect of court size on RPE or enjoyment (p > .05). These results suggest that it may be preferable to play SSG on a larger court when space is available. Alternatively, when space is limited the difference in energy expenditure between court sizes can be accounted for by an additional 2.3 min of play on a badminton court.     

Fair process revisited: Differential effects of interactional and procedural justice in the presence of social comparison information

The competing views of fairness theory ( [Folger and Cropanzano, 1998] and [Folger and Cropanzano, 2001]) and fairness heuristic theory (Van den Bos, Lind, Vermunt, & Wilke, 1997) were tested by studying the effects of interactional (IJ), procedural (PJ), and distributive justice (knowledge of others’ outcomes [OO]) upon evaluations of outcome fairness and customer satisfaction. The participants, 369 undergraduates, were randomly allocated to scenario-based experimental conditions. A 2 (IJ) × 2 (PJ) × 4 (OO) MANOVA and stepdown analyses provided evidence of “fair process” across all levels of distributive justice for outcome fairness (p<.001) and satisfaction (p<.001), but only in relation to the effects of interactional justice. No such effects were found for procedural justice. Implications for the development of justice theory are discussed.     

Clarifying relationships among work and family social support, stressors, and work-family conflict

Although work and family social support predict role stressors and work-family conflict, there has been much ambiguity regarding the conceptual relationships among these constructs. Using path analysis on meta-analytically derived validity coefficients (528 effect sizes from 156 samples), we compare three models to address these concerns and clarify relationships. Results revealed that social support, controlling for role involvement, is best viewed as an antecedent of role stressors and subsequent work-family conflict. Controlling for work and family involvement, work and family social support were most related to same domain role conflict (β = −.46, p < .05; β = −.43, p < .05) and role ambiguity (β = −.28, p < .05; β = −.33, p < .05). Subsequently, work role conflict and time demands were most related to work-to-family conflict (β = .39, p < .05; β = .21, p < .05), while family role conflict and role ambiguity were most related to family-to-work conflict (β = .22, p < .05; β = .24, p < .05). Implications for research and practice, along with suggestions for theoretical advances, are discussed.     

Reinforcement sensitivity theory as a predictor of senior-executive performance

This paper develops and tests links between the reinforcement sensitivity theory of personality and senior-executive job performance, hypothesising that the theory’s personality traits, known as ‘BIS’ and ‘BAS’, will interact to predict performance. 167 chief and second-tier executives completed Carver and White’s (1994)BIS/BAS Scales, and had their overall performance rated by a superior or peer using four items. Structural equation modeling showed that while BAS has no main effect and BIS has a marginally significant effect on performance (p = 0.07), BIS and BAS interact to predict performance (p = 0.01), the optimal scenario being a combination of high BAS and low BIS. These results show the importance of testing traits’ interactions in applied personality research.     

Cradling side preference is associated with lateralized processing of baby facial expressions in females

Women’s cradling side preference has been related to contralateral hemispheric specialization of processing emotional signals; but not of processing baby’s facial expression. Therefore, 46 nulliparous female volunteers were characterized as left or non-left holders (HG) during a doll holding task. During a signal detection task they were then asked to detect the emotional baby faces in a series of baby portraits with neutral and emotional facial expressions, presented either to the left or the right visual field (VFP). ANOVA revealed a significant HG × VFP interaction on response bias data (p < .05). Response bias was lowest when emotional baby faces were presented in the visual field of cradling side preference, suggesting that women’s cradling side preference may have evolved to save cognitive resources during monitoring emotional baby face signals.     

Tyrosine ameliorates heat induced delay in event related potential P300 and contingent negative variation

The efficacy of tyrosine, a catecholamine precursor, as a countermeasure in the reduction of cognitive decline during heat exposure (HE) using event-related potential P300, and contingent negative variation (CNV) was evaluated. Ten healthy males, age 20–30 years participated in the study. Volunteers received placebo or tyrosine (6.5 g) 90 min prior to HE (1.5 h in 45 °C + 30% RH). P300 latency was significantly increased (p < 0.01) during exposure with placebo, which was reduced significantly (p < 0.01) after tyrosine supplementation. There was an increase in CNV M100 latency (p < 0.05) and reaction time (p < 0.01) and decrease in M100 amplitude (p < 0.01) during HE with placebo, which returns to near normal level with the tyrosine administration. A significantly higher plasma norepinephrine (p < 0.05), dopamine and epinephrine levels were detected in tyrosine supplemented group post heat exposure. HE increases the brain catecholamine activity thereby reduces the plasma norepinephrine and dopamine level leading to a reduction in cognitive performances. Tyrosine supplementation increases the catecholamine level and reduces the impairment of cognitive performance during HE.     

Pointing gestures modulate domestic dogs’ search behavior for hidden objects in a spatial rotation problem

In the spatial domain, domestic dogs are highly inclined to search at the last location where they saw an object disappear and cannot infer that a hidden object has moved imperceptibly from one location to another. In the current study, we examined whether exposure to human social cues modulates dogs’ search behavior for hidden objects. In Experiment 1, twenty dogs were first trained to find an object they saw disappear inside a stationary container in the presence (social group) or absence (non-social group) of pointing gestures. In tests, the containers were rotated 180° around a central axis. The dogs in the non-social group systematically searched at the initial (now incorrect) hiding location, whereas the dogs in the social group chose correctly significantly above chance. In Experiment 2, we tested whether pre-exposure to human pointing has an impact on dogs’ use of gestures. No gestures were given during training and both the social and non-social conditions were administered to each of the ten dogs. In contrast to Experiment 1, the performance of dogs in the social condition dropped significantly and varied substantially from one dog to another. Overall, this study suggests that dogs’ tendency to use human signals is so strong that it even outweighs their spatial bias to search where they saw an object disappear; however, this penchant to use human gestures appears to be dependent on the degree of familiarity of the dog with these signals.     

