Episodic memory effects of gamma frequency precuneus transcranial magnetic stimulation in Alzheimer's disease: A randomized multiple baseline study

Episodic memory decline is the prominent neuropsychological feature of typical Alzheimer's Disease (AD), for which current treatments have a limited clinical response. Recently, gamma entrainment therapy has been used as a non-invasive treatment in AD, providing evidence that it may have the potential to alleviate brain pathology and improve cognitive function in AD patients. At the same time, the precuneus (PC) has been recognized as a key area involved in AD related memory deficits and as a key node of the Default Mode Network. This study aimed to investigate the effectiveness of a 40 Hz Transcranial Magnetic Stimulation (TMS) intervention, delivered bilaterally to the precuneus for 10 days, in improving the patients' episodic memory performance. Secondary outcome variables investigated included general cognitive function, semantic and spatial memory, as well as attention and executive function. A concurrent multiple baseline design across five cases was employed. Four patients completed the study. Visual analysis combined with effect size indices were used to evaluate changes across phases. An increase in the average level of immediate recalled words was observed in three out of four patients. Effect size indices indicated significant improvement of attention skills in two patients. No treatment effect was observed for semantic and visual memory, or for executive function. An immediate treatment effect was observed in all patients' general cognitive function as assessed with the Alzheimer's Disease Assessment Scale (mean reduction of 5 points), which was maintained and improved further three months post-treatment. The neuropsychological evaluations indicated improved performance three months post-treatment in immediate and delayed recall, attention, phonological verbal fluency, anxiety, and neuropsychiatric symptoms. This study provides preliminary evidence for the efficacy of a novel non-pharmacological treatment using gamma-band TMS in addressing cognitive dysfunction in AD.     

Modeling variability of force during isometric contractions of the quadriceps femoris

The authors modeled variability of force during continuous isometric contractions of the quadriceps femoris. Twenty adults (aged 25 +/- 6 years old) performed isometric leg extensions. Target forces were 11 percentages of maximum voluntary contraction (%MVC), ranging from 2 to 95%, and 5 absolute levels, from 25 to 225 N. The authors used standard deviation of absolute force, coefficient of variation, and signal-to-noise ratio as measures of variability. The results suggested a nonlinear relationship between variability and level of force, which could best be expressed as %MVC and not as absolute force. Variability for continuous isometric contractions was described best by a sigmoidal logistic function. The sigmoidal pattern of variability as a function of %MVC is consistent with physiological mechanisms.     

Force Control Is Greater in the Upper Compared With the Lower Extremity

The authors investigated whether force control is similar between the upper and lower limbs and between contractions that involve 1 or 2 joints. Six volunteers (27.5 ± 11.2 years of age) attempted to produce consistent discrete rapid force responses of 30, 60, and 90 N by using 6 different body postures, 3 with the upper and 3 with the lower limb. One of the postures for each limb involved 2 joints. The standard deviation of peak force and impulse (aggregate of the force-time curve) was significantly greater (?25%) for the lower limb than for the upper limb (p < .01). Contractions that involved 1 or 2 joints within a limb had similar variability. Therefore, the upper limb might have better control of force than the lower limb because of its extensive use in fine motor tasks in daily activities.     

View dependence in scene recognition after active learning

Human spatial encoding of three-dimensional navigable space was studied, using a virtual environment simulation. This allowed subjects to become familiar with a realistic scene by making simulated rotational and translational movements during training. Subsequent tests determined whether subjects could generalize their recognition ability by identifying novel-perspective views and topographic floor plans of the scene. Results from picture recognition tests showed that familiar direction views were most easily recognized, although significant generalization to novel views was observed. Topographic floor plans were also easily identified. In further experiments, novel-view performance diminished when active training was replaced by passive viewing of static images of the scene. However, the ability to make self-initiated movements, as opposed to watching dynamic movie sequences, had no effect on performance. These results suggest that representation of navigable space is view dependent and highlight the importance of spatial-temporal continuity during learning.     

The effects of prior knowledge and text structure on comprehension processes during reading of scientific texts

The aim of the present study was to investigate the effects of prior knowledge and text structure on cognitive processes during comprehension of scientific texts. To investigate the processes online, we used a think-aloud methodology in Experiment 1 and a reading time methodology in Experiment 2. In both experiments, we obtained offline comprehension measures and measures of individual differences in working memory and need for cognition. Across the two experiments, the results indicated that readers adjust their processing as a function of the interaction between prior knowledge and text structure. In particular, adjustments in theactual processes that take place during reading were observed for readers who had erroneous prior knowledge,but only when they read a text that was structured to explicitly refute this prior knowledge. Furthermore, the results showed that readers' memory for the text was affected by differences in their prior knowledge, independently of text structure. These findings contribute to our understanding of the relation between different factorsthat are associated with comprehension of scientific texts and have implications for theories of comprehension and conceptual change.     

