Learning without consciously knowing: Evidence from event-related potentials in sequence learning

This paper investigated how implicit and explicit knowledge is reflected in event-related potentials (ERPs) in sequence learning. ERPs were recorded during a serial reaction time task. The results showed that there were greater RT benefits for standard compared with deviant stimuli later than early on, indicating sequence learning. After training, more standard triplets were generated under inclusion than exclusion tests and more standard triplets under exclusion than chance level, indicating that participants acquired both explicit and implicit knowledge. However, deviant targets elicited enhanced N2 and P3 components for targets with explicit knowledge but a larger N2 effect for targets with implicit knowledge, revealing that implicit knowledge expresses itself in relatively early components (N2) and explicit knowledge in additional P3 components. The results help resolve current debate about the neural substrates supporting implicit and explicit learning.     

Too exhausted to remember: Ego depletion undermines subsequent event‐based prospective memory

Past research has consistently found that people are likely to do worse on high‐level cognitive tasks after exerting self‐control on previous actions. However, little has been unraveled about to what extent ego depletion affects subsequent prospective memory. Drawing upon the self‐control strength model and the relationship between self‐control resources and executive control, this study proposes that the initial actions of self‐control may undermine subsequent event‐based prospective memory (EBPM). Ego depletion was manipulated through watching a video requiring visual attention (Experiment 1) or completing an incongruent Stroop task (Experiment 2). Participants were then tested on EBPM embedded in an ongoing task. As predicted, the results showed that after ruling out possible intervening variables (e.g. mood, focal and nonfocal cues, and characteristics of ongoing task and ego depletion task), participants in the high‐depletion condition performed significantly worse on EBPM than those in the low‐depletion condition. The results suggested that the effect of ego depletion on EBPM was mainly due to an impaired prospective component rather than to a retrospective component.     

Increasing Students' Scientific Creativity: The “Learn to Think” Intervention Program

The “Learn to Think” (LTT) Intervention Program was developed for raising thinking abilities of primary and secondary school students. It has been implemented in more than 300 schools, and more than 200,000 students took part in the experiment over a 10‐year span. Several longitudinal intervention studies showed that LTT could promote the development of students' thinking ability, learning motivation, and learning strategy as well as raise academic performance in primary schools. This article describes a study of the influence and the delayed effects of LTT on the scientific creativity of secondary school students. One hundred and seven students were selected from a secondary school, 54 of them participated in the LTT every 2 weeks and the rest had not. The intervention lasted 2 years, and the delayed effect was explored half a year after terminating the intervention. The Scientific Creativity Test for Secondary School Students was used four times from pre‐test to delayed post‐test. The results indicated that the LTT did promote the development of scientific creativity of secondary school students, and the effects on the scientific creativity were not necessarily immediate, but tended to be long‐lasting.     

Do knee concentric and eccentric strength and sagittal-plane knee joint biomechanics differ between jumpers and non-jumpers in landing?

The purpose of this study was to investigate the differences of knee concentric and eccentric strength and impact related knee biomechanics between jumpers and non-jumpers during step-off landing tasks. Ten male college swimming athletes (non-jumpers) and 10 track and volleyball athletes (jumpers) were recruited to participate in two test sessions: a muscle strength testing session of concentric and eccentric extension for dominant knee joint at 60 °/s and 180 °/s and a landing testing session. The participants performed five trials of step-off landing in each of four conditions: soft and stiff landing from 0.4 m and 0.6 m landing heights. The three-dimensional kinematics and ground reaction force were recorded simultaneously during step-off landing conditions. The results showed that the jumpers had significantly greater peak knee eccentric extension and concentric flexion torques compared to the non-jumpers. No significant group effects were found for peak vertical ground reaction force and knee range of motion during landing. The jumpers had significantly greater knee contact flexion angle, maximum knee flexion angle and initial knee extension moment compared to the non-jumpers. These results suggest that these athletes adopted a favorable impact attenuation strategy that is related to the greater knee eccentric muscle strength and training.     

