The effects of hand and direction parameter preknowledge on choice reaction times

The two studies undertaken investigated how reaction times are affected by preknowledge concerning hand and direction parameters, and the order in which these data are disclosed. In the first experiment, preknowledge was manipulated by selecting 2-CRT pairs which had either a common hand or direction component. Reaction signal information content (as defined by the number of unknown response parameters) was controlled, but no parameter differences emerged. When parameter order was manipulated by sequential precuing, the ‘hand then direction’ order conferred a significant advantage. Motor preparation and response selection explanations for this effect are considered. Various difficulties with the paradigms used are discussed, including those of distinguishing between response selection and motor programming contributions, controlling and inferring the strategies adopted by subjects, and defining task difficulty. The prospects for independently fostering either response identification or motor preparation by means of an appropriate selection of precues are also discussed.     

The rapid-smoking technique: Subject characteristics and treatment outcome

There is a lack of consistency in findings regarding subject (S) characteristics and the effects of smoking-control programmes. Research workers appear to assume that abstinence and reduction in smoking rate are merely different points in the same continuum, and therefore seek to correlate S variables with percentage reductions in smoking rate. It is argued that abstinence and reduced smoking are more appropriately viewed as potentially discrete outcomes. Conceptualizing outcome in this manner, a discriminant function analysis was employed to determine whether it is possible to differentiate between Ss who do, or do not, abstain following participation in a treatment programme involving rapid-smoking. It was found that it is possible to discriminate between the two groups of Ss. Advantages deriving from this approach to the investigation of S characteristics and treatment outcome are discussed.     

Independent perceptual reversals for simultaneously presented ambiguous figures

In two successive experiments using the divided visual field paradigm with vertical or horizontal division, two ambiguous figures, the Rubin’s vase-face or the Necker cube, were projected to the right and left or to the upper and lower visual hemifields of 108 healthy volunteers. Stimulation time was 120 s. The main hypotheses were (a) that different percepts of the same ambiguous figure may be simultaneously experienced in the two hemifields and (b) that the type (vertical vs. horizontal) of visual field division influences the reversal frequency and the temporal interdependence of the percepts.Results from the first experiment showed that the temporal interdependence of reversals was very low for both ambiguous figures, suggesting that during part of the stimulation time the subjects could experience different percepts of the same figure (e.g. a vase in the right and face profiles in the left visual hemifields). The second experiment showed that this perceptual dissociation occurred on average during one third of the stimulation time. In both experiments the type of visual field division did not influence either frequency or temporal interdependence of the reversals. When one single ambiguous figure was presented in the centre of the screen, the number of reversals was approximately the sum of the reversals observed with two figures presented simultaneously each in one hemifield.     

Do we feel the same level of guilt about the wrongdoings of close ones and distant ones? The mediating role of behavioural control

Understanding whether and why individuals' emotional responses are different to the same behaviour performed by different others is important for understanding phenomena in social interaction. Given that there is no relevant research in Eastern culture testing such issues, the present research including two studies was conducted with Chinese samples and investigated whether Easterners experience more vicarious guilt about close ones' immoral behaviours than distant ones' immoral behaviours and the underlying mechanism of the effect. Study 1 showed that people felt more guilty when recalling close ones' misdeeds than distant ones' misdeeds. Study 2 replicated the findings of Study 1 using the scenario method and demonstrated that behavioural control partially mediated the effect of relationship closeness on vicarious guilt, that is, people reported more behavioural control over close ones' immoral behaviours, which in turn resulted in more vicarious guilt. Implications for social interaction and directions for future research are discussed.     

Behavioural adaptation and effectiveness of a Forward Collision Warning System depending on a secondary cognitive task

Forward Collision Warning Systems (FCWS) have been designed to enhance road safety by reducing the number of rear-end collisions. Nevertheless, little is known about how drivers adapt their behaviour over time when using this kind of system. In addition, these systems are expected to aid particularly distracted drivers. However, previous research has suggested that the effectiveness of the system could depend on the difficulty level of the secondary task. The objective of this study on driving simulator was twofold. Firstly, it consisted in evaluating the behavioural adaptation to an FCWS as well as analysing the possible consequences of driving without the system after a short period of adaptation. Secondly, it was to evaluate the effectiveness of the system according to two different difficulty levels of a cognitive secondary task. The results showed that drivers adapted their behaviour positively when the system was introduced. Nevertheless, both the effectiveness and the behavioural adaptation in the short term were dependent on the cognitive load induced by the secondary task. These findings suggest that the warning needs some attentional resources to be processed. Finally, no negative or transfer effect was observed following the removal of the system after a short period of adaptation.     

Behavioural adaptation or constraint? The effect of curve proximity on driving behaviour

Horizontal curves are typically associated with increased crash risk when compared with straight roads, but recent analyses have suggested that having more frequent sharp curves decreases the relative crash risk posed by each curve. Here, 90 drivers completed a simulated rural drive with either high proximity (160 m straight tangent between curves) or low proximity (1200 m tangent) curves. Curve proximity had a significant effect on approach speeds, with drivers in the high proximity curve drive showing significantly lower mean and maximum approach speeds before entering the curve. However, they also showed an unexpected tendency to higher speeds while negotiating the curve itself. The current study provides direct empirical evidence that driving behaviour on approach to a given curve is significantly affected by the proximity of other curves, and therefore highlights the need to factor in the characteristics of the road on approach to the curve, as well as the features of the curve itself when assessing risk.     

Other road users’ adaptations to increase safety in response to older drivers’ behaviour

Changes in physical and cognitive abilities not only challenge the driving ability of older adults, in some situations age-related changes in driving behaviour require other road users to adapt their behaviour to maintain a safe traffic situation. In this study, we aimed to map age-related differences in driving behaviour and assess the impact on other road users. A group younger and a group older adults drove four different routes containing challenging situations (e.g., merging into motorway traffic) in a driving simulator while measures of driving behaviour were collected. Other road users’ deceleration responses to the driver’s behaviour were also collected as a measure of behavioural adaptation. Our results showed similar driving performance between young and older drivers when task complexity was low, but reduced performance in older drivers when tasks requirements increased. Lower driving speed and longer waiting times that were observed in older drivers can be interpreted as compensatory behaviour aimed at creating more time to lower task requirements. Crucially, in a non-time critical situation this compensatory behaviour was found to be successful, however in a time-critical situation (merging onto a motorway) this strategy had negative side effects because other road users had to decelerate in order to keep a safe distance. Our results show the importance of anticipation and adaptation by other road users for the success of older driver’s strategies and traffic safety.