Age-Associated Differences in Positional Variability Are Greater With the Lower Limb

The authors’ purpose was to determine the interaction of age and limb used on positional variability at different loads. Eleven young adults and 10 older adults were asked to accurately match and maintain a horizontal target line with 5° abduction of their index finger and 5° dorsiflexion of their ankle for 20 s at loads ranging from 2 to 50% of the maximal load that could be lifted with each limb. The visual gain was kept constant at 1° (visual angle). Positional variability was greater in older adults for both limbs, nonetheless age-associated differences were greater for the ankle dorsiflexion task compared with the abduction of the index finger task. In addition, we found that, independent of age, motor output variability was greater with the lower limb. These results provide novel evidence that older adults may exhibit greater impairments in motor control with the foot compared with the finger. Furthermore, these findings support the idea, using a different task than previous literature, that the lower limb has greater motor output variability than the upper limb.     

Source credibility and the processing of refutation texts

The knowledge revision components framework (KReC) outlines the basic comprehension processes and text factors that can be accentuated to increase the potential for knowledge revision during reading. The goal of the present study was to explore source credibility as one such text factor. In Experiment 1, we established the utility of a set of refutation texts in influencing knowledge revision. Participants read ten refutation and ten control texts. The participants had faster reading times and higher posttest scores for the refutation than for the control texts, providing evidence for knowledge revision. In Experiment 2, we examined the influence of source credibility under normal reading conditions. Participants read 20 refutation texts, ten with high-credibility and ten with low-credibility sources. The reading times and posttest scores suggested that knowledge revision unfolded successfully, independent of credibility. Using the same texts, in Experiment 3 we examined the influence of direct instructions that made the credibility of the source of information more salient. When the credibility of the source was made salient, the revision process was disrupted in the low-credibility condition, as evidenced by slower reading times and lower posttest scores than in the high-credibility condition. The results add to our understanding of the factors that constrain knowledge revision during the reading of refutation texts, and are discussed in the context of the extant literature and KReC.     

Revisiting the simple view of reading

Background Reading component models such as the Simple View of Reading (SVR; Gough & Tunmer, 1986 ; Hoover & Gough, 1990 ) provide a concise framework for describing the processes and skills involved when readers comprehend texts. According to the Independent Review of the Teaching of Early Reading ( Rose, 2006 ) strong evidence for the SVR comes from Factor Analysis of datasets on different measures of reading showing dissociation between decoding skills and comprehension. To the best of our knowledge, only two such published studies exist to date. Of these, only one of is in English and this explores children between the age of 7 and 10 years. Aims To explore the SVR in English‐speaking children aged 4 and 6 using Factor Analysis. Samples 116 4 ‐year‐olds and 116 6 ‐year‐olds in the US; 103 6 ‐year‐olds in Canada. Methods All children were administered a battery of decoding and comprehension related measures. Results Factor Analysis of the diverse measures undertaken independently by two research teams in different countries demonstrated that listening comprehension and decoding measures loaded as distinct factors in both samples of young English‐speaking children. Conclusions The present findings provide important support for the generality and validity of the SVR framework as a model of reading.     

More than words: Rethinking sustainability communications through neuroscientific methods

In the era when the overarching problem of climate change, threatening the entire humanity and all life on earth, demands actions and behavioural change from all of the societal agents, including governments, organizations, companies and individuals, the world fails to achieve unity on the matter of existence of the problem, cause of the problem and on the solution of the problem. Since the scientific consensus on climate change is achieved, this article tries to examine why it is so hard to convey the message of needed behavioural change. The neuromarketing study presented in this article focuses on marketing communications that try to convey the message that would lead to the consumers' mental, emotional and behavioural change. Effectiveness of the branded environmental videos was evaluated utilizing the neuroscience approach. Electroencephalogram and an eye-tracking device were used to register the implicit brain reactions of the study participants viewing the branded videos. For comparison reasons, the branded videos selected for the study use two different approaches for conveying the message. The first approach relies on narrative, words and logic, whilst the second one appeals primarily to emotions. The aim of the study was to answer the question whether the words are enough or is there more to it?     

阅读困难可否补救? 两种理论驱动干预方案的比较(英文)

本研究是一个进行中的纵向实验的一部分,该实验旨在比较一个认知干预方案(PREP:PASS阅读促进方案)和一个主要关注语音、命名速度和意义成分的神经心理方案(DEST-RT:DEST补救工具)在阅读困难补救中的效能。从320位儿童构成的初始样本中,选择4组儿童,并一年级接受四周干预后,对他们在许多认知、语言、阅读和正字法测量上的表现进行比较:两个实验组共28名伴有阅读困难的儿童(每组n=14),平均年龄6岁6个月,分配到PREP和DEST-RT补救方案中,两组儿童基于年龄、性别、父母教育水平、非言语和言语能力进行匹配,同时也考虑他们的认知和语言表现剖面;一个阅读水平匹配组(RA-C,n=19),也存在阅读困难,不接受任何处理;一个实足年龄匹配组(CA-C,n=30)。结果表明,所有四组儿童在所有认知、语言、阅读和正字法测量上均随时间而改善;与CA-C和DEST-RT相比,PREP组在继时性加工上进步显著;在正字法选择,这一在单词加工中利用视觉-字形信息的正字法加工任务上,PREP组的表现也优于DEST-RT组;最后,在语音敏感性、字母数字的RAN、单词阅读(真词和假词)及段落理解等方面,PREP和DEST-RT的表现均显著优于CA-C和RA-C。讨论部分,则着重讨论设计理论驱动的低成本且能有效改善阅读表现的补救方案的必要性。