Self-Efficacy and the Prediction of Domain-Specific Cognitive Abilities

ABSTRACT We evaluated predictors of performance in 4 specific cognitive ability domains: verbal, numerical, spatial, and mechanical. The predictors were individual differences in self-efficacy beliefs, self-enhancement tendencies, and cross-domain abilities. Our university students' beliefs about their verbal, numerical, and spatial capabilities correlated well with their actual performance on standardized tests (verbal r =.33, numerical r =.27, spatial r =.36). In contrast, the students' self-efficacy for mechanical tasks did relatively poorly in predicting mechanical test performance ( r =.10). Most interesting were two other findings: (a) The best predictor of domain performance was level of cross-domain performance by far, even for mechanical tasks, and (b) self-enhancement tendencies added to cross-domain abilities and self-efficacy beliefs in the prediction of performance. The results are discussed in terms of possible mechanisms explaining how one's score on a maximal performance task can be affected by self-efficacy beliefs and self-enhancement tendencies.     

Observing behavior and atypically restricted stimulus control

Restricted stimulus control refers to discrimination learning with atypical limitations in the range of controlling stimuli or stimulus features. In the study reported here, 4 normally capable individuals and 10 individuals with intellectual disabilities (ID) performed two-sample delayed matching to sample. Sample-stimulus observing was recorded with an eye-tracking apparatus. High accuracy scores indicated stimulus control by both sample stimuli for the 4 nondisabled participants and 4 participants with ID, and eye tracking data showed reliable observing of all stimuli. Intermediate accuracy scores indicated restricted stimulus control for the remaining 6 participants. Their eye-tracking data showed that errors were related to failures to observe sample stimuli and relatively brief observing durations. Five of these participants were then given interventions designed to improve observing behavior. For 4 participants, the interventions resulted initially in elimination of observing failures, increased observing durations, and increased accuracy. For 2 of these participants, contingencies sufficient to maintain adequate observing were not always sufficient to maintain high accuracy; subsequent procedure modifications restored it, however. For the 5th participant, initial improvements in observing were not accompanied by improved accuracy, an apparent instance of observing without attending; accuracy improved only after an additional intervention that imposed contingencies on observing behavior. Thus, interventions that control observing behavior seem necessary but may not always be sufficient for the remediation of restricted stimulus control.     

Emotional context at learning systematically biases memory for facial information

Emotion influences memory in many ways. For example, when a mood-dependent processing shift is operative, happy moods promote global processing and sad moods direct attention to local features of complex visual stimuli. We hypothesized that an emotional context associated with to-be-learned facial stimuli could preferentially promote global or local processing. At learning, faces with neutral expressions were paired with a narrative providing either a happy or a sad context. At test, faces were presented in an upright or inverted orientation, emphasizing configural or analytical processing, respectively. A recognition advantage was found for upright faces learned in happy contexts relative to those in sad contexts, whereas recognition was better for inverted faces learned in sad contexts than for those in happy contexts. We thus infer that a positive emotional context prompted more effective storage of holistic, configural, or global facial information, whereas a negative emotional context prompted relatively more effective storage of local or feature-based facial information     

Influence of In substitution and plastic deformation on AsGa-related photoluminescence in GaAs

Abstract

Low-temperature photoluminescence experiments have been carried out on semi-insulating GaAs crystals undoped or containing ～5 × 10¹⁹ In atoms cm^?3. A broad band peaking around 0·8eV is observed which is generally related to the antisite defect As_Ga. The effect of In substitution or plastic deformation is to shift this band towards higher energies by 10–25 meV. This positive energy shift is quantitatively accounted for by considering the stress fields induced by the incorporation of indium or the creation of dislocations.     

