A sensory contact model for the study of aggressive and submissive behavior in male mice

The technique for simultaneous development of aggressive and submissive behaviors as a result of successive experiences of defeats or victories in daily intermale confrontations in male mice permanently living under sensory contact conditions is offered for behavioral, pharmacological, and neurophysiological studies of mechanisms of agonistic social relations. Distant sensory contact is achieved by placing a pair of males into a common cage separated by a transparent partition with holes permitting visual contact and the individuals perceiving each other's odors but preventing any physical at contact all times except for 10-min daily tests. These conditions essentially elicit aggression in winner males and quickly result in submission by losers of the same strain of mice. The meaning of consecutive stages of the technique, the problem of controls, and applications of this model are discussed.     

Gamma is a Measure of the Accuracy of Predicting Performance on One Item Relative to Another Item,not of the Absolute Performance on an Individual Item Comments on Schraw (1995)

The recent paper by Schraw ( Measures of feeling-of-knowing accuracy: a new look at an old problem , Applied Cognitive Psychology, 1995, 9, 321—332) is flawed by several inaccuracies and by Schraw's failure to distinguish between two fundamentally different aspects of the accuracy of metacognitive predictions: (1) calibration (aka absolute accuracy, defined in terms of whether the predicted value assigned to a single item is followed by the occurrence of that value on the criterion test), and (2) resolution (aka relative accuracy, defined in terms of whether the predicted performance on one item relative to another item is followed by the occurrence of that ordering of the two items on the criterion test). Because of these (and other) problems, his recommendations seem misleading and counterproductive.     

Mothers' Perceptions of Infants Labelled ‘Depressed’

Forty-four depressed and non-depressed mothers participated in a videotaped interaction with their own infant and then rated the videotape using the Infant Stereotyping Scale and the Interaction Rating Scale. In addition, one half of the mothers rated a videotape of an unfamiliar infant who was labelled psychologically ‘depressed’ and the other half rated a videotape of the same infant with no label given. Both the depressed and non-depressed mothers rated the ‘depressed’ labelled infant more negatively than the non-labelled infant on the attributes of physical potency, cognitive competence, sociability and difficult behaviour. Physical appearance was the only rating that was not biased by the ‘depressed’ label. Mothers' ratings of their own infants were more positive than their ratings of the non-labelled stimulus infant. Depressed mothers did not see their infants more negatively except on one rating. They rated the physical appearance of their own infant more negatively than non-depressed mothers.     

The breathing bear with preterm infants: Effects on sleep,respiration, and affect

This study investigated the sleep/wake states, respiration, and affective behaviors of premature infants who were provided à “breathing” bear in the isolette from 33 to 35 weeks conceptional age (CA). The Breathing Bear is à source of rhythmic stimulation that is optional for the infants. Its “breathing” reflects the breathing rate of the individual infant. At 33 weeks CA, 27 premature infants were provided à Breathing Bear (BrBr) and 26 were given à Non-Breathing Bear (N-BrBr). At 35 weeks, interfeed observations for an average of 1.7 hours were made of the babies' states and state-specific behaviors, along with respiration recordings. By 35 weeks, the BrBr babies showed less wakefulness, more quiet sleep, fewer startles in quiet sleep, and less crying than the N-BrBr babies. In addition, they were more likely to smile and N-BrBr babies were more likely to grimace in active sleep. These findings replicate and extend previous reports of effects of the Breathing Bear on neurobehavioral organization. They also suggest that less negative affect is expressed by the BrBr babies; and they point to the importance of future study of preterm infants' affective expressions, both in sleep and in waking.     

