在不同事件率条件下人格倾向类型对认知性警戒的影响

本研究采用两种事件率 ,考察了人格倾向类型对认知性警戒的影响。实验结果表明 :(1 )事件率是影响作业绩效的一个重要因素。事件率与人格倾向存在着交互作用。 (2 )认知性警戒作业的应激效应与事件率有关 ,随着事件率的上升 ,受试者在作业过程中的应激水平明显增高。 (3 )根据对被试自觉疲劳的测量结果 ,在认知性警戒作业中 ,内倾者与外倾者间应激水平存在差异。     

Effects of green tea extract on learning, memory, behavior and acetylcholinesterase activity in young and old male rats

Objective

To study the effects of green tea extract administration on age-related cognition in young and old male Wistar rats.

Methods

Young and old rats were orally administered 0.5% green tea extract for a period of eight weeks and were evaluated by passive avoidance, elevated maze plus paradigm and changes in acetylcholinesterase activity.

Results

Treatment of young and old rats with the extract resulted in no significant difference in performance on the rota rod treadmill test/righting reflex time. Green tea extract significantly improved learning and memory in older rats, with increased retention latency to enter difference in passive avoidance test. In the elevated maze test, green tea treatment resulted in significantly more number of entries in the enclosed arm by the young and old rats. Decline in acetylcholinesterase activity was observed in the cerebrum of green tea treated old rats in comparison to the green tea treated young rats.

Conclusion

Green tea extract administration is effective in enhancing learning and memory in aged rats, and hence, may serve useful in reversing age-related deficits.     

Freeze or flee? Negative stimuli elicit selective responding

Humans preferentially attend to negative stimuli. A consequence of this automatic vigilance for negative valence is that negative words elicit slower responses than neutral or positive words on a host of cognitive tasks. Some researchers have speculated that negative stimuli elicit a general suppression of motor activity, akin to the freezing response exhibited by animals under threat. Alternatively, we suggest that negative stimuli only elicit slowed responding on tasks for which stimulus valence is irrelevant for responding. To discriminate between these motor suppression and response-relevance hypotheses, we elicited both lexical decisions and valence judgments of negative words and positive words. Relative to positive words (e.g., kitten), negative words (e.g., spider) elicited slower lexical decisions but faster valence judgments. Results therefore indicate that negative stimuli do not cause a generalized motor suppression. Rather, negative stimuli elicit selective responding, with faster responses on tasks for which stimulus valence is response-relevant.     

Differentiating between ADHD sub-types on CCPT measures of sustained attention and vigilance

The aim of the study was to test whether sustained attention and vigilance, often considered as the same phenomenon, dissociate on the Conners' Continuous Performance Test, and whether subjects with ADHD-Inattentive type and ADHD-Combined type differ with regard to these measures. Sixty-five healthy controls and 67 subjects with ADHD between 9 and 16 years of age participated in the study. The ADHD-I group performed below control children on Hit Reaction Time Block Change, considered to measure sustained attention and the ADHD-C group scored below controls on Hit Reaction Time Inter-Stimulus-Interval, considered to measure vigilance. Comparing the two clinical groups showed a test by group interaction, with ADHD-I subjects performing below ADHD-C subjects with regard to sustained attention and above ADHD-C subjects with regard to vigilance. Sustained attention on the CCPT correlated specifically with parent and teacher ratings of inattention, but not with ratings of hyperactivity-impulsivity, while vigilance correlated with all symptom ratings.     

音乐对驾驶警觉的影响及其理论模型

驾车时听音乐非常普遍。唤醒理论认为, 音乐可以使驾驶员处于最佳唤醒水平, 有利于驾驶警觉的维持。但是, 根据中枢容量有限理论, 音乐也会使驾驶员分心, 危害道路安全。动态模型在已有研究的基础上提出, 音乐对驾驶警觉起到唤醒抑或分心影响, 取决于音乐复杂性、驾驶情境要求及驾驶员个体差异等诸多因素的动态调节。最新的补偿控制理论则强调, 驾驶员自我调控是恢复动态平衡的关键。而未来的研究应关注驾驶员心理负荷的测量、智能车载音乐系统的开发以及驾驶员培训等领域。     

Acute effect of stretching modalities on global coordination and kicking accuracy in 12–13 year-old soccer players

