Intentional action: conscious experience and neural prediction

Intentional action involves both a series of neural events in the motor areas of the brain, and also a distinctive conscious experience that "I" am the author of the action. This paper investigates some possible ways in which these neural and phenomenal events may be related. Recent models of motor prediction are relevant to the conscious experience of action as well as to its neural control. Such models depend critically on matching the actual consequences of a movement against its internally predicted effects. However, it remains unclear whether our conscious experience of action depends on a precise matching process, or a retrospective inference that "I" must have been responsible for a particular event. We report an experiment in which normal subjects judged the perceived time of either intentional actions, involuntary movements, or subsequent effects (auditory tones) of these. We found that the subject's intention to produce the auditory tone produced an intentional binding between the perceived times of the subject's action and the tone. However, if the intention was interrupted by an imposed involuntary movement, followed by the identical tone, no such binding occurred. The phenomenology of intentional action requires an appropriate predictive link between intentions and effects, rather than a retrospective inference that "I" caused the effect.     

Transcranial direct-current stimulation enhances implicit motor sequence learning in persons with Parkinson's disease with mild cognitive impairment

Implicit motor sequence learning (IMSL) is affected in Parkinson's disease (PD). Research in healthy young participants shows the potential for transcranial direct-current stimulation (tDCS) over the primary motor cortex (M1) to enhance IMSL. In PD, only null effects have been reported to date. We determined concurrent, short-term, and long-term effects of anodal tDCS over M1 on IMSL, as measured by the serial reaction time (SRT) task, in persons with PD with mild cognitive impairment (MCI). Concurrent (anodal/sham tDCS intervention during the SRT task), short-term (5 min post-intervention), and long-term (1 week post-intervention) effects on IMSL were evaluated in persons with idiopathic PD (Hoehn and Yahr stage II-III) with MCI. Results of 11 persons with PD (8 men and 3 women; mean age = 77.1 years; mean disease duration = 7.7 years) showed significant IMSL in the anodal (p = .016), but not in the sham tDCS condition (p = .937). Post-hoc analyses showed that IMSL reached statistical significance at 1 week post-intervention (p < .001). Anodal tDCS over M1 exerted beneficial effects on IMSL in persons with PD with MCI, in particular one week post-intervention. Our study is the first to report a positive effect of tDCS on IMSL in PD. Further research should include a larger, more cognitively diverse sample and additional follow-up periods.     

Cognitive stimulation for healthy older adults through computer-based programs: a review of the literature / Estimulación cognitiva para personas mayores sanas mediante programas computarizados: una revisión de la literatura

Abstract

Cognitive stimulation programs are widely used as a preventive tool for cognitive decline in older adults, as they can favour positive ageing by maintaining older persons’ autonomy and preserving their cognitive functions. Because of this, and due to its potentially easy application on a large scale and at a low cost, the incorporation of technologies for the cognitive stimulation of older adults has become an area of growing interest. This review outlines the advantages and disadvantages of computer-based cognitive stimulation programs aimed at healthy older adults, focusing on aspects that influence their effectiveness and future direction. Twenty-five articles were considered, including original studies, literature reviews and meta-analyses, published between 2013 and 2017. It was concluded that there is a need to generate more randomized studies with active control groups to assess the effectiveness of cognitive stimulation through computer-based programs, as well as develop designs to establish strategies that increase older adults’ adherence and ensure their motivation to carry out these activities.     

社会拥挤对消费者感官刺激偏好的影响及机制研究

本研究通过1个田野实验和2个实验室实验探讨了社会拥挤对消费者感官刺激偏好的影响及内在机制。相比于不拥挤,社会拥挤会增加消费者对强(vs.弱)感官刺激的偏好(实验1),这一效应受感知控制缺失驱动(实验2)。权力感对社会拥挤与消费者感官刺激偏好的关系起到调节作用(实验3),即当个体的权力感较高时,社会拥挤对强感官刺激偏好的促进作用才成立;反之,这种效应便会消失。     

Infants' attention to an adult's demonstration of object functions: evidence for a comparator process

The present study was motivated by a concern with the cognitive processes that infants bring to bear on stimulation offered by adults. As previous studies have highlighted the importance of parental stimulation with objects, this study consisted of an experimental investigation of this context of stimulation. It was hypothesized that adults' actions that demonstrate the functions of toys activate a comparator process in 9-month-old infants. It was predicted that prior exposure to the toy in a stationary state would increase attention to a demonstrative action, as the comparator process requires time over and above the local processing of an event. This prediction was borne out: 9-month-olds infants' attention to the demonstration of the functions of a toy was augmented by immediate prior exposure to the toy in a stationary state. By contrast, attention to other actions which did not demonstrate specific functions was either significantly reduced by prior exposure to the toy, or unaffected. Moreover, 16-month-olds who are better able to perform a broad range of actions with objects, did not show increased attention to a demonstration of functions when prior exposure to the toy was provided. © 1998 John Wiley & Sons, Ltd.     

