Hyperspecificity in visual implicit learning: learning of spatial layout is contingent on item identity

Humans conduct visual search faster when the same display is presented for a 2nd time, showing implicit learning of repeated displays. This study examines whether learning of a spatial layout transfers to other layouts that are occupied by items of new shapes or colors. The authors show that spatial context learning is sometimes contingent on item identity. For example, when the training session included some trials with black items and other trials with white items, learning of the spatial layout became specific to the trained color--no transfer was seen when items were in a new color during testing. However, when the training session included only trials in black (or white), learning transferred to displays with a new color. Similar results held when items changed shapes after training. The authors conclude that implicit visual learning is sensitive to trial context and that spatial context learning can be identity contingent.     

Predictive validity of a multidisciplinary model of reemployment success

The authors propose a multidisciplinary model of the predictors of reemployment and test its predictive validity for explaining reemployment success. Predictor variables from the fields of economics, sociology, and psychology are incorporated into the model. Reemployment success is conceptualized as a construct consisting of unemployment insurance exhaustion and reemployment speed, and for reemployed persons, job improvement, job-organization fit, and intention to leave the new job. Direct, mediated, and moderated relationships were hypothesized and tested, clarifying the role of the variables in the reemployment process and outcome. The authors' proposal and examination of a multidisciplinary model of reemployment success contributes to a literature that has not tended to adequately cross disciplinary boundaries.     

Evolution of disability in late 19th century America: Civil War pensions for Union Army veterans with musculoskeletal conditions

This article examines the evolution of musculoskeletal (MSK) disability and its impact on mortality and work patterns in the late 19th century in America, in the context of the Civil War disability policy scheme. The study was conducted on 17,702 Union Army (UA) Civil War veterans. Of these, 10,789 were examined and diagnosed with major MSK conditions, rheumatism, sciatica, and spinal curvature, between 1862 and 1907. Analyses examine MSK (i) prevalence rates by birth cohort and age group; (ii) fatality rates as compared with other disabilities; (iii) risk rates by occupation type; and (iv) lifespan for MSK patients. MSK conditions are commonly claimed disabilities within the Civil War data set, with prevalence rates increasing with age. Regression studies show that working in clerical and professional (relative to manual labor) occupations decreases the likelihood of being examined for and diagnosed with MSK conditions. MSK patients examined at older ages tended to have longer lifespan than those examined at younger ages. The findings suggest that changes in age, environmental, and occupational conditions during the late 19th century affected MSK condition prevalence and the average lifespan of MSK patients. Implications for contemporary disability policy are discussed.     

Linking sight and sound: fMRI evidence of primary auditory cortex activation during visual word recognition

We describe two studies that used repetition priming paradigms to investigate brain activity during the reading of single words. Functional magnetic resonance images were collected during a visual lexical decision task in which nonword stimuli were manipulated with regard to phonological properties and compared to genuine English words. We observed a region in left-hemisphere primary auditory cortex linked to a repetition priming effect. The priming effect activity was observed only for stimuli that sound like known words; moreover, this region was sensitive to strategic task differences. Thus, a brain region involved in the most basic aspects of auditory processing appears to be engaged in reading even when there is no environmental oral or auditory component.     

Screening alloy electrocatalysts by combining magnetron sputtering and scanning electrochemical microscopy

A high-throughput approach for developing materials is revolutionizing the current trial-and-error mode with great potential for accelerating the process. Here, we propose a simple approach combining multitarget sputtering and scanning electrochemical microscopy for the screening of hydrogen evolution reaction (HER) electrocatalysts. The ternary Co–Ni–Cu system is used as to demonstrate the feasibility of the strategy. The optimized composition for a HER catalyst is determined to be Co₁₄Ni₅₃Cu₃₃.     

Twinning in the structure of the ‘decagonal’ phase Al65Cu20Co15

Abstract

The existence of twinning in the pseudo-decagonal phase Al₆₅Cu₂₀Co₁₅ has been established through TEM studies. From electron diffraction patterns, a rhombic crystalline lattice with a very large unit cell is easily identified. Diffraction patterns for microtwinned regions exhibit splitting and distortion of the reflections which is a result of the overlap of lattices which are rotated by 36° with respect to one another. While patterns from single components of the twins exhibit only pseudo-tenfold symmetry, those from the microtwinned regions exhibit nearly perfect tenfold symmetry.     

