A test of the generalizability of a recently suggested conceptual model for assessment center ratings

The present study replicated and extended research concerning a recently suggested conceptual model of the underlying factors of dimension ratings in assessment centers (ACs) proposed by Hoffman, Melchers, Blair, Kleinmann, and Ladd that includes broad dimension factors, exercise factors, and a general performance factor. We evaluated the criterion-related validity of these different components and expanded their nomological network. Results showed that all components (i.e., broad dimensions, exercises, general performance) were significant predictors of training performance. Furthermore, broad dimensions showed incremental validity beyond exercises and general performance. Finally, relationships between the AC factors and individual difference constructs (e.g., Big Five, core self-evaluations, positive and negative affectivity) supported the construct-related validity of broad dimensions and provided further insights in the nature of the different AC components.     

Rumination in migraine: Mediating effects of brooding and reflection between migraine and psychological distress

Objective: The relationship between migraine and psychological distress has been consistently reported in cross-sectional and longitudinal studies. We hypothesised that a stable tendency to perseverative thoughts such as rumination would mediate the relationship between migraine and psychological distress.

Design and Main Outcomes Measures: Self-report questionnaires measuring depressive rumination, current psychological distress and migraine symptoms in two independent European population cohorts, recruited from Budapest (N = 1139) and Manchester (N = 2004), were used. Structural regression analysis within structural equation modelling was applied to test the mediational role of brooding and reflection, the components of rumination, between migraine and psychological distress. Sex, age and lifetime depression were controlled for in the analysis.

Results: Migraine predicted higher brooding and reflection scores, and brooding proved to be a mediator between migraine and psychological distress in both samples, while reflection mediated the relationship significantly only in the Budapest sample.

Conclusions: Elevated psychological distress in migraine is partially attributed to ruminative response style. Further studies are needed to expand our findings to clinical samples and to examine how rumination links to the adjustment to migraine.     

Two Modulatory Inputs Exert Reciprocal Reinforcing Effects on Synaptic Input of Premotor Interneurons for Withdrawal in Terrestrial Snails

A cluster of serotonergic cells in the rostral part of pedal ganglia of the terrestrial snail Helix lucorum was shown previously to participate in modulation of withdrawal behavior, and to be necessary for elaboration of aversive withdrawal conditioning in intact snails. In the present experiments local extracellular stimulation of the serotonergic cells elicited a pairing-specific increase (difference between paired and explicitly unpaired sessions was significant, P<0.01) of synaptic responses in the premotor interneurons involved in withdrawal to paired nerve stimulation. Intracellular stimulation of only one Pd4 cell from the pedal group of serotonergic neurons increased (P<0.05) synaptic responses to contingent test nerve stimulation significantly in the same premotor interneurons for 2–3 hr.     

Inclined Weight-Loaded Walking at Different Speeds: Pelvis-Shoulder Coordination,Trunk Movements and Cost of Transport

Although studied at level surface, the trunk kinematics and pelvis-shoulder coordination of incline walking are unknown. The aim of this study was to evaluate the speed effects on pelvis-shoulder coordination and trunk movement and the cost of transport (C) during unloaded and loaded (25% of body mass) 15% incline walking. We collected 3-dimensional kinematic and oxygen consumption data from 10 physically active young men. The movements were analyzed in the sagittal plane (inclination and range of trunk motion) and the transverse plane (range of shoulder and pelvic girdle motion and phase difference). The rotational amplitude of the shoulder girdle decreased with load at all speeds, and it was lower at the highest speeds. The rotational amplitude of the pelvic girdle did not change with the different speeds. The phase difference was greater at optimal speed (3 km.hr^?1, at the lowest C) in the loaded and the unloaded conditions. The trunk inclination was greater with load and increased with speed, whereas the range of trunk motion was lower in the loaded condition and decreased with increasing speed. In conclusion, the load decreased the range of girdles and trunk motion, and the pelvis-shoulder coordination seemed to be critical for the incline walking performance.     

CAREGIVER–CHILD INTERACTION,CAREGIVER TRANSITIONS,AND GROUP SIZE AS MEDIATORS BETWEEN INTERVENTION CONDITION AND ATTACHMENT AND PHYSICAL GROWTH OUTCOMES IN INSTITUTIONALIZED CHILDREN

This report describes a secondary analysis of data from a comprehensive intervention project which included training and structural changes in three Baby Homes in St. Petersburg, Russian Federation. Multiple mediator models were tested according to the R.M. Baron and D.A. Kenny ( 1986 ) causal‐steps approach to examine whether caregiver–child interaction quality, number of caregiver transitions, and group size mediated the effects of the intervention on children's attachment behaviors and physical growth. The study utilized a subsample of 163 children from the original Russian Baby Home project, who were between 11 and 19 months at the time of assessment. Results from comparisons of the training and structural changes versus no intervention conditions are presented. Caregiver–child interaction quality and number of caregiver transitions fully mediated the association between intervention condition and attachment behavior. No other mediation was found. Results suggest that the quality of interaction between caregivers and children in institutional care is of primary importance to children's development, but relationship context may play a less direct mediational role, supporting caregiver–child interactions.     

