Mechanisms of spontaneous activity in developing spinal networks

Developmental ordering, 1 item preceding another in development, is a primary piece of evidence in developmental research. However, testing developmental ordering hypotheses is remarkably difficult; the problem is that researchers rarely have absolute measures (ratio scales). Therefore, directly comparing 2 measures is often not sensible. This article demonstrates that, depending on the type of scale, the observed data pattern is constrained by the underlying relationship. Although the observed data pattern may not reflect the exact relationship, it does limit the possible relationships. Researchers can use this information to reject potential underlying relationships. An application of the method of strong inference (J. R. Platt, 1964) is outlined whereby researchers can use observed data patterns to systematically reject competing developmental ordering hypotheses. The approach requires only standard statistical methods and assumptions.     

Developmental ordering, scale types, and strong inference.

Developmental ordering, 1 item preceding another in development, is a primary piece of evidence in developmental research. However, testing developmental ordering hypotheses is remarkably difficult; the problem is that researchers rarely have absolute measures (ratio scales). Therefore, directly comparing 2 measures is often not sensible. This article demonstrates that, depending on the type of scale, the observed data pattern is constrained by the underlying relationship. Although the observed data pattern may not reflect the exact relationship, it does limit the possible relationships. Researchers can use this information to reject potential underlying relationships. An application of the method of strong inference (J. R. Platt, 1964) is outlined whereby researchers can use observed data patterns to systematically reject competing developmental ordering hypotheses. The approach requires only standard statistical methods and assumptions. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Using comparison data to differentiate categorical and dimensional data by examining factor score distributions: Resolving the mode problem.

Factor-analytic research is common in the study of constructs and measures in psychological assessment. Latent factors can represent traits as continuous underlying dimensions or as discrete categories. When examining the distributions of estimated scores on latent factors, one would expect unimodal distributions for dimensional data and bimodal or multimodal distributions for categorical data. Unfortunately, identifying modes is subjective, and the operationalization of counting local maxima has not performed very well. Rather than locating and counting modes, the authors propose performing parallel analyses of categorical and dimensional comparison data and calculating an index of the relative fit of these competing structural models. In an extensive Monte Carlo study, the authors replicated prior results for mode counting and found that trimming distributions' tails helped. However, parallel analyses of comparison data achieved much greater accuracy, improved base rate estimation, and afforded consistency checks with other taxometric procedures. Two additional studies apply this approach to empirical data either known to be categorical or presumed to be dimensional. Each study supports this new method for factor-analytic research on the latent structure of constructs and measures in psychological assessment. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Developmental change in young children's spatial grouping activity.

The aim of this study was to provide the kinds of detailed data necessary for formulating and eventually testing hypotheses about the conceptual bases of spatial behavior for children 1 to 4 years of age. Forty children between 18 and 42 months of age were tested on four spontaneous block construction tasks. A set of six measures was used to analyze both the products and the process of spatial grouping. The measures included: a categorical analysis of overall configuration of spatial groupings, number of spatial loci or points of origin in a construction, number of directions in which a construction extended in space, types of spatial relations generated, number of different kinds of relations in a construction, and the process of construction. The results confirm and elaborate previously established developmental findings for each measure. Moreover, comparison and integration of data across the set of measures yielded both distinctive profiles of spatial grouping activity at 18 and 42 months and evidence of systematic developmental change between these ages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Categorical perception of bird song: How do great tits (Parus major) perceive temporal variation in their song?

Studies on mammals (especially humans) have shown that categorical perception of continuous variation is common with certain speech sounds. In great tits (Parus major), certain songs have been classified by researchers (e.g., P. K. McGregor and J. R. Krebs; see record 1982-32003-001) on the basis of one continuous variable, phrase length. This experiment tested whether songs that varied in this feature were perceived categorically. The birds were trained to discriminate between two reference songs that differed only in phrase length. They were then presented with test songs that formed a continuum between the two reference stimuli. In two experiments with different song stimuli, the birds did not respond to test songs in a categorical fashion (i.e., the response functions were linear or near-linear as opposed to the step-functions or sigmoid curves predicted from categorical perception). This evidence suggests that great tits did not perceive continuous variation in the phrase length of their own songs categorically. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Intrasexual competition and body weight dimorphism in anthropoid primates

