Cross-cultural effects on drivers' hazard perception : validating a test paradigm for developing countries

The hazard perception skill of a driver refers to their ability to identify potentially dangerous events on the road, and is one of the only driving-specific skills that has been consistently linked to accident rates. Hazard perception tests are used in several developed countries as part of the driver licensing curriculum, however little research has been done in developing countries where road safety is a primary concern. The extent to which hazard perception skill transfers to different driving environments is also unclear. This thesis therefore has two major aims: to examine hazard perception in a cross-cultural context, and to validate a hazard perception test for potential use in driver licensing in lower-income, developing countries. Most of the experiments in this thesis compare hazard perception skill in drivers from the UK – where hazard perception testing is well established – and drivers from Malaysia – a developing country with a high accident rate where hazards frequently occur. Typically, hazard perception skill is assessed by showing participants clips filmed on the road and asking them to respond as soon as they detect a developing hazard, with shorter response times reflecting greater levels of skill. Chapter 2 presents evidence that Malaysian drivers may be desensitized to hazardous road situations and thus have increased response times to hazards, creating validity issues with the typical paradigm. Subsequent chapters therefore use a predictive paradigm called the “What Happens Next?” test that requires drivers to predict hazards, leaving performance unaffected by hazard desensitization. Malaysian drivers predicted hazards less accurately than UK drivers in all cross-cultural experiments, indicating that exposure to a greater number of hazards on Malaysian roads did not have a positive effect on participants’ predictive hazard perception skill. Further experiments indicated that explicit knowledge plays a minor role in the “What Happens Next?” test, and that experienced drivers appear to compensate for reduced visual information more effectively than novices. Experienced drivers from both Malaysia and the UK also outscored novices in all experiments using the predictive paradigm, suggesting the “What Happens Next?” test provides a valid measure of hazard perception skill and may offer a practical alternative for hazard perception testing in developing and even developed countries

Cross-cultural effects on drivers' hazard perception : validating a test paradigm for developing countries

The hazard perception skill of a driver refers to their ability to identify potentially dangerous events on the road, and is one of the only driving-specific skills that has been consistently linked to accident rates. Hazard perception tests are used in several developed countries as part of the driver licensing curriculum, however little research has been done in developing countries where road safety is a primary concern. The extent to which hazard perception skill transfers to different driving environments is also unclear. This thesis therefore has two major aims: to examine hazard perception in a cross-cultural context, and to validate a hazard perception test for potential use in driver licensing in lower-income, developing countries. Most of the experiments in this thesis compare hazard perception skill in drivers from the UK – where hazard perception testing is well established – and drivers from Malaysia – a developing country with a high accident rate where hazards frequently occur. Typically, hazard perception skill is assessed by showing participants clips filmed on the road and asking them to respond as soon as they detect a developing hazard, with shorter response times reflecting greater levels of skill. Chapter 2 presents evidence that Malaysian drivers may be desensitized to hazardous road situations and thus have increased response times to hazards, creating validity issues with the typical paradigm. Subsequent chapters therefore use a predictive paradigm called the “What Happens Next?” test that requires drivers to predict hazards, leaving performance unaffected by hazard desensitization. Malaysian drivers predicted hazards less accurately than UK drivers in all cross-cultural experiments, indicating that exposure to a greater number of hazards on Malaysian roads did not have a positive effect on participants’ predictive hazard perception skill. Further experiments indicated that explicit knowledge plays a minor role in the “What Happens Next?” test, and that experienced drivers appear to compensate for reduced visual information more effectively than novices. Experienced drivers from both Malaysia and the UK also outscored novices in all experiments using the predictive paradigm, suggesting the “What Happens Next?” test provides a valid measure of hazard perception skill and may offer a practical alternative for hazard perception testing in developing and even developed countries

