Does Multitasking Impair Studying? Depends on Timing

It is often said that contemporary students frequently study while ‘multitasking’. However, this rather diffuse term encompasses situations that vary as to the whether the learner controls the pace at which educational materials are provided. On the basis of prior cognitive research, we hypothesize that this may well be a critical determinant of interference. Three studies required students to read or listen to several short historical narratives and also to engage in five to eight very short conversations (akin to an instant messaging conversation). In Experiment 1, subjects read the narratives; here, multitasking marginally increased total time spent reading the narratives, especially when it occurred at random times. However, final memory for the narratives was not significantly affected. Similar results were obtained when the narratives were presented in audio format and the learner could pause them while conversing (Experiment 2). By contrast, when audio narratives did not pause, interruptions reduced comprehension performance (Experiment 3). Copyright © 2013 John Wiley & Sons, Ltd.     

The Martyrdom Effect: When Pain and Effort Increase Prosocial Contributions

Most theories of motivation and behavior (and lay intuitions alike) consider pain and effort to be deterrents. In contrast to this widely held view, we provide evidence that the prospect of enduring pain and exerting effort for a prosocial cause can promote contributions to the cause. Specifically, we show that willingness to contribute to a charitable or collective cause increases when the contribution process is expected to be painful and effortful rather than easy and enjoyable. Across five experiments, we document this “martyrdom effect,” show that the observed patterns defy standard economic and psychological accounts, and identify a mediator and moderator of the effect. Experiment 1 showed that people are willing to donate more to charity when they anticipate having to suffer to raise money. Experiment 2 extended these findings to a non‐charity laboratory context that involved real money and actual pain. Experiment 3 demonstrated that the martyrdom effect is not the result of an attribute substitution strategy (whereby people use the amount of pain and effort involved in fundraising to determine donation worthiness). Experiment 4 showed that perceptions of meaningfulness partially mediate the martyrdom effect. Finally, Experiment 5 demonstrated that the nature of the prosocial cause moderates the martyrdom effect: the effect is strongest for causes associated with human suffering. We propose that anticipated pain and effort lead people to ascribe greater meaning to their contributions and to the experience of contributing, thereby motivating higher prosocial contributions. We conclude by considering some implications of this puzzling phenomenon. Copyright © 2011 John Wiley & Sons, Ltd.     

Team Perceived Trustworthiness in a Complex Military Peacekeeping Simulation

Antecedents to trust (propensity to trust, perceived trustworthiness) and trust behaviors were examined in relation to team performance in a complex eight-mission military peacekeeping simulation. Teams were colocated or distributed and stayed in the same or transferred to a different context at task transfer. In Experiment 1, an ability and competence factor accounted for most of the variance in perceived trustworthiness and greater perceptions of teammates' abilities/competences predicted posttransfer performance. One's perception of how others perceived one's ability/competence increased over missions. In Experiment 2, propensity to trust did not predict performance; however, trust in others' and one's own ability/competence and trust behaviors predicted performance. At task and/or context transfer, teams produced more monitoring and less cooperating language in their communication.     

Parenting and the dysregulation profile predict executive functioning in children with acquired brain injury

Background: Children with acquired brain injury (ABI) present with high rates of psychological disorders commonly accompanied by deficits in hot and cold executive functions (EFs). Impairments in EFs have been reported to precede mental health problems. Moreover, children who are vulnerable to developing mental health problems in adulthood frequently present with a dysregulation profile in childhood, characterized by impairments in cognitive, behavioral and emotional regulation. Objective: To identify profiles of behaviors associated with impairment in hot and cold EFs and compare injury factors, environmental stressors and dysregulation profile between them. Methods: A latent profile analysis was conducted with 77 children with ABI aged between 6 and 12. Injury factors, child IQ, environmental stressors and the dysregulation profile were compared between these behavioral profiles. Logistic regressions were conducted to predict profile membership. Results: Two profiles were identified: Profile M, with mild deficits (1–2 SD above the mean) in working memory and social skills, and profile C, presenting clinically significant deficits (2–3 SD above the mean) in shift, initiate, working memory, planning and social skills and mild deficits in inhibit, emotional control and task monitor. Proximal environmental stressors (dysfunctional parenting practices, parental stress, parent’s executive dysfunction, anxiety-trait, and depressive symptoms) and dysregulation symptoms predicted profile membership, whereas injury factors, child IQ and distal environmental stressors did not. Conclusion: Following ABI, children with profile C are at risk of mental health problems and present with more proximal stressors. The dysregulation profile may be useful as a proxy for risk for later mental health problems in children with ABI.     

