Understanding and estimating the power to detect cross-level interaction effects in multilevel modeling

[Correction Notice: An Erratum for this article was reported in Vol 97(5) of Journal of Applied Psychology (see record 2012-18665-001). The article contained production-related errors in a number of the statistical symbols presented in Table 1, the Power in Multilevel Designs section, the Simulation Study section, and the Appendix.] Cross-level interaction effects lie at the heart of multilevel contingency and interactionism theories. Researchers have often lamented the difficulty of finding hypothesized cross-level interactions, and to date there has been no means by which the statistical power of such tests can be evaluated. We develop such a method and report results of a large-scale simulation study, verify its accuracy, and provide evidence regarding the relative importance of factors that affect the power to detect cross-level interactions. Our results indicate that the statistical power to detect cross-level interactions is determined primarily by the magnitude of the cross-level interaction, the standard deviation of lower level slopes, and the lower and upper level sample sizes. We provide a Monte Carlo tool that enables researchers to a priori design more efficient multilevel studies and provides a means by which they can better interpret potential explanations for nonsignificant results. We conclude with recommendations for how scholars might design future multilevel studies that will lead to more accurate inferences regarding the presence of cross-level interactions. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

"Understanding and estimating the power to detect cross-level interaction effects in multilevel modeling": Correction to Mathieu, Aguinis, Culpepper, and Chen (2012)

Reports an error in "Understanding and Estimating the Power to Detect Cross-Level Interaction Effects in Multilevel Modeling" by John E. Mathieu, Herman Aguinis, Steven A. Culpepper and Gilad Chen (Journal of Applied Psychology, Advanced Online Publication, May 14, 2012, np). The article contained production-related errors in a number of the statistical symbols presented in Table 1, the Power in Multilevel Designs section, the Simulation Study section, and the Appendix. All versions of this article have been corrected. (The following abstract of the original article appeared in record 2012-12670-001.) Cross-level interaction effects lie at the heart of multilevel contingency and interactionism theories. Researchers have often lamented the difficulty of finding hypothesized cross-level interactions, and to date there has been no means by which the statistical power of such tests can be evaluated. We develop such a method and report results of a large-scale simulation study, verify its accuracy, and provide evidence regarding the relative importance of factors that affect the power to detect cross-level interactions. Our results indicate that the statistical power to detect cross-level interactions is determined primarily by the magnitude of the cross-level interaction, the standard deviation of lower level slopes, and the lower and upper level sample sizes. We provide a Monte Carlo tool that enables researchers to a priori design more efficient multilevel studies and provides a means by which they can better interpret potential explanations for nonsignificant results. We conclude with recommendations for how scholars might design future multilevel studies that will lead to more accurate inferences regarding the presence of cross-level interactions. (PsycINFO Database Record (c) 2012 APA, all rights reserved).     

Apraxia and Alzheimer’s Disease: Review and Perspectives

Apraxia is one of the cognitive deficits that characterizes Alzheimer’s disease. Despite its prevalence and relevance to diagnosing Alzheimer’s disease, this topic has received little attention and is without comprehensive review. The review herein is aimed to fill this gap by first presenting an overview of the impairment caused in different clinical situations: pantomime of tool use, single tool use, real tool use, mechanical problem solving, function and manipulation knowledge tasks, and symbolic/meaningless gestures. On the basis of these results, we then propose alternative interpretations regarding the nature of the underlying mechanisms impaired by the disease. Also presented are principal methodological issues precluding firm conclusions from being drawn.     

Interactive Effects of Team and Task Shared Mental Models as Related to Air Traffic Controllers' Collective Efficacy and Effectiveness

We assessed the influence of task and team shared mental models (SMMs) on team effectiveness, as mediated by collective efficacy. Using a sample of 422 air traffic controllers representing 43 Navy teams from land-based towers, task SMMs exhibited a significant linear relationship with team effectiveness, whereas team SMMs did not. Moreover, the interaction of team and task SMMs was positively related to team effectiveness. Collective efficacy was found to mediate the relationship between task SMMs (but not team SMMs or their interaction) and team effectiveness. Results are discussed in terms of the complex nature of SMMs and team outcomes.     

Selective attention to facial identity and emotion in children

Three age groups of participants (6–8 years, 9–11 years, adults) performed two tasks: A face recognition task and a Garner task. In the face recognition task, the participants were presented with 20 faces and then had to recognize them among 20 new faces. In the Garner tasks, the participants had to sort, as fast as possible, the photographs of two persons expressing two emotions by taking into account only one of the two dimensions (identity or emotion). When the sorting task was on one dimension, the other dimension was varied either in a correlated, a constant or an orthogonal way in distinct subsessions. The results indicated an increase in face recognition abilities. They also showed an interference of identity in the emotion-sorting task that was similar in the three age groups. Nevertheless, an interference of emotion in the identity-sorting task was significant only for the children and was more important for the youngest group. These observations suggest that the development in face recognition ability rests on the development of the ability to attend selectively to identity, without paying attention to emotional facial expression.     