Discontinuous precipitation initiated at interphase boundaries in a Zn-rich Zn-6.3 at.% Ag alloy

Discontinuous precipitation in a two-phase Zn-rich Zn-6.3at.%Ag alloy has been studied. It has been shown that the eta/epsilon interphase boundaries have the ability to initiate discontinuous precipitation as do the eta/eta grain boundaries. The back-polishing method is used to show the interconnection between a discontinuous precipitate colony and the eta/epsilon interphase boundary. The reaction front velocity of discontinuous precipitation initiated at the eta/eta grain boundary is 12-90% higher than that of discontinuous precipitation initiated at the eta/epsilon interphase boundary under various ageing temperatures.     

Characterisation of magnesium oxide and its interface with α-Mg in Mg–Al-based alloys

Magnesium oxide (MgO) films and particles have been collected by pressurised filtration of a Mg-8.6wt%Al-0.67wt%Zn (AZ91D) alloy melt. The morphology of the oxides and their interfaces with the α-Mg phase were investigated by high-resolution transmission electron microscopy. It was found that the oxide films consisted of large numbers of sub-micrometre-sized MgO particles, and that melt shearing can effectively break up the oxide films and disperse the oxide particles. For the first time, orientation relationships (ORs) of OR I: [1?1?1]_MgO～2° from (0?0?0?1)_α-Mg and (0?1?1)_MgO?//[2?1?1?0)_α-Mg; and OR II: (1?1?1)_MgO//(1?1?0?1)_α-Mg and [0?1?1]_MgO//[1?2?1?1]_α-Mg, were observed between the MgO particles and the α-Mg matrix. The calculated Bramfitt planar disregistries were 5.5% and 2.5% for the two ORs, respectively, indicating good lattice matching between MgO and α-Mg at the interface. With the evidence of grain refinement effect observed in the sheared AZ91D magnesium alloy, the possibility of MgO particles to act as potent nucleants for heterogeneous nucleation of α-Mg grains is discussed in terms of the crystallographic criterion.     

TEM observation of oxide scale formed on a Ti–Al–Zr alloy oxidized at 360°C in alkaline steam

Ti–Al–Zr alloy has been oxidized at 360°C in alkaline steam at a pressure of 10.3?±?0.7?MPa. Cross-sectional transmission electron microscopy (TEM) observations indicated that the oxide scale of Ti–Al–Zr alloy was composed of outer and inner subscales, in which the outer layer consists of anatase-TiO₂ and the inner layer a mixture of TiO and Ti₂O. The thickness of the Ti₂O, TiO and anatase-TiO₂ were approximately 50, 100 and 400?nm, respectively. These results were confirmed by X-ray energy dispersive spectrometry (EDS) measurements. The enhanced corrosion of titanium alloys in LiOH solution is attributed to a high hexagonal Ti₂O to tetragonal TiO₂ phase transformation rate induced by the substitution of Li⁺ for Ti⁴⁺ in the oxide layer.     

Wear behaviour of a gradient surface produced by a punching process in a Cu-30 Ni alloy

The grain size variation in a gradient surface produced by a punching and recovery process on a Cu-30Ni alloy has been observed by atomic force microscopy. The friction characteristics of the gradient surface in a 3.5 wt% NaCl solution were investigated using a micro-indenter probe, a pin-on-disc type tribometer, a strain sensor and an optical microscope. The results showed that the hardness and grain size can be well represented by the Hall–Petch relationship when the gain size is more than 30?nm. The wear rate, friction coefficient and adhesive force all increase depth below the surface. These variations are attributed to a gradual increasing grain size with depth. The morphologies of the worn track were also studied to understand further the corrosive wear behaviour of gradient surfaces.     

Understanding scale-dependent yield stress of metals at micrometre scales

The mechanical softening behaviour of micrometre-scale metals (free-standing metal foils and wires) with decreasing either the geometrical or the microstructural scale (i.e. the smaller, the weaker) has recently been reported. Here, we present a mechanism-based model to understand the softening behaviour, which is based on competition between the effects of surface grain relaxation and the interior grain strengthening effect. The model describes well the yield stress of Cu foils with different ratios of the thickness to grain size.