Hand preference status and reach kinematics in infants

Infants show age-related improvements in reach straightness and smoothness over the first years of life as well as a decrease in average movement speed. This period of changing kinematics overlaps the emergence of handedness. We examined whether infant hand preference status is related to the development of motor control in 53 infants ranging from 11 to 14 months old. Hand preference status was assessed from reaching to a set of 5 objects presented individually at the infant's midline; infants were classified into ‘right preference’ or ‘no preference’ groups. Three-dimensional (3-D) recordings were made of each arm for reaches under two distinct conditions: pick up a ball and fit it into the opening of a toy (grasp-to-place task) or pick up a Cheerio^® and consume it (grasp-to-eat task). Contrary to expectations, there was no effect of hand preference status on reach smoothness or straightness for either task. On the grasp-to-eat task only, average speed of the left hand differed as a function of hand preference status. Infants in the no preference group exhibited higher left hand average speeds than infants in the right preference group. Our results suggest that while behavioral differences in the use of the two hands may be present in some infants, these differences do not appear to be systematically linked to biases in motor control of the arms early in development.     

Preferences for suicide prevention strategies among university students in Japan: a cross-sectional study using full-profile conjoint analysis

In Japan, implementation of suicide prevention policies is mainly supported by public funds. However, it is unclear what kinds of suicide prevention strategies people prefer. We conducted a survey to clarify people’s preferences regarding suicide prevention strategies adopted in Japan. This was a cross-sectional self-administered questionnaire survey. Participants were recruited through a lecture held by the first author at their university. We distributed questionnaires to 324 people present at the lecture; 249 completed questionnaires were included in the final analysis. We estimated suicide prevention strategy preferences using full profile conjoint analysis. For all six prevention strategies, the inclusion of each strategy in the policy profile was statistically significantly related to the positive evaluation of the overall policy profile. Marginal Willingness to Pay (MWTP) for restriction of access to means showed the highest value of the six suicide prevention strategies. MWTP was the lowest for public awareness activities. Preferred suicide prevention strategies in Japan are restriction of access to means and enhancement of psychiatric services. The results of this study indicate the strategies that are preferred have a high level of evidence of suicide prevention and do not directly intervene in a person’s free will to die by suicide.     

Effects of perception on public bike-and-ride: A survey under complex,multifactor mode-choice scenarios

Bicycles are an environmentally-friendly, energy-saving mode of transportation. Public bike-and-ride is a term used to describe the use of public bicycles combined with transit as a means of transportation. A new stated preference (SP) design scheme based on the factors respondents felt were most important was proposed to augment the traditional SP design under complex multi-factor and multi-level situations. iPads were used to automatically administer the survey under each design scheme and collect the choice behavior data for public bike-and-ride. The concept of perceived psychological distance was further proposed and used to estimate Logit models. Comparative analysis of these models shows for the traditional SP design scheme, some factors, including perceived psychological distance, have reduced statistically significant effects on public bike-and-ride choice relative to the new SP design scheme. This indicates that in scenarios with complex decisions, the decision-makers would reduce their consideration of some factors and simplify their decision process making the new SP survey design scheme more suitable to analyze their choice behavior in those cases. Model analysis showed that perceived psychological distance for each traveler is the most critical factor during the decision process for travel behavior analysis. Finally, sensitivity analysis was conducted to determine which factors in the new survey design were important to increase the share of public bike-and-ride users. Practical findings for promoting public bike-and-ride use are presented in addition to theoretical references for improving the traditional survey methods.     

语义联系对关联再认神经机制的调节

已有研究显示,关联再认可记录到分别反映双重加工模型的两阶段（即熟悉和回忆）的ERP成分（即FN400和LPC成分）,且具有高语义联系配对的关联再认可通过整合在基于熟悉加工的基础上完成。然而,不同语义联系对关联再认神经机制的影响及单个项目的熟悉和回忆加工的调节作用尚未揭示。为此,本研究比较了主题相关和类别相关图形关联再认的波形波幅异同,并分析了单个项目的熟悉和回忆加工对配对识别的影响。结果显示,主题相关和类别相关条件的旧配对、重组配对和“旧+新”配对均记录到反映熟悉加工的FN400成分,主题相关条件的旧配对、重组配对和“旧+新”配对均记录到反映回忆加工的LPC成分,类别相关条件的旧配对记录到LPC成分。表明关联再认的神经机制受语义联系所调节,单个项目的熟悉程度可影响配对识别时的神经机制,上述结论支持双重加工模型。     

Two-Stage maximum likelihood estimation in the misspecified restricted latent class model

The maximum likelihood classification rule is a standard method to classify examinee attribute profiles in cognitive diagnosis models (CDMs). Its asymptotic behaviour is well understood when the model is assumed to be correct, but has not been explored in the case of misspecified latent class models. This paper investigates the asymptotic behaviour of a two-stage maximum likelihood classifier under a misspecified CDM. The analysis is conducted in a general restricted latent class model framework addressing all types of CDMs. Sufficient conditions are proposed under which a consistent classification can be obtained by using a misspecified model. Discussions are also provided on the inconsistency of classification under certain model misspecification scenarios. Simulation studies and a real data application are conducted to illustrate these results. Our findings can provide some guidelines as to when a misspecified simple model or a general model can be used to provide a good classification result.     

Response acquisition by zebrafish (Danio rerio) with delayed reinforcement

Zebrafish (Danio rerio) is a common vertebrate animal model in biomedical research and is a promising species for studying how genes interact with environmental factors in determining behavior. The present study investigated how reinforcement parameters affect zebrafish behavior by assessing response acquisition with delayed reinforcement, which has been studied with other species (e.g., rats, pigeons, humans, etc.) but not with zebrafish. Twenty‐four experimentally naïve subjects were exposed to a tandem fixed‐ratio 1 differential‐reinforcement‐of‐other‐behavior x‐s schedule of reinforcement, where x varied across subjects. There were six different delay‐to‐reinforcement durations and sets of four fish were assigned to each delay duration. All of the fish assigned to a 0‐, 0.5‐, or 1‐s delay acquired responding. Two fish acquired responding with a 3‐s delay and one fish appeared to have acquired it with a 6‐s delay although the latter result was less clear. None acquired responding with a 12‐s delay. These results suggest that zebrafish behavior is sensitive to delays to reinforcement and the time frame over which reinforcement is effective may be limited approximately to 6 s. This time frame is shorter than that found with other species. Practical and theoretical implications of the present finding are discussed.     

The role of preference in speed choice

Individual differences with regard to speed preference may be a source of speed heterogeneity and conflicts in traffic, such as tailgating and dangerous overtaking. The main aim of the current study was to explore drivers’ speed preferences when driving for different reasons (saving money on fuel, driving safely, driving for fun or driving as usual) and the relationship of these preferences to observed speeds and self-reported speed. 193 drivers were interviewed at five different locations, and were asked about their speeds on roads they had just travelled. Drivers’ speeds on these roads were also sampled with a speed gun. The results showed large differences between speeds chosen for different driving purposes; the lowest speeds were chosen when the goal was economy and the highest when driving for fun. In addition, there were individual differences in speed preferences such that some drivers indicated that their usual speed was above what they believed was a safe speed while others indicated that they usually drove even slower than what they thought was safe. These differences may account for much of the speed heterogeneity observed in on-road behaviour. The results also showed that drivers’ speed choices are highly influenced by their usual speeds, even more so than their beliefs regarding what constitutes a safe speed, which may help explain non-compliance with speed limits. No relationship was found between speed choice and risk perception.