数学学习困难初中生的N-back任务表现特征

目的：分析数学学习困难初中生与学习优秀初中生的核心认知过程机制差异。方法：采用N-back任务作为测查工作记忆能力的指标,分析初中42名数困生和53名数优生的表现差异。结果：两组学生在0-back任务中无显著差异,在1-back和2-back任务中的差异逐渐增大。回归分析表明2-back和1-back任务对数学成绩有显著影响。结论：1）随着认知负荷增高,数困生和数优生的表现差距增大。数学学习困难的核心认知缺损是工作记忆能力而非简单认知加工过程。2）N-back任务能有效预测数学学习成绩。     

Generalized full-information item bifactor analysis

Full-information item bifactor analysis is an important statistical method in psychological and educational measurement. Current methods are limited to single-group analysis and inflexible in the types of item response models supported. We propose a flexible multiple-group item bifactor analysis framework that supports a variety of multidimensional item response theory models for an arbitrary mixing of dichotomous, ordinal, and nominal items. The extended item bifactor model also enables the estimation of latent variable means and variances when data from more than 1 group are present. Generalized user-defined parameter restrictions are permitted within or across groups. We derive an efficient full-information maximum marginal likelihood estimator. Our estimation method achieves substantial computational savings by extending Gibbons and Hedeker's (1992) bifactor dimension reduction method so that the optimization of the marginal log-likelihood requires only 2-dimensional integration regardless of the dimensionality of the latent variables. We use simulation studies to demonstrate the flexibility and accuracy of the proposed methods. We apply the model to study cross-country differences, including differential item functioning, using data from a large international education survey on mathematics literacy.     

Colateralization of Broca's area and the visual word form area in left-handers: fMRI evidence

Language production has been found to be lateralized in the left hemisphere (LH) for 95% of right-handed people and about 75% of left-handers. The prevalence of atypical right hemispheric (RH) or bilateral lateralization for reading and colateralization of production with word reading laterality has never been tested in a large sample. In this study, we scanned 57 left-handers who had previously been identified as being clearly left (N = 30), bilateral (N = 7) or clearly right (N = 20) dominant for speech on the basis of fMRI activity in the inferior frontal gyrus (pars opercularis/pars triangularis) during a silent word generation task. They were asked to perform a lexical decision task, in which words were contrasted against checkerboards, to test the lateralization of reading in the ventral occipitotemporal region. Lateralization indices for both tasks correlated significantly (r = 0.59). The majority of subjects showed most activity during lexical decision in the hemisphere that was identified as their word production dominant hemisphere. However, more than half of the sample (N = 31) had bilateral activity for the lexical decision task without a clear dominant role for either the LH or RH, and three showed a crossed frontotemporal lateralization pattern. These findings have consequences for neurobiological models relating phonological and orthographic processes, and for lateralization measurements for clinical purposes.     

A Sociocultural Approach to Narcissism: The Case of Modern China

Using large Internet samples, we examined the possible influence of sociodemographic factors on the Chinese self‐concept and in particular, on the level of narcissism. We found that (i) younger persons are more narcissistic than older ones; (ii) persons from higher socioeconomic classes are more narcissistic than those from lower socioeconomic classes; (iii) persons from only‐child families are more narcissistic than those from families with multiple children; (iv) persons from urban areas are more narcissistic than those from rural areas; and (v) individualistic values are predictive of individual differences in narcissism. The findings suggest that sociocultural changes contribute to the rise of narcissism in China. Copyright © 2011 John Wiley & Sons, Ltd.     

Career adaptability,job search self-efficacy and outcomes: A three-wave investigation among Chinese university graduates

Based on career construction theory, the current research examined the role of career adaptability in Chinese university graduates' job search process (N = 270). Results from a three-wave survey study showed that the four dimension of career adaptability (measured at wave 1) correlated positively with university graduates' job search self-efficacy (measured at wave 2) and their employment status (measured at wave 3). Among graduates who became employed, career adaptability dimensions also predicted positively their person–environment (P–E) fit perceptions (measured at wave 3). The results further showed that with the effects of demographics (gender, age, education level and major) and family background (family economical status and parental education) controlled for, when putting the four dimensions of career adaptability together, career concern and career control served as the strongest predictors for job search self-efficacy, which further mediated the positive effects of these two dimensions on employment status. In addition, career control also had indirect effect on P–E fit through the mediation of job search self-efficacy. Additional analyses using the global indicator of career adaptability also supported this mediation model such that career adaptability significantly predicted employment status and P–E fit, with these relations mediated by job search self-efficacy. These findings carry implications for research on career construction theory, as well as career education and career counseling practices.     