Body weight dimorphism in anthropoid primates has been thought to be a consequence of sexual selection resulting from male-male competition for access to mates. However, while monogamous anthropoids show low degrees of weight dimorphism, as predicted by the sexual selection hypothesis, polygynous anthropoids show high variation in weight dimorphism that is not associated with measures of mating system or sex ratio. This observation has led many to debate the role of other factors such as dietary constraints, predation pressure, substrate constraints, allometric effects, and phylogeny in the evolution of anthropoid weight dimorphism. Here, we re-evaluate variation in adult body weight dimorphism in anthropoids, testing the sexual selection hypothesis using categorical estimates of the degree of male-male intrasexual competition ("competition levels"). We also test the hypotheses that interspecific variation in body weight dimorphism is associated with female body weight and categorical estimates of diet, substrate use, and phylogeny. Weight dimorphism is strongly associated with competition levels, corroborating the sexual selection hypothesis. Weight dimorphism is positively correlated with increasing female body weight, but evidence suggests that the correlation reflects an interaction between overall size and behavior. Arboreal species are, on average, less dimorphic than terrestrial species, while more frugivorous species tend to be more dimorphic than folivorous or insectivorous species. Several alternative hypotheses can explain these latter results. Weight dimorphism is correlated with taxonomy, but so too are competition levels. We suggest that most taxonomic correlations of weight dimorphism represent "phylogenetic niche conservatism"; however, colobines show consistently low degrees of weight dimorphism for reasons that are not clear.     

Stages of change in methadone maintenance: Assessing the convergent validity of two measures.

This study compared 2 alternate measures of stage of change as conceived by J. O. Prochaska and C. C. DiClemente (see record 1983-26480-001). A sample of 276 methadone maintenance patients completed both categorical and dimensional measures of stage of change regarding quitting illicit drug use. The categorical measure places participants into 1 of 5 stages based on their stated intentions regarding future illicit drug use. The University of Rhode Island Change Assessment scale (URICA) provides continuous scores on 4 stage-of-change scales. Confirmatory factor analysis was used to assess the URICA's factor structure. The relationship between URICA scores and self-reported drug use was also assessed. Comparison of the URICA and the categorical measure using discriminant function analysis indicated limited convergence between the 2 measures and suggests that they may assess different aspects of readiness to change. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Are infant attachment patterns continuously or categorically distributed? A taxometric analysis of strange situation behavior.

Contemporary attachment research is based on the assumption that at least three types of infant attachment patterns exist: secure, avoidant, and resistant. It is not known, however, whether individual differences in attachment organization are more consistent with a continuous or a categorical model. The authors addressed this issue by applying P. E. Meehl's (1973, 1992) taxometric techniques for distinguishing latent types (i.e., classes, natural kinds) from latent continua (i.e., dimensions) to Strange Situation data on 1,139 fifteen-month-old children from the NICHD Study of Early Child Care. The results indicate that variation in attachment patterns is largely continuous, not categorical. The discussion focuses on the implications of dimensional models of individual differences for attachment theory and research. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Individual differences in working memory and comprehension: A test of four hypotheses.

A relationship has consistently been found between measures of working memory and reading comprehension. Four hypotheses for this relationship were tested in 3 experiments. In the 1st 2 experiments, a moving window procedure was used to present the operation–word and reading span tasks. High- and low-span Ss did not differentially trade off time on the elements of the tasks and the to-be-remembered word. Furthermore, the correlation between span and comprehension was undiminished when the viewing times were partialed out. Exp 3 compared a traditional experimenter-paced simple word-span and an S-paced span in their relationship with comprehension. The experimenter-paced word-span correlated with comprehension, but the S-paced span did not. The results of all 3 experiments support a general capacity explanation for the relationship between working memory and comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Risk mechanisms in development: Some conceptual and methodological considerations.

This commentary focuses on several issues concerning research on risk mechanisms that are raised in this special issue. First, we focus on what marks this special issue as distinctive in the ways in which risk research is conducted. Second, several general issues in research are highlighted, including sample characteristics, measurement strategies, specificity of risk factors and risk mechanisms, categorical vs. dimensional approaches to samples and measures, and definitions of development and transitions. Third, the challenges for integrating alternative models of risk are discussed, with special references to research on genetic and environmental influences on developmental psychopathology. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Statistical analysis of ordinal categorical status after therapies.