The fatigue limits of copper single crystals cyclically deformed at constant plastic strain amplitudes

Based on systematic surface observations, experimental measurements on the fatigue limits of differently oriented copper single crystals cyclically deformed at constant plastic strain amplitudes are summarized, and an orientation dependence of the fatigue limit is sketched. It was found that the fatigue limits of crystals depend mainly upon the low-strain-amplitude dislocation structures, which are characteristic of the particular crystal orientations. When multiple-slip deformation is the main mode of deformation and ultimately produces stable lowenergy dislocation structures such as labyrinth and cell structures, the fatigue limit can be improved notably.     

Approximant phases,phason planes and domain-boundary networks in Al−Ni−Rh alloys

Structurally complicated ξ′- and ξ-phases have been found, for the first time, in as-cast Al₇₃Ni₅Rh₂₂ and Al₇₅Ni₁₅Rh₁₀ alloys. The lattice parameters of these two phases were determined by means of electron diffraction and high-resolution transmission electron microscopy (HREM). These two phases have similar orthorhombic structures but with different lattice parameters of a?=?23.2?Å, b?=?16.4?Å, c?=?12.0?Å for the ξ′-phase and a?=?20.3?Å, b?=?16.4?Å, c?=?14.8?Å for the ξ-phase. A new two-dimensional domain-boundary network has also been observed in these two phases. Domain boundaries with normals closely parallel to the [001] direction are actually phason planes represented by a translation vector of r?=(1/2)a?+(1/2τ)c in the ξ′-phase and r=±(1/2τ²) a?+(τ/2)c in the ξ-phase, whereas the newly-found wide and zigzag boundaries perpendicular to the above set were attributed from the step-like boundary structures of domains related by a translation vector of r?=(1/τ)((1/2)a?+(1/2τ)c). The structural difference between the two types of planar faults is discussed.     

Unusual stress behaviour of CeO2-doped diamond-like carbon nanofilms

CeO₂-doped diamond-like carbon (DLC) films with thicknesses of 180–200 nm were deposited by unbalanced magnetron sputtering. When the CeO₂ concentration is in the range 5–8%, the residual compressive stress of the deposited films is reduced by 90%, e.g. from about 4.1 GPa to 0.5 GPa, whereas their adhesion strength increases. These effects are attributed to the dissolution of CeO₂ within the DLC amorphous matrix and a widening interface between the DLC film and the Si substrate, respectively.     

A new orthorhombic approximant of the icosahedral Al–Cu–Fe quasicrystal

We report on the formation of a new crystalline approximant phase of the icosahedral (i-)Al–Cu–Fe quasicrystal. This phase is formed during sintering of Al-based composites reinforced with i-AlCuFeB quasicrystalline particles. The structure of this phase has been characterized by transmission electron microscopy (TEM) and high-resolution electron microscopy (HREM). TEM revealed that it is a B-centred orthorhombic phase with lattice parameters a = 1.166 nm, b = 1.195 nm and c = 3.44 nm. Its chemical composition, as determined by electron energy loss spectroscopy (EELS), is close to Al_76.9Cu_2.7Fe_20.4, with an average number of valence electrons per atom e/a of 1.92, similar to the value in all other approximants of the i-phase discovered thus far. Initial results on local atomic arrangements along one of its pseudo-5-fold axes are also presented.     

Relationship between microstrain and lattice parameter change in nanocrystalline materials

A lattice distortion, represented by microstrain and lattice parameter change, is frequently observed in nanocrystalline (NC) materials. In this letter, we develop a quantitative model to account for this phenomenon. The internal stress induced by the excess volume at grain boundaries is suggested to be the main reason for the lattice distortion. NC materials, prepared by the milling and crystallization method, were used for analysis and comparison. Theoretical calculation shows a reasonable agreement with experimental observations in the grain-size range from 5 to 100 nm. Our results indicate that there is an inherent relationship between microstrain and lattice parameter change in NC materials.