Role of female behavior in controlling population growth in mice

Sex ratio does not appear to be a factor in generating the characteristic population growth curve. Freely growing populations of house mice, consisting of all females and one male, stopped their growth at approximately the same densities as normal sexratio populations used as references. The mechanism(s) of female control of population dynamics may be related to female aggressive behavior. As the all-female/one-male populations approached their maximum size, the females began to show wounding patterns and social hierarchies in much the same manner as males in populations with normal sex ratios. The male in each of the populations was severely wounded in the posterior region, and each lost its tail as a result of injuries which could have been inflicted only by the females. The female social hierarchy can be seen only when there has been reproduction and population growth. Assembled populations of all females rarely exhibit aggressive behavior. Female aggression becomes apparent only when the population approaches its maximum size and thereafter. These data are consistent with the hypothesis that males are competitive among themselves for territory and social rank, and ultimately to mate with the females. Other investigators have indicated that females respond to population size, which may reflect increased competition between the females with the establishment of territories. Thus female agression may control population growth, a role previously ascribed to male aggression.     

Reciprocal effects of motivation in physical education and self-reported physical activity

ObjectivesThe present study tested whether self-reported school and leisure-time physical activity have a reciprocal relationship with Physical Education (PE)-based motivational regulations described by self-determination theory. Participants were 635 11- and 12-year-old school children from the United Kingdom.Design & MethodA cross-lagged longitudinal design over two time points was employed. Study hypotheses were analyzed using latent factor reciprocal effects models.ResultsFollowing temporal invariance tests, data revealed positive relationships between both types of physical activity and subsequent changes in autonomous motivation, but not the oft-stated reverse relationship. No relationships were observed involving introjected regulation. Theoretically aligned relationships between external regulation and changes in physical activity were observed, but no reverse relationships. Both types of physical activity behavior were negatively associated with changes in amotivation in PE, but surprisingly, amotivation in PE positively predicted changes in leisure-time physical activity.ConclusionsIn general, physical activity participation may help children internalize reasons for partaking in PE and foster self-determination. However, the widespread theory that self-determined PE motives can develop school and leisure-time physical activity participation was not compellingly demonstrated.     

Degree of extraversion and physiological responses to physical pain and sadness

Extraversion is a personality frequently discussed as one of the strongest and most consistent factors that relates to individual subjective wellbeing. The goal of this study was to better understand how people with varying degrees of extraversion psychologically and physiologically respond differently to unpleasant circumstances. Emotional responses (e.g., levels of intensity, valence, and arousal) were assessed in determining the sensitivity level to negative stimuli that were specifically designed to provoke physical pain and sadness emotion. Physiological changes (e.g., heart rate (HR), blood volume pulse (BVP), and respiratory sinus arrhythmia (RSA)) were also measured during pain and sadness to observe sympathetic and parasympathetic activities. Our results showed that the degree of extraversion was associated with less unpleasant responses to sadness, less HR responses to both pain and sadness, and greater RSA responses to sadness. The findings suggest that the lower HR reactivity to painful and sad situations and greater RSA reactivity to sad situations in extraversion could be possibly due to increased parasympathetic activity. Additionally, enhanced parasympathetic activity to negative situations may explain an important mechanism underlying the positive connection between extraversion and subjective wellbeing.     

"Intentional physical injury" in grand mal seizure

An account of an unusual occurrence during a grand mal epileptic fit occurring during a sexual act (labium pudendi bite = "willful bodily harm").     

The effects of exergaming on physical activity in a third-grade physical education class

We compared the effects of exergaming and traditional physical education on physical activity among 4 active children who were not overweight and who had experience with the exergaming activities prior to the study. Results showed that exergaming produced substantially higher percentages of physical activity and opportunity to engage in physical activity. In addition, an evaluation of the exergaming equipment showed that exergaming stations were associated with differential levels of physical activity across participants.     