Helping Teams to Help Themselves: Comparing two Team‐Led Debriefing Methods

Team‐based structures have become more widely used in organizations. Therefore, it is important for team members to perform well in their current team and to build skills and enthusiasm for working on future teams. This study examined team debriefing, an intervention in which team members reflect on recent experiences to prepare for subsequent tasks. Prior researchers have shown that facilitated team debriefs work, but they have not examined how to enable teams to conduct their own debriefs or studied how debriefs affect individual level outcomes. Therefore, we compared 2 team‐led debriefing techniques: (a) an unguided debrief and (b) a guided debrief designed to incorporate lessons learned from prior debriefs. We collected data from 174 business students who were members of 35 teams from 9 sections of a Strategic Management course. Class sections were randomly assigned to one of the debriefing conditions, and teams completed 4 business cases over 10 weeks. A multilevel design was employed and a multistage model building approach was used to test the hypotheses using hierarchical linear modeling techniques. Results of this cluster randomized, quasi‐experimental design suggest that the team‐led guided debrief intervention resulted in superior team processes as compared to the unguided debriefing method. Team processes, in turn, related significantly to greater team performance and increased individual readiness for teamwork and enthusiasm for teaming. Implications for future research and practice are discussed.     

The role of context in remembering familar persons: insights from semantic dementia

Semantic dementia (SD) is a progressive condition characterized by an insidious and gradual breakdown in semantic knowledge. Patients suffering from this condition gradually lose their knowledge of objects and their attributes, concepts, famous persons, and public events. In contrast, these patients maintain a striking preservation of autobiographical memory. The aim of the present study was to examine in a patient suffering from SD the role of context in the ability to recall knowledge of familiar persons. In an experiment, patient J.M. was asked to name and identify familiar persons that appeared on family photographs from recent and remote periods of her life. In the first experimental condition, the pictures represented personally familiar persons present in a specific spatial and temporal context. In a second experimental condition, the pictures showed personally familiar persons who were presented without any specific episodic context. Results indicate that the patient was able to name and identify familiar persons irrespective of the context of presentation (with/without context) and of the time period (recent/remote). No temporal gradient was found using family photographs. Finally, in contrast with familiar persons, J.M. presented a severe anomia for celebrities. Results are discussed in light of recent research in the field.     

Investigating linear and interactive effects of shared mental models on safety and efficiency in a field setting

Linkages between 2 types of shared mental models (SMMs)--that is, positional-goal interdependencies and cue-strategy associations--and effectiveness in an air traffic control environment were investigated. Two types of SMMs were expected to contribute uniquely, as well as interact, to predict tower safety and efficiency. Using SMM data from 306 air traffic controllers, and corresponding archival efficiency and safety measures for 47 airports, the authors found no significant linear relationships between SMMs and either outcome measure. However, the 2 SMMs interacted with one another to predict both outcomes. Results are discussed in terms of the importance of measuring multiple types of SMMs, the examination of complex relationships, and the importance of indexing decisions.     

Delay-dependent working memory impairment in young-adult and aged 5-HT1BKO mice as assessed in a radial-arm water maze

Serotonin (5-HT) plays a modulatory role in mnemonic functions, especially by interacting with the cholinergic system. The 5-HT1B receptor is a key target of this interaction. The 5-HT1B receptor knockout mice were found previously to exhibit a facilitation in hippocampal-dependent spatial reference memory learning. In the present study, we submitted mice to a delayed spatial working memory task, allowing the introduction of various delays between an exposure trial and a test trial. The 5-HT1BKO and wild-type mice learned the task in a radial-arm water maze (returning to the most recent presented arm containing the escape platform), and exhibited a high level of performance at delays of 0 and 5 min. However, at the delay of 60 min, only 5-HT1BKO mice exhibited an impairment. At a delay of 90 min, all mice were impaired. Treatment by scopolamine (0.8 mg/kg) induced the same pattern of performance in wild type as did the mutation for short (5 min, no impairment) and long (60 min, impairment) delays. The 22-month-old wild-type and knockout mice exhibited an impairment at short delays (5 and 15 min). The effect of the mutation affected both young-adult and aged mice at delays of 15, 30, and 60 min. Neurobiological data show that stimulation of the 5-HT1B receptor inhibits the release of acetylcholine in the hippocampus, but stimulates this in the frontal cortex. This dual function might, at least in part, explain the opposite effect of the mutation on reference memory (facilitation) and delay-dependent working memory (impairment). These results support the idea that cholinergic-serotonergic interactions play an important role in memory processes.     

Opposed left and right brain hemisphere contributions to sexual drive: a multiple lesion case analysis

Brain topographical studies of normal men have have shown that sexual excitation is asymmetric in the brain hemispheres. Group studies of patients with unilateral epileptic foci and other studies of patients with unilateral brain lesions have come to the same conclusion. The present study reviewed previously published single case reports of patients with frank hypo or hypersexuality subsequent to a unilateral brain lesion. Hyposexual patients tended to have left hemisphere lesions (primarily of the temporal lobe), and hypersexual patients tended to have right hemisphere lesions (primarily of the temporal lobe) (p < 0.05). We interpret this double dissociation as part of a more general phenomenon of psychic tone similarly dissociated with regard to hemispheric control, including mood, psychomotor baseline, speech rate, and even immunity. The behavioral significance of this psychic tone is to modulate approach versus avoidance behavior.