Diagnosing fatigue in gait patterns by support vector machines and self-organizing maps

The aim of the study was to train and test support vector machines (SVM) and self-organizing maps (SOM) to correctly classify gait patterns before, during and after complete leg exhaustion by isokinetic leg exercises. Ground reaction forces were derived for 18 gait cycles on 9 adult participants. Immediately before the trials 7–12, participants were required to completely exhaust their calves with the aid of additional weights (44.4 ± 8.8 kg). Data were analyzed using: (a) the time courses directly and (b) only the deviations from each individual’s calculated average gait pattern. On an inter-individual level the person recognition of the gait patterns was 100% realizable. Fatigue recognition was also highly probable at 98.1%. Additionally, applied SOMs allowed an alternative visualization of the development of fatigue in the gait patterns over the progressive fatiguing exercise regimen.     

Motor execution affects action prediction

Previous studies provided evidence of the claim that the prediction of occluded action involves real-time simulation. We report two experiments that aimed to study how real-time simulation is affected by simultaneous action execution under conditions of full, partial or no overlap between observed and executed actions. This overlap was analysed by comparing the body sides and the movement kinematics involved in the observed and the executed action. While performing actions, participants observed point-light (PL) actions that were interrupted by an occluder, followed by a test pose. The task was to judge whether the test pose depicted a continuation of the occluded action in the same depth angle. Using a paradigm proposed by Graf et al., we independently manipulated the duration of the occluder and the temporal advance of the test pose relative to occlusion onset (occluder time and pose time, respectively). This paradigm allows the assessment of real-time simulation, based on prediction performance across different occluder time/pose time combinations (i.e., improved task performance with decreasing time distance between occluder time and pose time is taken to reflect real-time simulation). The PL actor could be perceived as from the front or back, as indicated by task instructions. In Experiment 1 (front view instructions), evidence of action simulation was obtained for partial overlap (i.e., observed and performed action corresponded either in body side or movement kinematics), but not for full or no overlap conditions. The same pattern was obtained in Experiment 2 (back view instructions), ruling out a spatial compatibility explanation for the real-time pattern observed. Our results suggest that motor processes affect action prediction and real-time simulation. The strength of their impact varies as a function of the overlap between observed and executed actions.     

Association between vigor and exhaustion during the workweek: a person-centered approach to daily assessments

The purpose of this quantitative diary study was to investigate daily vigor and exhaustion using a person-centered approach. The study also investigated whether and how experiences of vigor and exhaustion relate to a state of being recovered. A total of 256 Finnish employees filled in a diary questionnaire during five consecutive workdays. Vigor and exhaustion showed strong negative interdependence within and between days. However, by applying a person-centered analysis, we were able to differentiate three groups with meaningful variation in vigor and exhaustion. The groups were labeled as Constantly vigorous (n = 179), Concurrently vigorous and exhausted (n = 30) and Constantly exhausted (n = 43). The vigor-exhaustion groups were also characterized by their recovery experiences: The Constantly vigorous employees recovered well from work strain during the workweek whereas the Constantly exhausted group recovered poorly. Overall, while the results indicate that, typically, vigor and exhaustion are exclusive experiences, it is also possible for them to be experienced simultaneously from day to day at the moderate levels. Thus, positive and negative experiences may co-occur.     

Differentiating intolerance of uncertainty from three related but distinct constructs

Individual differences in uncertainty have been associated with heightened anxiety, stress and approach-oriented coping. Intolerance of uncertainty (IU) is a trait characteristic that arises from negative beliefs about uncertainty and its consequences. Researchers have established the central role of IU in the development of problematic worry and maladaptive coping, highlighting the importance of this construct to anxiety disorders. However, there is a need to improve our understanding of the phenomenology of IU. The goal of this paper was to present hypotheses regarding the similarities and differences between IU and three related constructs – intolerance of ambiguity, uncertainty orientation, and need for cognitive closure – and to call for future empirical studies to substantiate these hypotheses. To assist with achieving this goal, we conducted a systematic review of the literature, which also served to identify current gaps in knowledge. This paper differentiates these constructs by outlining each definition and general approaches to assessment, reviewing the existing empirical relations, and proposing theoretical similarities and distinctions. Findings may assist researchers in selecting the appropriate construct to address their research questions. Future research directions for the application of these constructs, particularly within the field of clinical and health psychology, are discussed.     

