Are there attentional demands associated with haptic modalities while walking in young,healthy adults?

Study designA prospective, observational study.ObjectivesTo assess the attentional demands of using haptic modalities during walking using a multi-task paradigm in young, healthy adults.SettingBiomechanics of Balance and Movement (BBAM) Lab, University of Saskatchewan.MethodsTwenty-two (12 male) young, healthy adults performed walking trials with and without a verbal reaction time (VRT) task, as well as with and without the use of haptic anchors and light touch on a railing. Walking performance was evaluated using normalized stride velocity and step width, and dynamic stability was evaluated using step width variability and medial-lateral margin of stability (ML MOS) and its variability.ResultsThere were no significant differences in VRT when walking with and without added haptic input and no interactions between the added VRT task and added haptic input. Step width increased and variability of the ML MOS increased during trials with the VRT task compared to trials without the VRT task. The ML MOS decreased when using both haptic tools with a greater decrease when using light touch on the railing compared to when using the haptic anchors. Normalized stride velocity and step width decreased when using light touch on the railing only.ConclusionBoth haptic tools affected stability during walking. Using the railing to add haptic input had a greater effect on walking stability and was the only haptic tool to affect walking performance. Attentional demands should be considered in future research and applications of adding haptic input during walking.     

Nonlinear approach to study the acute effects of static and dynamic stretching on local dynamic stability in lower extremity joint kinematics and muscular activity during pedalling

Researchers have reported contradictory results on the effect of static and dynamic stretching on subsequent performance. Due to the importance of performance through static and dynamic stretching, the aim of this study is to investigate the acute effects of static and dynamic stretching protocols on local dynamic stability in lower extremity joint kinematics and muscular activities during pedalling using a nonlinear dynamics approach. Using a randomised crossover trial design, fifteen active males participated voluntarily in this research (mass: 69.02 ± 10.52 kg, height: 174.00 ± 6.74 cm, and age: 21.20 ± 1.47 years) and completed a pedalling trial in situations of without stretching (WS), after static (SS), and dynamic stretching (DS) of lower extremity. The lower extremity joint angles in the sagittal plane and the electrical activity of soleus, gastrocnemius medialis, tibialis anterior, vastus medialis, biceps femoris, and rectus femoris muscles were collected during 30 pedalling cycles at 70 rates per minute. The results of the repeated measure ANOVA indicated that the knee and ankle angle largest LyE was significantly lower in DS compared to WS and SS. The largest LyE in muscle activity is also significantly lower for all the muscles after DS compared to WS and SS (P ≤ 0.05). Regarding the positive effects of DS on the joints and the muscle activity local dynamic stability, it is suggested to use DS than SS in the warm-up program before repetitive activities like pedalling.     

Age effects on the control of dynamic balance during step adjustments under temporal constraints

This study investigated the age effects on the control of dynamic balance during step adjustments under temporal constraints. Fifteen young adults and 14 older adults avoided a virtual white planar obstacle by lengthening or shortening their steps under free or constrained conditions. In the anterior–posterior direction, older adults demonstrated significantly decreased center of mass velocity at the swing foot contact under temporal constraints. Additionally, the distances between the ‘extrapolated center of mass’ position and base of support at the swing foot contact were greater in older adults than young adults. In the mediolateral direction, center of mass displacement was significantly increased in older adults compared with young adults. Consequently, older adults showed a significantly increased step width at the swing foot contact in the constraint condition. Overall, these data suggest that older adults demonstrate a conservative strategy to maintain anterior–posterior stability. By contrast, although older adults are able to modulate their step width to maintain mediolateral dynamic balance, age-related changes in mediolateral balance control under temporal constraints may increase the risk of falls in the lateral direction during obstacle negotiation.     

