Signal Detection Models with Random Participant and Item Effects

The theory of signal detection is convenient for measuring mnemonic ability in recognition memory paradigms. In these paradigms, randomly selected participants are asked to study randomly selected items. In practice, researchers aggregate data across items or participants or both. The signal detection model is nonlinear; consequently, analysis with aggregated data is not consistent. In fact, mnemonic ability is underestimated, even in the large-sample limit. We present two hierarchical Bayesian models that simultaneously account for participant and item variability. We show how these models provide for accurate estimation of participants’ mnemonic ability as well as the memorability of items. The model is benchmarked with a simulation study and applied to a novel data set. This research is supported by NSF grants SES-0095919 and SES-0351523, NIH grant R01-MH071418, a University of Missouri Research Leave grant and fellowships from the Spanish Ministry of Education and the University of Leuven, Belgium.     

Affective instability and suicidal ideation and behavior in patients with borderline personality disorder

This study employed an Experience Sampling Methodology (ESM) to test whether various elements of affective instability can predict future suicide ideation in patients with borderline personality disorder (BPD) and a history of recurrent suicidal behavior. Eighty-two individuals with BPD and a history of recurrent suicidal behavior were followed prospectively for one month during which time they recorded their current mood states, 6 times daily over three weeks. Accounting for a set of robust suicide risk factors in multiple regression analyses, only negative mood intensity was significantly related to intensity of self-reported suicide ideation and to number of suicidal behaviors over the past year. Other elements of affective instability examined (e.g., mood amplitude, dyscontrol, and reactivity) were not associated with future suicide ideation or with recent suicidal behavior. Affective instability in patients with BPD is highly variable from one individual to another and is characterized by high levels of intense negative mood. These negative mood states, versus other aspects of mood variability, seem to be more closely tied to the occurrence of suicidal ideation and behavior.     

The Relations of Effortful Control and Impulsivity to Children's Sympathy: A Longitudinal Study

The relations of children's (n = 214 at Time 1; M age = 6 years at Time 1) dispositional sympathy to adult-reported and behavioral measures of effortful control (EC) and impulsivity were examined in a longitudinal study including five assessments, each two years apart. Especially for boys, relatively high levels of EC and growth in EC were related to high sympathy. Teacher-reported impulsivity was generally modestly negatively related to measures of teacher-reported sympathy for boys, and a decline in impulsivity was linked to boys’ sympathy. Some findings suggested a positive association between impulsivity and children's self-reported sympathy. EC, especially when reported by teachers, was more often a unique predictor of sympathy than was impulsivity. Results generally support the argument that sympathetic individuals, especially boys, are high in EC and that EC is a more consistent predictor of sympathy than impulsivity.     

Fear and Disgust Responding to Heterogeneous Blood-Injection-Injury Stimuli: Distinctions from Anxiety Symptoms

Discrepancies exist in the literature regarding the unique role of disgust in Blood-Injection-Injury (BII) phobia. The present study attempts to clarify the discrepancy using a sample of analogue BII phobics (n = 40) and nonphobics (n = 40) who completed a series of questionnaires and were exposed to blood, mutilation, and injection pictures. The findings revealed that BII phobics reported greater disgust and contamination fears than nonphobics after controlling for anxious symptoms. When rating phobia-relevant pictures, BII phobics responded with greater fear and disgust than nonphobics after controlling for baseline anxiety scores. Furthermore, disgust was the dominant emotional response for BII phobics for the blood and mutilation stimuli. However, no differences were found between fear and disgust within the BII group when rating injection stimuli. The implications of these findings for better understanding the potential unique role of disgust in the etiology, maintenance, and treatment of BII phobia are discussed.

Disgust Sensitivity and Anxiety Disorder Symptoms: Psychometric Properties of the Disgust Emotion Scale

Recent research has implicated disgust sensitivity in the etiology of specific anxiety disorders. The Disgust Emotion Scale (DES) is a newly developed measure that was designed to improve the assessment of disgust sensitivity. The present study examines the psychometric properties of the DES. Exploratory factor analysis in Study 1 revealed five factors of disgust towards: (1) rotting foods, (2) blood and injection, (3) smells, (4) mutilation and death, and (5) small animals. The DES demonstrated adequate internal consistency and convergent validity. Significant positive correlations were found between the five factors of the DES and blood-injection-injury fears and obsessive-compulsive disorder symptoms. Confirmatory factor analysis in Study 2 provided support for the five-factor model. However, there was indication of item overlap within the factors. These findings suggest that the DES is a reliable measure of disgust as it relates to specific anxiety disorder symptoms.     