The aim of the study was to compare the effect of stretching procedures on global coordination and accuracy in instep soccer kicks achieved in different stress conditions. Twenty male young soccer players completed the global coordination test (GC), the instep kicking accuracy test in free (FKA) and in time-pressure (TPKA) conditions, either after static (SS), dynamic (DS), ballistic (BS) or no-stretching (CTR) protocols, on nonconsecutive days and in a randomized order. After performing a 5 min standardized intensity jogging (70% of MAV), followed by stretching exercises for 10 min, each participant completed, successively, the GC, FKA and TPKA tests. Accuracy data, heart-rate, rating of perceived exertion and task difficulty perception were recorded and analyzed using a two-way ANOVA. GC scores were analyzed using one way ANOVA with repeated measures. The results showed higher GC and TPKA performances after DS and BS procedures. However, there was no effect of the stretching procedures on FKA. The GC scores increased by 10.8% and 7.2% after DS and BS, respectively, but were not affected by SS. Compared to FKA, the TPKA accuracy significantly decreased by 20.2% after CTR (p < 0.01) and 30.7% SS (p < 0.001) with no significant difference after DS (10.1%; p > 0.05) and BS (11.0%; p > 0.05). The use of dynamic and ballistic stretching yielded to better GC scores and helped reducing the adverse effect of time-pressure on instep kicking accuracy. Consequently, dynamic and ballistic exercises can be recommended before practicing activities requiring coordination and lower limbs speed and accuracy.     

Understanding the coherence of the severity effect and optimism phenomena: Lessons from attention

Claims that optimism is a near-universal characteristic of human judgment seem to be at odds with recent results from the judgment and decision making literature suggesting that the likelihood of negative outcomes are overestimated relative to neutral outcomes. In an attempt to reconcile these seemingly contrasting phenomena, inspiration is drawn from the attention literature in which there is evidence that both positive and negative stimuli can have attentional privilege relative to neutral stimuli. This result provides a framework within which I consider three example phenomena that purport to demonstrate that people’s likelihood estimates are optimistic: Wishful thinking; Unrealistic comparative optimism and Asymmetric belief updating. The framework clarifies the relationships between these phenomena and stimulates future research questions. Generally, whilst results from the first two phenomena appear reconcilable in this conceptualisation, further research is required in reconciling the third.     

7～11岁儿童持续注意能力的性别差异研究

本研究采用颜色、图形和数字信号监测的三种警觉任务形式 ,来探索7～ 1 1岁儿童持续注意能力的性别差异。结果发现 ,男女儿童持续注意随时间的变化趋势一致 ;7岁男性儿童的持续注意能力优于女性儿童 ,而 9岁和 1 1岁男女儿童的持续注意能力各有自己的风格 ,男性儿童反应快而正确率低 ,女性儿童反应慢而正确率高。     

Fatigue risk management based on self-reported fatigue: Expanding a biomathematical model of fatigue-related performance deficits to also predict subjective sleepiness

Biomathematical models of fatigue can be used to predict neurobehavioral deficits during sleep/wake or work/rest schedules. Current models make predictions for objective performance deficits and/or subjective sleepiness, but known differences in the temporal dynamics of objective versus subjective outcomes have not been addressed. We expanded a biomathematical model of fatigue previously developed to predict objective performance deficits as measured on the Psychomotor Vigilance Test (PVT) to also predict subjective sleepiness as self-reported on the Karolinska Sleepiness Scale (KSS). Four model parameters were re-estimated to capture the distinct dynamics of the KSS and account for the scale difference between KSS and PVT. Two separate ensembles of datasets – drawn from laboratory studies of sleep deprivation, sleep restriction, simulated night work, napping, and recovery sleep – were used for calibration and subsequent validation of the model for subjective sleepiness. The expanded model was found to exhibit high prediction accuracy for subjective sleepiness, while retaining high prediction accuracy for objective performance deficits. Application of the validated model to an example scenario based on cargo aviation operations revealed divergence between predictions for objective and subjective outcomes, with subjective sleepiness substantially underestimating accumulating objective impairment, which has important real-world implications. In safety-sensitive operations such as commercial aviation, where self-ratings of sleepiness are used as part of fatigue risk management, the systematic differences in the temporal dynamics of objective versus subjective measures of functional impairment point to a potentially significant risk evaluation sensitivity gap. The expanded biomathematical model of fatigue presented here provides a useful quantitative tool to bridge this previously unrecognized gap.