War Experiences Inventory: Initial Psychometric and Structural Properties

We examined the structural and psychometric properties of the War Experiences Inventory (WEI) with data from 255 post deployed service members (224 men and 31 women). Results from principal components analyses yielded a five-factor solution assessing sexual trauma, combat exposure, interpersonal distress, circumstances of deployment, and personal injury. Psychometric analyses revealed scale scores were internally consistent; validity evidence showed WEI subscales were significantly correlated with measures of readjustment, PTSD, psychological distress, and alcohol abuse. Findings provide preliminary evidence of structural and psychometric properties of the WEI and its utility in assessing war-related experiences in operations in Afghanistan and Iraq.     

Unionization in the United States and India: An Empirical Investigation

Union voting intentions of 622 employees in the United States and 120 employees in India were investigated. Union beliefs and job satisfaction influenced voting intentions in both countries. Employer's willingness to correct workplace problems, presence of union members in the family, employment in the public sector, gender, and level of education influenced union voting intentions only in the U.S. sample.     

Impact of infralimbic inputs on intercalated amygdala neurons: a biophysical modeling study

Intercalated (ITC) amygdala neurons regulate fear expression by controlling impulse traffic between the input (basolateral amygdala; BLA) and output (central nucleus; Ce) stations of the amygdala for conditioned fear responses. Previously, stimulation of the infralimbic (IL) cortex was found to reduce fear expression and the responsiveness of Ce neurons to BLA inputs. These effects were hypothesized to result from the activation of ITC cells projecting to Ce. However, ITC cells inhibit each other, leading to the question of how IL inputs could overcome the inter-ITC inhibition to regulate the responses of Ce neurons to aversive conditioned stimuli (CSs). To investigate this, we first developed a compartmental model of a single ITC cell that could reproduce their bistable electroresponsive properties, as observed experimentally. Next, we generated an ITC network that implemented the experimentally observed short-term synaptic plasticity of inhibitory inter-ITC connections. Model experiments showed that strongly adaptive CS-related BLA inputs elicited persistent responses in ITC cells despite the presence of inhibitory interconnections. The sustained CS-evoked activity of ITC cells resulted from an unusual slowly deinactivating K(+) current. Finally, over a wide range of stimulation strengths, brief IL activation caused a marked increase in the firing rate of ITC neurons, leading to a persistent decrease in Ce output, despite inter-ITC inhibition. Simulations revealed that this effect depended on the bistable properties and synaptic heterogeneity of ITC neurons. These results support the notion that IL inputs are in a strategic position to control extinction of conditioned fear via the activation of ITC neurons.     

Transformed Facial Similarity as a Political Cue: A Preliminary Investigation

Experimental subjects evaluated a political candidate whose face was digitally altered to absorb the subjects' facial structure. For half of the subjects, the photograph of the candidate was morphed such that the image presented was a blend composed of 60% of the unfamiliar Caucasian male and 40% of the subject. For the other half the photograph was unaltered. Given previous research on implicit familiarity (Zajonc, 1968, 1980), we predicted that the morph would advantage the candidate. The results demonstrated no main effect of the similarity manipulation. However, there was a robust similarity by gender interaction. Male subjects evaluated the morphed candidate more favorably than the unaltered photograph, while female subjects rated him more negatively. We discuss potential explanations for this interaction effect and explore the possible implications of facial similarity as a political cue in both high- and low-information elections.     

Are Ethicality Perceptions of Different Counterproductive Behaviors Affected by Workplace Dependencies?1

Dependency theory posits that relationships in organizations are affected by perceived dependencies. The present paper investigated whether the perceived ethicality of various counterproductive behaviors depends on perceived dependencies. Falsifying time reports and using organizational resources for personal use were considered to be more unethical by individuals who scored low on dependency, whereas concealing one's errors was considered to be more unethical by individuals who scored high on dependency. These results were not attributable to social desirability bias. Implications are elaborated.     

