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.     

The effect of swinging the arms on muscle activation and production of leg force during ski skating at different skiing speeds

The study investigated the effects of arm swing during leg push-off in V2-alternate/G4 skating on neuromuscular activation and force production by the leg muscles. Nine skilled cross-country skiers performed V2-alternate skating without poles at moderate, high, and maximal speeds, both with free (SWING) and restricted arm swing (NOSWING). Maximal speed was 5% greater in SWING (P < 0.01), while neuromuscular activation and produced forces did not differ between techniques. At both moderate and high speed the maximal (2% and 5%, respectively) and average (both 5%) vertical force and associated impulse (10% and 14%) were greater with SWING (all P < 0.05). At high speed range of motion and angular velocity of knee flexion were 24% greater with SWING (both P < 0.05), while average EMG of m. biceps femoris was 31% lower (all P < 0.05) in SWING. In a similar manner, the average EMG of m. vastus medialis and m. biceps femoris were lower (17% and 32%, P < 0.05) during the following knee extension. Thus, swinging the arms while performing V2-alternate can enhance both maximal speed and skiing economy at moderate and, in particularly, high speeds.     

Multi-dimensional coordination in cross-country skiing analyzed using self-organizing maps

This study sought to ascertain how multi-dimensional coordination patterns changed with five poling speeds for 12 National Standard cross-country skiers during roller skiing on a treadmill. Self-organizing maps (SOMs), a type of artificial neural network, were used to map the multi-dimensional time series data on to a two-dimensional output grid. The trajectories of the best-matching nodes of the output were then used as a collective variable to train a second SOM to produce attractor diagrams and attractor surfaces to study coordination stability. Although four skiers had uni-modal basins of attraction that evolved gradually with changing speed, the other eight had two or three basins of attraction as poling speed changed. Two skiers showed bi-modal basins of attraction at some speeds, an example of degeneracy. What was most clearly evident was that different skiers showed different coordination dynamics for this skill as poling speed changed: inter-skier variability was the rule rather than an exception. The SOM analysis showed that coordination was much more variable in response to changing speeds compared to outcome variables such as poling frequency and cycle length.     

The effect of exercise intensity on joint power and dynamics in ergometer double-poling performed by cross-country skiers

The purpose of this study was to examine the effect of increasing exercise intensity on the role of joint powers in ergometer double poling (DP), while taking specific dynamic constraints into account. One main question was whether lower-body power contribution increased or decreased with increasing intensity. Nine male Norwegian national-level cross-country skiers performed ergometer DP at low, moderate, high and maximal intensity. Kinematics, and ground (GRF) and poling (F_poling) reaction forces were recorded and used in link segment modeling to obtain joint and whole-body dynamics. Joint powers were averaged over the cycle, the poling (PP) and recovery (RP) phases. The contribution of these average powers was their ratios to cycle average poling power. At all intensities, the shoulder (in PP) and hip (mostly in RP) generated most power. Averaged over the cycle, lower-body contribution (sum of ankle, knee and hip power) increased from ∼37% at low to ∼54% at maximal intensity (p < .001), originating mostly from increased hip contribution within PP, not RP. The generation of larger F_poling at higher intensities demanded a reversal of hip and knee moment. This was necessary to appropriately direct the GRF vector as required to balance the moment about center of mass generated by F_poling (control of angular momentum). This was reflected in that the hip changed from mostly absorbing to generating power in PP at lower and higher intensities, respectively. Our data indicate that power-transfer rather than stretch-shortening mechanisms may occur in/between the shoulder and elbow during PP. For the lower extremities, stretch-shortening mechanisms may occur in hip, knee and trunk extensors, ensuring energy conservation or force potentiation during the countermovement-like transition from body lowering to heightening. In DP locomotion, increasing intensity and power output is achieved by increased lower-body contribution. This is, at least in ergometer DP, partly due to changes in joint dynamics in how to handle dynamic constraints at different intensities.     