Explicit or implicit situation awareness? Measuring the situation awareness of train traffic controllers

Previous research on situation awareness (SA) predominantly focused on its explicit, reasoned, conscious features rather than on the implicit, intuitive, unconscious aspects that are often identified with expert operators. This research investigated implicit levels of SA of train traffic controllers (TTCs) in order to contribute to the body of knowledge on rail human factors research and SA. A novel approach was used to uncover levels of implicit SA through a set of three analyses: (1) fairly low SAGAT values with correlations between SAGAT scores and multiple performance indicators; (2) negative correlations between work experience and SAGAT scores; and (3) structurally lower level-1 SA (perception) scores in comparison to level-2 SA (comprehension) scores in accordance with Endsley’s three-level model. Two studies were conducted: A pilot study – which focused on SA measurements with TTCs in a monitoring mode (N = 9) – and the main study, which involved TTCs from another control center (N = 20) and three different disrupted conditions. In the pilot study, SA was measured through the situation-awareness global assessment technique (SAGAT), perceived SA and observed SA, and performance was measured through punctuality and unplanned stops of trains before red signals. In the main study, SA was measured through SAGAT, and perceived SA and multiple performance indicators, such as arrival and departure punctuality and platform consistency, were assessed. In both studies, the set of three analyses showed consistent and persistent indications of the presence of implicit SA. Endsley’s three-level model and related SAGAT method can be constrained by the presence of these intuitive, unconscious processes and inconsistent findings on correlations between SAGAT scores and performance. These findings provide insights into the SA of TTCs in the Netherlands and can support the development of training programs and/or the design of a new traffic management system.     

Evolutionary possibilities: Can a society be constrained so that “the good” self-organizes?

Can a human society be constrained in such a way that self-organization will thereafter tend to produce outcomes that advance the goals of the society? Such a society would be self-organizing in the sense that individuals who pursue only their own interests would none-the-less act in the interests of the society as a whole, irrespective of any intention to do so. The paper sketches an agent-based model that identifies the conditions that must be met if such a self-organizing society is to emerge. The model draws heavily on an understanding of how self-organizing societies have emerged repeatedly during the evolution of life on Earth. The model demonstrates that the key enabling requirement for a self-organizing society is ‘consequence-capture’. Broadly this means that all agents in the society must capture sufficient of the beneficial (and harmful) consequences of their actions for the goals of the society. ‘Consequence-capture’ can be organized in a society by appropriate management (systems of evolvable constraints) that suppresses free riders and supports pro-social actions. In human societies these constraints include institutions such as systems of governance and social norms. If a self-organizing society is to emerge, consequence-capture must apply to all agents in the society, including those involved in the establishment and adaptation of institutions. If this is achieved, the result will be a fully self-organizing society in which the interests of all agents (including individuals, firms, multi-national corporations, political organizations, institutions and governments) are aligned with the interests of the society as a whole.     

Pupil dilation patterns reflect the contents of consciousness

The study of human consciousness has historically depended on introspection. However, introspection is constrained by what can be remembered and verbalized. Here, we demonstrate the utility of high temporal resolution pupillometry to track the locus of conscious attention dynamically, over a single trial. While eye-tracked, participants heard several musical clips played diotically (same music in each ear) and, later, dichotically (two clips played simultaneously, one in each ear). During dichotic presentation, participants attended to only one ear. We found that the temporal pattern of pupil dilation dynamics over a single trial discriminated which piece of music was consciously attended on dichotic trials. Deconvolving these pupillary responses further revealed the real-time changes in stimulus salience motivating pupil dilation. Taken together, these results show that pupil dilation patterns during single-exposure to dynamic stimuli can be exploited to discern the contents of conscious attention.     

ON AGGRESSION TURNED AGAINST THE SELF

Deliberate self‐harm is a common presenting problem suffered by young people. Several patients referred to the NHS outpatient clinic where I work have been able to stop harming themselves during intensive psychoanalytic psychotherapy. In this paper, I shall discuss a variety of motives for persistent cutting by one adolescent girl. I am most interested to show how the healthier part of her personality overcame her motives for harming herself, and eventually allowed her to make use of my understanding of a sadomasochistic internal object that worked against us.