Auditory and visual semantic priming using different stimulus onset asynchronies: An event-related brain potential study

Semantic priming effects (behavioral and electrophysiological) were compared in the visual and auditory modalities across three stimulus onset asynchronies (SOAs; 0, 200, and 800 ms). When both prime and target were presented in the visual modality (the prime just to the left of a fixation point and the target to the right) there were N400 priming effects present across the three SOAs. However, the N400 in the 0-ms SOA condition extended longer in time (800 vs. 500 ms) than in the other SOAs. When both the prime and target were presented in the auditory modality (the prime to the right ear and the target to the left), the largest priming effects were found for the 800-ms SOA. Moreover, there was a relatively early priming effect present in the 0- and 800-ms SOA conditions but not in the 200-ms condition. The results are discussed in terms of modality differences in the time course of word comprehension processes.     

THE INTERACTION OF RESPONSES IN THE BRAIN TO SEMANTIC STIMULI

Long time-constant EEG recording during paired stimuli has led to the discovery of the contingent negative variation or expectancy wave (Walter, 1964). This effect is produced when a conditional stimulus signals that an imperative stimulus demanding action, decision, or attention will follow at a short, constant time interval. Symbolic and meaningful stimuli were presented to subjects tachistoscopically, and the evoked responses in the brain were electronically averaged. The cerebral evoked responses to such psychological stimuli are more complex than to flashes. A slow negative DC potential shift (CNV) was seen during the interval between an auditory ready signal and the visual exposure if recognition of the stimulus was required, or if it was interesting. Following the visual exposure, a slow positive DC shift occurred. The method has been developed to study the brain responses to psychological stimuli. The amplitude of the responses relates to the information content and subjective factors rather than to the physical strength of the stimulus.     

注意缺陷多动障碍儿童脑电生物反馈治疗前后汉字认知电位的比较研究

目的 通过对脑电生物反馈治疗前后注意缺陷多动障碍(ADHD)儿童视听整合持续操作测试(IVA-CPT)和执行语义启动任务的认知电位(ERP)变化的比较,探讨反馈治疗对ADHD儿童汉字认知影响的机制.方法 ADHD儿童21例(男性20例,女性1例),均经脑电生物反馈治疗20次,采用汉字语义启动任务(相关、不相关、假字组)对ADHD治疗前后进行测试,采用BESA软件提取认知电位进行比较分析并对IVA-CPT进行比较.结果 ①IVA-CPT结果:ADHD患儿注意总商数治疗后[(84.5±16.34)分]高于治疗前[(69.11±31.18)分,P<0.05].②ERP-N2:汉字相关任务Cz导联N2波幅治疗后[(-3.95±5.63)μV]低于治疗前[(-10.14±8.27)μV],差异有显著性(P<0.01).③ERP-P3:汉字不相关任务Cz导联P3潜伏期治疗后[(619.24±63.64)ms]短于治疗前[(660.76±67.88)ms,P<0.05].结论 脑电生物反馈能改善ADHD的注意缺陷能力,提高ADHD工作疗前记忆能力及汉字认知速度,易化患儿汉字认识过程;表现在汉字ERP为相关N2波幅降低,不相关P3潜伏期缩短.汉字刺激ERP可以作为评价ADHD患儿反馈疗效的参考依据.     

本体在糖尿病领域知识表示与语义推理研究和应用综述

检索PubMed、IEEE/IET Electronic Library、ACM、万方、知网、维普等中英文数据库以及搜索引擎Google Scholar、百度学术中有关本体在糖尿病领域研究和应用的文献,了解相关现状,总结主要研究内容,结果表明近10年来本体在糖尿病领域的研究成果增长较迅速,在语义理解方面有着比较明显的优势。     

Increases in synthetic cannabinoids-related harms: Results from a longitudinal web-based content analysis