Effect of chronic ethanol administration on intermale aggression in rats

An experiment was performed to study the effect of chronic ethanol administration on intermale aggression in rats using a 24-hour resident-intruder test. During the resident-intruder test residents displayed virtually all of the agonistic behaviors, and intruders displayed virtually all of the defensive behaviors. Intruders treated with ethanol displayed more defensive behavior and elicited more agonistic behavior than control intruders. Twenty minutes into the resident-intruder test intruders showed the greatest increase in corticosterone (338% vs. 129%), while residents showed the greatest increase in testosterone (103% vs. 18%). On the 2nd day of the resident-intruder test intruders lost more weight than residents (21.5 g vs. 10.2 g). Plasma corticosterone levels remained elevated for the intruders, and in particular for those intruders displaying defensive behaviors regardless of the resident's behavior. Plasma testosterone levels remained elevated for those residents that were paired with intruders that displayed defensive behaviors regardless of the resident's behavior. The frequency and severity of biting attacks by ethanol residents was significantly greater than that of control residents. In addition, the locus of biting attack shifted from the upper back of intruders paired with control residents to the flanks, tail, lower feet, and ventral surface on intruders paired with ethanol residents.     

Hungry people prefer larger bodies and objects: The importance of testing boundary effects

Several lab-based studies have indicated that when people are hungry, they judge larger women's bodies as more attractive, compared to when they are satiated. These satiety-dependent judgements are assumed to provide explanatory power when it comes to the noted cross-cultural differences in attitudes towards women's adiposity, whereby people who live in regions that are under greater nutritional stress tend to have more favourable attitudes towards bigger bodies. However, it is premature to assume that women's bodies are the proper or actual domain of the satiety-dependent judgement shifts found within research study testing contexts until stimuli other than female bodies have also been tested: The research programme falls into the trap of confirmation bias unless we also seek out disconfirmatory evidence and test the boundaries of the effects of hunger. Accordingly, we collected attractiveness judgements of female and male bodies manipulated to vary in size by varying level of adiposity, and objects manipulated to vary in size, from 186 participants who also reported their current hunger level. We found that larger sizes of stimuli in general, and women's bodies in particular, especially when judged by women, were judged as more attractive by the hungrier participants. We discuss these patterns in the context of the Insurance Hypothesis, the Environmental Security Hypothesis, and the impact of hunger on acquisition.     

Causal illusion as a cognitive basis of pseudoscientific beliefs

Causal illusion has been proposed as a cognitive mediator of pseudoscientific beliefs. However, previous studies have only tested the association between this cognitive bias and a closely related but different type of unwarranted beliefs, those related to superstition and paranormal phenomena. Participants (n = 225) responded to a novel questionnaire of pseudoscientific beliefs designed for this study. They also completed a contingency learning task in which a possible cause, infusion intake, and a desired effect, headache remission, were actually non-contingent. Volunteers with higher scores on the questionnaire also presented stronger causal illusion effects. These results support the hypothesis that causal illusions might play a fundamental role in the endorsement of pseudoscientific beliefs.     

Conversation Orientation Moderates the Relationship between Information Sharing of Medically Assisted Reproduction and Child Adjustment

Parents who experienced infertility have increasingly used medically assisted reproduction (MAR) to add children to their families over the past few decades. These parents will need to decide if they will tell their children about being conceived using MAR. Although MAR information sharing operates within family contexts, little is known about the role of conversation orientation—one family contextual factor—in child outcomes associated with MAR information sharing in middle childhood. Derived from the Family Communication Patterns Theory, this study proposes that conversation orientation moderates the associations between MAR information sharing and children's psychosocial adjustment. This proposal was tested using a sample of 81 6- to 12-year-old MAR-conceived children from 55 families and a structured observational measure of conversation orientation. Multiple regression analyses showed that MAR information sharing interacted with conversation orientation to influence children's behavioral and attention problems but not emotional problems. In families with high conversation orientation, MAR information sharing was not significantly associated with children's behavioral and attention problems. In families with low conversation orientation, MAR information sharing was significantly associated with an increase in children's behavioral and attention problems. Results of this exploratory study demonstrate the potential significance of general communication orientation in understanding child outcomes of MAR information sharing and highlight the needed family context nuances in MAR research.