Heuristic and linear models of judgment: matching rules and environments

Much research has highlighted incoherent implications of judgmental heuristics, yet other findings have demonstrated high correspondence between predictions and outcomes. At the same time, judgment has been well modeled in the form of as if linear models. Accepting the probabilistic nature of the environment, the authors use statistical tools to model how the performance of heuristic rules varies as a function of environmental characteristics. They further characterize the human use of linear models by exploring effects of different levels of cognitive ability. They illustrate with both theoretical analyses and simulations. Results are linked to the empirical literature by a meta-analysis of lens model studies. Using the same tasks, the authors estimate the performance of both heuristics and humans where the latter are assumed to use linear models. Their results emphasize that judgmental accuracy depends on matching characteristics of rules and environments and highlight the trade-off between using linear models and heuristics. Whereas the former can be cognitively demanding, the latter are simple to implement. However, heuristics require knowledge to indicate when they should be used.     

Immunotoxic cholinergic lesions in the basal forebrain reverse the effects of entorhinal cortex lesions on conditioned odor aversion in the rat

Conditioned odor aversion (COA) corresponds to the avoidance of an odorized-tasteless solution (conditioned stimulus, CS) previously paired with toxicosis. COA occurs only when the interstimulus interval (ISI) is kept short, suggesting that the memory trace of the odor is subject to rapid decay. Previous experiments have shown that the entorhinal cortex (EC) is involved in the acquisition of COA, since lesion of the EC rendered COA tolerant to long ISI. Because EC lesions induce a septo-hippocampal cholinergic sprouting, the present experiment investigated whether COA tolerance to long ISI may be linked to this sprouting reaction. In a first experiment, male Long-Evans rats subjected to bilateral excitotoxic EC lesions combined to intracerebroventricular infusions of the selective cholinergic immunotoxin 192 IgG-saporin were exposed to odor-toxicosis pairing using a long ISI (120 min). Results showed that EC-lesioned rats displayed COA with the long ISI but not the control groups. In rats with EC combined to 192 IgG-saporin lesions, histological analysis demonstrated no evidence for cholinergic septo-hippocampal sprouting. In a second experiment, animals with 192-IgG saporin lesion showed a marked COA with a short ISI (5 min). These results suggest that the COA with the long ISI found in rats with EC lesions might involve a functional activity related to the EC lesion-induced hippocampal cholinergic sprouting. As the injection of 192 IgG-saporin alone did not affect COA with a short ISI, our data also point to a possible role of hippocampal cholinergic neurons in the modulation of memory processes underlying COA.     

Adolescent maternity: A risk factor in poverty situations?

This paper describes the psychosocial characteristics of adolescent mothers living in poverty in urban communities of Uruguay, whose children are now 0 to 5 years old. A sample of 965 mothers representative of the poor urban communities in the entire country was studied. One hundred thirty-six of these mothers were adolescents, 19 years old or younger. Six major areas were explored: socioeconomic status and social support, family characteristics, child-rearing practices, maternal and paternal availability, and characteristics of the child. In the group of children 2 to 5 years of age, psychomotor development was explored using the Test de Desarrollo Psicomotor (TEPSI). Psychosocial risk and child development were compared for adolescent and nonadolescent poor urban mothers. Children in both groups showed negative effects. It was not found that children of adolescent mothers did worse than those of nonadolescent mothers. Therefore, it was concluded that adolescent maternity is a complex phenomenon that cannot be viewed in isolation from the social environment in which it takes place. The results indicated that in poor communities the poverty-related risk factors may obscure the effect of the age-related ones.     

An experimental approach to the study of learned aggression

The sensory contact technique increases aggressiveness in male mice and allows aggressive types of behavior to be formed as a result of the repeated experience of victories in daily agonistic confrontations. Some behavioral domains confirm the development of learned aggression in males similar to those in humans. The features are repeated experience of aggression reinforced by victories; elements of learned behavior after periods of confrontation; intent, measured by increase of the aggressive motivation prior to agonistic confrontation; and decreased emotionality, estimated by parameters of open‐field behavior. Relevant situation provokes increases in aggression (boundary aggression). This review summarizes data on the influence of positive fighting experience in daily intermale confrontations on the behavior, neurochemistry, and physiology of aggressive mice (winners). This sort of experience changes many characteristics in individual and social behaviors, these having been estimated in different tests and in varied situations. Some physiological parameters are also changed in the winners. Neurochemical data confirm the activation of brain dopaminergic systems and functional inhibition of serotonergic system in winners under the influence of the repeated experience of aggression. The expression of the neurochemical and behavioral changes observed in winners has been found to depend on the mouse strain and on the duration of their agonistic confrontations. Aggr. Behav. 26:241–256, 2000. © 2000 Wiley‐Liss, Inc.