How does glance behavior influence crash and injury risk? A ‘what-if’ counterfactual simulation using crashes and near-crashes from SHRP2

As naturalistic driving data become increasingly available, new analyses are revealing the significance of drivers’ glance behavior in traffic crashes. Due to the rarity of crashes, even in the largest naturalistic datasets, near-crashes are often included in the analyses and used as surrogates for crashes. However, to date we lack a method to assess the extent to which driver glance behavior influences crash and injury risk across both crashes and near-crashes. This paper presents a novel method for estimating crash and injury risk from off-road glance behavior for crashes and near-crashes alike; this method can also be used to evaluate the safety impact of secondary tasks (such as tuning the radio). We apply a ‘what-if’ (counterfactual) simulation to 37 lead-vehicle crashes and 186 lead-vehicle near-crashes from lead-vehicle scenarios identified in the SHRP2 naturalistic driving data. The simulation combines the kinematics of the two conflicting vehicles with a model of driver glance behavior to estimate two probabilities: (1) that each event becomes a crash, and (2) that each event causes a specific level of injury. The usefulness of the method is demonstrated by comparing the crash and injury risk of normal driving with the risks of driving while performing one of three secondary tasks: the Rockwell radio-tuning task and two hypothetical tasks. Alternative applications of the method and its metrics are also discussed. The method presented in this paper can guide the design of safer driver–vehicle interfaces by showing the best tradeoff between the percent of glances that are on-road, the distribution of off-road glances, and the total task time for different tasks.     

Online monitoring of the social presence effects in a two‐person‐like driving video game using near‐infrared spectroscopy

We examined how a friend's presence affects a performer's prefrontal activation in daily‐life activities using two wireless portable near‐infrared spectroscopy (NIRS) devices. Participants played a driving video game either solely in the single group or with a friend in the paired group. The two groups (single and paired) were subdivided according to their game proficiency (low and high). The NIRS data demonstrated a significant interaction of group by proficiency. Low‐proficiency players in the paired group showed lower activation than those in the single group, but high‐proficiency players did not. In the paired group, high‐proficiency players showed higher activation than low‐proficiency players, but not in the single group. These results suggest that NIRS detects social presence effects in everyday situations: decreasing prefrontal activation in low‐proficiency performers due to tension reduction and increasing prefrontal activation in high‐proficiency performers due to increased arousal.     

Motor excitability during movement preparation in Tourette syndrome

Tourette syndrome (TS) is a neurodevelopmental disorder characterized by the occurrence of motor and vocal tics. TS has been linked to the impaired operation of cortical‐striatal‐thalamic‐cortical circuits that give rise to hyper‐excitability of cortical motor areas, which may be exacerbated by dysfunctional intra‐cortical inhibitory mechanisms. That said, many individuals gain control over their tics during adolescence and it has been suggested that this increased control arises as a result of the development of mechanisms that operate to suppress corticospinal excitability (CSE) ahead of volitional movements. Here we used single‐pulse transcranial magnetic stimulation (TMS) in conjunction with a manual Go/NoGo task to investigate alterations in CSE ahead of volitional movements in a group of adolescents with TS (N = 10). Our study demonstrated that CSE, as measured by TMS‐induced motor‐evoked potentials (MEPs), was significantly reduced in the TS group in the period immediately preceding a finger movement. More specifically, we show that individuals with TS, unlike their age‐matched controls, do not exhibit the predicted increase in mean MEP amplitude and decrease in MEP variability that immediately precede the execution of volitional movements in typically developing young adults. Finally, we report that the magnitude of the rise in MEP amplitude across the movement preparation period in TS is significantly negatively correlated with clinical measures of motor tic severity, suggesting that individuals with severe motor tics are least able to modulate motor cortical excitability.     

