Which mechanical invariants are associated with the perception of length and heaviness of a nonvisible handheld rod? Testing the inertia tensor hypothesis

It has been suggested that the inertia tensor governs many instances of haptic perception. However, the evidence is inconclusive because other candidate mechanical parameters (i.e., invariants) were not or were insufficiently controlled for in pertinent experiments. By independently varying all candidate mechanical parameters, the authors were able to test the role of the inertia tensor relative to that of other mechanical parameters. The results showed that length perception during rod wielding is not governed by the inertia tensor alone but also by the static moment. In contrast to previous reports, length perception during rod holding and heaviness perception during rod wielding were found to be unrelated to the inertia tensor and strongly related to the static moment.     

On the locus of speed-accuracy trade-off in reaction time: inferences from the lateralized readiness potential

Lateralized readiness potentials (LRPs) were used to determine the stage(s) of reaction time (RT) responsible for speed-accuracy trade-offs (SATs). Speeded decisions based on several types of information were examined in 3 experiments, involving, respectively, a line discrimination task, lexical decisions, and an Erikson flanker task. Three levels of SAT were obtained in each experiment by adjusting response deadlines with an adaptive tracking algorithm. Speed stress affected the duration of RT stages both before and after the start of the LRP in all experiments. The latter effect cannot be explained by guessing strategies, by variations in response force, or as an indirect consequence of the pre-LRP effect. Contrary to most models, it suggests that SAT can occur at a late postdecisional stage.     

Effects of processing fluency on comparative performance judgments

Research has shown that performance predictions are biased by the impact of processing fluency. However, existing data are inconclusive with regard to comparative judgments of performance. In five experiments, participants in an easy condition gave more favorable comparative judgments than participants in a difficult condition. Participants judged their performance more favorably if they named colors of non-color words rather than non-matching color words (Experiment 1), if they had to generate six words of a category rather than 12 words (Experiment 2), if they had to run in place for 15 s rather than 2 min (Experiment 3), but the latter result holds only true if participants were not active in sports (Experiment 4). When 67% of the items in a recognition test were old words, participants thought that their recognition performance was better than when 33% of the items were old words, although recognition performance did not differ between groups (Experiment 5). We discuss this result in the light of recent theories about effects of processing fluency on judgments.     

Modulation of gait during visual adaptation to dark

The authors investigated the modulation of gait during dark adaptation. Twenty-five women (mean age = 72 years, SD = 5 years) walked back and forth on an arbitrarily uneven walkway during normal lighting at speeds ranging from slow to fast. Participants then performed 20 trials at preferred speed after sudden reduction of lighting; the authors compared those trials with point estimates at equivalent speeds representing normal lighting. The authors estimated speed, cadence, mediolateral trunk acceleration, and mediolateral interstep trunk-acceleration variability for each trial. Participants compensated for sudden reduction of lighting by reducing their walking speed. Compared with performance at equivalent speeds during normal lighting, cadence, trunk acceleration, and interstep trunk-acceleration variability initially increased. All variables showed an asymptotic approximation toward normal values during 60-90 s of walking in subdued lighting. The authors suggest that the sudden transition from normal to marginal lighting, rather than marginal lighting itself, may challenge locomotor control.     

Simple reaction time and statistical facilitation: a parallel grains model

A race-like model is developed to account for various phenomena arising in simple reaction time (RT) tasks. Within the model, each stimulus is represented by a number of grains of information or activation processed in parallel. The stimulus is detected when a criterion number of activated grains reaches a decision center. Using the concept of statistical facilitation, the model accounts for many classical effects on mean simple RT, including those of stimulus area, stimulus intensity, stimulus duration, criterion manipulations, redundant stimuli, and the dissociation between intensity effects on simple RTs and temporal order judgments. The model is also consistent with distributional properties of simple RTs.     

Developmental trajectories of childhood disruptive behaviors and adolescent delinquency: a six-site,cross-national study

This study used data from 6 sites and 3 countries to examine the developmental course of physical aggression in childhood and to analyze its linkage to violent and nonviolent offending outcomes in adolescence. The results indicate that among boys there is continuity in problem behavior from childhood to adolescence and that such continuity is especially acute when early problem behavior takes the form of physical aggression. Chronic physical aggression during the elementary school years specifically increases the risk for continued physical violence as well as other nonviolent forms of delinquency during adolescence. However, this conclusion is reserved primarily for boys, because the results indicate no clear linkage between childhood physical aggression and adolescent offending among female samples despite notable similarities across male and female samples in the developmental course of physical aggression in childhood.     

