[Show abstract][Hide abstract] ABSTRACT: Landing an aircraft is a complex task that requires effective attentional control in order to be successful. The present study examined how anxiety may influence gaze behavior during the performance of simulated landings. Participants undertook simulated landings in low visibility conditions which required the use of cockpit instruments in order to obtain guidance information. Landings were performed in either anxiety or control conditions, with anxiety being manipulated using a combination of ego-threatening instructions and monetary incentives. Results showed an increase in percentage dwell time towards the outside world in the anxiety conditions. Visual scanning entropy, which is the predictability of visual scanning behavior, showed an increase in the randomness of scanning behavior when anxious. Furthermore, change in scanning randomness from the pre-test to anxiety conditions positively correlated with both the change in cognitive anxiety and change in performance error. These results support the viewpoint that anxiety can negatively affect attentional control.
Journal of Applied Research in Memory and Cognition. 06/2014; 3:63-71.
[Show abstract][Hide abstract] ABSTRACT: Purpose: A driving simulator was used to examine the relationship between motion perception and driving performance. Although motion perception test scores have been shown to be related to driving safety, it is not clear which combination of tests are the best predictors and whether motion perception training can improve driving performance. Methods: In Experiment 1, 60 younger drivers (22.4 ± 2.5 years) completed three motion perception tests [2D motion-defined letter (MDL) identification, 3D motion in depth sensitivity (MID), and dynamic visual acuity (DVA)] followed by two driving tests [emergency braking (EB) and hazard perception (HP)]. In Experiment 2, 20 drivers (21.6 ± 2.1 years) completed 6 weeks of motion perception training (using the MDL, MID and DVA tests) while 20 control drivers (22.0 ± 2.7 years) completed an online driving safety course. EB performance was measured pre- and post-training. Results: In Experiment 1, both MDL (r = .34) and MID (r=.46) significantly correlated with EB score. The change in DVA score as a function of target speed (i.e., "velocity susceptibility") was most strongly correlated with HP score (r = -.61). In Experiment 2, the motion perception training group had a significant decrease in brake reaction time on the EB test from pre-post while there was no significant change for the control group: t(38) = 2.24, p = 0.03. Conclusions: Tests of 3D motion perception are the best predictor of EB while DVA velocity susceptibility is the best predictor of hazard perception. Motion perception training appears to result in faster braking responses.
[Show abstract][Hide abstract] ABSTRACT: Perception of hill slant is exaggerated in explicit awareness. Proffitt (Perspectives on Psychological Science 1:110-122, 2006) argued that explicit perception of the slant of a climb allows individuals to plan locomotion in keeping with their available locomotor resources, yet no behavioral evidence supports this contention. Pedestrians in a built environment can often avoid climbing stairs, the man-made equivalent of steep hills, by choosing an adjacent escalator. Stair climbing is avoided more by women, the old, and the overweight than by their comparators. Two studies tested perceived steepness of the stairs as a cue that promotes this avoidance. In the first study, participants estimated the steepness of a staircase in a train station (n = 269). Sex, age, height, and weight were recorded. Women, older individuals, and those who were heavier and shorter reported the staircase as steeper than did their comparison groups. In a follow-up study in a shopping mall, pedestrians were recruited from those who chose the stairs and those who avoided them, with the samples stratified for sex, age, and weight status. Participants (n = 229) estimated the steepness of a life-sized image of the stairs they had just encountered, presented on the wall of a vacant shop in the mall. Pedestrians who avoided stair climbing by choosing the escalator reported the stairs as steeper even when demographic differences were controlled. Perceived steepness may to be a contextual cue that pedestrians use to avoid stair climbing when an alternative is available.
[Show abstract][Hide abstract] ABSTRACT: The aim of this study was to investigate if duration of decaffeinated green tea extract (dGTE) ingestion plays a role in augmenting fat oxidation rates during moderate-intensity exercise.
In a cross-over, placebo controlled design, 19 healthy males [x± SD age: 21 ± 2 y; weight 75.0 ± 7.0 kg; body mass index (BMI) 23.2 ± 2.2 kg[BULLET OPERATOR]m; maximal oxygen consumption (V˙O2max) 55.4 ± 4.6 mL[BULLET OPERATOR] kg[BULLET OPERATOR]min] ingested dGTE and placebo (PLA) for 28 days, separated by a 28 day wash-out period. On the first day (dGTE 1 or PLA 1) and following 7 days (dGTE 7 or PLA 7) and 28 days (dGTE 28 or PLA 28) participants completed a 30-min cycle exercise bout (50% Wmax), 2 hours after ingestion. Indirect calorimetry was used to calculate rates of whole body fat and carbohydrate oxidation during exercise. Blood samples were collected at rest and during exercise for analysis of plasma fatty acids (FA), glycerol and epigallocatechin gallate (EGCG).
Ingestion of dGTE did not significantly change whole body fat oxidation rates during exercise on day 1, 7 or 28 compared to PLA. There were also no changes in plasma concentrations of FA and glycerol at rest and during exercise as a result of dGTE ingestion at any time point compared to PLA. Plasma EGCG concentrations, immediately prior to the exercise bout, in the three dGTE trials were elevated compared with PLA but not different between 1, 7 and 28 days.
In contrast to previous reports we found that duration of dGTE ingestion had no effect on whole body fat oxidation rates or fat metabolism-related blood metabolites during exercise in physically active healthy males.