Positive Traits Linked to Less Pain through Lower Pain Catastrophizing

The present study examined the association between positive traits, pain catastrophizing, and pain perceptions. We hypothesized that pain catastrophizing would mediate the relationship between positive traits and pain. First, participants (n = 114) completed the Trait Hope Scale, the Life Orientation Test-Revised, and the Pain Catastrophizing Scale. Participants then completed the experimental pain stimulus, a cold pressor task, by submerging their hand in a circulating water bath (0 °C) for as long as tolerable. Immediately following the task, participants completed the Short-Form McGill Pain Questionnaire (MPQ-SF). Pearson correlation found associations between hope and pain catastrophizing (r = −.41, p < .01) and MPQ-SF scores (r = −.20, p < .05). Optimism was significantly associated with pain catastrophizing (r = −.44, p < .01) and MPQ-SF scores (r = −.19, p < .05). Bootstrapping, a non-parametric resampling procedure, tested for mediation and supported our hypothesis that pain catastrophizing mediated the relationship between positive traits and MPQ-SF pain report. To our knowledge, this investigation is the first to establish that the protective link between positive traits and experimental pain operates through lower pain catastrophizing.     

The impact of mediodorsal thalamic lesions on olfactory attention and flavor perception

Olfactory attention may be important in generating odor-induced tastes - an arguably universal form of synesthesia - by ensuring that the taste concurrent is captured by the nose and olfaction, not by the mouth and gustation (oral-capture). To examine the role of olfactory attention in generating odor-induced tastes and oral capture we tested a small sample (n = 4) of participants with likely impairments in olfactory attention - individuals with mediodorsal thalamic nucleus (MDNT) lesions. These participants were compared to two sets of controls on tests of olfactory attention, oral capture, odor and flavor perception, and control tasks. MDNT participants demonstrated impaired olfactory attention and enhanced oral capture. Greater oral capture was associated with greater olfactory attentional impairment. These findings imply that olfactory attention may be important in attributing odor-induced tastes to the olfactory modality. However, unlike for visual binding and for the neurodevelopmental synesthesias, where attention may be necessary to demonstrate both phenomena, olfactory attention deficits did not impair flavor binding or the experience of odor-induced tastes.     

Partners’ Attributions for Service Members’ Symptoms of Combat-Related Posttraumatic Stress Disorder

The association of service members’ combat-related PTSD with partners’ distress is weaker when spouses/partners believe that service members experienced more traumatic events during deployment. Also, when simultaneously examining partners’ perceptions of all PTSD symptoms, perceptions of reexperiencing symptoms (the symptoms most obviously connected to traumatic events) are significantly negatively related to distress in partners. These findings are consistent with the notion that partners may be less distressed if they make external, rather than internal, attributions for service members’ symptoms. The present study explicitly tests this possibility. Civilian wives of active duty service members completed measures regarding their own marital satisfaction, their perceptions of service members’ combat exposure during deployments, their perceptions of service members’ symptoms of PTSD, and their attributions for those symptoms. External attributions were significantly positively associated with perceptions of combat exposure (r_p = .31) and reexperiencing symptoms (β = .33) and significantly negatively associated with perceptions of numbing/withdrawal symptoms (r_p = –.22). In contrast, internal attributions were significantly negatively associated with perceptions of reexperiencing symptoms (β = –.18) and significantly positively associated with perceptions of numbing/withdrawal symptoms (β = .46). Internal attributions significantly moderated the negative association of PTSD symptoms with marital satisfaction, such that the association strengthened as internal attributions increased. These findings are the first explicit support for an attributional understanding of distress in partners of combat veterans. Interventions that alter partners’ attributions may improve marital functioning.     

Do dogs get the point? A review of dog–human communication ability

In recent years evidence has accumulated demonstrating that dogs are, to a degree, skilful in using human forms of communication, making them stand out in the animal kingdom. Neither man's closest relative, the chimpanzee, nor dog's closest living relative, the wolf, can use human communication as flexibly as the domestic dog. This has led to the hypothesis that dogs’ skills in this domain may be a result of selection pressures during domestication, which have shaped dogs’ skills tremendously. One hypothesis, the so-called by-product hypothesis, suggests that dogs have been selected against fear and aggression and as a by-product this paved the way for the evolution of generally more flexible social cognitive skills, which surpassed those of their ancestor, the wolf. Another hypothesis, the adaptation hypothesis, has claimed that dogs may have been specifically selected for certain tasks for which using human forms of communication was necessary. As of yet, the mechanism underlying dogs’ understanding of human forms of communication is not fully understood. We argue here that understanding the mechanism involved will also shed light on possible evolutionary scenarios. We argue that the evidence to date suggests that dogs’ understanding of human forms of communication may be more specialized than was predicted by some and may be best explained as the result of a special adaptation of dogs to the specific activities humans have used them for.