The effects of the arm swing on biomechanical and physiological aspects of roller ski skating

This study analyzed the biomechanical and physiological effects of the arm swing in roller ski skating, and compared leg-skating (i.e. ski skating without poles) using a pronounced arm swing (SWING) with leg-skating using locked arms (LOCKED). Sixteen elite male cross-country skiers performed submaximal stages at 10, 15 and 20 km h⁻¹ on a 2% inclined treadmill in the two techniques. SWING demonstrated higher peak push-off forces and a higher force impulse at all speeds, but a longer cycle length only at the highest speed (all P < .05), indicating a lower force effectiveness with SWING at the two lowest speeds. Additionally, the flexion–extension movement in the lower limbs was more pronounced for SWING. Oxygen uptake was higher for SWING at the two lowest speeds (both P < .05) without any differences in blood lactate. At the highest speed, oxygen uptake did not differ between SWING and LOCKED, but the RER, blood lactate and ventilation were lower with SWING (all P < .05). Taken together, these results demonstrate that utilizing the arm swing in roller ski skating increases the ski forces and aerobic energy cost at low and moderate speeds, whereas the greater forces at high speed lead to a longer cycle length and smaller anaerobic contribution.     

The effect of speed limit credibility on drivers' speed choice

Credibility of speed limits is a key factor affecting drivers’ compliance with speed limits. Two experiments were conducted to investigate how credibility of speed limits affects judgments of appropriate speed. The first experiment aimed to establish speeds deemed appropriate by investigating Malaysians drivers’ judgments of the appropriate speed to drive based on photographs of roads with the speed limit sign erased. Drivers chose speeds which correlated with but were higher than the actual speed limits of the roads. Analysis of road characteristics suggested they based their decisions mainly on features of the road itself rather than of the roadside. The second experiment tested the impact of credibility of speed limit information on the speed drivers judged appropriate. Drivers judged the appropriate speed to drive for the same photographs as in Experiment 1 with speed limit information provided. Four conditions were included: two conditions where the speed limit posted was 10% higher or 10% lower than the appropriate speed established in Experiment 1 (credible speed limits), and two conditions where the posted speed limit was 50% higher or 50% lower than the appropriate speed (non-credible speed limits). Posted speed limits did affect drivers’ judgments about the appropriate speed to drive. Credibility also influenced judgments whereby drivers selected appropriate speeds consistent with the speed limits for the 10% lower condition, but not for speed limits that deviated highly from the appropriate speed judged in Experiment 1.     

Driving speed choice: The role of conscious monitoring and control (reinvestment) when driving

This study aimed to examine the role of reinvestment - the propensity to consciously monitor and control actions (movement specific reinvestment) and to consciously monitor and evaluate decision making processes (Decision specific reinvestment) while driving in everyday risky scenarios. The study also aimed to evaluate the association between reinvestment and previously validated driver attitude measures. Fifty one participants completed a series of questionnaires (Driving Self-Efficacy Scale, Driver Attitude Questionnaire, Movement Specific Reinvestment Scale, Decision Specific Reinvestment Scale) after which they completed a test phase in a driving simulator. In the test phase, driving scenarios included roads with different markings (i.e., double yellow, wide centrelines, wire rope barriers, Audio Tactile Profiled markings) and alerting scenarios (i.e., police car present, high crash risk area sign, reduced speed zone). Results revealed that on risky roads (wide centrelines), participants with a high propensity for decision specific reinvestment drove slower than those with a low propensity. Driver experience, attitudes towards speeding and scores on the Decision Reinvestment subscale of the Decision Specific Reinvestment Scale significantly predicted speed choice. More experienced participants with higher scores on the Decision Reinvestment subscale were more likely to drive slower and participants with worse attitudes towards speeding were likely to drive faster. Participants with a low propensity for movement specific reinvestment (specifically, Movement Self-Consciousness) reduced their speed to a greater extent than those with a high propensity when driving in the police car scenario. There was some evidence to suggest that high decision specific and movement specific reinvesters were more likely to be involved in crashes and receive driving infringements. The current study is the first to demonstrate a significant relationship between reinvestment and driving. The implications of these findings for road safety are discussed.     

The role of values in the choice shift

In Study I, the self-ideal discrepancy in risk taking was found to be unrelated to the strength of values relevant to the risks under consideration, and the other-self discrepancy was found to be related to these values only by virtue of one of its components, inital preference. Hence the use of these discrepancies as measures of value strength must be questioned. This casts doubt on some of the evidence formerly thought to support the assumption that values provide the force that drives the choice shift. In Study II, two hypotheses derived from this assumption were not supported. In light of this result, and closely related negative findings from two other studies, it would appear that this assumption must either be discarded or revised. Some possible lines of revision are suggested. Some of the results were also prejudicial to two theories about the mechanism through which values or other forces allegedly produce the shift: norm-comparison theory and pluralistic-ignorance theory.     

