An Experimental Study of the Development of Democratic Behavior

Psychologists are becoming increasingly aware of the importance of an analysis of complex social phenomena, especially in the area of democratic behavior. If we wish to know how democratic behavior develops, and how its development can be controlled, we must be able to evaluate the effects of various types of experiences on its growth and ultimate pattern. It is the purpose of this paper to describe briefly a series of tests which have been devised to study democratic behavior at the elementary school level, and to indicate the effects on behavior of certain special experiences that have been introduced

Distortions of Subjective Time Perception Within and Across Senses

Background: The ability to estimate the passage of time is of fundamental importance for perceptual and cognitive processes. One experience of time is the perception of duration, which is not isomorphic to physical duration and can be distorted by a number of factors. Yet, the critical features generating these perceptual shifts in subjective duration are not understood. Methodology/Findings: We used prospective duration judgments within and across sensory modalities to examine the effect of stimulus predictability and feature change on the perception of duration. First, we found robust distortions of perceived duration in auditory, visual and auditory-visual presentations despite the predictability of the feature changes in the stimuli. For example, a looming disc embedded in a series of steady discs led to time dilation, whereas a steady disc embedded in a series of looming discs led to time compression. Second, we addressed whether visual (auditory) inputs could alter the perception of duration of auditory (visual) inputs. When participants were presented with incongruent audio-visual stimuli, the perceived duration of auditory events could be shortened or lengthened by the presence of conflicting visual information; however, the perceived duration of visual events was seldom distorted by the presence of auditory information and was never perceived shorter than their actual durations. Conclusions/Significance: These results support the existence of multisensory interactions in the perception of duration and, importantly, suggest that vision can modify auditory temporal perception in a pure timing task. Insofar as distortions in subjective duration can neither be accounted for by the unpredictability of an auditory, visual or auditory-visual event, we propose that it is the intrinsic features of the stimulus that critically affect subjective time distortions

Sequential Analysis of Mastery Behavior in 6- and 12-Month-Old Infants

We examined the pattern and direction of behaviors that reflect infants\u27 underlying mastery motivation. The sequences of mastery behavior were analyzed in a sample of 67 infants when they were 6 and 12 months old. We computed (a) the frequencies of each of six categories of mastery behavior, transitional probabilities, and z scores for each possible behavior change between the categories and (b) the transitions from a mastery behavior to an instance of positive affect. The analyses revealed significant age changes in the frequency of each category; however, the significant transitional probabilities among the six categories displayed a similar organization at both ages. The transitions from a mastery behavior to an instance of positive affect suggest that it is persistent, goal-directed behaviors that contribute to an infant\u27s feeling of efficacy

Spiked-in Data Set for BMC Notes paper

Dilution series of experimentsN

The Organization of Exploratory Behavior in Down Syndrome and Non-delayed Infants.

The exploratory behaviors of a sample of 11 infants with Down syndrome and 11 nondelayed infants, matched on Bayley mental raw scores and gender, were analyzed. Transitional probabilities and z scores were computed for each possible behavior change as well as frequencies of each behavior. The analyses revealed significant differences in how the 2 samples distribute their exploratory activities. The significant transitional probabilities among the 6 behavioral states revealed a pattern of similarities and differences. In general, both groups of infants organized their exploratory activities in a similar manner. However, there were differences that appeared to depend on the level of exploratory sophistication. The results are discussed in the context of the similarities and differences between the samples

Performance of variable selection methods using stability-based selection

Background: Variable selection is frequently carried out during the analysis of many types of high-dimensional data, including those in metabolomics. This study compared the predictive performance of four variable selection methods using stability-based selection, a new secondary selection method that is implemented in the R package BioMark. Two of these methods were evaluated using the more well-known false discovery rate (FDR) as well. Results: Simulation studies varied factors relevant to biological data studies, with results based on the median values of 200 partial area under the receiver operating characteristic curve. There was no single top performing method across all factor settings, but the student t test based on stability selection or with FDR adjustment and the variable importance in projection (VIP) scores from partial least squares regression models obtained using a stability-based approach tended to perform well in most settings. Similar results were found with a real spiked-in metabolomics dataset. Group sample size, group effect size, number of significant variables and correlation structure were the most important factors whereas the percentage of significant variables was the least important. Conclusions: Researchers can improve prediction scores for their study data by choosing VIP scores based on stability variable selection over the other approaches when the number of variables is small to modest and by increasing the number of samples even moderately. When the number of variables is high and there is block correlation amongst the significant variables (i.e., true biomarkers), the FDR-adjusted student t test performed best. The R package BioMark is an easy-to-use open-source program for variable selection that had excellent performance characteristics for the purposes of this study.Medicine, Faculty ofNon UBCSurgery, Department ofReviewedFacult

Relation Between Mastery Behavior in Infancy and Competence in Early Childhood

The failure of developmental tests in infancy to predict later competence may be because the tests ignore important dimensions of infant functioning. Yarrow and Pedersen (1976) have suggested that one such dimension could be mastery behavior, which involves persistence and investigation. Fifty-three infants were observed at 6 and 12 months during two 24-min play sessions. The Bayley Scales of Infant Development were given at 6 and 12 months, and the McCarthy Scales of Children\u27s Abilities at 30 months. Measures of competence in infancy (successful task completion during play and the Bayley scores) were not strongly correlated with the 30-month McCarthy Scales. In contrast, infant mastery behavior during play strongly predicted McCarthy scores: The time spent investigating toys at 6 months, and persistence in solving tasks at 12 months, were behaviors significantly positively correlated with the McCarthy Scales. Thus, infant behaviors that predict later competence do not remain static, but change with age. More importantly, infants\u27 mastery behavior appears to be a more effective predictor of later development than their competence with either toys or developmental tests