Context effects on the perceived physical attractiveness of faces

Four experiments were conducted to study the nature of context effects on the perceived physical attractiveness of faces. In Experiment 1, photos of faces scaled on attractiveness were presented in sets of three, with target faces appearing in the middle flanked by two context faces. The target faces were of average attractiveness, with the context faces being either high, average, or low in attractiveness. The effect of the context was one of assimilation, rather than contrast, regardless of whether the persons in the photos were portrayed to be associated. This result was interpreted in terms of a “generalized halo effect” for judgments of the physical attractiveness of stimuli within a group. Presenting the persons of a set as friends enhanced the perceived attractiveness of the target face but only when the context did not contain a face of low attractiveness. In Experiment 2, the assimilation effect was observed to carry over to influence ratings of the target faces several minutes after the context faces had been removed. Experiment 3 showed the assimilation effect to be robust regardless of whether the context was composed of two faces or one, but Experiment 4 showed the assimilation effect to be evident only when the context faces were presented simultaneously with the target.     

Emotional effect of physical aggression among adults in the general population in a Canadian province

The emotional effect of personal involvement in physical aggression was examined in a random sample of 1,753 adults from Ontario, Canada, using Computer Assisted Telephone Interviewing (response rate of 67%). Respondents reported a range of emotional responses from feeling good or justified to feeling angry, upset, terrified, disgusted, hurt, and embarrassed. Open-ended responses regarding emotional response were rated by the authors for 149 incidents of aggression, which yielded five categories: (1) positive impact 4%, (2) no feeling or no effect 31%, (3) mildly negative 20%, (4) moderately negative 28%, and (5) severely negative 17% (Kappa statistic of interrater agreement=.77). The substantial proportion of incidents involving positive or no emotional response suggests that a greater understanding of aggression among individuals can be gained by the development and application of a quantitative measure of emotional response that reflects the full range of emotions (positive and negative), using dimensions identified in this study such as feeling upset, fear, and anger.     

An exploration of psychological and physical injury schemas in civil cases

Civil plaintiffs often seek compensation for their psychological injuries. Yet little is known about jurors' preconceived notions (or schemas) for a prospective plaintiff's pain and suffering. The present studies examined (a) whether jurors have psychological injury schemas (Studies 1 and 2), (b) whether their existence and development vary by the type of civil case (Studies 1 and 2) or its severity (Study 2), and (c) how psychological injury schemas compare with physical injury schemas on a number of theoretically and legally relevant judgments (e.g., injury severity, availability, and plaintiff credibility; Study 2). Study 1 (N = 233) presented undergraduate mock jurors with 2 negligence incidents (car accident and slip and fall) and 2 intentional tort incidents (sexual assault and kidnapping) and asked them to report the typical incident and injuries that would result from the defendant's conduct. Results supported the sparse existence of psychological injury schemas but found that they were more developed in the kidnapping and sexual assault incidents than in the car accident and slip and fall incidents. Study 2 (N = 288) additionally manipulated incident schema severity (mild vs. severe) while having participants separately report and rate their psychological and physical injury schemas on judgments of legal and theoretical interest. Results indicated that although mock jurors' psychological injury schemas contained fewer injuries than their physical injury schemas, the reported psychological injuries were rated as more severe than physical injuries. We discuss how schemas may underlie the disparate treatment of psychological and physical injuries by legal decision‐makers.     

Prevalence of traumatic brain injury in an inpatient psychiatric population

This study investigated the prevalence of traumatic brain injury (TBI) in an inpatient psychiatric population. We hypothesized increased prevalence of TBI relative to the general population due to a variety of risk factors observed in psychiatric patients. One hundred (mean age = 34) psychiatric inpatients completed the revised Head Injury Questionnaire. Chart review of 17 subjects reporting injuries established whether injuries were documented in medical records. Sixty-eight percent of this psychiatric population reported one or more injuries in which they were unconscious or dazed. This number is higher than the prevalence in the general population. Injuries were generally of mild to moderate severity; multiple injuries were common. Chart review of 17 subjects reporting TBI indicated that histories of TBI had not been noted in the medical record. Finally, 63% of TBI subjects reported that their injury predated the onset of their psychiatric symptoms. These results suggest a possible role of TBI in psychiatric symptomatology and have implications for psychiatric treatment in this population.     

