Minimal information to determine affine shape equivalence

Participants judged the affine equivalence of 2 simultaneously presented 4-point patterns. Performance level (d') varied between 1.5 and 2.7, depending on the information available for solving the correspondence problem (insufficient in Experiment 1a, superfluous in Experiment 1b, and minimal in Experiments 1c, 2a, 2b) and on the exposure time (unlimited in Experiments 1 and 2a and 500 ms in Experiment 2b), but it did not vary much with the complexity of the affine transformation (rotation and slant in Experiment 1 and same plus tilt in Experiment 2). Performance in Experiment 3 was lower with 3-point patterns than with 4-point patterns, whereas blocking the trials according to the affine transformation parameters had little effect. Determining affine shape equivalence with minimal-information displays is based on a fast assessment of qualitatively or quasi-invariant properties such as convexity/ concavity, parallelism, and collinearity.     

Human sensitivity to phase perturbations in natural images: a statistical framework

Fourier-phase information is important in determining the appearance of natural scenes, but the structure of natural-image phase spectra is highly complex and difficult to relate directly to human perceptual processes. This problem is addressed by extending previous investigations of human visual sensitivity to the randomisation and quantisation of Fourier phase in natural images. The salience of the image changes induced by these physical processes is shown to depend critically on the nature of the original phase spectrum of each image, and the processes of randomisation and quantisation are shown to be perceptually equivalent provided that they shift image phase components by the same average amount. These results are explained by assuming that the visual system is sensitive to those phase-domain image changes which also alter certain global higher-order image statistics. This assumption may be used to place constraints on the likely nature of cortical processing: mechanisms which correlate the outputs of a bank of relative-phase-sensitive units are found to be consistent with the patterns of sensitivity reported here.     

The concept of education

Studies in Philosophy and Education -     

Comparison of the efficacy of two name-learning techniques: expanding rehearsal and name-face imagery

Two name-learning techniques were compared: expanding rehearsal and name-face imagery. Participants studied name-face associations and were given a cued recall test in which they were presented with a face and were to recall the name. They were presented with either an expanding rehearsal schedule (expanding condition), a distinctive facial feature coupled with a word phonologically similar to the last name and an interactive image linking the name and facial feature (name-face imagery condition), or a no memory (control) strategy. The expanding rehearsal schedule led to superior name learning relative to the name-face imagery and control conditions after a 15-min (Experiment 1) or 48-hr (Experiment 2) retention interval. In Experiment 3, the retrieval practice explanation was tested but not supported; we argue that an encoding variability interpretation is consistent with the overall pattern of results. Applied implications are also discussed.     

Reducing playground bullying and supporting beliefs: an experimental trial of the steps to respect program

Six schools were randomly assigned to a multilevel bullying intervention or a control condition. Children in Grades 3-6 (N=1,023) completed pre- and posttest surveys of behaviors and beliefs and were rated by teachers. Observers coded playground behavior of a random subsample (n=544). Hierarchical analyses of changes in playground behavior revealed declines in bullying and argumentative behavior among intervention-group children relative to control-group children, increases in agreeable interactions, and a trend toward reduced destructive bystander behavior. Those in the intervention group reported enhanced bystander responsibility, greater perceived adult responsiveness, and less acceptance of bullying/aggression than those in the control group. Self-reported aggression did not differ between the groups. Implications for future research on the development and prevention of bullying are discussed.     

Developmental psychology and public policy: progress and prospects

This article outlines a framework for developmentally oriented policy research. Drawing from U. Bronfenbrenner's (1995) dynamic developmental systems theory, the authors suggest ways in which the key tenets of process, persons, context, and time can inform policy research in developmental psychology and can be used to support a causal interpretation of the results of those analyses. Conceptualizing public policies from a dynamic developmental systems perspective has a variety of implications for future research, and this article considers some of these implications.     

Neural mechanisms of affective interference in schizotypy

Negatively valenced stimuli foster cognitive impairment in schizotypy and schizophrenia. To identify relevant brain mechanisms, the authors had 16 positive-schizotypy and 16 control participants perform an emotional Stroop task, judging the ink color of negative and neutral words during functional magnetic resonance imaging (fMRI) of regional brain activity. Schizotypy individuals showed increased right and decreased left activity in dorsolateral prefrontal cortex, indicating a deficit in maintenance of attentional set in the presence of negative emotional distractors. They also showed abnormal activity in ventral limbic areas, including decreased activity in nucleus accumbens and increased activity in hippocampus and amygdala, a circuit involved in the integration of cognitive and affective processes. These results indicate that aspects of emotion-cognition processes and the brain mechanisms that implement them are similar in schizotypy and schizophrenia.