老年人整体运动知觉衰退的视觉机制——基于知觉模板模型

整体运动知觉存在年龄相关的衰退,然其老化的视觉机制仍不清楚。本研究分别招募34名青年人和老年人为研究对象,采用随机点阵范式,首次以动态速度为外部噪声考察了这一问题。结果发现,老年组整体运动一致性阈值显著高于青年组,且中等速度下的差异较小,证明整体运动知觉存在老化效应,且老化程度受到速度的影响。对两组数据进行知觉模板拟合发现,以青年组为基准,老年组表征内部加法噪声和排除外部噪声能力的 A_a 和 A_f 均大于1,且 A_a >> A_f ,提示老年人整体运动知觉的衰退可能源于其内部加法噪声的增强和排除外部噪声能力的减弱,其中内部加法噪声的增强更为显著。     

How is the visual working memory load of driver influenced by information density of traffic signs?

The rapid development of urban roads has resulted in an increase in the amount of information that needs to be displayed on traffic signs. The overloading of information on traffic signs may increase drivers’ visual cognition burden and cause driving errors. It could be an important factor affecting driving safety and result in accidents. To enable drivers to cognize traffic signs, the information density that they could endure under reasonable workload levels should be determined. In this study, we designed and implemented trials to analyze drivers’ visual working memory load (VWML) caused by different information densities (including stimulus intensity (SI) and interval time of stimulus (IS)) of traffic signs. Twenty-four paid participants (12 females) with a mean age of 23.38 years (SD = 1.38) participated in laboratory simulation trials based on the memory retrieval approach. Subjective ratings (rating scale mental effort (RSME)), and performance measurement based on reaction time and accuracy of information-matching task were measured to reflect drivers’ VWML at different information densities. The results show that information density is an important factor affecting drivers’ VWML. The following are the significant observations of the study: (1) The subjective ratings on mental effort increased with increase in the SI. Meanwhile, it first decreased and then increased with increase in the IS. (2) The response accuracy results show that a high accuracy (≥0.7) was achieved by drivers in an IS of 15 s when the SI was at most 14.16 bit/m². Correspondingly, the drivers underwent less mental workload as a result of their better short-term memory characteristic. (3) The mean reaction time was over 1800 ms when the SI was over 14.16 bit/m². This indicated a reduction in the information-processing capability of the drivers. The results indicate that cognition of information of unreasonable density on traffic signs would increase drivers’ VWML. This would, in turn, result in an increase in their reaction time and decrease in accuracy. The threshold of information density was also determined through the experiment. It would satisfy the information demand of drivers and prevent information redundancy. The results contribute to an understanding of drivers’ VWML while cognizing traffic signs with different information densities and provide safety, effectiveness, and information continuity considerations for the design and setting of traffic signs.     

An eye-tracking study of the effects of dimensions of speed limit traffic signs on a mountain highway on driverś perception

Signs control and regulate traffic, anticipating potential dangers, prescribing correct behaviors, and disambiguating likely conflicts in priority. In Brazil, traffic accidents on highways located in mountain rural areas are mainly related to the design of roads and speeding, rather than to the impact of traffic flow. Since drivers highly depend on their visual perceptions for adopting driving behaviors, this study analyzes driver perception during a trip and the response of this parameter to changes in the diameter of vertical speed limit signs in a driver simulator equipped with an eye-tracking system. The objective was to investigate whether an increase in the plate size would enhance driver perception and influence drivers’ compliance with speed limits. Fifty-five volunteers were asked to drive twice on a 10-km mountain route, after which one of the diameters, namely 75, 100, 120, and 150 cm, used according to several Brazilian and American standards, was randomly chosen. The results showed the size of the traffic signs did not affect dependent variables number of fixations, percentage of perceived signals, time of observation, perception distance, and non-compliance with the speed limit. The most significant result was the relationship between speed variability and guided round, since the driver’s performance was improved with the distance along the studied stretch. The outcomes can be useful for the development of strategies that manage speeding on roads by improving and implementing low-cost interventions in low-income countries.     

Field testing anti-speeding messages

PurposeDetermine whether anti-speeding messages displayed on roadside variable message signage (VMS) influence drivers’ speed choice selections.MethodSpeed detection tubes were installed across a single carriageway 60 km/h limit road section at positions prior to, immediately after, and at a longer distance from VMS display of anti-speeding messages during study Week2. Bi-directional vehicle speed data were collected continuously during the week prior to VMS installation (Week1), throughout the week that the anti-speeding messages were displayed (Week2), and a post-display week (Week3).ResultsOf six separately measured locations, Week2 southbound mean speeds (facing signage) and percent of drivers/riders exceeding the signed speed limit were consistently below those recorded during Week1 for all time periods. Aggregated Week3 (post-VMS) southbound data for all time periods, showed consistent patterns for mean speed and percent of drivers exceeding the signed speed limit, being higher than in Week2 (VMS displayed) but lower than during Week1 (pre-VMS).DiscussionCompared with Week1, messages influenced aggregate driver speed selection during Week2, with a residual positive effect (slower speeds) in Week3. While all three messages had positive effects, differences occurred in relative effectiveness between daytime (school and non-school hours) and night-time periods. Separately disaggregated data revealed differential effects for the three messages.ConclusionsFindings demonstrated the value of implementing theoretically informed message content and provided evidence for the impact that roadside road safety messaging can have on driver speed selection.     