ICAT: a computational model for the adaptive control of fixation durations

Eye movements depend on cognitive processes related to visual information processing. Much has been learned about the spatial selection of fixation locations, while the principles governing the temporal control (fixation durations) are less clear. Here, we review current theories for the control of fixation durations in tasks like visual search, scanning, scene perception, and reading and propose a new model for the control of fixation durations. We distinguish two local principles from one global principle of control. First, an autonomous saccade timer initiates saccades after random time intervals (local-I). Second, foveal inhibition permits immediate prolongation of fixation durations by ongoing processing (local-II). Third, saccade timing is adaptive, so that the mean timer value depends on task requirements and fixation history (Global). We demonstrate by numerical simulations that our model qualitatively reproduces patterns of mean fixation durations and fixation duration distributions observed in typical experiments. When combined with assumptions of saccade target selection and oculomotor control, the model accounts for both temporal and spatial aspects of eye movement control in two versions of a visual search task. We conclude that the model provides a promising framework for the control of fixation durations in saccadic tasks.     

Semen Loss and Sexual Anxiety Among Young Unmarried Men: Being Young and Vulnerable in Rural India

Premarital sex remains stigmatized even as the unmarried period of life is lengthening in India. This paper examines how young unmarried men in rural central India conceptualize and understand their sexual health and vulnerability. The data is qualitative, derived from four focus group discussions (N = 38 persons) of young unmarried males that were carried out in conjunction with a larger study on male involvement in reproductive health in the central Indian state of Madhya Pradesh in 2005. Young, unmarried rural men experience a wide range of functional situations which are culturally defined as health problems, such as “weakness,” thought to be caused by masturbation, nocturnal ejaculations, and the loss of semen. Despite constraints on communication on sexuality with married men, young unmarried men largely share with them the culturally hegemonic notion of semen loss as a health hazard. All four discussions pointed to the negative image of psycho-physiological changes related to maturation and further, to the belief that the reproductive functions of men can render them vulnerable and even harm them. Sexual anxiety in young men may in part reflect young men’s socially dependent and insecure life situation and social suffering. Young, unmarried rural men see marriage as the only release from sexual health problems although temporary relief is sought from private health care providers. In the future, men’s unmarried life stage is bound to lengthen in rural India, and consequently sexual health prior to the commencement of active intercourse should receive more attention in public health services and sex education.     

The Influence of Avoidance Temperament and Avoidance‐Based Achievement Goals on Flow

In the present research, we conducted two studies designed to examine the joint influence of avoidance temperament and avoidance‐based achievement goals on the experience of flow on a creativity task. In both a laboratory study (N = 101; M_age = 22.61, SD_age = 4.03; 74.3% female) and a naturalistic study (N = 102; M_age = 16.23, SD_age = 1.13; 48% female), participants high in avoidance temperament were shown to experience greater flow when performance‐avoidance goals were induced; no differences were found in any of the other three achievement goal conditions from the 2 × 2 achievement goal framework. These findings reveal a short‐term benefit for a disposition‐goal match grounded in avoidance motivation, and point to the need for more research on both avoidance‐based matches and the short‐term versus long‐term implications of such matches.     

The affect heuristic,mortality salience,and risk: Domain‐specific effects of a natural disaster on risk‐benefit perception

We examine how affect and accessible thoughts following a major natural disaster influence everyday risk perception. A survey was conducted in the months following the 2004 south Asian Tsunami in a representative sample of the Swedish population (N = 733). Respondents rated their experienced affect as well as the perceived risk and benefits of various everyday decision domains. Affect influenced risk and benefit perception in a way that could be predicted from both the affect‐congruency and affect heuristic literatures (increased risk perception and stronger risk‐benefit correlations). However, in some decision domains, self‐regulation goals primed by the natural disaster predicted risk and benefit ratings. Together, these results show that affect, accessible thoughts and motivational states influence perceptions of risks and benefits.     

Criterion Validity is Maintained When Items are Evaluatively Neutralized: Evidence from a Full‐scale Five‐factor Model Inventory

The original version and an evaluatively neutralized version (with items rephrased to reduce popularity) of a personality inventory were compared. The results revealed (i) similar criterion validity across three different sets of self‐rated behaviours, (ii) stronger relations to the rated social desirability of criteria for the original version and (iii) less correlation between factors for the neutralized version. We take the results to indicate that evaluative neutralization is a viable technique for reducing social desirability in self‐ratings. Implications for test construction are discussed. Copyright © 2014 European Association of Personality Psychology