BackgroundSynthetic Cannabinoid Receptor Agonists (SCRA), also known as “K2” or “Spice,” have drawn considerable attention due to their potential of abuse and harmful consequences. More research is needed to understand user experiences of SCRA-related effects. We use semi-automated information processing techniques through eDrugTrends platform to examine SCRA-related effects and their variations through a longitudinal content analysis of web-forum data.MethodEnglish language posts from three drug-focused web-forums were extracted and analyzed between January 1st 2008 and September 30th 2015. Search terms are based on the Drug Use Ontology (DAO) created for this study (189 SCRA-related and 501 effect-related terms). EDrugTrends NLP-based text processing tools were used to extract posts mentioning SCRA and their effects. Generalized linear regression was used to fit restricted cubic spline functions of time to test whether the proportion of drug-related posts that mention SCRA (and no other drug) and the proportion of these “SCRA-only” posts that mention SCRA effects have changed over time, with an adjustment for multiple testing.Results19,052 SCRA-related posts (Bluelight (n = 2782), Forum A (n = 3882), and Forum B (n = 12,388)) posted by 2543 international users were extracted. The most frequently mentioned effects were “getting high” (44.0%), “hallucinations” (10.8%), and “anxiety” (10.2%). The frequency of SCRA-only posts declined steadily over the study period. The proportions of SCRA-only posts mentioning positive effects (e.g., “High” and “Euphoria”) steadily decreased, while the proportions of SCRA-only posts mentioning negative effects (e.g., “Anxiety,” ‘Nausea,” “Overdose”) increased over the same period.ConclusionThis study’s findings indicate that the proportion of negative effects mentioned in web forum posts and linked to SCRA has increased over time, suggesting that recent generations of SCRA generate more harms. This is also one of the first studies to conduct automated content analysis of web forum data related to illicit drug use.     

Automatic Activation of Alcohol Concepts in Response to Positive Outcomes of Alcohol Use

Seventy-one subjects with various levels of drinking experience completed a computerized semantic priming task. Prime phrases (describing positive outcomes of drinking alcohol or neutral phrases) were presented immediately before a target word (either alcohol-related or not). The results replicated earlier basic research examining the effects of semantically related primes on the processing of subsequent words. Furthermore, the results provided evidence that, for heavy drinking subjects, the presentation of phrases describing positive drinking outcomes significantly primed, or facilitated, responses to the alcohol-related words. These results are consistent with the view that for some individuals, thoughts about certain outcomes automatically prime, or make accessible, concepts related to alcohol use. An increase in the accessibility of these concepts has important implications for behavioral decisions about alcohol consumption.     

Caspase-6 activity predicts lower episodic memory ability in aged individuals

Caspase-6 (Casp6), a cysteinyl protease that induces axonal degeneration, is activated early in Alzheimer Disease (AD) brains. To determine whether Casp6 activation is responsible for early cognitive impairment, we investigated the abundance of Casp6 activity, paired helical filament–1 (PHF-1) phosphorylated Tau and amyloid beta peptide (Aβ) pathology by immunohistochemistry in the hippocampal formation of aged non–cognitively impaired (NCI) individuals. Casp6 activity was restricted to the entorhinal cortex (ERC) and CA1 regions of the hippocampus. Pathology scores were then correlated with cognitive scores obtained within 1 year of death. Regression analyses revealed that ERC and CA1 Casp6 activity were the main contributor to lower episodic memory performance, whereas ERC PHF-1 pathology predicted lower semantic and working memory performance. Aβ did not correlate with any of the cognitive tests. Because Casp6 activity and PHF-1 pathology are intimately associated with AD pathology and memory decline is an early event in AD, we conclude that Casp6 activity and PHF-1 immunoreactivity in ERC identifies aged individuals at risk for developing AD.     

Semantic and phonological fluency in children with Down syndrome: Atypical organization of language or less efficient retrieval strategies?

In this study the verbal fluency procedure was used to investigate the organization of semantic and phonological representations in children with Down syndrome (DS) and typically developing children, matched pairwise for receptive vocabulary age. Productivity was found to be significantly reduced in the DS group in both the semantic and the phonological tasks. However, group differences in the number of clusters as opposed to cluster size suggest that this may reflect less efficient retrieval strategies rather than differences in the organization of linguistic representations. Together the findings point to executive deficits in Down syndrome rather than deviant language processes.