The role of contingency in classical conditioning

The assumption that classical conditioning depends on a contingent relation between the conditioned stimulus (CS) and the unconditioned stimulus (US), which was proposed some decades ago as an alternative to the traditional contiguity assumption, still is widely accepted as an empirical generalization, if no longer as a theoretical postulate. The first support for the contingency assumption was provided by experiments in which occasional CS-US pairings produced no response to the CS in random training--i.e., training in which the probability of the US was the same in the presence and absence of the CS. Those early experiments, the results of which too often are taken at face value, are reconsidered along with various later experiments that show conditioning, both of the CS and its context, in random training. The evidence suggests that CS-US contingency is neither necessary nor sufficient for conditioning and that the concept has long outlived any usefulness it may once have had in the analysis of conditioning.     

The role of uncertainty in attentional and choice exploration

Psychonomic Bulletin & Review - The exploitation-exploration (EE) trade-off describes how, when making a decision, an organism must often choose between a safe alternative with a known pay-off,...     

Spoilt for choice: The role of counterfactual thinking in the excess choice and reversibility paradoxes

Contrary to popular belief many choice options and the ability to reverse one's initial choice are sometimes associated with decreased chooser satisfaction. Two studies investigated the role of counterfactual thinking in explaining these paradoxes. Participants chose drawing implements from either a limited (6) or extensive (24) choice set (Study 1), or an expected reversible/non-reversible selection (Study 2). Following a drawing task, satisfaction with their chosen implement was rated under either high or low cognitive load to manipulate the availability of counterfactual alternatives. In Study 1 satisfaction was higher with limited vs. extensive choice under low load. The number of counterfactuals generated mediated this effect. Under high load the pattern was reversed. Participants in Study 2 generated more counterfactuals when reversibility was expected under low but not high load and this partially mediated the impact of expected reversibility on revealed satisfaction. Implications for theoretical understanding of these paradoxes are discussed.     

The role of familiarity in binary choice inferences

In research on the recognition heuristic (Goldstein & Gigerenzer, Psychological Review, 109, 75–90, 2002), knowledge of recognized objects has been categorized as “recognized” or “unrecognized” without regard to the degree of familiarity of the recognized object. In the present article, we propose a new inference model—familiarity-based inference. We hypothesize that when subjective knowledge levels (familiarity) of recognized objects differ, the degree of familiarity of recognized objects will influence inferences. Specifically, people are predicted to infer that the more familiar object in a pair of two objects has a higher criterion value on the to-be-judged dimension. In two experiments, using a binary choice task, we examined inferences about populations in a pair of two cities. Results support predictions of familiarity-based inference. Participants inferred that the more familiar city in a pair was more populous. Statistical modeling showed that individual differences in familiarity-based inference lie in the sensitivity to differences in familiarity. In addition, we found that familiarity-based inference can be generally regarded as an ecologically rational inference. Furthermore, when cue knowledge about the inference criterion was available, participants made inferences based on the cue knowledge about population instead of familiarity. Implications of the role of familiarity in psychological processes are discussed.     

Culture and the role of choice in agency

Three cross-cultural studies conducted among U.S. and Indian adults compared perceptions of helping friends in strongly versus weakly expected cases, views of helping family versus strangers, and responses to a self-determination motivation scale. Expectations to help family and friends were positively correlated with satisfaction and choice only among Indians and not among Americans. Also, whereas U.S. respondents associated lesser satisfaction and choice with strongly versus weakly socially expected helping, Indian respondents associated equal satisfaction and choice with the 2 types of cases. Providing evidence of the importance of choice in collectivist cultures, the results indicate that social expectations to meet the needs of family and friends tend to be more fully internalized among Indians than among Americans. Methodologically, the results also highlight the need to incorporate items that tap more internalized meanings of role-related social expectations on measures of motivation in the tradition of self-determination theory.     

