Failure of Retrospective Inference in Rats' Taste Aversion

Three experiments explored the possibility of retrospective inference in the rat. Experiment 1 revealed that poisoning of an element of a taste compound after single compound poisoning enhanced aversion to the other element, and that presentation of an element without poison after the compound poisoning reduced aversion to the other element. These results were opposite to those predicted by retrospective inference. Experiment 2 eliminated some confounding variables and examined the effect of element poisoning after compound poisoning. The result again was opposite to what the retrospective view predicts. The results, however, accorded with the idea that within-compound learning was established during compound presentation, and subsequent poisoning or nonpoisoning of one element affected response to the other element via the within-compound learning. In Experiment 3, the possibility of within-compound learning was reduced by using sequential presentation of tastes, but there was no indication of retrospective inference even under this condition.     

Societal risks as seen by a Norwegian public

In two studies, questionnaires originally developed to study risk perception in the United States were administered to Norwegian students. Level of perceived risk in Norway was clearly below American scores for most hazards, but slightly above what has been found in a parallel Hungarian study. Norwegians were more concerned than both Hungarians and Americans about narcotics, but less than Americans about chemicals used in food and agriculture, and less than Hungarians about a number of common, everyday hazards. When ratings on nine risk characteristics were factor analyzed, a two dimensional solution was found with Fatal risk and Involuntary risk as the two most important dimensions. Ratings of general death risk, harm risk, and death risk for those exposed were highly correlated, but appeared to be unrelated to the number of people believed to be exposed to the hazard.     

Risk compensation theory and bicycle helmets – Results from an experiment of cycling speed and short-term effects of habituation

It has been suggested that the safety benefits of bicycle helmets are limited by risk compensation. The current study contributes to explaining whether the potential safety effects of bicycle helmets are reduced by cyclists’ tendency to cycle faster when wearing them (as a result of risk compensation), and if this potential reduction can be associated with a change in perceived risk. A previous study (Fyhri & Phillips, 2013) showed that non-routine helmet users did not increase their speed immediately after being given a helmet to wear, while routine helmet users cycled more slowly. The current study tests whether the previously found reduction in speed in response to helmet removal – as an indirect indicator of risk compensation – could be established in non-routine helmet users, after a period of habituation while cycling with a helmet.We did this by conducting a randomized crossover trial, in which we used GPS-derived speed calculations and self-reported risk perception. To test the effect of habituation, we used a design where each participant took part in two rounds with a break between and each round having two trips. We collected the data in June 2015. Non-routine helmet users (N = 31) were recruited in the field (along cycle routes in Oslo), and through a sample drawn from the Falck National register of bicycle owners. In the first phase of the study, all participants were asked to complete a test route (2.4 km downhill) with and without a helmet. In the second phase of the experiment, conducted after 1.5–2 h, the same participants again completed the test route with and without a helmet. In the time between the first and second phases of the experiment, all participants were given helmets, and told to use them on a predefined bicycle route.Habituation to the helmet between the first and second phases of the experiment did not produce any decrease (with helmet removal) in speed, on top of the habituation that occurred while cycling down the hill (the order effect). Mean speed difference for cycling with/without a helmet before the break was −0.76 km/h, after the break this difference was 0.32 km/h; 95% CIs [−0.5, 2.9] and [−0.9, 1.5]. We argue that risk compensation is an unlikely effect of using a bicycle helmet, and probably cannot explain any adverse effects related to helmet legislation.     

Reducing young drivers’ crash risk: Are we there yet? An ecological systems-based review of the last decade of research

The involvement of young novice drivers in road crashes and violations has remained a significant transport and public health issue worldwide. Despite extensive evidence that multiple individual, social, and environmental factors contribute to risk while driving, crashes among young novice drivers have decreased only marginally. There is a need to define clear indicators of risk as well as develop effective interventions.The current study reviews the literature on young novice drivers, including empirical studies, systematic reviews, and crash reports published over the past ten years to provide a synthesis of risk and protective factors across multiple domains, from individual characteristics, to social influences, to behavioural and social interventions, to the car and road environment. Adopting an ecological systems perspective, we discuss links between these domains to clarify the strongest indicators of risk for young novice drivers as compared to experienced drivers, and we collate the available evidence on social and environmental factors that can improve young drivers’ behaviour so to reduce the rate of their road crashes.Among the factors discussed, the incomplete maturation of cognitive skills crucial to safe driving (visual scanning, hazard anticipation, handling of in-vehicle distractions) and the higher susceptibility to social influences (especially peers and parents) emerged as the strongest determinants of discrepancies in performance between young novice and experienced drivers. Growing awareness of the complex array of factors intervening synergistically in young drivers’ risk, as well as technological advancements have led to the design of interventions with some level of effectiveness, however, further research and more robust programmes adopting ecological and holistic approaches are needed to fully address the young driver problem.     

