Response times on test items are easily collected in modern computerized testing. When collecting both (binary) responses and (continuous) response times on test items, it is possible to measure the accuracy and speed of test takers. To study the relationships between these two constructs, the model is extended with a multivariate multilevel regression structure which allows the incorporation of covariates to explain the variance in speed and accuracy between individuals and groups of test takers. A Bayesian approach with Markov chain Monte Carlo (MCMC) computation enables straightforward estimation of all model parameters. Model-specific implementations of a Bayes factor (BF) and deviance information criterium (DIC) for model selection are proposed which are easily calculated as byproducts of the MCMC computation. Both results from simulation studies and real-data examples are given to illustrate several novel analyses possible with this modeling framework.

As no internationally agreed-upon method for determining safe speed values currently exists, collecting vast amounts of information on conventional ship behaviour could be used to train autonomous ship intelligence in determining safe speeds in different conditions. This requires speed data collected from conventional ships to resemble what can be described as safe speeds. To test this, the Automatic Identification System (AIS) and environmental data – namely visibility, mean wind speed and significant wave height – were collected and merged for two study areas in Norway in the period between 27 March 2014 and 1 January 2021. Regression analyses based on 47,490 unique vessel transits were conducted and supplemented by two graphical methods for revealing relationships between variables. Contrary to the contemporary understanding of safe speed, reduced visibility did not lead to significantly reduced transit speeds. Wind and waves caused a reduction in speed in the open ocean, but not in coastal waters. Transit speeds were lower in coastal waters than in the open ocean.

We make hundreds of decisions every day, many of them extremely quickly and without much explicit deliberation. This motivates two important open questions: What is the minimum time required to make choices with above chance accuracy? What is the impact of additional decision-making time on choice accuracy? We investigated these questions in four experiments in which subjects made binary food choices using saccadic or manual responses, under either “speed” or “accuracy” instructions. Subjects were able to make above chance decisions in as little as 313 ms, and choose their preferred food item in over 70% of trials at average speeds of 404 ms. Further, slowing down their responses by either asking them explicitly to be confident about their choices, or to respond with hand movements, generated about a 10% increase in accuracy. Together, these results suggest that consumers can make accurate every-day choices, akin to those made in a grocery store, at significantly faster speeds than previously reported.

We used correlation and spectral analyses to investigate the cognitive structures and processes producing biased judgments. We used 5 different sets of driving problems to exemplify problems that trigger biases, specifically: (1) underestimation of the impact of occasional slow speeds on mean speed judgments, (2) overestimation of braking capacity after a speed increase, (3) the time saving bias (overestimation of the time saved by increasing a high speed further, and underestimation of time saved when increasing a low speed), (4) underestimation of increase of fatal accident risk when speed is increased, and (5) underestimation of the increase of stopping distance when speed is increased. The results verified the predicted biases. A correlation analysis found no strong links between biases; only accident risk and stopping distance biases were correlated significantly. Spectral analysis of judgments was used to identify different decision rules. Most participants were consistent in their use of a single rule within a problem set with the same bias. The participants used difference, average, weighed average and ratio rules, all producing biased judgments. Among the rules, difference rules were used most frequently across the different biases. We found no personal consistency in the rules used across problem sets. The complexity of rules varied across problem sets for most participants.

In this study, we focus on the temporal behaviors – speed and rhythm – of outward foreign direct investment (OFDI) by emerging multinational enterprises (EMNEs) and examine the effect of such behaviors on innovation performance. Using a learning perspective, we argue that OFDI speed has an inverted U-shaped effect on EMNEs’ innovation performance, whereas the relationship between the uneven rhythm of OFDI and innovation performance is negative. The results, based on OFDI panel data of 1,092 Chinese firms, support our predictions that a moderate OFDI speed and a more regular pattern of OFDI expansion provide sources of competitiveness and contribute to firms’ innovation performance.

Trematode transmission in aquatic habitats from molluscan intermediate host to vertebrate or invertebrate target host is typically undertaken by a free-living stage known as cercariae. Active locomotion by cercariae is a key aspect of the transmission process with the swimming speed potentially contributing to infection success. Individual cercarial species swim at different speeds but the significance of this to infection potential has not been determined. This study, using data from the scientific literature, investigates the role of swimming speed in relation to cercarial morphology, host-searching strategies and target host species. Larger cercariae swim faster than smaller ones with tail length being the principal factor controlling locomotion rates. Different cercarial morphotypes swim at different speeds, in particular, furcocercariae, with the exception of the schistosomes, being faster swimmers than mono-tailed cercariae. Host-searching behaviour has a significant influence on swimming speeds with ‘active-searching’ strategies swimming slower than those adopting ‘active-waiting’ or ‘prey mimcry’ strategies. Vertebrate-infecting cercariae swim faster than those infecting invertebrates with species targeting fish demonstrating the highest locomotion rates and those targeting arthropods the slowest speeds. The adaptions of individual cercarial swimming speeds to biological variables and their interactions with the physical processes of aquatic habitats are discussed.

