Influence of dominance on the development of play fighting in pairs of male Syrian golden hamsters (Mesocricetus auratus)

In the highly social rat, male juvenile and adult subordinates initiate more playful contacts with dominant pairmates than vice versa. This study examined the effect of dominance on playful contacts in the relatively asocial golden hamster. Pairs of male hamsters were reared together from weaning, and their play was filmed in the juvenile (28-36 days) and the young adult (60-70 days) stages of development. By the adult stage, it became clear that one pairmate was dominant over the other. The dominant pairmate launched all aggressive attacks (i. e., bites to the lower flanks and rump), and the subordinate pairmate performed all the submissive gesturing (e. g., tail up submissive posture). Playful contact, which in this species involves gentle nibbling of the posterior cheeks, was more frequently launched by the dominant than by the subordinate. This was not only true at the adult stage, but also at the juvenile stage, before dominance-subordination relationships were sharply polarized. Therefore, it would appear that in the relatively asocial hamster, the subordinates tend to avoid playful contact with dominants. This is markedly different to rats, where the subordinates actively seek out and engage dominants in play. This contrast further supports our hypothesis that subordinate male rats use play as a means of maintaining familiarity with dominants. © 1993 Wiley-Liss, Inc.     

Novel odors evoke risk assessment and suppress appetitive behaviors in mice

The effects of four novel odors on risk assessment by mice (i. e., flat back approach, stretched attention, immobility) and the suppression of appetitive behaviors were examined in two experiments. When novel odors were presented in a straight runway, subjects spent significantly less time in the odor compartment, relative to controls, when it contained sheep wool, chocolate, or citronella (but not cat fur) odors. Risk assessment behaviors occurred at similar levels among all groups and appetitive behaviors were not suppressed by the novel odors. When odorants were scattered over one half of the subjects' home cage floor in Experiment 2, all novel odors increased the duration of at least on e risk assessment measure and/or suppressed appetitive behaviors (i. e., eating, grooming, rearing). The results clearly reveal that a reasonably wide range of novel odors evoke at least some level of risk assessment which presumably reflects increased fearfulness. The odors of sheep wool and cat fur induced a wider range of such responses than did chocolate or cinnamon suggesting that mammalian odors may be particularly effective stimuli. If so, however, it is clear that predator odors are not uniquely effective in this regard. Experiment 1 also underscores the importance of the testing environment in assessing the behavioral effects of novel odors in mice. © 1993 Wiley-Liss, Inc.     

Logistic positive exponent family of models: Virtue of asymmetric item characteristic curves

The paper addresses and discusses whether the tradition of accepting point-symmetric item characteristic curves is justified by uncovering the inconsistent relationship between the difficulties of items and the order of maximum likelihood estimates of ability. This inconsistency is intrinsic in models that provide point-symmetric item characteristic curves, and in this paper focus is put on the normal ogive model for observation. It is also questioned if in the logistic model the sufficient statistic has forfeited the rationale that is appropriate to the psychological reality. It is observed that the logistic model can be interpreted as the case in which the inconsistency in ordering the maximum likelihood estimates is degenerated.The paper proposes a family of models, called the logistic positive exponent family, which provides asymmetric item chacteristic curves. A model in this family has a consistent principle in ordering the maximum likelihood estimates of ability. The family is divided into two subsets each of which has its own principle, and includes the logistic model as a transition from one principle to the other. Rationale and some illustrative examples are given.     

A hierarchical latent response model for inferences about examinee engagement in terms of guessing and item-level non-response

In low-stakes assessments, test performance has few or no consequences for examinees themselves, so that examinees may not be fully engaged when answering the items. Instead of engaging in solution behaviour, disengaged examinees might randomly guess or generate no response at all. When ignored, examinee disengagement poses a severe threat to the validity of results obtained from low-stakes assessments. Statistical modelling approaches in educational measurement have been proposed that account for non-response or for guessing, but do not consider both types of disengaged behaviour simultaneously. We bring together research on modelling examinee engagement and research on missing values and present a hierarchical latent response model for identifying and modelling the processes associated with examinee disengagement jointly with the processes associated with engaged responses. To that end, we employ a mixture model that identifies disengagement at the item-by-examinee level by assuming different data-generating processes underlying item responses and omissions, respectively, as well as response times associated with engaged and disengaged behaviour. By modelling examinee engagement with a latent response framework, the model allows assessing how examinee engagement relates to ability and speed as well as to identify items that are likely to evoke disengaged test-taking behaviour. An illustration of the model by means of an application to real data is presented.     