Transport risk evaluations associated with past exposure to adverse security events in public transport

The current study aims to examine differences in risk evaluations according to whether individuals have been exposed to adverse security events in transport during the last five years. In addition, a path model is tested where risk evaluations predict intentions to use public transport and use of such transport in these groups. The results are based on a survey conducted in a randomly obtained representative sample of the Norwegian urban public (n = 1043). The results showed that individuals who had been exposed to adverse security events in public transport reported substantially higher risk perception of experiencing security issues in such transport than those who were not exposed. Exposed individuals also reported higher probability judgements and more worry of experiencing injury in public transport. The path model showed that high probability judgements of experiencing injury in public transport were related to a lower intention of using such transport, whereas corresponding worry in the private motorized sector predicted a stronger intention to use public transport. Demand for risk mitigation in the public transport sector was found to be more relevant for intentions to use public transport than similar demands in the private motorized sector. The path model and coefficients were not found to differ significantly according to exposure to security events in public transport. The findings are discussed in relation to the role of negative risk experiences for risk evaluations in transport.     

Age and gender comparisons of driving while sleepy: Behaviours and risk perceptions

To assist road safety professionals in developing effective strategies to combat the risk associated with driving while fatigued, a survey was administered to 1000 Australian drivers. Participants reported their past behaviours in regards to driving while sleepy and their perceptions of risk associated with driving fatigued as compared to speeding and driving under the influence of alcohol. Although participants appeared to be aware of the substantial risk associated with driving while sleepy, many drivers reported that they frequently drive when sleepy. Age and gender comparisons, revealed that risk taking behaviour in regards to driving while sleepy is occurring across all age groups and in both male and female drivers. Overall young to middle age drivers and male drivers reported the highest frequency of driving while sleepy and reported the lowest perceived personal risk in regards to driving while sleepy.     

When and for whom do frequencies facilitate performance? On the role of numerical literacy

The thesis that the mind is better prepared to process frequencies—as compared to other numerical formats—continues to be debated. A recent aspect of this issue is the role of numeracy (numerical literacy; one's ability to understand and work with numerical information) and specifically the argument that individual differences in numeracy interact with numerical formats. This interaction, either that frequencies improve performance only for those of low numeracy or that frequencies work only for those of high numeracy, would suggest that better performance using frequencies could be due to (nonevolutionary) numeracy effects. The three present studies revisited prior work with cumulative probability, Bayesian reasoning, and scenario risk assessments to study the effects of numeracy on frequency facilitation. Results from these experiments consistently failed to replicate previous findings of interactions; however, a more consistent finding emerged of a straightforward frequency effect. The lack of interactions and observations of frequency main effects lend support to the evolutionary explanation of the frequency effect. In addition, some possible statistical processes are proposed to explain the observation of interactions in past studies.     

Colour specificity in episodic and in perceptual object recognition with enhanced colour impact

In three experiments we investigated the perceptual specificity of explicit (old-new object recognition) and implicit memory (word-picture matching) for colour. In order to enhance the impact of colour on processing, we increased the number of colours per object and we impaired shape information. We presented multicoloured pictures (Experiment 1), blurred and partially occluded pictures (Experiment 2) and coloured line drawings in visual noise (Experiment 3). Experiments 1 and 2 had an intentional study phase; the study phase of Experiment 3 was an incidental colour or category naming task. Changing colour from study to test always had negative effects on episodic recognition although colour was irrelevant. In contrast, in the matching task old pictures were generally matched faster than new ones independent of their colour congruence. In Experiment 3, an additional small advantage of congruent colours and of semantic processing occurred. We conclude that two different memory representations contribute to these tasks. Changes of an achromatic, more abstract representation, that is used in normal object recognition, and a representation of the specific exemplar that includes colour. This latter token is used in episodic recognition as well as in unusual perceptual tasks (Experiment 3).     

Risk aversion in information seeking

The information gain model argues that participants select alternatives with a larger expected value of information gain. The present study investigated risk aversion in information seeking to examine whether the expected value always determines information-seeking behaviour. For this investigation, we used a scale method selection task in which participants were required to select one of two scales for weighing coins in order to find an underweight coin. Two experiments showed that participants more frequently selected the alternative that provided information gain without risk, although its expected information gain was smaller. This finding indicates the presence of risk aversion in information seeking, suggesting that information-seeking behaviour is affected by risk associated with obtaining information gain.