Knowledge and economic growth—creativity,learning and knowledge utilization

The purpose of this study is to discuss the dynamic interdependence of knowledge and economic growth. We show that the traditional economics, which treats knowledge as parameters and is mainly developed within linearized, stable and static frameworks can hardly explain the modern economic complexity. We argue that it is necessary to treat creativity, learning and knowledge utilization as endogenous dynamic processes of social and economic evolution. To handle with the complicated dynamic interdependence of wealth and knowledge accumulation, we need to apply genuine nonlinear dynamic theory. In particular, we discuss possible benefits of government's intervention in education and science to the society when the social and economic evolution is characterized of nonlinearity, instability and multi‐equilibria.     

Dynamic Regulation Responding to an External Stimulus: A Differential Equation Model

This study examines the dynamic regulation process responding to an external stimulus. The damped oscillator model has been used to describe this process. However, the model does not allow a nonzero steady state, even though the oscillations may continue and do not necessarily damp toward zero. This study introduces the driven damped oscillator model which has an additional parameter to identify different patterns of the steady state. Three methods, generalized local linear approximation, continuous time structural equation modeling, and analytic solutions of differential equations are provided to estimate model parameters. A simulation study indicates that parameters in the driven damped oscillator model are well recovered. The model is then illustrated using a data set on the daily reports of sales after a sale promotion. Potential applications and possible expansions of this model are also discussed.     

Evaluating Word in Phrase: The Modulation Effect of Emotional Context on Word Comprehension

The present study aims to explore the influence of emotional context on word evaluation. Participants were asked to read an “adjective + noun” phrase, where the adjective could be a positive or negative word, and the noun could be a positive, neutral or negative word, and then to make an emotional evaluation on the emotional tone of the target noun based on a 9-point Likert scale. In a control condition, an isolated noun was presented with no context. Results showed that positive context made the evaluation of target words bias toward positive tone, while negative context shaped the evaluation of target words toward negative tone. The modulatory effect of negative context was greater than that of positive context in shaping evaluation of emotional words with opposite valence. Moreover, the modulatory effect of emotional context was constrained by the inherent meaning of target word. The present study demonstrated the flexibility as well as the relative stability of emotional meaning of word.     

Language aptitude for pronunciation in advanced second language (L2) Learners: Behavioural predictors and neural substrates

Individual differences in second language (L2) aptitude have been assumed to depend upon a variety of cognitive and personality factors. Especially, the cognitive factor phonological working memory has been conceptualised as language learning device. However, strong associations between phonological working memory and L2 aptitude have been previously found in early-stage learners only, not in advanced learners. The current study aimed at investigating the behavioural and neurobiological predictors of advanced L2 learning. Our behavioural results showed that phonetic coding ability and empathy, but not phonological working memory, predict L2 pronunciation aptitude in advanced learners. Second, functional neuroimaging revealed this behavioural trait to be correlated with hemodynamic responses of the cerebral network of speech motor control and auditory-perceptual areas. We suggest that the acquisition of L2 pronunciation aptitude is a dynamic process, requiring a variety of neural resources at different processing stages over time.     

Hydrogen-induced cold cracking in heat-affected zone of low-carbon high-strength steel

The Y-groove cracking test by submerged arc welding was employed to study the susceptibility of a low-carbon high-strength steel to hydrogen-induced cold cracking (HICC). The morphology of hydrogen cracks was observed using an electron probe microscope. The results showed that the heat-affected zone (HAZ) has a higher susceptibility to HICC than the weld metal and that increasing heat input can improve the HICC resistance of the weldment. The intergranular microcracking is the main HICC mode at the lowest heat input condition, accompanied with some transgranular microcracks attached to complex inclusions. In combination with phase transformation behaviour in sub-zones, the effect of the phase transformation sequence is proposed to try to illustrate the fact that the fine-grained HAZ has higher probability of hydrogen cracking than the coarse-grained HAZ owing to the occurrence of hydrogen enrichment in the fine-grained HAZ after the transformation.     

A phase-field model for deformation twinning

We propose a phase-field model for modeling microstructure evolution during deformation twinning. The order parameters are proportional to the shear strains defined in terms of twin plane orientations and twinning directions. Using a face-centered cubic Al as an example, the deformation energy as a function of shear strain is obtained using first-principle calculations. The gradient energy coefficients are fitted to the twin boundary energies along the twinning planes and to the dislocation core energies along the directions that are perpendicular to the twinning planes. The elastic strain energy of a twinned structure is included using the Khachaturyan's elastic theory. We simulated the twinning process and microstructure evolution under a number of fixed deformations and predicted the twinning plane orientations and microstructures.