Bayesian multidimensional scaling for the estimation of a Minkowski exponent

The Minkowski property of psychological space has long been of interest to researchers. A common strategy has been calculating the stress in multidimensional scaling for many Minkowski exponent values and choosing the one that results in the lowest stress. However, this strategy has an arbitrariness problem—that is, a loss function. Although a recently proposed Bayesian approach could solve this problem, the method was intended for individual subject data. It is unknown whether this method is directly applicable to averaged or single data, which are common in psychology and behavioral science. Therefore, we first conducted a simulation study to evaluate the applicability of the method to the averaged data problem and found that it failed to recover the true Minkowski exponent. Therefore, a new method is proposed that is a simple extension of the existing Euclidean Bayesian multidimensional scaling to the Minkowski metric. Another simulation study revealed that the proposed method could successfully recover the true Minkowski exponent. BUGS codes used in this study are given in the Appendix.     

Body Image Alterations in Adults Due to Cerebrovascular Insufficiency

Changes in body image boundary were investigated in eighty-one patients with cerebrovascular insufficiency having varying degrees and sites of impairment. Barrier and Penetration scores were derived from the Rorschach according to the Fisher and Cleveland technique and were correlated with several indices of impairment and analyzed for changes over a two year period. Penetration scores were associated with three measures of intellectual ability. Barrier scores were correlated with verbal ability and vertebrobasilar angiogram. Barrier changed over time with a quadratic trend while Penetration did not change.     

Interacción persona x situación en la predicción de la personalidad: algunas especificaciones del factor personal

RESUMEN

Este trabajo intenta determinar si la multidimensionalidad de la Ansiedad-rasgo (A-trait), medida por el S-R GTA (Inventario E-R del Rasgo General de Ansiedad) está referida a diferentes perfiles de personalidad. Los resultados del análisis de regresión lineal múltiple usando la escala de “Locus of Control” interno-externo, el Inventario Psicológico de California, la Escala de Confianza interpersonal, como medidas predictivas, confirmaron la existencia de diversos perfiles de personalidad para una de las cuatro facetas de la Ansiedad-rasgo. Estos hallazgos atestiguan la multidimensionalidad del Inventario E-R del Rasgo General Ansiedad y la importancia de especificar la situación en la medida de la Ansiedad.     

Social exclusion mediates the relationship between psychopathy and aggressive humor style in noninstitutionalized young adults

Previous research indicates a positive relationship between psychopathy and various negative humor styles. The purpose of the present study was to investigate social exclusion as a possible mediator of the association between psychopathy and negative humor styles in noninstitutionalized young adults. One hundred and thirty-nine university students participated by responding to questionnaires that assess psychopathy, the experience of exclusion from friends, and four humor styles (self-enhancing, affiliative, aggressive, and self-defeating). There was a significant positive association between psychopathy, social exclusion, and aggressive styles of humor, and a negative association between psychopathy and affiliative styles of humor. Moreover, the results of a mediation analysis indicated that the association between psychopathy and aggressive humor style is completely explained by the experience of social exclusion. These results suggest that high psychopathic participants who are socially excluded use an aggressive humor style more often than low psychopathic individuals. The present study provides further insights into the role played by social environmental factors in the links between psychopathy and associated interpersonal characteristics.     

Imitation,Inspiration, and Creation: Cognitive Process of Creative Drawing by Copying Others' Artworks

To investigate the cognitive processes underlying creative inspiration, we tested the extent to which viewing or copying prior examples impacted creative output in art. In Experiment 1, undergraduates made drawings under three conditions: (a) copying an artist's drawing, then producing an original drawing; (b) producing an original drawing without having seen another's work; and (c) copying another artist's work, then reproducing that artist's style independently. We discovered that through copying unfamiliar abstract drawings, participants were able to produce creative drawings qualitatively different from the model drawings. Process analyses suggested that participants' cognitive constraints became relaxed, and new perspectives were formed from copying another's artwork. Experiment 2 showed that exposure to styles of artwork considered unfamiliar facilitated creativity in drawing, while styles considered familiar did not do so. Experiment 3 showed that both copying and thoroughly viewing artwork executed using an unfamiliar style facilitated creativity in drawing, whereas merely thinking about alternative styles of artistic representation did not do so. These experiments revealed that deep encounters with unfamiliar artworks—whether through copying or prolonged observation—change people's cognitive representations of the act of drawing to produce novel artwork.     