Qualitative and quantitative performance on the Halstead Finger Tapping test may help differentiate brain dysfunctional patients from normal controls. “Normal” and “abnormal” finger tapping patterns during this task have been characterized and illustrated pictorially. Data from 65 patients with traumatic brain injury (TBI) and 15 normal controls support the dual proposition that (1) abnormal finger tapping patterns are more commonly observed in TBI patients than in controls and (2) the frequency of abnormal finger movements may relate to the severity of TBI during the acute stages after trauma. Future prospective studies are needed to replicate these findings. (JINS, 2003, 9, 128–133.)

Objectives: A wealth of studies provide evidence for action simulation during language comprehension. Recent research suggests such action simulations might be sensitive to fine-grained information, such as speed. Here, we present a crucial test for action simulation of speed in language by assessing speed comprehension in patients with Parkinson’s disease (PD). Based on the patients’ motor deficits, we hypothesized that the speed of motion described in language would modulate their performance in semantic tasks. Specifically, they would have more difficulty processing language about relatively fast speed than language about slow speed. Methods: We conducted a semantic similarity judgment task on fast and slow action verbs in patients with PD and age-matched healthy controls. Participants had to decide which of two verbs most closely matched a target word. Results: Compared to controls, PD patients were slower making judgments about fast action verbs, but not for judgments about slow action verbs, suggesting impairment in processing language about fast action. Moreover, this impairment was specific to verbs describing fast action performed with the hand. Conclusions: Problems moving quickly lead to difficulties comprehending language about moving quickly. This study provides evidence that speed is an important part of action representations. (JINS, 2017, 23, 412–420)

We examined two-wave longitudinal changes in two indicators of neurocognitive speed (i.e., mean rate, intraindividual variability) using one simple and three complex reaction time tasks. Participants included idiopathic Parkinson's disease (PD) patients, with and without incipient dementia, and normal controls. At baseline, there were 45 patients (26 men, 19 women) with idiopathic PD who ranged from 65 to 84 years (M = 71.3; SD = 4.5) and 47 matched controls (27 men, 20 women) who ranged from 65 to 84 years (M = 71.4; SD = 4.9). The 18-month longitudinal sample comprised of 74 returning participants (43 controls; 31 PD patients) who had no cognitive impairment or dementia at both waves. Ten of the 31 PD patients returning for Time 3 had dementia or cognitive impairment. These constituted the PD with incipient dementia (PDID) group. Repeated measures analyses of variance showed that the PD and PDID groups were slower over time on the reaction time tasks, whereas the controls improved their performance over time on all tasks. Inconsistency distinguished the two clinical groups (i.e., the PDID group but not the PD group became more inconsistent over time). Changes in neurocognitive speed and inconsistency may be valid clinical markers of PDID. (JINS, 2012, 18, 1–9)

Healthy participants (n = 237) aged 45–79 were tested neuropsychologically with tests of memory, speed, and cognitive control and followed up for 3–5 years (mean, 3.4 years). The sample was genotyped for apolipoprotein E (APOE) and CHolinergic Receptor for Nicotine Alpha 4 (CHRNA4), and genetic effects on cognitive function at initial testing and on cognitive decline was studied. We predicted relatively stronger effects of APOE on memory, and of CHRNA4 on speeded tasks. The predictions were partially confirmed, but we found interactive effects of APOE and CHRNA4 in several cognitive domains. Being an APOE ε4/CHRNA4 TT carrier was associated with slower and less efficient performance, and with steeper decline in speed tasks and in delayed recall. Age dependent genetic effects were found for both APOE and CHRNA4, where old participants (60–79 years) showed a negative influence of TT carrier status on initial memory performance, but a tendency for steeper memory decline in ε4 carriers. Inconsistent and small effects of APOE reported in previous studies of healthy groups may be caused by failure to consider epistasis of APOE with nicotinic receptor and other genes. (JINS, 2010, 16, 424–432.)

The kinematics of each joint of the guinea pig Cavia porcellus were studied during the locomotor cycle at increasing speed by high-speed cinefluorography. The main objective was to reveal the functional specific features of these structural elements in each dynamic phase of the cycle and also which limb joints are important during the increase of animal speed. Most of the analysed angles in C. porcellus were affected as the speed increased, both in trot and gallop. However, only a few of them were correlated with speed. There were also differences with respect to symmetrical or asymmetrical gaits. Both pairs of limbs responded differently to the increase of speed; while the forelimb joints modified the duration of their action (frequency) more than the amplitude (stride length), the hindlimbs acted inversely. The movements of the joints during the stance phase changed dramatically with speed, particularly in the hindlimb. At knee level, the flexion amplitude increases to maintain the stiffness of the leg spring, a principle previously discussed as essential for the running process. In the swing phase, inertial effects are the main constraints and, as in the stance phase, the knee joint in the swing phase is correlated with speed both during trot and gallop, confirming the major importance of this joint to increasing speed.