Conscious perception of flickering stimuli in binocular rivalry and continuous flash suppression is not affected by tACS-induced SSR modulation

The content of conscious perception is known to correlate with steady-state responses (SSRs), yet their causal relationship remains unclear. Can we manipulate conscious perception by directly interfering with SSRs through transcranial alternating current stimulation (tACS)? Here, we directly addressed this question in three experiments involving binocular rivalry and continuous flash suppression (CFS). Specifically, while participants (N = 24) viewed either binocular rivalry or tried to detect stimuli masked by CFS, we applied sham or real tACS across parieto-occipital cortex at either the same or a different frequency and phase as an SSR eliciting flicker stimulus. We found that tACS did not differentially affect conscious perception in the forms of predominance, CFS detection accuracy, reaction time, or metacognitive sensitivity, confirmed by Bayesian statistics. We conclude that tACS application at frequencies of stimulus-induced SSRs does not have perceptual effects and that SSRs may be epiphenomenal to conscious perception.     

Effects of suppression and acceptance on emotional responses of individuals with anxiety and mood disorders

The present investigation compared the subjective and physiological effects of emotional suppression and acceptance in a sample of individuals with anxiety and mood disorders. Sixty participants diagnosed with anxiety and mood disorders were randomly assigned to one of two groups. One group listened to a rationale for suppressing emotions, and the other group listened to a rationale for accepting emotions. Participants then watched an emotion-provoking film and applied the instructions. Subjective distress, heart rate, skin conductance level, and respiratory sinus arrhythmia were measured before, during, and after the film. Although both groups reported similar levels of subjective distress during the film, the acceptance group displayed less negative affect during the post-film recovery period. Furthermore, the suppression group showed increased heart rate and the acceptance group decreased heart rate in response to the film. There were no differences between the two groups in skin conductance or respiratory sinus arrhythmia. These findings are discussed in the context of the existing body of research on emotion regulation and current treatment approaches for anxiety and mood disorders.     

Dimensionality of psychosocial responses to marital disruption

The purpose of the study was to assess whether psychosocial responses to marital disruption were best arranged along one single dimension ranging from maximum positive to maximum negative responses, or whether positive and negative responses constituted two separate and distinct dimensions. Participants were 658 recently divorced individuals. A confirmatory factor analysis revealed that a two-factor model provided a better fit to the data than a one-factor model. Moreover, a number of external variables differentiated between positive and negative responses, indicating that such responses reflect two separate domains. Thus, the findings support the notion that psychosocial responses after marital disruption comprise a bidimensional rather than a unidimensional pattern. The findings are discussed within the general framework of positive-negative asymmetry and the idea that positive and negative evaluations belong to different psychological system.     

Speech anxiety and rapid emotional reactions to angry and happy facial expressions

The aim was to explore whether people high as opposed to low in speech anxiety react with a more pronounced differential facial response when exposed to angry and happy facial stimuli. High and low fear participants were selected based on their scores on a fear of public speaking questionnaire. All participants were exposed to pictures of angry and happy faces while facial electromyographic (EMG) activity from the Corrugator supercilii and the Zygomaticus major muscle regions was recorded. Skin conductance responses (SCR), heart rate (HR) and ratings were also collected. Participants high as opposed to low in speech anxiety displayed a larger differential corrugator responding, indicating a larger negative emotional reaction, between angry and happy faces. They also reacted with a larger differential zygomatic responding, indicating a larger positive emotional reaction, between happy and angry faces. Consistent with the facial reaction patterns, the high fear group rated angry faces as more unpleasant and as expressing more disgust, and further rated happy faces as more pleasant. There were no differences in SCR or HR responding between high and low speech anxiety groups. The present results support the hypothesis that people high in speech anxiety are disposed to show an exaggerated sensitivity and facial responsiveness to social stimuli.     

性别选择与法律之回应——法理视野中的变性手术

变性人的出现对社会秩序及法律制度提出了挑战。自然人生而具有的人作为社会主体定在的自由和健康权利,为变性人享有性别选择的权利提供了法理支撑。在权利确认后,很有必要在变性手术的对象、施行者及程序上作出规范的应对,而变性人术后的社会角色及权利保护也应该得到法律的适时回应,以实现法的秩序、公正等价值。     

Bayesian Risk Assessment in Genetic Testing for Autosomal Dominant Disorders with Age-Dependent Penetrance

Risk assessment is an essential component of genetic counseling and testing, and the accuracy of risk assessment is critical for decision making by consultands. However, it has been shown that genetic risk calculations may have high error rates in practice. Risk calculations for autosomal dominant disorders are frequently complicated by age-dependent penetrance and sensitivities of less than 100% in genetic testing. We provide methods of risk calculation for prototypical pedigrees of a family at risk for an autosomal dominant disorder with age-dependent penetrance. Our risk calculations include scenarios in which the sensitivity of genetic testing is less than 100%, and in which the sensitivity of genetic testing varies for different family members at risk. Our Bayesian methods permit autosomal dominant disease probabilities to be calculated accurately, taking into account all relevant information. Our methods are particularly useful for hereditary cancer syndromes, in which genetic testing can seldom achieve 100% sensitivity. Our methods can be applied to many different scenarios, including those where the sensitivity of genetic testing varies for different family members at risk. The content of this publication does not necessarily reflect the views or policies of the Department of Health and Human Services, nor does mention of trade names, commercial products, or organizations imply endorsement by the U.S. Government.