Learning nonwords: the Hebb repetition effect as a model of word learning

Page and Norris [(2008). Is there a common mechanism underlying word-form learning and the Hebb repetition effect? Experimental data and a modelling framework. In A. Thorn &; M. P. A. Page (Eds.), Interactions between short-term and long-term memory in the verbal domain; (2009). A model linking immediate serial recall, the Hebb repetition effect and the learning of phonological word forms. Philosophical Transactions of the Royal Society B: Biological Sciences, 364(1536), 3737–3753. doi:10.1098/rstb.2009.0173] have suggested that the Hebb [(1961). Distinctive features of learning in the higher animal. In J. F. Delafresnaye (Ed.), Brain mechanisms and learning (pp. 37–46). Oxford: Blackwell] repetition paradigm can be considered as a laboratory analogue of word learning. In Hebb learning experiments, the lists of items to be learned are presented as discrete sequences. In contrast, novel words are, by definition, always heard as a single coarticulated whole. Might this undermine the claim that Hebb learning can shed light on word learning? Here we report an experiment comparing learning sequences of isolated syllables with learning the same sequences spoken as a single coarticulated nonword. The pattern of learning was similar in the two cases, suggesting that the Hebb repetition paradigm can indeed provide valuable insights into the way novel word forms are learned.     

A longitudinal analysis of the attention networks in 6- to 11-year-old children

Attention is critical for everyday functioning. Posner and Petersen’s model of attention describes three neural networks involved in attention control—the alerting network for arousal, the orienting network for selecting sensory input and reorienting attention, and the executive network for the regulatory control of attention. No longitudinal research has examined relative change in these networks in children. A modified version of the attention network task (ANT) was used to examine changes in the three attention networks, three times over 12 months, in 114 6-, 8- and 10-year-olds. Findings showed that the alerting network continued to develop over this period, the orienting network had stabilized by 6 years, and the conflict network had largely stabilized by 7 years. The reorienting of attention was also assessed using invalid cues, which showed a similar developmental trajectory to the orienting attention network and had stabilized by 6 years. The results confirm that age 6 to 7 years is a critical period in the development of attention, in particular executive attention. The largest improvement over the evaluation period was between 6 and 7 years; however, subtle changes were found in attention beyond 8 years of age.     

The automatic activation of emotion words measured using the emotional face-word Stroop task in late Chinese–English bilinguals

In the current study, late Chinese–English bilinguals performed a facial expression identification task with emotion words in the task-irrelevant dimension, in either their first language (L1) or second language (L2). The investigation examined the automatic access of the emotional content in words appearing in more than one language. Significant congruency effects were present for both L1 and L2 emotion word processing. Furthermore, the magnitude of emotional face-word Stroop effect in the L1 task was greater as compared to the L2 task, indicating that in L1 participants could access the emotional information in words in a more reliable manner. In summary, these findings provide more support for the automatic access of emotional information in words in the bilinguals’ two languages as well as attenuated emotionality of L2 processing.     

经颅直流电刺激对健康人群反应抑制的影响

反应抑制是指抑制不恰当的或不符合当前需要的行为的能力, 研究表明反应抑制主要与额下回、背外侧前额叶和前辅助运动区的功能有关。经颅直流电刺激(tDCS)是一种非侵入式脑刺激技术, 近年来对健康人群使用tDCS刺激相应脑区从而影响反应抑制功能的研究日益增多, 但主要研究结果不一致。阐明tDCS影响反应抑制具体的神经机制、减少tDCS研究的异质性、探索更有效的tDCS刺激方式和确定tDCS效果的年龄依赖性差异已成为目前亟待解决的问题。     

任务切换理论争议新证据

任务切换是研究认知控制的主要范式之一。大量研究发现切换试次比重复试次的反应时更长,错误率更高,这种差异称为切换代价。任务切换时所产生切换代价的理论解释主要有惯性论、重构论和联结论。近十年来,这些理论均获得新的实验支持和发展,但其争议依旧,没有哪一理论能成功解释任务切换的所有效应。未来研究可以建立整合模型,以准确描述切换代价产生的认知机制。     

阈上阈下启动刺激在不同锻炼人群中引发自动评价的特点

双加工理论认为锻炼行为形成中自动加工（系统1）和熟虑加工（系统2）是两个相互作用但又截然不同的信息处理系统,其中自动评价通过触发系统1的自动加工过程激活运动记忆自发的心理联想,并对运动进行情感评价,从而影响锻炼行为。本研究的目的是检测锻炼相关刺激在不同锻炼人群中引发的自动评价特点。采用评价启动任务范式,实验1和实验2分别给予阈上和阈下锻炼词或非锻炼词作为启动刺激,之后要求被试对积极或者消极目标词进行按键反应。研究结果显示无论阈上还是阈下呈现锻炼启动词,均表现为锻炼组对积极目标词反应速度更快。结果表明：锻炼人群对于锻炼词具有积极自动评价。