Microstructure and martensitic transformation behaviors of a Ti–Ni–Hf–Cu high-temperature shape memory alloy ribbon

The Ti₃₆Ni₄₁Hf₁₅Cu₈ melt-spun ribbon undergoes a B2 ? B19′ transformation upon cooling and heating. When the Ti₃₆Ni₄₁Hf₁₅Cu₈ melt-spun ribbon is annealed at 873 K for 1 h, the spherical (Ti, Hf)₂Ni particles with a diameter of 20–40 nm precipitate in the grain interior. The fine (Ti, Hf)₂Ni precipitates improve the stability of phase transformation temperatures and cause martensite domains, with (001) compound twins in three orientations dominant instead of (011) type I twins. {111}-, {113}- and (001)//{111}-type boundaries are observed among these martensite domains. When the (Ti,Hf)₂Ni precipitates coarsen, (011) type I twins become main martensite structures in the ribbon annealed at 973 K for 1 h.     

Contextual knowledge reduces demands on working memory during reading

An experiment is reported in which young, middle-aged, and older adults read and recalled ambiguous texts either with or without the topic title that supplied contextual knowledge. Within each of the age groups, the participants were divided into those with high or low working memory (WM) spans, with available WM capacity further manipulated by the presence or absence of an auditory target detection task concurrent with the reading task. Differences in reading efficiency (reading time per proposition recalled) between low WM span and high WM span groups were greater among readers who had access to contextual knowledge relative to those who did not, suggesting that contextual knowledge reduces demands on WM capacity. This position was further supported by the finding that increased age and attentional demands, two factors associated with reduced WM capacity, exaggerated the benefits of contextual knowledge on reading efficiency. The relative strengths of additional potential predictors of reading efficiency (e.g., interest, effort, and memory beliefs), along with knowledge, WM span, and age, are reported. Findings showed that contextual knowledge was the strongest predictor of reading efficiency even after controlling for the effects of all of the other predictors.     

Variable solutions to the same problem: aberrant practice effects in object naming by three aphasic patients

Although deficits in confrontation naming are a common consequence of damage to the language areas of the left cerebral hemisphere, some patients with aphasia show relatively good naming ability. We measured effects of repeated practice on naming latencies for a set of pictured objects by three aphasic patients with near-normal naming ability and by neurologically intact young and older adults. While the non-injured participants showed a systematic reduction in overall mean latencies and reduced trial-to-trial latency variability, the aphasic patients did not. Examination of the latency distributions suggests that successful naming by aphasic patients may come about by different underlying operations.     

Career adaptability and proactive work behaviour: A relational model

Research on career adaptability has found that it helps people adapt at work. However, in modern uncertain and dynamic work environment, people need to perform proactive work behaviour to ensure individual effectiveness. Thus, to understand how career adaptability advances career development, it is necessary to examine its influences on proactive work behaviour. Adopting a relational perceptive, the current paper proposed leader-member exchange and perceived coworker support as the mediators and future work self salience as a moderator. Data were collected with a three-wave design in China. Findings largely supported the propositions, albeit showing partial mediation effects. This study extends existing understandings of the role of career adaptability at work, provides a new perspective about why it influences work-related outcomes and enriches the knowledge about the antecedents of proactive work behaviour.     

SEPARATING SPEED FROM AUTOMATICITY IN A PATIENT WITH FOCAL BRAIN ATROPHY

Abstract— Automatic processes are characterized as being rapid, as requiring little attentional effort, and as obligatory (once initialed, the activity cannot be inhibited or controlled). In contrast, controlled processes are slower, require attention, and are non-obligatory. This distinction appears in the Stroop effect the interference that appears when a person tries to name the color of the ink in which a word is printed when the word spells the name of a different color. This effect has historically been attributed to an automatic reading of the color name interfering with the slower, less automatic, naming of the ink color (MacLeod, 1991, Stroop, 1935). In this report, we describe a patient with focal brain atrophy whose speed of reading was no faster than his speed of naming colors, but who still showed the classic Stroop effect. This finding critically challenges the traditional identification of automaticity with processing speed.