A new tool for equating lexical stimuli across experimental conditions

In cognitive psychology and psycholinguistics, lexical characteristics can drive large effects, which can create confounds when word stimuli are intended to be unrelated to the effect of interest. Thus, it is critical to control for these potential confounds. As an alternative to randomly assigning word bank items to stimulus lists, we present LIBRA (Lexical Item Balancing & Resampling Algorithm), a MATLAB-based toolbox for quickly generating stimulus lists of user-determined length and number that can be closely equated on any number of lexical properties. The toolbox comprises two scripts: a genetic algorithm that performs the inter-list balancing, and a tool for filtering/trimming long omnibus word lists based on simple criteria, prior to balancing. Relying on randomized procedures often results in substantially unbalanced experimental conditions, but our method guarantees that the lists used for each experimental condition contain no meaningful differences. Thus, the lexical characteristics of the specific words used will add an absolute minimum of bias/noise to the experiment in which they are applied. •Our toolbox balances word lists for arbitrary lexical properties to control confounds in cognitive psychology research. •Our toolbox performs more efficiently than pure randomization or balancing manually. •A graphical user interface is provided for ease of use

Deep-Learning-Based Multivariate Pattern Analysis (dMVPA): A Tutorial and a Toolbox

In recent years, multivariate pattern analysis (MVPA) has been hugely beneficial for cognitive neuroscience by making new experiment designs possible and by increasing the inferential power of functional magnetic resonance imaging (fMRI), electroencephalography (EEG), and other neuroimaging methodologies. In a similar time frame, “deep learning” (a term for the use of artificial neural networks with convolutional, recurrent, or similarly sophisticated architectures) has produced a parallel revolution in the field of machine learning and has been employed across a wide variety of applications. Traditional MVPA also uses a form of machine learning, but most commonly with much simpler techniques based on linear calculations; a number of studies have applied deep learning techniques to neuroimaging data, but we believe that those have barely scratched the surface of the potential deep learning holds for the field. In this paper, we provide a brief introduction to deep learning for those new to the technique, explore the logistical pros and cons of using deep learning to analyze neuroimaging data – which we term “deep MVPA,” or dMVPA – and introduce a new software toolbox (the “Deep Learning In Neuroimaging: Exploration, Analysis, Tools, and Education” package, DeLINEATE for short) intended to facilitate dMVPA for neuroscientists (and indeed, scientists more broadly) everywhere

A predictive hazard perception paradigm differentiates driving experience cross-culturally

Hazard perception (HP) tests are used in several developed countries as part of the driver licensing process, where they are believed to have improved road safety; however, relatively little HP research has been conducted in developing countries, which account for 80% of the world’s road fatalities. Previous research suggests that drivers in these countries may be desensitized to hazardous road situations and thus have increased response latencies to hazards, creating validity issues with the typical HP reaction time paradigm. The present study compared Malaysian and UK drivers’ HP skills when watching video clips filmed in both countries, using a predictive paradigm where hazard criterion could not affect performance. Clips filmed in the UK successfully differentiated experience in participants from both countries, however there was no such differentiation in the Malaysian set of videos. Malaysian drivers also predicted hazards less accurately overall, indicating that exposure to a greater number of hazards on Malaysian roads did not have a positive effect on participants’ predictive hazard perception skill. Nonetheless the experiential discrimination noted in this predictive paradigm may provide a practical alternative for hazard perception testing in developing countries

Variability in the analysis of a single neuroimaging dataset by many teams

Data analysis workflows in many scientific domains have become increasingly complex and flexible. To assess the impact of this flexibility on functional magnetic resonance imaging (fMRI) results, the same dataset was independently analyzed by 70 teams, testing nine ex-ante hypotheses1. The flexibility of analytic approaches is exemplified by the fact that no two teams chose identical workflows to analyze the data. This flexibility resulted in sizeable variation in hypothesis test results, even for teams whose statistical maps were highly correlated at intermediate stages of their analysis pipeline. Variation in reported results was related to several aspects of analysis methodology. Importantly, a meta-analytic approach that aggregated information across teams yielded significant consensus in activated regions across teams. Furthermore, prediction markets of researchers in the field revealed an overestimation of the likelihood of significant findings, even by researchers with direct knowledge of the dataset2-5. Our findings show that analytic flexibility can have substantial effects on scientific conclusions, and demonstrate factors possibly related to variability in fMRI. The results emphasize the importance of validating and sharing complex analysis workflows, and demonstrate the need for multiple analyses of the same data. Potential approaches to mitigate issues related to analytical variability are discussed