Probing the human brain with stimulating electrodes: The story of Roberts Bartholow’s (1874) experiment on Mary Rafferty

Roberts Bartholow’s 1874 experiment on Mary Rafferty is widely cited as the first demonstration, by direct application of stimulating electrodes, of the motor excitability of the human cerebral cortex. The many accounts of the experiment, however, leave certain questions and details unexamined or unresolved, especially about Bartholow’s goals, the nature and quality of the evidence, and the experiment’s role in the history of theory and research on localisation of function. In this article, we try to fill these gaps and to tell the full story. We describe Bartholow’s career up to 1874, review the theoretical and empirical background for the experiment, and present Bartholow’s own account of the experiment as well as those of his supporters and critics. We then present our own analysis, assess the experiment’s influence on contemporaneous scientific opinion about cortical excitability, and trace its citation record into our own time. We also review and assess ethical criticisms of Bartholow and their effects on his career, and we close by discussing the role we think the experiment deserves to play in the history of theory and research on cortical excitability.     

英语词汇记忆中关键字母法效应的条件研究——基于初一学生的干预研究

通过干预范式和中介刺激法, 随机选取112名初中一年级学生为被试, 采用一系列自编的材料和工具, 考察了关键字母法效应的三个条件:识别关键字母、提取同分异构词和提取同分异构词释义。结果表明:(1)如果要求准确的回忆, 从短期和长期看, 识别关键字母和提取同分异构词都是关键字母法效应的必要条件, 提取同分异构词释义是关键字母法效应的充分条件。(2)如果只要求大致的回忆, 从长期看, 识别关键字母是关键字母法效应的必要条件, 提取同分异构词是关键字母法效应潜在的充分条件, 而提取同分异构词释义则是关键字母法效应的充分条件。     

Neural functional organization of hallucinations in schizophrenia: Multisensory dissolution of pathological emergence in consciousness

Although complex hallucinations are extremely vivid, painful symptoms in schizophrenia, little is known about the underlying mechanisms of multisensory integration in such a phenomenon. We investigated the neural basis of these altered states of consciousness in a patient with schizophrenia, by combining state of the art neuroscientific exploratory methods like functional MRI, diffusion tensor imaging, cortical thickness analysis, electrical source reconstruction and trans-cranial magnetic stimulation. The results shed light on the functional architecture of the hallucinatory processes, in which unimodal information from different modalities is strongly functionally connected to higher-order integrative areas.     

Aggressive behavior induced by electrical stimulation in the midbrain central gray of male rats

Electrical stimulation via electrodes implanted in the lateral hypothalamus may induce intraspecific aggressive behavior. Small electrolytic lesions placed via these electrodes resulted in a five– to tenfold increase in the current threshold for aggression. Degenerating fibers were stained by means of the Fink-Heimer method and could be followed caudally to the dorsal midbrain central gray and to the mammillary bodies. A few axons could be traced rostrally to the medial septum. Aggression could be induced from 10 of 112 electrodes implanted in the central gray; the other electrodes elicited either locomotion, vocalization, jump, or “alarm-like reactions.” The morphology of the induced aggression was similar to the morphology of the hypothalamically induced aggression, though it was often accompanied with motor disturbances and was less intense. Hypothalamic stimulation was combined with simultaneous central gray stimulation in rats with electrodes both in the hypothalamus and in the central gray. Hypothalamic thresholds for aggression could be lowered by this stimulation of the central gray, even when no aggressive responses were observed during central gray stimulation alone. This suggests that, although aggression is not manifest, electrical stimulation may activate neural tissue involved in aggressive behavior. It is concluded that in rats central gray and hypothalamus are part of the same neural network mediating intraspecific aggression.     

工作记忆刷新及其训练效应——经颅直流电刺激的作用

工作记忆刷新是执行功能的重要成分之一。以往研究结合n-back任务和经颅直流电刺激（transcranial direct current stimulation ,tDCS）技术探究刷新能力,发现tDCS技术能够一定程度上增强刷新训练效果并引起大脑神经元相关活动的变化,其增强效果能够维持一定的时间,且能够迁移到其他认知任务之中。但tDCS的干预效果在各项研究中存在一定的差异性。其作用效果会受到训练任务与训练方式、电流强度、电极布局和训练时间间隔等因素的影响。未来研究可以探索tDCS结合刷新训练的最佳刺激参数,以获得最优化的干预效果。