The role of inhibition and speed of processing in mathematics

The current study highlights the importance of inhibitory ability in facilitating performance in mathematics. To understand the role of inhibition in mathematical knowledge, this study tested 102 college students on a series of standardized complex math exercises. Inhibition tasks varied by task and stimuli (letters, numbers, and arrows). The result showed stronger associations between math abilities and strength of inhibition with more inhibition found for the flanker task (involving inhibition of peripheral stimuli) than for the Navon task (requiring inhibition of a potential response). The results supported the view that Inhibition in general (which is not unique to numerical stimuli) is associated with math abilities. General, rather than specific inhibition was associated with math abilities and finally, speed of processing masked the relationship between math and inhibition. These results confirm the assumption that the relation between inhibition and math performance is modulated by the task that measures the inhibition, and by additional predictors such as processing speed.     

The development, validation, and application of a video-based technique for measuring an everyday risk-taking behavior: drivers' speed choice

Drivers' choice of speed is an important aspect of everyday risk-taking behavior because it has been shown to be one of the most important predictors of road accident involvement. This research developed, validated, and applied a measure of drivers' speed choice that combined a high degree of experimental control with external and ecological validity. In Study 1, a video-simulation measure of drivers' speed choice was developed and found to relate specifically to speed-related accident involvement, implying a degree of external validity. In Study 2, the measure was used to investigate the effect of auditory feedback on drivers' speed choice. It was found that increasing the level of internal car noise decreased drivers' preferred speeds. Further analyses indicated that this was likely due to perceptual effects on speed estimation. Results are discussed in terms of road safety and the ability of video-based measures to facilitate experimental control over tasks involving complex ecological stimuli.     

Expectations and perceptions at school transitions: The role of peer status and aggression

This study integrated research on aggression, peer status, and social and academic functioning across the middle- and high-school transitions. We examined how peer status and aggression are related to adolescents' expectations about their academic and social functioning in a new school system before the transition into that system, and their perceived academic and social functioning after the transition. Social preference, perceived popularity, overt and relational aggression, and social and academic expectations were assessed in Grades 5 and 8; identical peer status and aggression constructs and perceived social and academic functioning were assessed in Grades 6 and 9. Results indicated moderate correlations between adolescents' social and academic expectations and perceived functioning across both school transitions. Girls reported higher social and academic functioning than boys did in most cases. Perceived popularity was consistently positively associated with academic and social expectations for middle and high school, whereas social preference was associated with perceived social functioning in both middle school and high school. The link between aggression and outcome variables varied by age and was moderated by gender and peer status.     

Temporal coordination during bimanual reach-to-grasp movements: The role of vision

The performance of bimanual movements involving separate objects presents an obvious challenge to the visuo-motor system: Visual feedback can only be obtained from one target at a time. To overcome this challenge overt shifts in visual attention may occur so that visual feedback from both movements may be used directly (Bingham, Hughes, & Mon-Williams, 2008; Riek, Tresilian, Mon-Williams, Coppard, & Carson, 2003). Alternatively, visual feedback from both movements may be obtained in the absence of eye movements, presumably by covert shifts in attention (Diedrichsen, Nambisan, Kennerley, & Ivry, 2004). Given that the quality of information falls with increasing distance from the fixated point, can we obtain the level of information required to accurately guide each hand for precision grasping of separate objects without moving our eyes to fixate each target separately? The purpose of the current study was to examine how the temporal coordination between the upper limbs is affected by the quality of visual information available during the performance of a bimanual task. A total of 11 participants performed congruent and incongruent movements towards near and/or far objects. Movements were performed in natural, fixate-centre, fixate-left, and fixate-right vision conditions. Analyses revealed that the transport phase of incongruent movements was similar across vision conditions for the temporal aspects of both the transport and grasp, whereas the spatial aspects of grasp formation were influenced by the quality of visual feedback. We suggest that bimanual coordination of the temporal aspects of reach-to-grasp movements are not influenced solely by overt shifts in visual attention but instead are influenced by a combination of factors in a task-constrained way.     

Judgments of mean speed and predictions of route choice

How are driving speeds integrated when speeds vary along a route? In a first study, we examined heuristic processes used in judgments of mean speed when the mean speeds on parts of the trip varied. The judgments deviated systematically from objective mean speeds because the distances driven at different speeds were given more weight than travel time spent on the different distances. The second study showed that when there was a 10–15 min pause during a travel the effect on the mean speed decrease was underestimated for driving speeds of 90 km/h and higher. In the third study, the objective mean speeds and the subjective biased mean speed judgments were used to predict choices between routes with different speed limits. The results showed that subjective judgments predicted decisions to maximize mean speed significantly better than objective mean speeds. Finally, some applied and basic research implications of the results were discussed.