Mental rotation: effects of dimensionality of objects and type of task

The original studies of mental rotation estimated rates of imagining rotations that were much slower when two simultaneously portrayed three-dimensional shapes were to be compared (R. Shepard & J. Metzler) than when one two-dimensional shape was to be compared with a previously learned two-dimensional shape (Cooper and her associates). In a 2 X 2 design, we orthogonally varied dimensionality of objects and type of task. Both factors affected reaction times. Type of task was the primary determiner of estimated rate of mental rotation, which was about three times higher for the single-stimulus task. Dimensionality primarily affected an additive component of all reaction times, suggesting that more initial encoding is required for three-dimensional shapes. In the absence of a satisfactory way of controlling stimulus complexity, the results are at least consistent with the proposal that once three-dimensional objects have been encoded, their rotation can be imagined as rapidly as the rotation of two-dimensional shapes.     

The detection of fake-bad and fake-good responding on the Millon Clinical Multiaxial Inventory III

The purpose of this study was to examine the effectiveness of the 3 Modifying Indices of the Millon Clinical Multiaxial Inventory III (MCMI-III) in the detection of fake-bad and fake-good responding. The sample consisted of 160 psychiatric outpatients. Paired t tests were performed to examine the effects of instructional set (faking vs. standard instructions). As hypothesized, instructional set produced significant differences on Scale X, Scale Y, and Scale Z in both fake-bad and fake-good analyses. Single-scale cutoff scores were as effective as multiple-scale cutoffs. The overall rates of successful classification indicated moderate effectiveness and utility of the MCMI-III Modifying Indices in the detection of dissimulated responding. When base rates were varied to more closely approximate a general clinical population, overall classification accuracy increased, but identification of faking (positive predictive power) gradually eroded with declining base-rate estimates. At lower base rates of faking, MCMI-III standard cutoff points yielded a high number of false positives.     

Why are hispanics at greater risk for PTSD?

Several studies have found that Hispanic Americans have higher rates of posttraumatic stress disorder (PTSD) than non-Hispanic Caucasian and Black Americans. The authors identified predictors of PTSD symptom severity that distinguished Hispanic police officers (n=189) from their non-Hispanic Caucasian (n=317) and Black (n=162) counterparts and modeled them to explain the elevated Hispanic risk for PTSD. The authors found that greater peritraumatic dissociation, greater wishful thinking and self-blame coping, lower social support, and greater perceived racism were important variables in explaining the elevated PTSD symptoms among Hispanics. Results are discussed in the context of Hispanic culture and may be important for prevention of mental illness in the fastest growing ethnic group in the United States.     

THE EFFECT OF REPERTORY GRID SCALE SIZE AND RATING DIRECTION ON STRUCTURAL MEASURES OF DIFFERENTIATION

Previous work by Soldz and Soldz (1989) indicated that variations in repertory grid features can have a significant impact on the interpretation of the Landfield Functionally Independent Construction Score (FIC), which is a measure of cognitive differentiation. In this study, we showed that four different grid measures (FIC, Total number of zeroes, and the number of midpoint ratings used to indicate either equality or nonapplicability) can be effected by the use of a certain scale size (3-point, 7-point, 13-point), and by the direction of administration (completing the grid in a downwards direction vs. an across-wise direction). In addition, correlations between the number of zero ratings and the total FIC scores for each of the different scale sizes and directions showed evidence to support and to qualify previous work conducted by Soldz and Soldz (1989). In general, high positive correlations were found, suggesting the impact of zero ratings on FIC scores. But the magnitude of the correlations between the zero ratings and the total FIC scores varied as a function of the scale size, the direction of administration, and the meaning of the zero rating (neutrality vs. nonapplicability), raising theoretical, as well as procedural, considerations for future repertory grid research.     

Associations between childhood trauma and emotion-modulated psychophysiological responses to startling sounds: a study of police cadets

Childhood trauma may confer risk for adult psychopathology by altering emotional and physiological responses to subsequent stressors. Few studies have distinguished effects of childhood trauma from effects of current Axis I psychopathology on adult psychophysiological reactivity. The authors exposed 90 psychiatrically healthy police cadets to startling sounds under increasing threat of shock while assessing their eyeblink electromyogram (EMG), skin conductance (SC), and heart rate responses. When compared with those who did not endorse early trauma (n = 65), cadets reporting childhood trauma (n = 25) reported less positive emotion and showed greater SC responses across all threat levels. They also showed threat-dependent elevations in reported negative emotions and EMG responses. Results suggest that childhood trauma may lead to long-lasting alterations in emotional and psychophysiological reactivity even in the absence of current Axis I psychopathology.     

Vigor predicting health outcomes in a high risk occupational context

Feelings of vigor are associated with positive consequences in the work place but these relationships have not yet been assessed in a high-risk occupational context. The current study assessed the relationships between feelings of vigor on physical health symptoms, functional impairment, and depression symptoms among U.S. service members who recently returned from a combat deployment. U.S. service members were asked to complete questionnaires at 2 time points. Significant positive correlations were found between combat experiences and the 3 outcomes. Significant negative correlations were found for feelings of vigor and each outcome. Regression analyses indicated a significant effect for feelings of vigor such that higher feelings of vigor at Time 1 predicted better physical health and fewer depression symptoms at Time 2. There was no significant effect for functional impairment. Results demonstrate the potential importance of maintaining or improving feelings of vigor throughout the work day, especially for those with high risk occupations.