Locus of the single-channel bottleneck in dual-task interference.

Two experiments used the locus-of-cognitive-slack method to determine whether dual-task interference occurs before or after the response selection stage. The experiments used the overlapping tasks paradigm, in which 2 signals, each requiring a different speeded choice response, are presented in rapid succession. In Exp 1, stimulus–response (S–R) compatibility was manipulated by varying whether Task 2 stimuli were mapped onto their responses by a rule or arbitrarily. Compatibility effects were additive with the effects of degree of task overlap, manipulated by varying the stimulus onset asynchrony between the signals. Exp 2 examined 2 additional forms of S–R compatibility: symbolic compatibility (arrows vs letters) and spatial compatibility (the "Simon" effect). Effects of symbolic compatibility were additive with effects of degree of task overlap, whereas the effects of spatial compatibility and degree of task overlap were underadditive. It is argued that only a central-bottleneck model provides a consistent account of these results. The nature of the central bottleneck is considered. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

突破语言瓶颈跨越能力障碍——土木工程专业双语教学的探索与实践

本文分析了土木工程专业大学本科生专业英语学习与应用方面存在的瓶颈问题,提出双语教学改革的新思路,在知识结构的系统性、专业学习的针对性和语言环境的培育方面进行了有益的尝试和探索,经过几年的教学实践收到了良好的效果.     

Can mental rotation occur before the dual-task bottleneck?

The effect of character disorientation on mirror–normal judgments was found to be partially attenuated with increasing task overlap with a preceding tone-frequency discrimination judgment. These results suggest that orientation-sensitive processing, used to prepare disoriented stimuli for mirror–normal discrimination, can be initiated and proceed in parallel with mental activities required for a tone-frequency discrimination task. The attenuation indicates that at least some of the orientation effect on mirror–normal discriminations had its locus prior to the dual-task processing bottleneck. The possibility that the partial attenuation of the orientation effect was due to attenuation of the effect of orientation on character identification, but not on the mental rotation required for mirror–normal judgments, was examined and rejected. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

瓶颈中颗粒流动的堵塞行为

颗粒物质流经瓶颈时难以预知的堵塞现象是1个古老且令人困惑的难题。本文选取3种球形颗粒,统计分析颗粒流出小于临界开口尺寸锥形瓶颈的颗粒数,探讨堵塞转变的概率分布特征和物理机制。结果显示:(1)堵塞前流出瓶颈的颗粒数概率分布存在1个峰值,峰值前概率呈幂函数增长,峰值后概率为指数衰减;(2)颗粒的密度、弹性系数及表面摩擦等因素影响颗粒间的接触时间、堵塞结构稳定性和堵塞概率分布。当瓶颈开口尺寸低于临界尺寸,且颗粒流态由稀疏流转变为密集流后,堵塞转变必将发生。     

Central bottleneck influences on the processing stages of word production.

Does producing a word slow performance of a concurrent, unrelated task? In 2 experiments, 108 participants named pictures and discriminated tones. In Experiment 1, pictures were named after cloze sentences; the durations of the word-production stages of lemma and phonological word-form selection were manipulated with high- and low-constraint cloze sentences and high- and low-frequency-name pictures, respectively. In Experiment 2, pictures were presented with simultaneous distractor words; the durations of lemma and phoneme selection were manipulated with conceptually and phonologically related distractors. All manipulations, except the phoneme-selection manipulation, delayed tone-discrimination responses as much as picture-naming responses. These results suggest that early word-production stages-lemma and phonological word-form selection-are subject to a central processing bottleneck, whereas the later stage-phoneme selection-is not. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Response activation in overlapping tasks and the response-selection bottleneck.

The authors investigated the impact of response activation on dual-task performance by presenting a subliminal prime before the stimulus in Task 2 (S2) of a psychological refractory period (PRP) task. Congruence between prime and S2 modulated the reaction times in Task 2 at short stimulus onset asynchrony despite a PRP effect. This Task 2 congruence effect was paralleled by a Task 1 congruence effect and emerged exclusively under conditions of cross talk, whereas it did not occur under dual-task conditions preventing cross talk between tasks. This suggests that response activation operates during the PRP in dual tasks and affects the response times in Task 2 via cross talk between common processing elements at prebottleneck stages but not by directly affecting the postbottleneck stages. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Analysis of genetic diversity at the DQA loci in African cattle: evidence for a BoLA-DQA3 locus

The effects of exercise on the generation of active oxygen species and radical-scavenging capacity were studied in physically active and sedentary young and old rats. Exercise increased the hydroxyl radical content in all tissues of physically active young rats, except in the plasma. In old rats, the basal level of the radical increased significantly in plasma, heart, and skeletal muscles, but decreased in liver; and physical activity decreased it to that of young rats in most cases. With exercise, the content of reduced glutathione increased in plasma, heart, and skeletal muscles of young rats, whereas that of oxidized glutathione markedly decreased in liver and increased in brain and white gastrocnemius muscle. The total glutathione levels in these tissues changed in a similar way, indicating that glutathione was released from the pool in the liver. In rats allowed to run voluntarily for 5 weeks, the effects were more pronounced than in the sedentary rats. The ratio of reduced to total glutathione, which indicates the capacity to reduce glutathione, increased in plasma, heart, and soleus muscle of sedentary young rats after exercise, and increased further in those undergoing physical activity. In old rats, the reduced glutathione level increased in plasma, heart, liver, and brain, even though the total decreased. These results suggest that physical activity enhances the endogenous ability to defend against oxidative stress. In old rats, even though glutathione synthesis is decreased, the regenerating capacity seems to be increased in order to compensate for the increased oxidative stress.     

