Muscular Activation Pattern of Bilateral Extensors Response to Asymmetric Hand Lifting During Trunk Flexion–extension Performance

The authors' purpose was to test the effect of asymmetric hand lifting on muscular activation patterns of 3 bilateral extensors. Eighteen male university students without back pain were volunteered. Each performed flexion–extension randomly with conditions of right lifting, left lifting, and nonlifting. Surface electromyography from bilateral thoracic, lumbar erector spinae, and hamstring was recorded. The cross-correlation and relative intensity in paired muscles of bilateral extensors was calculated in flexion as well as extension period. The results showed that the cross-correlation coefficient was decreased and the phase lag as well as the relative intensity of bilateral extensors was increased significantly in thoracic level. The phase lag as well as the relative intensity of bilateral extensors was increased significantly in lumbar level. It was concluded that asymmetric lifting has a significant effect on muscular activation of bilateral extensors in thorax level, which causes the ipsilateral extensor to activate larger and longer. Asymmetric lifting also has some effect on muscular activation of bilateral extensors in lumbar level but with less extent than in thorax level, which causes contralateral extensor to activate larger and longer. Asymmetric lifting seems to have no significant effect on muscular activation of bilateral hamstring.     

The fate of completed intentions

The goal of this research was to determine whether and how people deactivate prospective memory (PM) intentions after they have been completed. One view proposes that PM intentions can be deactivated after completion, such that they no longer come to mind and interfere with current tasks. Another view is that now irrelevant completed PM intentions exhibit persisting activation, and continue to be retrieved. In Experiment 1, participants were given a PM intention embedded within the ongoing task during Phase 1, after which participants were told either that the PM task had been completed or suspended until later. During Phase 2, participants were instructed to perform only the ongoing task and were periodically prompted to report their thoughts. Critically, the PM targets from Phase 1 reappeared in Phase 2. All of our measures, including thoughts reported about the PM task, supported the existence of persisting activation. In Experiment 2, we varied conditions that were expected to mitigate persisting activation. Despite our best attempts to promote deactivation, we found evidence for the persistence of spontaneous retrieval in all groups after intentions were completed. The theoretical and practical implications of this potential dark side to spontaneous retrieval are discussed.     

Semantic computations of truth based on associations already learned

This article sets forth a detailed theoretical proposal of how the truth of ordinary empirical statements, often atomic in form, is computed. The method of computation draws on psychological concepts such as those of associative networks and spreading activation, rather that the concepts of philosophical or logical theories of truth. Axioms for a restricted class of cases are given, as well as some detailed examples.     

任务定势对自动语义激活过程调节作用的ERP研究

摘要：本研究致力于探讨自上而下的因素对自动加工的影响。选取的自上而下因素为任务定势,自动加工过程为自动语义激活过程。研究采用ERPs技术,中文词汇为刺激,利用掩蔽启动范式,采用反应时和N400为指标。实验任务有三个：对问号后出现的词进行生物/非生物的词汇分类判断;对圆圈后出现的词进行是否含上下结构的字的词汇结构判断;对带“*”的词进行真词/假词判断。研究发现先前完成的任务形成的任务定势会对随后的自动语义激活过程产生调节作用：在词汇分类判断任务后,掩蔽启动刺激对靶刺激产生启动效应。在词汇结构判断任务后,掩蔽启动刺激对靶刺激没产生显著的启动效应。     

刻板印象激活效应对社会分类的影响

采用改进的flanker范式,探讨了刻板印象激活效应对社会分类的影响,并考察了匹配刺激出现概率对刻板印象激活效应影响社会分类的调节作用。实验一发现,性别刻板印象激活后,按性别分类时,匹配刺激中和不匹配刺激中面孔分类反应时之间的差异是显著的,但按年龄分类时,二者间的差异不显著。实验二表明,匹配刺激出现概率为80%时和50%时,匹配刺激中和不匹配刺激中面孔分类反应时之间的差异是显著的;但当匹配刺激出现概率为20%时,二者间的差异不显著。结果表明,刻板印象激活效应对与该刻板印象对应的社会分类有显著的影响,对与该刻板印象无关社会分类不会产生影响。刻板印象激活效应对社会分类的影响受匹配刺激出现概率的调节。     