Appropriate statistical analysis of clinical data based on ordinal categorical outcome scales is discussed. Chi-square analysis is inappropriate for testing the superiority of one therapy over another when outcome is ordinal categorical. Emphasized is estimation of clinically informative effect sizes after statistical significance has been attained with the Mann-Whitney U test. Little-used informative measures of effect size are related to estimation of the probability that a client given one therapy will have an outcome superior to that of a client given another therapy. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Testing the degree of cross-sectional and longitudinal dependence between two discrete dynamic processes.

Developmental research often involves studying change across 2 or more processes or constructs simultaneously. A natural question in this work is whether change in these 2 processes is related or independent. Associative latent transition analysis (ALTA) was designed to test hypotheses about the degree to which change in 2 discrete latent variables is related. The ALTA model is a type of latent class model, which is a categorical latent variable model based on categorical indicators. In the ALTA approach, level and change on 1 variable is predicted by level and change in another. Two types of hypotheses are discussed: (a) broad hypotheses of dependence between the 2 discrete latent variables and (b) targeted hypotheses comparing specific patterns of change between levels of the discrete variables. Both types of hypotheses are tested via nested model comparisons. Analyses of relations between psychological state and substance use illustrate the model. Recent psychological state and recent substance use were found to be associated cross-sectionally and longitudinally, implying that change in recent substance use was related to change in recent psychological state. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cognitive functioning in young "social drinkers": Is there impairment to detect?

Literature on the cognitive effects of nonexcessive alcohol use suggests that relatively high-quantity-per-occasion use may be related to subsequent decreases in sober-state abstracting skills in adults, but provides no clear prediction for youth. The need to identify persistent alcohol-intake effects on cognition is particularly acute for the period of adolescence and young adulthood because even slight damage may impair developmentally significant skills. We examine the relation between multiple measures of neuropsychological status and both continuous and categorical measures of alcohol-use patterns in an age- and sex-stratified sample of 1,308 18-, 21-, and 24-year-olds. The results of correlational and hierarchical regression analyses suggest that cognitive performance bears little direct relation to drinking behaviors in young nonclinical males and females. Although the data provide no strong support for the hypothesis of a causal relationship between alcohol use and cognitive functioning, there is a slight suggestion that frequent high-quantity consumption may become a salient parameter of use as subjects age. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Multiple comparison procedures updated

1. A common statistical flaw in articles submitted to or published in biomedical research journals is to test multiple null hypotheses that originate from the results of a single experiment without correcting for the inflated risk of type 1 error (false positive statistical inference) that results from this. Multiple comparison procedures (MCP) are designed to minimize this risk. The present review focuses on pairwise contrasts, the most common sort of multiple comparisons made by biomedical investigators. 2. In an earlier review a variety of MCP were described and evaluated. It was concluded that an effective MCP should control the risk of family-wise type 1 error, so as to ensure that not more than one hypothesis within a single family is falsely rejected. One-step procedures based on the Bonferroni or Sidák inequalities do this. For continuous data and under normal distribution theory, so does the Tukey-Kramer procedure for all possible pairwise contrasts of means and the Dunnett procedure for all possible pairwise contrasts of means with a control mean. 3. There is now a new class of MCP, based on the Bonferroni or Sidák inequalities but performed in a step-wise fashion. The members of this class have certain desirable properties. They: (i) control the family-wise type 1 error rate as effectively as the one-step procedures; (ii) are more powerful than the one-step Bonferroni or Sidák procedures, especially when hypotheses are logically related; and (iii) can be applied not only to continuous data but also to ordinal or categorical data. 4. Of the new step-wise MCP, Holm's step-down procedures are commended for their combination of accuracy, power and versatility. They also have the virtue of simplicity. Given the raw P values that result from conventional tests of significance, the adjustments for multiple comparisons can be made by hand or hand-held calculator. 5. Despite the corrective abilities of the new step-wise MCP, investigators should try to design their experiments and analyses to test a single, global hypothesis rather than multiple ones.     

