The intermixed-blocked effect in human perceptual learning is not the consequence of trial spacing

A robust finding in humans and animals is that intermixed exposure to 2 similar stimuli (AX/BX) results in better discriminability of those stimuli on test than does exposure to 2 equally similar stimuli in 2 separate blocks (CX_DX)--the intermixed-blocked effect. This intermixed-blocked effect may be an example of the superiority of spaced over massed practice; in the intermixed, but not the blocked exposure regime, each presentation of a given stimulus (e.g., AX) is separated from the next by the presentation of its partner (BX). Two experiments with human participants replicated the intermixed-blocked effect and showed that the effect was not due to the spacing of exposure trials. A mechanism for the intermixed-blocked effect is proposed, which combines theories from associative learning and memory.     

Effects of inhibiting of response on Tower of London performance

The purpose of this study was to determine if inhibiting responses improves performance on the Tower of London (TOL). The TOL has been assumed, though not experimentally proven, to be a measure of problem-solving ability. Problem solving involves inhibiting responses. Finding inhibition to be a factor in successfully completing TOL tasks would help to validate this tool and the research that utilizes it. Student volunteers were randomly assigned to two groups. Inhibition was induced in one of the groups by experimenter suggestion before each trial. The mean performance of the inhibited group was significantly higher, which suggests inhibiting responses increases TOL performance.     

Basic numerical capacities and prevalence of developmental dyscalculia: the Havana Survey

The association of enumeration and number comparison capacities with arithmetical competence was examined in a large sample of children from 2nd to 9th grades. It was found that efficiency on numerical capacities predicted separately more than 25% of the variance in the individual differences on a timed arithmetical test, and this occurred for both younger and older learners. These capacities were also significant predictors of individual variations in an untimed curriculum-based math achievement test and on the teacher scores of math performance over developmental time. Based on these findings, these numerical capacities were used for estimating the prevalence and gender ratio of basic numerical deficits and developmental dyscalculia (DD) over the grade range defined above (N = 11,652 children). The extent to which DD affects the population with poor ability on calculation was also examined. For this purpose, the prevalence and gender ratio of arithmetical dysfluency (AD) were estimated in the same cohort. The estimated prevalence of DD was 3.4%, and the male:female ratio was 4:1. However, the prevalence of AD was almost 3 times as high (9.35%), and no gender differences were found (male:female ratio = 1.07:1). Basic numerical deficits affect 4.54% of school-age population and affect more boys than girls (2.4:1). The differences between the corresponding estimates were highly significant (α < .01). Based on these contrastive findings, it is concluded that DD, defined as a defective sense of numerosity, could be a distinctive disorder that affects only a portion of children with AD.     

Attentional mechanisms in learned predictiveness

Cues that reliably predict an outcome in an initial phase of training (Phase 1) are learned faster in a second phase of training (Phase 2) than cues that were unreliable in Phase 1. This result is observed despite objectively equal relationships between the cues and the outcomes in Phase 2, and consequently constitutes a nonnormative bias in learning. The present experiments sought to confirm that this learned predictiveness effect is the product of attentional processes (Experiment 1), and to test further whether these processes are under voluntary control or are automatic in nature (Experiment 2). In addition to the usual outcome prediction measure, eye-gaze behavior was also monitored. The results indicated an important role for top-down strategic attentional processes in the learned predictiveness task. In contrast, no evidence for an automatic attentional bias was found.     

Peer and school problems in the lives of urban adolescents: Frequency, difficulty, and relation to adjustment

This study examined the occurrence of problem situations in the peer and school domains and their relation to adjustment among urban adolescents. Students from three urban middle schools (N = 176) serving a predominantly African American population rated 61 problem situations identified in a previous qualitative study and completed measures of adjustment. Ratings of frequency and difficulty confirmed the relevance of these situations for this population. Confirmatory factor analyses suggested that covariation in the frequency and difficulty of problem situations could be represented by separate factors representing peer situations involving friends, other peer situations, and school situations. The number of different problem situations experienced was significantly correlated with physical and relational aggression, delinquency, depression, anxiety, and self-worth. Several of these relations were strongest for peer situations that did not involve friends. There were few gender differences in the strength of these relations.     

What you don't know can hurt you: The effects of performance criteria ambiguity on sex differences in self-confidence1

Previous investigators have suggested that women display lower self-confidence than men across almost all achievement situations. The empirical validity of this suggestion is assessed in an experiment testing the hypothesis that performance evaluation guidelines moderate sex difference in self-confidence. Undergraduates read the guidelines by which their performance on an impending test would be evaluated. Guidelines were: ambiguous (A); clear—specifying the dimensions of performance to be examined, but not providing any examples of others' performance against which subjects' work would be compared (C); or clear with performance examples (CE). Subjects then completed the test and estimated how will they had done. Results showed the predicted pattern in conditions A and C: While women underestimated their actual performan?e much more than men when guidelines were ambiguous, they did not do so when guidelines were clear. Further, the rise in self-confidence for women from conditions A to C was greater than that for men. Also as predicted, both sexes' self-confidence and performance were higher in condition C than in condition A. Finally, although condition CE was expected to depress only women's self-confidence and performance, both sexes showed this effect. It is concluded that sex differences in self-confidence are moderated by situation variables and that programs designed to reduce such differences might be improved by a greater focus upon women's response to clearly specifiable factors in achievement settings.     

Two routes to perspective: Simulation and rule‐use as approaches to mentalizing

We review evidence relating to children's ability to acknowledge false beliefs within a simulation account according to which our focus is set by default to the world as we know it: hence, our current beliefs assume salience over beliefs that do not fall into this category. The model proposes that the ease with which we imaginatively shift from this default depends on the salience of our current belief, relative to the salience of the belief that is being simulated. However, children do use a rule‐based approach for mentalizing in some contexts, which has the advantage of protecting them from the salience of their own belief. Rule‐based mentalizing judgements might be faster, cognitively easier and less prone to error, relative to simulation‐based judgements that are much influenced by salience. We propose that although simulation is primary, rule‐based approaches develop as a shortcut; we thus grow from individuals capable of using only simulation into individuals capable of both techniques.     

ANXIETY, ALEXITHYMIA, AND DEPRESSION AS MEDIATORS OF THE ASSOCIATION BETWEEN CHILDHOOD ABUSE AND EATING DISORDERED BEHAVIOR IN AFRICAN AMERICAN AND EUROPEAN AMERICAN WOMEN

This study evaluated structural equation models of the associations among family functioning, childhood abuse, depression, anxiety, alexithymia, and eating disorder symptomatology in a sample of 412 European American and 192 African American female undergraduates. Additionally, the specific roles of anxiety, depression, and alexithymia as mediators were assessed. Each of these variables was a significant mediator of the association between childhood abuse and disordered eating. Finally, a test of invariance between the African American and European American subsamples was significant, highlighting the need for additional cross-cultural eating disorder research.