Clarifying Heterogeneity of Daytime and Nighttime Symptoms of Posttraumatic Stress in Combat Veterans With Insomnia

Daytime and nighttime symptoms of posttraumatic stress disorder (PTSD) are common among combat veterans and military service members. However, there is a great deal of heterogeneity in how symptoms are expressed. Clarifying the heterogeneity of daytime and nighttime PTSD symptoms through exploratory clustering may generate hypotheses regarding ways to optimally match evidence-based treatments to PTSD symptom profiles. We used mixture modeling to reveal clusters based on 6 daytime and nighttime symptoms of 154 combat veterans with insomnia and varying levels of PTSD symptoms. Three clusters with increasing symptom severity were identified (n1 = 50, n2 = 70, n3 = 34). These results suggest that, among veterans with insomnia, PTSD symptoms tend to exist on a continuum of severity, rather than as a categorical PTSD diagnosis. Hypotheses regarding possible targeted treatment strategies for veterans within each identified cluster, as well as ways to generalize these methods to other groups within the military, are discussed.     

Neural mechanisms underlying subsequent memory for personal beliefs:An fMRI study

Many fMRI studies have examined the neural mechanisms supporting emotional memory for stimuli that generate emotion rather automatically (e.g., a picture of a dangerous animal or of appetizing food). However, far fewer studies have examined how memory is influenced by emotion related to social and political issues (e.g., a proposal for large changes in taxation policy), which clearly vary across individuals. In order to investigate the neural substrates of affective and mnemonic processes associated with personal opinions, we employed an fMRI task wherein participants rated the intensity of agreement/disagreement to sociopolitical belief statements paired with neural face pictures. Following the rating phase, participants performed an associative recognition test in which they distinguished identical versus recombined face–statement pairs. The study yielded three main findings: behaviorally, the intensity of agreement ratings was linked to greater subjective emotional arousal as well as enhanced high-confidence subsequent memory. Neurally, statements that elicited strong (vs. weak) agreement or disagreement were associated with greater activation of the amygdala. Finally, a subsequent memory analysis showed that the behavioral memory advantage for statements generating stronger ratings was dependent on the medial prefrontal cortex (mPFC). Together, these results both underscore consistencies in neural systems supporting emotional arousal and suggest a modulation of arousal-related encoding mechanisms when emotion is contingent on referencing personal beliefs.     

Measuring Executive Function Deficits Following Head Injury: An Application of SMS Simulation Technology

The Psychological Record - Neuropsychological tests have limited sensitivity in identifying subtle residual cognitive impairments in patients with good medical recovery from head injury and...     

Semiparametric Thurstonian Models for Recurrent Choices: A Bayesian Analysis

We develop semiparametric Bayesian Thurstonian models for analyzing repeated choice decisions involving multinomial, multivariate binary or multivariate ordinal data. Our modeling framework has multiple components that together yield considerable flexibility in modeling preference utilities, cross-sectional heterogeneity and parameter-driven dynamics. Each component of our model is specified semiparametrically using Dirichlet process (DP) priors. The utility (latent variable) component of our model allows the alternative-specific utility errors to semiparametrically deviate from a normal distribution. This generates a robust alternative to popular Thurstonian specifications that are based on underlying normally distributed latent variables. Our second component focuses on flexibly modeling cross-sectional heterogeneity. The semiparametric specification allows the heterogeneity distribution to mimic either a finite mixture distribution or a continuous distribution such as the normal, whichever is supported by the data. Thus, special features such as multimodality can be readily incorporated without the need to overtly search for the best heterogeneity specification across a series of models. Finally, we allow for parameter-driven dynamics using a semiparametric state-space approach. This specification adds to the literature on robust Kalman filters. The resulting framework is very general and integrates divergent strands of the literatures on flexible choice models, Bayesian nonparametrics and robust time series specifications. Given this generality, we show how several existing Thurstonian models can be obtained as special forms of our model. We describe Markov chain Monte Carlo methods for the inference of model parameters, report results from two simulation studies and apply the model to consumer choice data from a frequently purchased product category. The results from our simulations and application highlight the benefits of using our semiparametric approach.