Negative estimate of variance-accounted-for effect size: How often it is obtained,and what happens if it is treated as zero

Researchers recommend reporting of bias-corrected variance-accounted-for effect size estimates such as omega squared instead of uncorrected estimates, because the latter are known for their tendency toward overestimation, whereas the former mostly correct this bias. However, this argument may miss an important fact: A bias-corrected estimate can take a negative value, and of course, a negative variance ratio does not make sense. Therefore, it has been a common practice to report an obtained negative estimate as zero. This article presents an argument against this practice, based on a simulation study investigating how often negative estimates are obtained and what are the consequences of treating them as zero. The results indicate that negative estimates are obtained more often than researchers might have thought. In fact, they occur more than half the time under some reasonable conditions. Moreover, treating the obtained negative estimates as zero causes substantial overestimation of even bias-corrected estimators when the sample size and population effect are not large, which is often the case in psychology. Therefore, the recommendation is that researchers report obtained negative estimates as is, instead of reporting them as zero, to avoid the inflation of effect sizes in research syntheses, even though zero can be considered the most plausible value when interpreting such a result. R code to reproduce all of the described results is included as supplemental material.     

Facilitation of corticospinal excitability during motor imagery of wrist movement with visual or quantitative inspection of EMG activity

The present study investigated facilitation of corticospinal excitability during motor imagery of wrist movement with visual or quantitative inspection of background electromyographic (EMG) activity. Ten healthy participants imagined wrist extension from a first-person perspective in response to a start cue. Transcranial magnetic stimulation was delivered to the motor cortex 2 sec. after the start cue. EMG signals were recorded from the extensor carpi radialis muscle. Trials with background EMG activity were discarded based on visual inspection. Both motor-evoked potential (MEP) and background EMG amplitudes increased during motor imagery. The amount of increase in MEP amplitude was positively correlated with the amount of increase in background EMG amplitude during motor imagery. The statistically significant increase in MEP amplitude during motor imagery disappeared when the effect of muscle activity was statistically eliminated or after trials with background EMG activity were discarded based on strict quantitative criteria. Facilitation of corticospinal excitability during motor imagery of wrist movement depends partially on muscle activity. Discarding background EMG activity during motor imagery based on visual inspection is not sufficient to equalize background EMG amplitude between resting and motor imagery. Discarding trials with background EMG activity through strict quantitative criteria is useful to equalize background EMG amplitude between at rest and during motor imagery.     

Conduction aphasia, sensory-motor integration, and phonological short-term memory - an aggregate analysis of lesion and fMRI data

Conduction aphasia is a language disorder characterized by frequent speech errors, impaired verbatim repetition, a deficit in phonological short-term memory, and naming difficulties in the presence of otherwise fluent and grammatical speech output. While traditional models of conduction aphasia have typically implicated white matter pathways, recent advances in lesions reconstruction methodology applied to groups of patients have implicated left temporoparietal zones. Parallel work using functional magnetic resonance imaging (fMRI) has pinpointed a region in the posterior most portion of the left planum temporale, area Spt, which is critical for phonological working memory. Here we show that the region of maximal lesion overlap in a sample of 14 patients with conduction aphasia perfectly circumscribes area Spt, as defined in an aggregate fMRI analysis of 105 subjects performing a phonological working memory task. We provide a review of the evidence supporting the idea that Spt is an interface site for the integration of sensory and vocal tract-related motor representations of complex sound sequences, such as speech and music and show how the symptoms of conduction aphasia can be explained by damage to this system.     

Observation system for the control of the hive environment by the honeybee (<Emphasis Type="Italic">Apis mellifera</Emphasis>)

The honeybee can control its hive environment to survive drastic changes in the field environment. To study the control of multiple environmental factors by honeybees, in this experiment, we developed a continual and simultaneous monitoring system for the temperature, moisture, and carbon dioxide (CO₂) concentration in a honeybee hive. Changes in hive weight, CO₂ production rate, and honeybee behavior were also monitored to estimate energy costs and behavioral activity for the environmental regulation. Measurements were conducted in August 2008. We found that the honeybee hive has a microclimate different from the ambient climate, and that the difference was partly accompanied by changes in honeybee activity. Our results also suggest that hive temperature, humidity, and CO₂ concentrations are controlled by different mechanisms. Additional monitoring of the hive environment and honeybee behavior for longer periods would enable us to understand the mechanisms of environmental control by honeybees, which is one of the behaviors that define honeybees as social insects.