加工速度、工作记忆与液态智力发展的关系

有关儿童液态智力 (fluid intelligence) 发展的年龄特征早已有了较明确的一致性结论。然而,儿童液态智力发展的机制问题到现在仍知之甚少。早期零星的研究观察到,随着儿童年龄的增长,其信息加工速度变快,工作记忆能力和液态智力亦提高。由此可推测,对儿童液态智力与加工速度、工作记忆能力关系的考察有助于阐明儿童液态智力发展的机制问题。 近10多年已有不少研究分别探讨了液态智力与加工速度、液态智力与工作记忆的关系,并已开始同时探讨液态智力与加工速度和工作记忆的关系。但令人惊讶的是,有关儿童液态智力发展与加工速度、工作记忆关系问题的综合探讨几成空白,到目前为止,仅有极少量的研究 (Fry 和Hale, 1996; Miller和Vernon, 1996) 探讨了这一问题,其中Fry 和Hale (1996) 还提出了一个模型 (the developmental cascade model) 试图解释儿童液态智力发展的机制,随后Fry 和Hale (2000)进一步阐明并坚持了这一观点。Fry 和Hale的观点是,儿童液态智力的发展取决于儿童工作记忆能力的发展,而工作记忆能力的发展又进一步取决于儿童信息加工速度能力的发展。这就是说,加工速度和工作记忆是儿童液态智力发展的两个关键因素,其中加工速度又是第一作用因素。Fry 和Hale (1996, 2000) 提出了她们的观点后,后续研究在国际上仍十分少见。但来自于发展领域之外的研究似乎不支持Fry 和Hale (1996, 2000)的观点。研究发现(Conway et al., 2002),仅工作记忆能很好预测液态智力的变化,而加工速度不能很好预测液态智力的变化。 该研究从南京市中小学随机选取了243名10到18岁的健康儿童（男生127名,女生116名）。所有被试共完成7项任务,包括2项液态智力任务测试（瑞文标准推理测验和卡特尔文化公平智力测验,以原始分作为数据分析指标）、3项加工速度任务测试（数字抄写、字母串比较和符号串比较）、2项工作记忆任务（数字工作记忆和视空间工作记忆）。验证性因素分析发现这7项任务所测量的正是液态智力、加工速度和工作记忆这3个因子,且这3个因子间存在显著的相关。但随后的结构方程模型分析表明,从工作记忆到液态智力间存在显著路径,但从加工速度到液态智力并不存在显著路径,工作记忆几乎可完全解释儿童液态智力的发展变化（85.4%）,且可以解释81.6%的加工速度的发展变化量。仅当不考虑工作记忆这一因素时,加工速度才能解释50%的液态智力的发展变化。这表明,工作记忆是儿童液态智力发展的基础,而加工速度则不是。这一结果在以三个变量的平均标准分数为基础所进行的层级回归分析 (hierarchical regression analyses)中亦得到了证实。 总体上,该研究并不支持Fry 和Hale (1996, 2000)的观点。工作记忆是儿童液态智力发展的关键因素,而加工速度则不是。加工速度与液态智力存在显著相关,其原因可能在于,加工速度反映的是儿童液态智力的同一年龄内个体差异而不是年龄间差异（即发展性变化）。本研究同时对工作记忆之所以是儿童液态智力发展的基础的可能原因进行了讨论。     

Judgments of mean speed and predictions of route choice

How are driving speeds integrated when speeds vary along a route? In a first study, we examined heuristic processes used in judgments of mean speed when the mean speeds on parts of the trip varied. The judgments deviated systematically from objective mean speeds because the distances driven at different speeds were given more weight than travel time spent on the different distances. The second study showed that when there was a 10–15 min pause during a travel the effect on the mean speed decrease was underestimated for driving speeds of 90 km/h and higher. In the third study, the objective mean speeds and the subjective biased mean speed judgments were used to predict choices between routes with different speed limits. The results showed that subjective judgments predicted decisions to maximize mean speed significantly better than objective mean speeds. Finally, some applied and basic research implications of the results were discussed.     

Relationships between three auditory inspection time tasks and processing speed

This study investigated the relationship between a spatial auditory inspection time task and previous versions of AIT, as well as the relationships of these tasks with visual inspection time (VIT) and general speediness (Gs). A total of 96 university undergraduates (age mean (M) = 20.0 years, standard deviation (SD) = 4.0 years) completed three AIT tasks, VIT, auditory reaction time (ART) and visual reaction time (VRT), and two Gs marker tests. Auditory inspection time‐spatial (AIT‐S) did not relate to VIT, but it did relate to the Gs marker tests. It also loaded moderately on a Gs factor along with VIT. Neither of the alternate AIT tasks showed any consistent relationships to reaction time (RT) or Gs measures. The AIT‐S task did, however, share substantial variance with its predecessors, suggesting that performance on all AIT tasks relies to some extent on similar processes. Further research is required to determine the nature of these processes.     

