Repeated-measures contrasts for "multiple-pattern" hypotheses

Contrast analysis of repeated-measures data generally focuses on hypotheses when only 1 pattern of results is of theoretical interest. This article articulates a framework for contrast analysis in repeated-measures contexts in which researchers have hypotheses relevant to 1 potential pattern or multiple potential patterns of results. For example, a researcher might ask whether participants exhibit a pattern of (a) immediate symptom reduction or (b) delayed symptom reduction. Alternatively, the researcher might ask whether 2 or more groups exhibit 2 or more patterns to differing degrees. Building on the familiar logic and computational procedures for 1-pattern hypotheses, the authors present a contrast analysis framework that integrates analysis of 1-pattern and multiple-pattern hypotheses and accommodates 1 group or multiple groups of participants.     

New lessons from knockout mice: The role of serotonin during development and its possible contribution to the origins of neuropsychiatric disorders

Serotonin (5-HT) modulates numerous processes in the central nervous system that are relevant to neuropsychiatric function and dysfunction. It exerts significant effects on anxiety, mood, impulsivity, sleep, ingestive behavior, reward systems, and psychosis. Serotonergic dysfunction has been implicated in several psychiatric conditions but efforts to more clearly understand the mechanisms of this influence have been hampered by the complexity of this system at the receptor level. There are at least 14 distinct receptors that mediate the effects of 5-HT as well as several enzymes that control its synthesis and metabolism. Pharmacologic agents that target specific receptors have provided clues regarding the function of these receptors in the human brain. 5-HT is also an important modulator of neural development and several groups have employed a genetic strategy relevant to behavior. Several inactivation mutations of specific 5-HT receptors have been generated producing interesting behavioral phenotypes related to anxiety, depression, drug abuse, psychosis, and cognition. In many cases, knockout mice have been used to confirm what has already been suspected based on pharmacologic studies. In other instances, mutations have demonstrated new functions of serotonergic genes in development and behavior.     

r equivalent: A simple effect size indicator

The purpose of this article is to propose a simple effect size estimate (obtained from the sample size, N, and a p value) that can be used (a) in meta-analytic research where only sample sizes and p values have been reported by the original investigator, (b) where no generally accepted effect size estimate exists, or (c) where directly computed effect size estimates are likely to be misleading. This effect size estimate is called r(equivalent) because it equals the sample point-biserial correlation between the treatment indicator and an exactly normally distributed outcome in a two-treatment experiment with N/2 units in each group and the obtained p value. As part of placing r(equivalent) into a broader context, the authors also address limitations of r(equivalent).     

Pavlov in Spain

Reflexology has been present throughout Spanish science since the last third of the nineteenth century and its importance can be seen in the works of authors such as Martín Salazar, Ramón y Cajal, Gómez Oca?a, Simarro and Turró. The most important research in Reflexology in Spain takes place a) at the Schools of Neurophysiology and Psychology in Barcelona and Madrid, b) with a group of authors specializing in pathological medicine and c) in the Military's Health Department, Pavlov's work was received in Spain with special interest. Fernández-Espa?a, who could be considered the "first Spanish Pavlovian," emphasized Pavlov's work in a series dedicated to the study of objective psychology which was published between 1914 and 1924. Planelles was the first investigator to develop a program in pavlovian experimentation, presenting his results in 1935. The Civil War (1936-1939) ended these and many other Spanish projects in psychology. After the war, interest in Reflexology and Pavlov's theories slowly rose again, first through psychosomatic medicine and then in the 60's because of the works of such authors as Monserrat-Esteve, Rof Carballo and Colodrón. The progressive inclusion of psychology in the Schools of Philosophy and Arts after 1968 marked the beginning of a new era.     

Stereotype development in Andalusian children

Social psychologists have shown a profound interest in intergroup relationships, but there are very few papers focusing on the developmental aspects that explain the psychological mechanisms involved in the construction of group and cultural identity. Our research aims to explore how the self-categorization of Andalusian children evolves. We tried to assess the degree to which they self-identify as Andalusian, Spanish, and European, and how this identification changes with age. We were also interested in the affective evaluation of different groups (French, Italian, English, German, Spanish, Catalonian, and Andalusian) made by Andalusian children. Furthermore, we analyzed the relationship between self-categorization and the evaluation of these groups. Results show that the development of national (autonomous community) identity in these children is influenced by their cognitive development, as well as by the relationships among the regional communities of Spain and the relationships between Spain and other countries. The peculiarity of Andalusians as a group is that they assume both identities: Spanish and Andalusian, from a very early age. In-group favoritism is an extended phenomenon at all ages, and Andalusian children have a negative stereotype of the other Spanish groups and other European communities.     