快慢读者利用语境信息的差异：加工深度的作用

通过主题扫描和阅读理解两种加工深度不同的任务,考察快慢读者预测性效应差异的来源及加工深度在其中发挥的作用。被试在两种任务情境下阅读分别包含高低预测性目标词的96个句子框架,记录其眼动轨迹。结果显示：预测性效应仅在阅读理解任务中出现,快速读者在早期眼动指标上就表现出了预测性效应,慢速读者在晚期眼动指标上才表现出预测性效应。结果表明：加工深度调节快慢读者预测性效应的大小;在自然阅读情境下快慢读者的预测性效应表现符合预测编码框架假设。     

中文阅读中快速读者与慢速读者的词频效应

在熟练的中文阅读中,个体阅读效率越高,词汇加工效率是否越高,目前还缺少直接证据。本研究通过记录快速读者与慢速读者在阅读含有高频或低频目标词句子时的眼动轨迹来考察该问题。结果发现,在第一遍注视时间、回视路径时间和总注视时间上,快速读者对高频词与低频词的注视时间无显著差异,但都短于慢速读者;而慢速读者对低频词的注视时间显著长于高频词。即快速读者的早期词汇识别和后期词汇整合效率都较高,不受词频影响;而慢速读者的整个词汇加工效率较低,受词频影响较大。这些结果表明两组读者的词汇加工模式具有本质差异,符合个体差异性观点与词汇质量假说。     

Dynamic dominance persists during unsupported reaching

Previous studies examining lateralization of arm movements focused on supported movements in the horizontal plane, removing the effects of gravity. The authors hypothesized that interlimb differences in free reaching would be consistent with the differences shown during supported reaching. Kinematic and kinetic data were collected for the forearm and upper arm segments in a 3-direction reaching task. Results showed lateralization of coordination, reflected by initial movement direction and trajectory curvature. The nondominant arm showed increased initial direction errors, and path curvature associated with a timing deficit between elbow and shoulder peak torques. These coordination deficits did not disrupt final position accuracy. The authors conclude that nondominant arm coordination deficits are similar to those reported previously for horizontal plane movements.     

4PLRT模型与3PLRT模型在瑞文标准推理测验中的比较研究

研究目的：考察反应时与智力的关系以及通过模型对比考察4PLRT模型特性。方法：以瑞文标准推理测验为例,对4PLRT模型与3PLRT模型作比较研究。结论：（1）项目时间参数与难度参数正相关,可以依据时间参数将瑞文标准测验划分成三大部分。（2）能力估计结果比较：由于项目参数和被试速度参数的作用,CTT条件下能力相等的不同被试在计时与非计时条件下存在差异。（3）关于被试的答题策略：被试会基于自身能力而充分权衡时间与准确性的关系。这两种不同模型下被试的能力值之间的比较也说明了时间是一个重要的智力评估因子。     

Neurological subtle signs and cognitive development: A study in late childhood and adolescence

Introduction and Aim: Neurological subtle signs (NSS) are often observed during the neurological examination of children and tend to disappear with age. Their persistence into late adolescence or young adulthood has been related to psychiatric and neurocognitive disorders. To provide a better understanding of their functional basis, a longitudinal correlational study with neurocognitive measurements was performed.

Method: We conducted multiple regression and correlation analyses of NSS with demographic and cognitive measures on a subset of 341 healthy children (56% males), taking part in a longitudinal dental study. Participants, whose ages ranged between 11–15 years, at first evaluation, undertook yearly, during 5 years, a 6-item NSS exam (producing a total score ranging between 0–18) and a comprehensive battery of neurocognitive tests. Effects of age, gender, IQ, and 7 neurocognitive factors on NSS were analyzed.

Results: Over the years, NSS scores correlated consistently with selective attention (Stroop test), motor speed (finger tapping), and visuomotor speed (pegboard speed).

Discussion: These results suggest that the disappearance of NSS in late childhood and adolescence occurs primarily in parallel with the development of motor and visuomotor functions and secondarily in relation to higher order functions such as selective attention (Stroop) and executive control (B-A Trails difference).     

Processing Speed Weakness in Children and Adolescents with Non-Hyperactive but Inattentive ADHD (ADD)

DSM-IV-TR defines ADHD-Predominantly Inattentive as allowing up to five symptoms of hyperactivity/impulsivity, while theories of the inattentive type usually assume a group that is hypoactive and characterized by processing speed and cognitive interference deficits. In a community-recruited sample of 572 children and adolescents, a pure inattentive subtype of ADHD (ADD) was defined as those who met DSM-IV-TR criteria for ADHD-PI but had two or fewer hyperactive/impulsive symptoms. Processing and output speeds of those with ADD were compared to those identified with DSM-IV-TR ADHD combined type and non-ADHD controls. These results were then contrasted with those found when DSM-IV-TR defined ADHD-PI was compared with ADHD-C and controls. Processing and output speed were assessed with the Trailmaking A and B and the Stroop Naming Tests. Cognitive interference control was assessed with the interference score from the Stroop Task. Slower cognitive interference speed was found in the ADD vs. ADHD-C and controls comparisons, but not the ADHD-PI versus ADHD-C and controls comparisons. On output speed measures, ADD exhibited the slowest performance, significantly different from controls and the effect size for the set-shifting speed contrast (Trailmaking B) was double that of the ADHD-PI vs. control comparison. ADHD-Inattentive type as defined by the DSM-IV-TR is a heterogeneous condition with a meaningful proportion of those affected exhibiting virtually no hyperactive/impulsive symptoms. This subgroup may represent a distinct inattentive condition characterized by poor cognitive interference control and slow processing or output speed.