The effects of a rectangular rapid-flashing beacon on vehicle speed

In 2008, nearly 31% of vehicle fatalities were related to failure to adhere to safe vehicle speeds (National Highway Traffic Safety Administration [NHTSA], 2009). The current study evaluated the effect of a rectangular rapid-flashing beacon (RRFB) triggered by excessive speed on vehicle speed using a combined alternating treatments and reversal design. The percentage of vehicles traveling above 41 mph (66 km per hour) decreased by 20%, and speed distributions showed a shift toward lower speeds during the RRFB condition.     

Effects of age and the relationship between response time measures and psychometric intelligence in younger adults

The major goal of the present study was to investigate the potential influence of age on the relationship among performance measures derived from a Hick reaction time task and general intelligence (psychometric g). Participants were 130 male and 130 female younger adults (mean age: 24.6 years) covering a wide range of individual levels of intelligence. Results from structural-equation modelling analyses clearly indicate that there is no evidence for the notion of a general speed factor underlying psychometric g. A much more sufficient model is provided by the assumption that median reaction time (RTmd) and intraindividual variability of reaction time (RTSD), though highly correlated, reflect two distinct sources of variance for psychometric g. While age was negatively associated with RTmd, no such relationship could be established for RTSD.     

Contribution of temporal preparation and processing speed to simple reaction time in persons with Alzheimer’s disease and mild cognitive impairment

Temporal preparation was assessed in 15 Alzheimer’s disease (AD) patients, 20 persons with mild cognitive impairment (MCI) and 28 healthy older adults. Participants completed a simple reaction time task in which the preparatory interval duration varied randomly within two blocks (short versus long temporal window). Results indicated that AD and MCI patients had difficulty preparing for the shortest preparatory interval of the short temporal window. AD and MCI patients also had difficulty maintaining an optimal level of preparation up to 5 s within the short temporal window. These results suggest that AD and MCI patients might show difficulty preparing for rapidly occurring events and maintaining preparation over time. This phenomenon should be considered when using reaction time measures with such patients.     

自由拦截启动策略与信息利用

手的启动方向自由, 伸手拦截不同速度的运动小球。本研究通过考察手启动时的运动参数, 研究自由启动的情况下的信息利用和拦截策略, 并且考察了人的启动模式。结果发现, 自由拦截时手的拦截区域相对固定, 在物体快速运动情景下启动晚, 而在慢速下启动早, 可能综合利用了接触时间和距离信息, 存在速度伴随效应, 手的拦截启动策略为启动有相对稳定的角度和加速度, 并不随物体运动速度和物体大小的改变而改变。     

基本心理能力老化的认知机制

基本心理能力老化机制是认知老化领域研究热点之一。横断研究与追踪研究表明, 感觉功能、加工速度、工作记忆等信息加工资源的衰退导致了基本心理能力的衰退。但由于相关研究不能进行因果推论, 基本心理能力老化的认知机制尚存在争论。因此本项目拟采用实验室研究和干预实验设计, 通过操纵感觉功能(知觉压力水平)、干预加工速度与工作记忆, 考察基本心理能力的年龄差异的变化, 以期为认知老化理论的深化和拓展提供实验依据。     

Examination of the processing speed account in a population-based longitudinal study with narrow age cohort design

The processing speed account suggests that general slowing of mental processing speed results in an overall decline, especially age-related decline, in other cognitive domains. Support for the speed account comes mainly from cross-sectional studies with participants that vary in age (age-heterogeneous samples). This study investigated how well variations in processing speed predict change of episodic recall in a longitudinal framework and examined with the Narrow Age Cohort (NAC) design. Data were obtained from Betula, a population-based longitudinal study. Both 5-year (n= 490; Time 3 - Time 4) and 10-year follow-up results (n= 608; Time 1 - Time 3) were used. In both samples, which were subjected to prospective dementia screening, we found considerably weaker associations in longitudinal data compared to cross-sectional, and also weaker associations in age-homogeneous than in age-heterogeneous samples. The results provide little support for the speed account.     

Is Parental Knowledge of their Adolescent Offspring’s Whereabouts and Peer Associations Spuriously Associated with Offspring Delinquency?

Recent studies suggest that most of what parents know about their adolescent offspring's whereabouts and companions is the result of youth disclosure, rather than information gained through active parental monitoring. This raises the possibility that parental knowledge is spuriously correlated with youth delinquency solely because the most delinquent youth disclose the least information to parents (because they have the most to hide). We tested this spurious association hypothesis using prospective data on offspring of a nationally representative sample of US women, controlling demographic and contextual covariates. In separate analyses, greater parental knowledge of their offspring's peer associations at both 12-13 years and at 14-15 years was associated with lower odds of being in the top 1 standard deviation of youth-reported delinquency at 16-17 years, controlling for delinquency at the earlier ages. The extent to which parents set limits on activities with peers at 14-15 years did not mediate or moderate the association between parental knowledge and delinquency, but it did independently predict future delinquency among adolescents living in high-risk neighborhoods. This suggests that the association between parental knowledge and future delinquency is not solely spurious; rather parental knowledge and limit setting are both meaningful predictors of future delinquency.