How does verb aspect constrain event representations?

We investigated the relative contribution of perfective and imperfective aspectual cues on situation models. In Experiment 1, participants were more likely to choose pictures showing completed events than pictures showing ongoing events when they had read perfective sentences, but chose either picture after reading imperfective sentences. In Experiment 2, only one picture was presented and participants were faster to respond to completed pictures than to ongoing pictures when they had read perfective sentences, but showed no latency differences after reading the imperfective sentences. In Experiment 3, participants were faster to read perfective sentences after having seen completed pictures rather than intermediate pictures, but there was no difference for imperfective sentences. The consistent pattern of results demonstrates that readers construct mental representations of completed events when the perfective aspect is used to describe an event. The lack of effect on imperfective sentences and pictures suggests that each reader represents an in-progress event at varying stages of completion.     

Functional and pharmacological characterization of the first specific agonist and antagonist for the V1b receptor in mammals

By activating three distinct vasopressin receptor isoforms called V1a-R, V1b-R (V3-R) and V2-R, vasopressin (VP) mediates a wide number of biological effects in mammals and may be involved in several pathological states. Up to now only specific V1a and V2 receptor agonists and antagonists have been successfully designed. The role of the V1b-R still remains partially unknown, due to the lack of selective V1b-R ligands and orally-active molecules, which are crucial tools for investigating the central and peripheral functions or pathological disorders associated with this receptor. In this review, we report the biological and pharmacological properties of the first two specific V1b-R ligands: d[Cha4] AVP, a high affinity V1b-R agonist and SSR149415, a potent orally-active V1b-R antagonist with good selectivity with respect to other VP/OT receptor isoforms and able to control ACTH secretion in vitro and in vivo. Indeed, these molecules constitute invaluable tools for exploring the central and peripheral roles of VP mediated via V1b receptors. Interestingly, SSR149415 displays potent anxiolytic and antidepressant-like activities, indicating that this new class of drugs has a promising therapeutical potential in the treatment of stress-related disorders, anxiety and depression.     

Do We Know Which Interventions are Effective for Disruptive and Delinquent Girls?

Disruptive and delinquent girls are not well served by the mental health and juvenile justice systems. Interventions that have been developed for the behavior problems of boys are frequently applied to girls despite growing evidence for a female-specific phenotype, developmental course, and set of risk factors from middle childhood onwards. The current review demonstrates that evidence of the effectiveness of treatments for girls with disruptive and delinquent behaviors is extremely limited, with relatively few studies including sufficient numbers of females or reporting on treatment effects by gender. However, a small body of evidence suggests that interventions specifically designed to address female behavior problems or risk factors can be effective in ameliorating disruptive and delinquent behaviors in both pre-adolescence and adolescence. Multi-modal interventions that target interacting domains of risk also show promise. Methodological issues are discussed and recommendations are made for the development and evaluation of future interventions to prevent and reduce girls’ disruptive and delinquent behavior.     

Attentional bias affects change detection

Thirty smokers and 30 nonsmokers participated in aflicker study in which the role of attentional bias in change detection was examined. The participants observed picture pairs of everyday objects flicker on a computer screen until they detected the one object that had changed. In half of the pictures, a smoking-related object (e.g., a lighter) was included among smoking-unrelated objects (e.g., a spoon). Half of the smokers and half of the nonsmokers were aware of the experiment’s focus, and the other half were not. The smokers exhibited shorter detection latencies than did the nonsmokers when a smoking object changed and longer detection latencies when a nonsmoking object changed while a smoking object was present, and they exhibited detection latencies similar to those of the nonsmokers when smoking objects were not present. Interestingly, the nonsmokers displayed the same attentional bias as the smokers when they were aware of the experiment’s smoking focus, but they did not display any attentional bias when they were unaware. Thus, these findings provide evidence for long-term context-independent, as well as for short-term context-dependent, attentional bias.