Loci of signal probability effects and of the attentional blink bottleneck.

To investigate the locus of signal probability effects and the influence of stimulus quality on this locus, the authors manipulated probability in Task 2 of a psychological refractory period (PRP) paradigm. The effect was additive with stimulus onset asynchrony (SOA) when the target was not masked but underadditive with decreasing SOA when the target was masked. Even with masking, however, a range of probabilities had effects additive with SOA. The results suggest loci of stimulus probability before the PRP bottleneck as well as at or after the bottleneck. A second issue addressed was the locus of interference in the attentional blink (AB). The AB was larger when the probability of the first of 2 targets was lower. The results lead to the conclusion that one cause of the AB effect is a locus at least as late as the PRP bottleneck. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

大学英语学习瓶颈状态的形成与突破

在大学英语学习过程中，学生的学习存在着两个瓶颈状态。教师在教学过程中要培养学习者的自信心，树立积极的学习理念，掌握正确的英语语料信息处理方式，以帮助学生突破大学英语学习过程中的瓶颈状态，成功地进行英语学习，从“不知道怎么学”进入“了解学习过程，善于学习”的状态。     

锆石U-Pb年龄不一致原因浅析

单颗粒锆石U-Pb法是当前最重要的一种同位素定年方法，但由于放射成因铅的不同程度丢失而导致获得不一致的年龄数据。本文讨论了导致年龄数据不一致主要因素是由蜕晶化作用、重结晶作用、扩散作用和增生作用过程中产生的放射成因铅丢失，并提出为了获得具有明确地质意义的年龄数据，必须采用各种手段尽可能选择新鲜、结晶完好、成因单一的锆石作为测试对象。在定年方法中，应首选能进行微区分析的离子探针质谱法和激光探针-等离子质谱法。     

Development and validation of the Conflict in Adolescent Dating Relationships Inventory.

Four studies examined the Conflict in Adolescent Dating Relationships Inventory (CADRI), a measure of abusive behavior among adolescent dating partners. Exploratory factor analysis was used to refine items based on high school participants with dating experience (N?=?393; 49% female). Confirmatory factor analysis was used to derive and cross-validate the factor structure with participants from 10 high schools (N?=?1,019, 55% female; ages 14–16). The model structure fit for all grades and both sexes, with physical abuse, verbal abuse, and threatening behavior most representative of the underlying abuse factor. In Studies 3 and 4, the second-order abuse factor showed acceptable test–retest reliability, partner agreement, and correlation (significant for males only) between observer ratings of dating partners' interactions and youths' CADRI scores. Results support the CADRI as a measure of abusive behavior in adolescent dating relationships. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Learning to bypass the central bottleneck: Declining automaticity with advancing age.

Does advancing age reduce the ability to bypass the central bottleneck through task automatization? To answer this question, the authors asked 12 older adults and 20 young adults to first learn to perform an auditory–vocal task (low vs. high pitch) in 6 single-task sessions. Their dual-task performance was then assessed with a psychological refractory period paradigm, in which the highly practiced auditory–vocal task was presented as Task 2, along with an unpracticed visual–manual Task 1. Converging evidence indicated qualitative differences in dual-task performance with age: Whereas the vast majority of young adults bypassed the bottleneck, at most 1 of the 12 older adults was able to do so. Older adults are either reluctant to bypass the bottleneck (as a matter of strategy) or have lost the ability to automatize task performance. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

New bottleneck may occur with uncontrolled capacily expansions of zinc smelting

Since a new round of zinc smelting ca-pacity expansions is finding its way recent-ly in China,industry experts wish to raisethe attention of investors for not beingover optimistic,according to a report.     

Spiders crawl easily through the bottleneck: Visual working memory for negative stimuli.

The special status of spiders in the attentional bottleneck and visual working memory (VWM) was studied. 23 spider-fearfuls (SF) and 23 non-anxious controls (NACs) participated in a serial VWM-task. Each trial showed a 4 × 4 matrix of images and 5 of these were subsequently cued for 150 ms each. Afterwards, one of the 16 displayed images was hidden and probed. The spider image was included in the string of 5 cued images, among the 11 uncued items, or not at all. For both groups, memory was better for cued spiders than for other cued items. SFs also showed improved memory for uncued spiders. The relevance of the results for theories of attention and cognitive models of phobias are discussed. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

库牙克北部四连岩体锆石U-Pb定年及地球化学特征

沿库牙克断裂侵入的四连岩体,通过锆石LA-MC-ICP-MS U-Pb测年对其年龄进行测定,共获得5组处于晚奥陶世-早志留世之间。岩石类型主要为花岗闪长岩及黑云母花岗岩,岩石为钙碱性岩石,通过构造图解显示岩石类型为碰撞造山型中酸性岩浆岩。