Stress within a bicultural context for adolescents of Mexican descent

Folkman and Lazarus's theory of stress and coping was used to develop a measure assessing the perceived stress within a bicultural context. Middle school students of Mexican descent (N = 881) reported their perceived stress from intergenerational acculturation gaps, within-group discrimination, out-group discrimination, and monolingual stress. Although immigrant youths reported more total number of stressors, U.S.-born youths reported more stress from needing better Spanish and impact of parents' culture. Immigrant youths reported more stress from needing better English in school. Higher stress was associated with more depressive symptoms for both U.S.-born and immigrant youths. Although this study has identified some elements of stress, it has not identified positive coping mechanisms of the bicultural context for Latino youths.     

The effects of depression on the emotional responses of Spanish-speaking Latinas

Emotional responses (physiology, self-report, and facial expression) of 12 depressed and 10 nondepressed Spanish-speaking Latinas during sad and amusing film clips of human and animal content were compared. Depressed Latinas demonstrated less electrodermal reactivity across all the film clips and displayed fewer social smiles during the amusing-human film clip than nondepressed Latinas. No differences emerged for cardiovascular measures, reports of emotion, or facial expressions of happiness and negative emotion. Observed differences in electrodermal reactivity are similar to results from previous studies of Anglo Americans, suggesting that reduced electrodermal activity may be linked to depression across cultures. The findings also suggest that, for Latinas, depression may selectively alter expressions that serve interpersonal functions.     

“Mind the gaps”: An empirical approach to engineering ethics, 1997–2001

A survey on ethical issues in engineering was administered over a five-year period to Stanford engineering students and practicing engineers. Analysis of its results strongly suggests that important disconnects exist between the education of engineering students regarding ethical issues in engineering on the one hand, and the realities of contemporary engineering practice on the other. Two noteworthy consequences of these gaps are that the views of engineering students differ substantially over what makes an issue an ethical issue, while practicing engineers exhibit significant disagreement over what is the most important non-technical aspect of being a responsible engineering professional in contemporary society. These divergences impede the recognition of ethical issues and of specific moral responsibilities of engineers in concrete professional practice. It is argued that the use of suitably refined and probing surveys of engineering students and practicing engineers about ethical issues in engineering is an important although neglected empirical approach to the study of engineering ethics. Such an approach can enhance the prevailing case study method and combat over-tidy theoretical-analytical approaches to the subject. When a train arrives at a station in the London Underground, a public announcement cautions passengers to “mind the gap”, i.e. heed the space between the station platform and the carriage while entering or exiting. An early draft of this paper was presented at the International Conference on Ethics in Engineering and Computer Science, Case Western Reserve University, Cleveland, Ohio, March 21–23, 1999.     

The use of prosodic cues in language discrimination tasks by rats

Recent research with cotton-top tamarin monkeys has revealed language discrimination abilities similar to those found in human infants, demonstrating that these perceptual abilities are not unique to humans but are also present in non-human primates. Specifically, tamarins could discriminate forward but not backward sentences of Dutch from Japanese, using both natural and synthesized utterances. The present study was designed as a conceptual replication of the work on tamarins. Results show that rats trained in a discrimination learning task readily discriminate forward, but not backward sentences of Dutch from Japanese; the results are particularly robust for synthetic utterances, a pattern that shows greater parallels with newborns than with tamarins. Our results extend the claims made in the research with tamarins that the capacity to discriminate languages from different rhythmic classes depends on general perceptual abilities that evolved at least as far back as the rodents. Electronic Publication     

Timed picture naming: Extended norms and validation against previous studies

Factors affecting word retrieval were compared in a timed picture-naming paradigm for 520 drawings of objects. In prior timed and untimed studies by Snodgrass and Vanderwart (1980) and Snodgrass and Yuditsky (1996), concerns were raised that participants could not reliably name large numbers of items in a single session. We show that reliable results are obtained in a single session for 520 items and validate our method against previous findings by Snodgrass and colleagues for overlapping items. For these items, comparable levels of name agreement and latency are obtained, and we replicate effects of length, frequency, both objective and subjective age of acquisition, and visual complexity on reaction time (RT) and name agreement measures. Name agreement is unaffected by order of presentation, although there is a gradual increase in RTs across the session, requiring use of multiple random orders. Current extensions of our method include cross-linguistic, bilingual, developmental, and neuropsychological studies and comparisons of action naming and object naming.