What “Evidence” in Evidence-Based Medicine?

Topoi - The concept of evidence has gone unanalysed in much of the current debate between proponents and critics of evidence-based medicine. In this paper I will suggest that part of the...     

Leader-Follower Congruence in Need for Achievement and Work Outcomes: The Mediating Role of Leader-Member Exchange

While several studies have investigated the effect of employees’ need for achievement on their work-related outcomes, how leader-follower congruence in need for achievement is related to critical workplace outcomes remains underexplored. Integrating person-environment theory and similarity-attraction theory, this study investigated the influences of leader-follower congruence in need for achievement on followers’ job performance and job well-being through the mediating effect of leader-member exchange (LMX). Using cross-level polynomial regression and response surface analysis to analyze the data from 391 leaders and 1,124 followers, we found that leader-follower congruence in need for achievement had a positive effect on followers’ job performance and job well-being though the mediating role of LMX. The theoretical and managerial implications are further discussed.     

Validation of scales measuring attitudes and norms related to mammography screening in women veterans.

Validation of psychosocial measures for use in mammography screening research has been given inadequate attention in the literature. The authors report on the validation of 5 measures examining 4 attitudinal constructs (i.e., pros, cons, outcome expectations, and cancer worries) and 1 social influence construct (i.e., subjective norms) in a 22-item inventory. The study participants consisted of a national, randomly sampled population of women veterans (n = 2,910). After minor revision of scales, the authors found independent measures for 4 constructs: pros, cons, cancer worries, and subjective norms. The authors concluded that these scales have acceptable psychometric properties; support construct validity; and provide brief, reliable, and valid measures of attitudes toward and norms regarding mammography screening. These scales may be useful for intervention research.     

Long-term memory of haptic and visual information in older adults

ABSTRACT

The present study examined haptic and visual memory capacity for familiar objects through the application of an intentional free-recall task with three-time intervals in a sample of 78 healthy older adults without cognitive impairment. A wooden box and a turntable were used for the presentation of haptic and visual stimuli, respectively. The procedure consisted of two phases, a study phase that consisted of the presentation of stimuli, and a test phase (free-recall task) performed after one hour, one day or one week. The analysis of covariance (ANCOVA) indicated that there was a main effect only for the time intervals (F (2,71) = 12.511, p = .001, η² = 0.261), with a lower recall index for the interval of one week compared to the other intervals. We concluded that the memory capacity between the systems (haptic and visual) is similar for long retrieval intervals (hours to days).     

Lateral masking as a determinant of global dominance.

The term compound letter refers to a large (global) letter made up of small (local) letters. Reaction time to identify local letters is longer when local and global letters are different than when they are the same (the global dominance effect). The possible contribution of lateral masking to this effect was investigated. Lateral masking denotes reduced probability of identifying a stimulus when it is closely surrounded by other stimuli (as is the case for the local items in a compound stimulus). Three experiments were conducted in which the dependent measure was percentage of correct responses, rather than reaction time. In experiment 1 compound letters were used; accuracy of performance yielded evidence of global dominance such as obtained with reaction time measures. In experiments 2 and 3 the strength of lateral masking in geometrical forms was varied by varying the density of their component items. In agreement with earlier suggestions based on indirect evidence, the results directly implicated lateral masking as an important determinant of global dominance. However, lateral masking could not account fully for the experimental outcome. Factors beyond lateral masking, such as global precedence in the processing sequence or inhibitory interactions among low and high spatial-frequency components of the compound images are required in order to provide a comprehensive account of global dominance effects.     

Functional representation of 3d space in endogenous attention shifts

The aim of this study was to explore whether the attentional system, as far as an endogenous orienting is concerned, allocates resources along the sagittal plane and whether such a process is affected by, and is likely to be based on, different functional representations of 3D space in the brain. Several models make a main action-based distinction between representations of peripersonal space and of those extrapersonal space. Accordingly, if attention has to move from one representation to another, it should be possible to observe a decrease in performance during such a transition. To test this hypothesis three experiments were run in which participants performed a cued detection task. Cue stimuli were informative and were centrally located around the fixation point. Target stimuli were displayed at four different depth planes. In the first experiment, assuming that the border between the peripersonal space and the extrapersonal space was at 1 m from the observer, half the target stimuli were located in the peripersonal space and half in the extrapersonal space. The fixation point was located at 1 m from the observer. In the second experiment, the fixation point was moved at 2 m from the observer in order to rule out the possible effects of ocular motor programming. In the third experiment, in order to rule out effects related to the spatial layout of target stimuli (i.e., centre of mass effect) two target stimuli were located in the peripersonal space and six in the extrapersonal space. In all the experiments, besides a validity effect, we observed greater reaction times when attention shift was across spatial representations than when it was within the same representation. The implications for action-oriented models of attention are discussed.     

The Moderating Influence of Disorder on Coached Overreporting Using the MMPI-2-RF

Overreporting has always been a concern within psychological evaluations. The Minnesota Multiphasic Personality Inventory-2-Restructured Form (Ben-Porath &; Tellegen, 2008/2011 Ben-Porath, Y. S., &; Tellegen, A. (2008/2011). MMPI-2-RF (Minnesota Multiphasic Personality Inventory—2 Restructured Form): Manual for administration, scoring, and interpretation. Minneapolis, MN: University of Minnesota Press. [Google Scholar]) contains validity scales designed for detecting noncredible responses. In this study, 270 undergraduates were instructed to feign either schizophrenia, posttraumatic stress disorder (PTSD) or generalized anxiety disorder (GAD); some participants were coached on symptoms and validity scales. Results at both the individual protocol and mean validity scale score levels suggest that each feigned disorder moderates the effectiveness of coaching on validity scale detection. One finding of this study suggests that schizophrenia is generally more difficult to successfully feign than PTSD or GAD. Another finding suggests that the majority of individuals able to avoid detection as symptom overreporters are able to successfully endorse at least some disorder-relevant symptoms. We suggest that future research focus on the systematic exploration of other factors influencing the effectiveness of validity scales as well as the development of validity scales designed to detect the overreporting of internalizing forms of psychopathology.