Productive Failure

This study demonstrates an existence proof for productive failure: engaging students in solving complex, ill-structured problems without the provision of support structures can be a productive exercise in failure. In a computer-supported collaborative learning setting, eleventh-grade science students were randomly assigned to one of two conditions to solve problems in Newtonian kinematics. In one condition, students solved ill-structured problems in groups followed by well-structured problems individually. In the other condition, students solved well-structured problems in small groups followed by well-structured problems individually. Finally, all students solved ill-structured problems individually. Groups who solved ill-structured problems expectedly struggled with defining and analyzing the problems, resulting in poor quality of solutions. However, despite failing in their collaborative efforts, these students outperformed their counterparts in the well-structured condition on individual near- and far-transfer measures subsequently, suggesting a latent productivity in what initially seemed to be failure.     

Productive Failure in Learning Math

When learning a new math concept, should learners be first taught the concept and its associated procedures and then solve problems, or solve problems first even if it leads to failure and then be taught the concept and the procedures? Two randomized‐controlled studies found that both methods lead to high levels of procedural knowledge. However, students who engaged in problem solving before being taught demonstrated significantly greater conceptual understanding and ability to transfer to novel problems than those who were taught first. The second study further showed that when given an opportunity to learn from the failed problem‐solving attempts of their peers, students outperformed those who were taught first, but not those who engaged in problem solving first. Process findings showed that the number of student‐generated solutions significantly predicted learning outcomes. These results challenge the conventional practice of direct instruction to teach new math concepts and procedures, and propose the possibility of learning from one's own failed problem‐solving attempts or those of others before receiving instruction as alternatives for better math learning.     

fMRI and cognitive dysfunction in schizophrenia

Despite being one of the most prevalent psychiatric conditions, SCHIZOPHRENIA is still poorly understood, with no clear objective biological marker. The advent of neuroimaging has enabled in vivo investigations to complement older techniques, and has revealed important insights. fMRI provides a means to assess the neurobiological theory that schizophrenia is caused by abnormal fronto-temporal lobe connections. In studies of language abnormalities, fMRI can explicitly assess the hypothesis that the normal lateralization of language is reversed in schizophrenia. Longitudinal fMRI studies, and studies examining the effects of medication, suggest that the technique has further potential to advance our understanding of this complex disorder.     

Using fMRI to investigate

Using fMRI, we investigated the functional organization of prefrontal cortex (PFC) as participants briefly thought of a single just-experienced item (i.e., refreshed an active representation). The results of six studies, and a meta-analysis including previous studies, identified regions in left dorsolateral, anterior, and ventrolateral PFC associated in varying degrees with refreshing different types of information (visual and auditory words, drawings, patterns, people, places, or locations). In addition, activity increased in anterior cingulate with selection demands and in orbitofrontal cortex when a nonselected item was emotionally salient, consistent with a role for these areas in cognitive control (e.g., overcoming “mental rubbernecking”). We also found evidence that presenting emotional information disrupted an anterior component of the refresh circuit. We suggest that refreshing accounts for some neural activity observed in more complex tasks, such as working memory, long-term memory, and problem solving, and that its disruption (e.g., from aging or emotion) could have a broad impact.     

生产力价值论

所谓“生产力价值论” ,是指生产过程中所形成的价值是由投入生产的各生产要素经有机组合所产生的合力即生产力所创造的。劳动价值论只承认劳动创造价值 ,忽视了劳动是劳动者与其他生产要素相结合才能进行 ,仅有劳动者单个要素 ,劳动无法进行 ,因而也无从创造价值的事实     

Optimization of Blocked Designs in fMRI Studies

Blocked designs in functional magnetic resonance imaging (fMRI) are useful to localize functional brain areas. A blocked design consists of different blocks of trials of the same stimulus type and is characterized by three factors: the length of blocks, i.e., number of trials per blocks, the ordering of task and rest blocks, and the time between trials within one block. Optimal design theory was applied to find the optimal combination of these three design factors. Furthermore, different error structures were used within a general linear model for the analysis of fMRI data, and the maximin criterion was applied to find designs which are robust against misspecification of model parameters.     

Number of events and reliability in fMRI

Relatively early in the history of fMRI, research focused on issues of power and reliability, with an important line concerning the establishment of optimal procedures for experimental design in order to maximize the various statistical properties of such designs. However, in recent years, tasks wherein events are defined only a posteriori, on the basis of behavior, have become increasingly common. Although these designs enable a much wider array of questions to be answered, they are not amenable to the tight control afforded by designs with events defined entirely a priori, and little work has assessed issues of power and reliability in such designs. We demonstrate how differences in numbers of events—as can occur with a posteriori event definition—affect reliability, both through simulation and in real data.     

Productive syntax abilities in Huntington's and Parkinson's diseases

This study examined syntactic changes in the spoken discourse of patients with Huntington's (HD) or Parkinson's disease (PD) and explored possible relationships between their syntactic changes and concomitant cognitive and motoric symptoms. Patient and control groups participated in a conversational discourse activity and completed a battery of standardized speech and cognitive tests. The HD group used shorter and fewer grammatically complete utterances than their healthy, age-matched peers, whereas there were no significant syntactic differences between PD patients and their healthy, age-matched peers or between PD and HD patients. Productive syntax abilities in HD and PD were meaningfully related to both neuropsychological and motor speech changes. These findings indicate that patients with subcortical disease, at least those with HD, may present with language production deficits and that these deficits are most likely the product of not only motor speech limitations (i.e., dysarthria) but also underlying cognitive impairments.     

国外事件相关功能磁共振成像研究概况

尽管正电子放射层描(Positron Emission Tomography,PET)在过去的15年中是主要的脑成像技术,但最近几年,功能磁共振成像(functional Magnetic Resonance Imaging,fM-RI)在认知神经科学中所具有的优势已超过PET。因为,相对于PET,fMRI具有如下优势：1)不需注射放射性同位素的无损伤成像;2)有较好的时、空问分辨率。fMRI已迅速成为研究行为神经基础的一种有力的技术工具。本文将介绍