Verbal, behavioural and physiological assessment of the generalization of exposure-based fear reduction in a spider-anxious population

Clinical fear of spiders was assessed in 39 patients before and after exposure treatment and at a 3-month follow-up. The assessment included behavioral, physiological and self-report measures. Some patients were tested in the treatment context (group Same), while others were tested in a different context (group Different). Both groups demonstrated a significant fear reduction from pre- to post-treatment in all measures, which persisted at the 3-month follow-up. Contrary to our expectations, no clear difference was observed between the groups at any moment. However, a 1-year follow-up test of the self-report measure revealed a return of fear in group Same, but not in group Different. These results show (1) that the effects of exposure treatment persisted over contexts and time in the short term, and (2) that conducting treatment and tests in different contexts enhanced efficiency of exposure treatment in the long term.     

Tau and Kappa effects in physical space: the case of audition

The organization of spatio-temporal information in an auditory memory task was studied in two experiments. Stimuli consisted of four different configurations of eight sequentially presented beeps. In two configurations, the stimuli were space-time congruent, with (constant or variable) inter-stimulus distances corresponding to (constant or variable) inter-stimulus time intervals. In the other two configurations, the stimuli were space-time incongruent, with (constant or variable) inter-stimulus distances not corresponding to (variable or constant) inter-stimulus time intervals. After a learning phase consisting of 20 presentations of the target configuration, participants reproduced the spatial (Experiment 1) or temporal (Experiment 2) characteristics of the target 60 times in succession without re-examining the target configuration. Accuracy (with respect to the target) and variability (between responses) were found to evolve independently. In the incongruent space-time conditions, effects of variable inter-stimulus time intervals or distances on the reproduction of, respectively, constant distances (Tau effect) or constant time intervals (Kappa effect) were observed, while the reverse was not the case. Thus, dimensional interference occurred when the dimension to be ignored was variable. The results are discussed in the light of the distinction between properties of the stabilized mental image and the process of stabilization.     

The role of anxiety sensitivity in subjective and physiological responses to social and physical stressors

This study examined the specificity of the relationship between anxiety sensitivity (AS), a measure of catastrophizing about arousal-related sensations, and pain responses, by examining the effect of AS on responses to stressors of a physical and social nature. Healthy men and women (n = 129) between the ages of 18 and 25 years were recruited from the community to participate in a study examining subjective, cognitive and behavioural responses to different types of stressors. Participants were randomly assigned to one of 3 groups: (i) a neutral condition in which they sat quietly and read a popular magazine; (ii) a social stress condition in which they anticipated having to give a self-disclosing speech; and (iii) a physical stress condition in which they were presented with 3 countdown to shock trials where a mild electrical shock was administered on the non-dominant arm. Subjective ratings and physiological responses were recorded in anticipation of the stressor and immediately after stress exposure. Results indicated that AS was indirectly related to pain ratings via its effect on anticipatory anxiety ratings. AS was associated with anticipatory anxiety ratings, regardless of whether the stressor was of a physical or social nature. Furthermore, AS was not shown to be directly associated with exaggerated subjective or physiological reactions to the physical stressor. These results indicate that the role of AS in pain responses may be mediated through a global effect on anxiety, and limited to the anticipatory stage of the pain experience. If future studies yield similar findings in pain patients, then they would suggest that interventions for helping individuals high in AS should focus on catastrophic thinking in anticipation of stressors in general, rather than on pain-specific stressors.     

The effects of exergaming on physical activity among inactive children in a physical education classroom

Childhood obesity, which is due in part to lack of physical activity, is a serious concern that requires the attention of the behavioral community. Although excessive video game play has been noted in the literature as a contributor to childhood obesity, newer video gaming technology, called exergaming, has been designed to capitalize on the reinforcing effects of video games to increase physical activity in children. This study evaluated the effects of exergaming on physical activity among 4 inactive children in a physical education (PE) classroom. Results showed that exergaming produced substantially more minutes of physical activity and more minutes of opportunity to engage in physical activity than did the standard PE program. In addition, exergaming was socially acceptable to both the students and the PE teacher. Exergaming appears to hold promise as a method for increasing physical activity among inactive children and might be a possible intervention for childhood obesity.