Medicine and science in sports and exercise 10/2013;
[Show abstract][Hide abstract] ABSTRACT: The concept of bracketed morality has received empirical support in several sport studies (e.g., Bredemeier & Shields, 1986a, 1986b). However, these studies have focused on moral reasoning. In this research, we examined bracketed morality with respect to moral behavior in sport and university contexts, in two studies. Male and female participants (Study 1: N = 331; Study 2: N = 372) completed questionnaires assessing prosocial and antisocial behavior toward teammates and opponents in sport and toward other students at university. Study 2 participants also completed measures of moral disengagement and goal orientation in both contexts. In most cases, behavior in sport was highly correlated with behavior at university. In addition, participants reported higher prosocial behavior toward teammates and higher antisocial behavior toward opponents in sport than toward other students at university. The effects of context on antisocial behavior were partially mediated by moral disengagement and ego orientation. Our findings extend the bracketed morality concept to prosocial and antisocial behavior.
Journal of Sport and Exercise Psychology 10/2013; 35(5):449-63.
[Show abstract][Hide abstract] ABSTRACT: The present study examined the relationship between habitual physical activity, life events stress, the diurnal rhythms of cortisol and DHEA, and the cortisol: dehydroepiandrosterone (DHEA) ratio in older adults. Thirty six participants aged ≥ 65 reported their habitual physical activity, and indicated if a particular event happened to them in the past year (stress incidence) and how stressful they perceived the event to be (stress severity). Older adults with higher stress severity demonstrated a significantly higher cortisol:DHEA ratio. Individuals with higher stress incidence scores, who did not participate in aerobic exercise had a significantly higher cortisol:DHEA ratio and flatter DHEA diurnal rhythm compared with those who regularly participated in aerobic exercise. In conclusion, life events stress may have a negative impact on the cortisol:DHEA ratio in older adults. Under conditions of high stress exposure, exercise may protect older adults from an increased cortisol:DHEA ratio and flatter DHEA diurnal rhythm.
[Show abstract][Hide abstract] ABSTRACT: Through the work of John Coote, research into the role of muscle afferent involvement in cardiorespiratory control has had strong links with Birmingham since the late 1960s. This brief review gives an historical background to John's early work and how his research and mentorship of colleagues continues to have a profound influence on the field today.
[Show abstract][Hide abstract] ABSTRACT: In a recent paper, we provided independent evidence on the accuracy of 'haptically' measured geographical slant perception (Taylor-Covill & Eves, 2013). Durgin (2013) argues that the devices used in our work, namely the palm-board, and palm-controlled inclinometer (PCI), are not measures of perception. In response, we outline four failures of replication in the laboratory work of Durgin and colleagues on which they base their model of slant perception. We also highlight fundamental differences between the perceptual tasks Durgin and colleagues ask of participants relative to those of Proffitt and colleagues' traditional measures. These subtle differences might help explain how the two groups have arrived at discrepant conclusions.
[Show abstract][Hide abstract] ABSTRACT: The autonomic responses to exercise are orchestrated by the interactions of several central and peripheral neural mechanisms. This short report will focus on the role of peripheral feedback from skeletal muscle afferents in the autonomic control of the heart during exercise in humans. Heart rate responses to passive calf stretch are abolished with cardiac parasympathetic blockade, indicating that the activation of mechanically sensitive skeletal muscle afferents (muscle mechanoreceptors) can inhibit cardiac parasympathetic activity and likely contribute to the increase in heart rate at the onset of exercise. Recent experiments show that the partial restriction of blood flow to the exercising skeletal muscles, to augment the activation of metabolically sensitive skeletal muscle afferents (muscle metaboreceptors) in humans, evokes an increase in heart rate that is attenuated with β1-adrenergic blockade thus suggesting that this response is principally mediated via an increase in cardiac sympathetic activity. Heart rate remains at resting levels during isolated activation of muscle metaboreceptors with post-exercise ischemia following handgrip; unless cardiac parasympathetic activity is inhibited, whereupon a sympathetically mediated increase in heart rate is unmasked. During post-exercise ischemia following leg cycling exercise heart rate appears to remain elevated due to withdrawal of parasympathetic tone and/or the activation of sympathetic activity to the heart. Although the importance of skeletal muscle afferent feedback to the autonomic control of the heart during exercise is incontrovertible, the complexity of cardiac sympathetic-parasympathetic interactions and the absence of direct intraneural recordings in humans mean that it remains incompletely understood.
[Show abstract][Hide abstract] ABSTRACT: Circumstances may render the consequence of falling quite severe, thus maximising the motivation to control postural sway. This commonly occurs when exposed to height and may result from the interaction of many factors, including fear, arousal, sensory information and perception. Here, we examined human vestibular-evoked balance responses during exposure to a highly threatening postural context. Nine subjects stood with eyes closed on a narrow walkway elevated 3.85 m above ground level. This evoked an altered psycho-physiological state, demonstrated by a twofold increase in skin conductance. Balance responses were then evoked by galvanic vestibular stimulation. The sway response, which comprised a whole-body lean in the direction of the edge of the walkway, was significantly and substantially attenuated after ~800 ms. This demonstrates that a strong reason to modify the balance control strategy was created and subjects were highly motivated to minimise sway. Despite this, the initial response remained unchanged. This suggests little effect on the feedforward settings of the nervous system responsible for coupling pure vestibular input to functional motor output. The much stronger, later effect can be attributed to an integration of balance-relevant sensory feedback once the body was in motion. These results demonstrate that the feedforward and feedback components of a vestibular-evoked balance response are differently affected by postural threat. Although a fear of falling has previously been linked with instability and even falling itself, our findings suggest that this relationship is not attributable to changes in the feedforward vestibular control of balance.
European Journal of Neuroscience 08/2013;
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