Changes in step variability of new walkers with typical development and with Down syndrome

Models of human gait are based on adult locomotion. C. E. Bauby and A. D. Kuo (2000) proposed that adults rely on passive mechanisms at the spinal level to control motion in the anteroposterior direction and rely on direct monitoring of postural control in the lateral direction. The authors' purpose in this study was to determine if that model applies to control at the onset of walking in typically developing toddlers (n = 9) and in toddlers with Down syndrome (n = 6). Their longitudinal data suggested that toddlers control gait in a distinctly different manner than adults do. An adult pattern of control emerges with experience. In addition, the effect of experience on the emergence of that pattern is magnified by task-specific early intervention. The present data support the emergence and discovery of efficient patterns of control in this fundamental human behavior.     

Hindsight bias as a function of anchor distance and anchor plausibility

This study explored the influence of anchor distance on hindsight bias and how the subjective plausibility of different anchors moderates this relation. In addition to the standard memory design used in hindsight bias research, participants were asked to indicate the range of values for possible answers to difficult almanac questions. Varying anchor distance on the basis of each participant's individual range of possible answers showed (1) that anchor plausibility decreased with increasing anchor distance following a non-linear monotone function, (2) that size of hindsight bias initially increased with increasing anchor distance but, from a certain distance, started to decrease, and (3) that hindsight bias was found to be always higher for plausible than for implausible anchors.     

SARA: A cognitive process model to simulate the anchoring effect and hindsight bias

The cognitive process model "SARA" aims to explain the anchoring effect and hindsight bias by making detailed assumptions about the representation and alteration of item-specific knowledge. The model assumes that all processes, namely generating an estimate, encoding new information (i.e., the "anchor"), and reconstructing a previously generated estimate, are based on a probabilistic sampling process. Sampling probes long-term memory in order to retrieve information into working memory. Retrieval depends on the associative strength between this information and the currently active retrieval cues. Encoding the anchor may alter this associative pattern ("selective activation") or the anchor may serve as a retrieval cue, thus directing memory search ("biased reconstruction"). Both processes lead to systematically changed retrieval probabilities, thus causing the anchoring effect or hindsight bias. The model is completely formalised and implemented as a computer program. A series of simulations demonstrates the power of SARA to reproduce empirical findings and to predict new ones.     

Demand Transitions and Sustained Attention

A recent report by the National Research Council (Huey & Wickens, 1993) has identified transitions in task demand as an important dimension for study in vigilance research. This experiment tested the possibility that the effects of such transitions follow a relatively simple psychophysical rule—they are characterized by contrast effects. Transitions in task demand were achieved by shifting subjects from single-task to dual-task monitoring and vice versa. These transitions produced changes in subjects' sensing and decision-making functions that were far more intricate than simple contrast effects. The demand transition issue offers a complex research challenge on both basic and applied levels and warrants further investigation.     

Psychometric Properties and Clinical Cut-Off Scores of the Spanish Version of the Social Anxiety Scale for Adolescents

Psychotic (P) and Non-Psychotic (N-P) retardates were compared on 13 Rorschach “indicators” of psychosis using a matched pairs technique. Two of the 13 signs were found to significantly differentiate between groups with the P group demonstrating a lower F% and higher C' responding than the N-P group.     

Is There Still Time?

In this article we intend to discuss the psychoanalysis of elderly patients and, also, to review certain prejudices that are based upon the psychoanalytic technique and theory.     

How Should We Assess the Fit of Rasch-Type Models? Approximating the Power of Goodness-of-Fit Statistics in Categorical Data Analysis

We investigate the performance of three statistics, R ₁, R ₂ (Glas in Psychometrika 53:525–546, 1988), and M ₂ (Maydeu-Olivares & Joe in J. Am. Stat. Assoc. 100:1009–1020, 2005, Psychometrika 71:713–732, 2006) to assess the overall fit of a one-parameter logistic model (1PL) estimated by (marginal) maximum likelihood (ML). R ₁ and R ₂ were specifically designed to target specific assumptions of Rasch models, whereas M ₂ is a general purpose test statistic. We report asymptotic power rates under some interesting violations of model assumptions (different item discrimination, presence of guessing, and multidimensionality) as well as empirical rejection rates for correctly specified models and some misspecified models. All three statistics were found to be more powerful than Pearson’s X ² against two- and three-parameter logistic alternatives (2PL and 3PL), and against multidimensional 1PL models. The results suggest that there is no clear advantage in using goodness-of-fit statistics specifically designed for Rasch-type models to test these models when marginal ML estimation is used.     

One, two, three, four, or is there something more? Numerical discrimination in day-old domestic chicks

Human adults master sophisticated, abstract numerical calculations that are mostly based on symbolic language and thus inimitably human. Humans may nonetheless share a subset of non-verbal numerical skills, available soon after birth and considered the evolutionary foundation of more complex numerical reasoning, with other animals. These skills are thought to be based on the two systems: the object file system which processes small values (<3) and the analogue magnitude system which processes large magnitudes (>4). Infants’ ability to discriminate 1 vs. 2, 1 vs. 3, 2 vs. 3, but not 1 vs. 4, seems to indicate that the two systems are independent, implying that the conception of a continuous number processing system is based on precursors that appear to be interrupted at or about the number four. The findings from the study being presented here indicating that chicks are able to make a series of discriminations regarding that borderline number (1 vs. 4, 1 vs. 5, 2 vs. 4) support the hypothesis that there is continuity in the number system which processes both small and large numerousness.     

Brief treatment with alprazolam and behavioral guidance in panic disorder

Abstract

Thirty-two patients with panic disorder, with or without agoraphobic limitations, were treated with alprazolam (mean dose 3.5 mg/d) plus brief behavioral guidance in an open study during eight weeks. The sample had a notorious severity in the frequency of panics and phobic avoidance but was only mildly depressed. Before starting treatment the presence of demoralized mood and extensive avoidance were significant indicators of clinical severity, whereas the presence of dizziness as a relevant somatic complaint was not related to higher severity. After eight weeks of treatment a clinical improvement equal to or exceeding 80% of change was obtained in all cases (29) who completed treatment. Ninety-two percent of the patients were panic free at the end of treatment. There were significant reductions in all the scales with comparable declines in the subgroups formed according to the presence or absence of agoraphobic avoidance and demoralization. The data suggested that moderate doses of alprazolam could be a quick and effective treatment for panic-agoraphobic patients in the short term. The behavioral guidance probably helped in reducing agoraphobic avoidance and in obtaining global good effectiveness although this awaits controlled tests. Finally, the similarity in the response to treatment regardless of the presence of extensive avoidance or demoralized mood argues in favor of not considering the different variants of panic-agoraphobic syndrome differently, at least in samples with similar severity to the present one.