Cross-cultural effects on drivers' hazard perception

Hazard perception tests are used in several developed countries as part of the driver licensing curriculum, however little research has been done in developing countries where road safety is a primary concern. We conducted a cross-cultural hazard perception study to examine the transferability of hazard perception skills between Malaysia and the UK, using hazard clips filmed in both countries. The results showed that familiarity with both the driving environment and type of hazard facilitated drivers' ability to discriminate hazards in a timely manner, although overall drivers viewed and responded to hazards largely similarly regardless of origin. Visual strategies also appeared to be moderated mainly by the immediate driving environment rather than driver origin. Finally, Malaysian drivers required a higher threshold of danger than UK drivers before they would identify a situation as hazardous, possibly reflecting the more hazardous road environment in Malaysia. We suggest that hazard perception testing in developing countries requires a test where performance cannot be confounded with differing thresholds for hazardousness

A New Tool for Equating Lexical Stimuli Across Experimental Conditions

Extensive work in cognitive psychology and psycholinguistics has demonstrated that lexical characteristics are capable of driving large effects, however when word lists serve a utility function and are intended to be unrelated to the effect of interest such as in most working memory or long-term memory paradigms, it is critical to control for these potentially confounding lexical effects. As an alternative to randomly assigning word bank items to stimulus lists, we present LIBRA, a MATLAB-based toolbox for quickly generating stimulus word lists of user-determined length and number, which can be closely equated on an arbitrary number of lexical properties. The toolbox comprises two scripts; one is the main genetic algorithm that performs the inter-list balancing, and the other provides functionality for filtering/trimming long omnibus word lists based on several simple criteria, prior to balancing. We demonstrate that relying on purely randomized procedures often results in substantially unbalanced experimental conditions. In contrast, our method guarantees that the lists used for each experimental condition contain no meaningful differences, and thus that the lexical characteristics of the specific words used will add an absolute minimum of bias/noise to the experiment in which they are applied

Continuous spinal anaesthesia: A retrospective analysis of 318 cases

Background and Aims: Continuous spinal anaesthesia (CSA) is an underutilised anaesthetic technique. Our objectives were to evaluate the use of CSA in our institution, its efficacy, ease to use and safety. Methods: This was a retrospective analysis conducted in a tertiary centre. Records of all patients who underwent surgery and received CSA between December 2008 and July 2017 were reviewed. Their demographic profiles, type and duration of surgery were analysed. The outcomes measured were the success of CSA, technical evaluation and difficulties encountered, intraoperative haemodynamics, usage of vasopressors and any reported complications. Statistical analysis was done using Chi-square test. Results: Three hundred and eighteen patients (94%) successfully underwent surgery using CSA. Twenty cases (6%) had failed CSA, of which five of them had CSA insertion failure, while the rest failed to complete the operation under CSA, thus requiring conversion to general anaesthesia. Patients who have had an initial intrathecal local anaesthetic (LA) volume ≥1.5 ml had higher odds (odds ratio (OR) 2.78; 95% confidence interval [CI], 1.70–4.57) of developing hypotension compared to those who had <1.5 ml (P < 0.001). There were no reported post-dural puncture headache, neurological sequelae or infection. Conclusion: CSA is a useful anaesthetic technique with low failure rate. The key to achieving haemodynamic stability is by giving a small initial bolus, then titrating the block up to required height using aliquots of 0.5 ml of intrathecal LA through the catheter