The insidious effects of failing to include design-driven correlated residuals in latent-variable covariance structure analysis

In practice, the inclusion of correlated residuals in latent-variable models is often regarded as a statistical sleight of hand, if not an outright form of cheating. Consequently, researchers have tended to allow only as many correlated residuals in their models as are needed to obtain a good fit to the data. The current article demonstrates that this strategy leads to the underinclusion of residual correlations that are completely justified on the basis of measurement theory and research design. In many designs, the absence of such correlations will not substantially harm the fit of the model; however, failure to include them can change the meaning of the extracted latent variables and generate potentially misleading results. Recommendations include (a) returning to the full multitrait-multimethod design when measurement theory implies the existence of shared method variance and (b) abandoning the evil-but-necessary attitude toward correlated residuals when they reflect intended features of the research design.     

The effects of attrition on baseline comparability in randomized experiments in education: a meta-analysis

Using meta-analysis, randomized experiments in education that either clearly did or clearly did not experience student attrition were examined for the baseline comparability of groups. Results from 35 studies suggested that after attrition, the observed measures of baseline comparability of groups did not differ more than would be expected given sampling error. The degree of either overall or differential attrition did not relate to baseline comparability, a finding that held under sensitivity analyses. Also, both overall and differential attrition rates were unrelated to posttest effect sizes. All of these analyses, however, lacked sufficient statistical power to detect small but potentially meaningful effects. Results suggest caution is warranted when applying quality scales and other blanket rules pertaining to attrition that are meant to either serve as inclusion-exclusion criteria or in scoring study quality. Much greater attention is needed to both the reporting of attrition in primary studies and to the development of conceptual and empirical models of the attrition process. These developments would aid further investigation of the relation between attrition and study outcomes.     

The neurobiology of virtual reality pain attenuation.

During the past decade, virtual reality (VR) has gained recognition as a means of attenuating pain during medical procedures. However, while investigators have examined the effects of virtual environments on level of distraction, subjective pain intensity, and brain activity, there have been only a handful of investigations into the neurobiological mechanisms associated with VR's efficacy. In an effort to explain how VR may alter pain perception and produce analgesia, as well as to guide the development of novel and improved VR pain treatments, this review aims to link the wealth of empirical data examining the neurobiology of pain to the growing field of VR. This review is separated into three main sections: (a) a brief overview of the current literature on the use of VR for the treatment of pain; (b) a review of the basic neurobiology of how pain is detected, processed, and controlled by the brain; and (c) an exploration into how current VR pain treatments may impact the pain system to produce analgesia. In addition, the future of VR for pain treatment is discussed, including how current treatments might be improved and novel ways to use VR to treat pain might be developed. Speculation on future VR interventions is based on our current understanding of how the brain processes pain and how VR appears to alter this process and produce analgesia.     

The shape of threat: simple geometric forms evoke rapid and sustained capture of attention

Previous work has indicated that simple geometric shapes underlying facial expressions are capable of conveying emotional meaning. Specifically, a series of studies found that a simple shape, a downward-pointing "V," which is similar to the geometric configuration of the face in angry expressions, is perceived as threatening. A parallel line of research has determined that threatening stimuli more readily capture attention. In five experiments, the authors sought to determine whether this preferential processing was also present for the simple geometric form of a downward-pointing "V." Using a visual search paradigm, across these experiments the authors found that, when embedded in a field of other shapes, downward-pointing V's were detected faster and, in some cases, more accurately than identical shapes pointing upward. These findings indicate that the meaning of threat can be conveyed rapidly with minimal stimulus detail. In addition, in some cases, during trials of homogeneous fields of stimuli, fields of downward-pointing V's led to slower response times, suggesting that this shape's ability to capture attention may also extend to difficulty in disengaging attention as well.