Personality, development, and counseling psychology: Depth, ambivalence, and actualization.

Although there is a profound connection between personality and developmental psychology on the one hand and counseling psychology on the other, this relationship has been marked by ambivalence. Reasons for this are discussed, and it is suggested that the relationship is moving in the direction of actualization. Four substantive areas are explored in which personality and developmental psychology both inform and are influenced by counseling psychology: career behavior, cultural identity, psychoanalysis, and adult development. Finally, the "healthy personality" is examined as an area of personality and developmental psychology in which counseling psychology has not fulfilled its promise, and the importance and possible directions of such work are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Regression models: calculating the confidence interval of effects in the presence of interactions

The main goal of regression analysis (multiple, logistic, Cox) is to assess the relationship of one or more exposure variables to a response variable, in the presence of confounding and interaction. The confidence interval for the regression coefficient of the exposure variable, obtained through the use of a computer statistical package, quantify these relationships for models without interaction. Relationships between variables that present interactions are represented by two or more terms, and the corresponding confidence intervals can be calculated 'manually' from the covariance matrix. This paper suggests an easy procedure for obtaining confidence intervals from any statistical package. This procedure is applicable for modifying variables which are continuous as well as categorical.     

Rorschach developmental level and intelligence factors.

Attempted to provide a more complete exploration of the relationship between Rorschach developmental level scores and intelligence than has appeared to date in the literature. Factor scores for both the WAIS and Rorschach measures were used in comparing test protocols obtained from 86 16–68 yr old psychiatric inpatients. Results reaffirm a relationship between intellectual level and developmental level. Further, the relationship was found to be of a general nature. It did not rely specifically on verbal, perceptual, or memory factors. Results also indicate that the relationship held for females as well as males. (25 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Subjective expectation, outcome discrepancy, and job satisfaction.

Investigated subjective expectation as a source of satisfaction valence associated with job outcomes. Four variables were of major interest: desired outcome, actual outcome, subjective expectation, and job satisfaction. The following hypotheses were tested, using 3 measures of satisfaction in a laboratory analog study with 120 undergraduates: (a) A positive linear relationship exists between "actual outcome–desired outcome" discrepancy and job satisfaction. (b) A negative linear relationship exists between subjective expectation and job satisfaction. Results on all dependent measures support the 1st hypothesis. Support for the 2nd hypothesis was evident but not consistent across the 3 satisfaction measures. The problem of equivalence of satisfaction measures is discussed, as is the relationship of the results to existing research and implications for further investigation. (French summary) (21 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The use of aftereffects in the study of relationships among emotion categories.

The perception of visual aftereffects has been long recognized, and these aftereffects reveal a relationship between perceptual categories. Thus, emotional expression aftereffects can be used to map the categorical relationships among emotion percepts. One might expect a symmetric relationship among categories, but an evolutionary, functional perspective predicts an asymmetrical relationship. In a series of 7 experiments, the authors tested these predictions. Participants fixated on a facial expression, then briefly viewed a neutral expression, then reported the apparent facial expression of the 2nd image. Experiment 1 revealed that happy and sad are opposites of one another; each evokes the other as an aftereffect. The 2nd and 3rd experiments reveal that fixating on any negative emotions yields an aftereffect perceived as happy, whereas fixating on a happy face results in the perception of a sad aftereffect. This suggests an asymmetric relationship among categories. Experiments 4-7 explored the mechanism driving this effect. The evolutionary and functional explanations for the category asymmetry are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Home environment and cognitive development in the first 3 years of life: A collaborative study involving six sites and three ethnic groups in North America.

Attempted to examine the generalizability of environment/development relationships among 3 ethnic groups across the first 3 years of life. Social status did not show a consistent relationship to either quality of home environment or children's developmental status across the various groups. Results indicated a fairly consistent relationship between HOME scores and children's developmental status, although there were some ethnic and social status differences in the relationship. Measures of specific aspects of the child's home environment, such as parental responsivity and availability of stimulating play materials, were more strongly related to child developmental status than global measures of environmental quality such as SES. When the child's developmental status and early home environment were both very low, the likelihood of poor developmental outcomes was markedly increased compared with cases when only one was low. (PsycINFO Database Record (c) 2010 APA, all rights reserved)