A Bayesian Modeling Approach for Generalized Semiparametric Structural Equation Models

In behavioral, biomedical, and psychological studies, structural equation models (SEMs) have been widely used for assessing relationships between latent variables. Regression-type structural models based on parametric functions are often used for such purposes. In many applications, however, parametric SEMs are not adequate to capture subtle patterns in the functions over the entire range of the predictor variable. A different but equally important limitation of traditional parametric SEMs is that they are not designed to handle mixed data types—continuous, count, ordered, and unordered categorical. This paper develops a generalized semiparametric SEM that is able to handle mixed data types and to simultaneously model different functional relationships among latent variables. A structural equation of the proposed SEM is formulated using a series of unspecified smooth functions. The Bayesian P-splines approach and Markov chain Monte Carlo methods are developed to estimate the smooth functions and the unknown parameters. Moreover, we examine the relative benefits of semiparametric modeling over parametric modeling using a Bayesian model-comparison statistic, called the complete deviance information criterion (DIC). The performance of the developed methodology is evaluated using a simulation study. To illustrate the method, we used a data set derived from the National Longitudinal Survey of Youth.     

Positive emotion modulates cognitive control: An event‐related potentials study

There is substantial evidence to indicate that negative emotion can modulate cognitive control processing. However, only a few studies have investigated this effect with positive emotion. Therefore, the present study explored the electrophysiological correlates of the impact of positive emotional stimuli on cognitive control, using event‐related potentials (ERPs). Sixteen healthy young adults completed a modified Simon task (Simon, 1969). Behavioral data indicated that reaction times were faster for positive emotional stimuli than for neutral emotional stimuli in the incongruent condition, but not in the congruent condition, which suggested that positive emotion expedited conflict resolution. The ERP data showed that two negative ERP components (N300–400 and N450–550) were associated with the positive emotional stimuli in the incongruent minus congruent condition. It is suggested that these components may respectively be related to the conflict monitoring (N300–400) and response selection (N450–550) stages of cognitive control processing. Overall, our results indicated that positive emotion could facilitate cognitive control processing. These results are in line with the neuropsychological theory, according to which, positive emotion could modulate cognitive control mediated by increased dopamine levels in frontal brain areas.     

Discriminant Analysis Using Mixed Continuous,Dichotomous, and Ordered Categorical Variables

This article proposes an intuitive approach for predictive discriminant analysis with mixed continuous, dichotomous, and ordered categorical variables that are defined via an underlying multivariate normal distribution with a threshold specification. The classification rule is based on the comparison of the observed data logarithm probability density functions. To reduce the computational burden, the analysis is conducted in the context of a confirmatory factor analysis model with independent error measurements. Identification of the dichotomous and ordered categorical variables is discussed. Results are obtained by implementations of a Monte Carlo expectation maximization (MCEM)algorithm and a path sampling procedure. Probabilities of misclassification are estimated via the idea of the “jackknife” method. A real example is given to illustrate the proposed method.     

Statistical extraction affects visually guided action

The visual system summarizes average properties of ensembles of similar objects. We demonstrated an adaptation aftereffect of one such property, mean size, suggesting it is encoded along a single visual dimension (Corbett, et al., 2012), in a similar manner as basic stimulus properties like orientation and direction of motion. To further explore the fundamental nature of ensemble encoding, here we mapped the evolution of mean size adaptation over the course of visually guided grasping. Participants adapted to two sets of dots with different mean sizes. After adaptation, two test dots replaced the adapting sets. Participants first reached to one of these dots, and then judged whether it was larger or smaller than the opposite dot. Grip apertures were inversely dependent on the average dot size of the preceding adapting patch during the early phase of movements, and this aftereffect dissipated as reaches neared the target. Interestingly, perceptual judgements still showed a marked aftereffect, even though they were made after grasping was completed more-or-less veridically. This effect of mean size adaptation on early visually guided kinematics provides novel evidence that mean size is encoded fundamentally in both perception and action domains, and suggests that ensemble statistics not only influence our perceptions of individual objects but can also affect our physical interactions with the external environment.