Towards a computational theory of experience

A standing challenge for the science of mind is to account for the datum that every mind faces in the most immediate – that is, unmediated – fashion: its phenomenal experience. The complementary tasks of explaining what it means for a system to give rise to experience and what constitutes the content of experience (qualia) in computational terms are particularly challenging, given the multiple realizability of computation. In this paper, we identify a set of conditions that a computational theory must satisfy for it to constitute not just a sufficient but a necessary, and therefore naturalistic and intrinsic, explanation of qualia. We show that a common assumption behind many neurocomputational theories of the mind, according to which mind states can be formalized solely in terms of instantaneous vectors of activities of representational units such as neurons, does not meet the requisite conditions, in part because it relies on inactive units to shape presently experienced qualia and implies a homogeneous representation space, which is devoid of intrinsic structure. We then sketch a naturalistic computational theory of qualia, which posits that experience is realized by dynamical activity-space trajectories (rather than points) and that its richness is measured by the representational capacity of the trajectory space in which it unfolds.     

The behavioral activation for depression scale-short form: development and validation

Following a landmark component analysis of cognitive therapy by Jacobson and colleagues (1996), there has been renewed interest in behavioral activation (BA) treatments for depression. The Behavioral Activation for Depression Scale (BADS) was developed to measure when and how clients become activated over the course of BA treatment. Multiple studies have provided initial support for the BADS but have also identified several potential problems. Four studies were conducted in order to develop and provide initial evaluation of a short form of the BADS that addresses these concerns. In Study 1, an exploratory factor analysis was conducted on existing data using the original BADS in order to identify items to retain for the short form. In Study 2, these items were administered to a new sample of college students with elevated depressive symptoms and were analyzed with exploratory and confirmatory factor analyses. Study 3 examined the predictive validity of the BADS-SF by examining the BADS-SF and depression scores in relation to activity tracking and reward-value ratings over the course of 1 week. Study 4 examined BADS-SF data over the course of BA treatment for two clients using cross-lagged panel correlations. With one client, changes in BADS-SF scores led changes in depression scores by 1 week, whereas with the other client changes in BADS-SF and depression scores occurred concurrently. These studies resulted in a nine-item scale that demonstrated good item characteristics as well as acceptable internal consistency reliability, construct validity, and predictive validity.     

The effect of attending to motor overflow on its voluntary inhibition in young and older adults

Motor overflow refers to involuntary movement or muscle activity coinciding with voluntary movement. We examined whether 16 young adults (18-30 years) and 16 older adults (50-80 years) could voluntarily inhibit overflow. Participants performed a finger pressing task, exerting 50% of their maximal force. Overflow was concurrently recorded in the non-task hand. In the first condition, participants were not made aware of their motor overflow. Then participants, though informed of it, were asked to ignore their overflow. Finally, participants were requested to inhibit overflow with, and then without visual feedback, or vice versa. Overflow was exacerbated when older adults were unaware of it, and was reduced once they were informed. For young adults there was no significant difference between these conditions. Both Age Groups could significantly reduce overflow when so requested, independent of visual feedback. Thus motor overflow can be modulated by higher order cognitive control with directed attention.     

Neuroimaging and neuroenergetics: Brain activations as information-driven reorganization of energy flows

There is increasing focus on the neurophysiological underpinnings of brain activations, giving birth to an emerging branch of neuroscience – neuroenergetics. However, no common definition of “brain activation” exists thus far. In this article, we define brain activation as the information-driven reorganization of energy flows in a population of neuroglial units that leads to an overall increase in energy utilization in this population. On the basis of this definition, the key aspects of modern biochemical and biophysical approaches to neuroenergetics are considered from the perspective of the links between these approaches within the context of the free energy minimization principle and the neurophysiological conception of deviance detection. In this light, we consider brain basal activity as subserving internal representations of the environment (predictive coding), and brain activation as reflecting the level of deviance from predictive coding.     

与当前任务无关的规则对自动反应激活过程的影响

摘要：本研究致力于探讨自上而下的任务因素对自动反应激活过程的影响。研究包含两个实验,采用掩蔽启动范式,选取字母和数字作为刺激,任务因素为与当前任务无关的处于预备状态的任务规则。实验一初步验证了与当前无关的处于预备状态的任务规则可以影响自动反应激活过程;实验二进一步证明了这种影响具有广泛性,即与当前无关的任务规则所设定的所有刺激系列都可以影响当前任务中的反应启动过程。研究总结论为：与当前任务目的无关、且存在自动刺激-反应联结的其他任务规则也能通过对被掩蔽的启动刺激反应的调节来影响对靶刺激的反应,从而影响启动效应的发生。