Affordance-based control of braking in cycling: Experience reveals differences in the style of control.

We investigated whether in an in-situ collision avoidance experiment cyclists regulate braking by adopting an affordance-based control strategy. Within an affordance-based control strategy for braking, deceleration is controlled relative to the maximum achievable deceleration rather than by nulling out deviations from ideal deceleration, and potentially allowing for different braking styles. Twenty active- and eighteen inactive-cyclists were asked to cycle on a straight path in an indoor gym and to stop as close as possible in front of a stationary obstacle. Maximum achievable deceleration was manipulated by loading the bike: no-load, load-5 kg, and load-10 kg. Two approach distances were used to vary cycling speed. Participants in both groups stopped farther from the obstacle when approaching with long- than short-initial distance conditions. No systematic effects of loading on braking performance and control were found across the two groups. However, both groups did increase the magnitude of brake adjustments as ideal deceleration increased and got closer to the action boundary, even when current deceleration approached the ideal deceleration. This indicates that participants adopted an affordance-based control strategy for braking. Two braking styles were identified: an aggressive style, characterized by a late braking onset and a high, steep peak in ideal deceleration, and a conservative style, characterized by an early braking onset and gradual, linear increase in ideal deceleration. The aggressive braking style was more prevalent among the active-cyclists. We suggest that the braking styles emerge from differences in calibration between information and action. The novelty of our work lies in confirming that cyclists adopt an affordance-based control strategy in an in-situ experiment and in demonstrating and explicating how affordance-based control can incorporate the emergence of different styles of braking.

The GRP78-PERK axis contributes to memory and synaptic impairments in Huntington's disease R6/1 mice.

Increasing evidence indicates that a key factor in neurodegenerative diseases is the activation of the unfolded protein response (UPR) caused by an accumulation of misfolded proteins in the endoplasmic reticulum (ER stress). Particularly, in Huntington's disease (HD) mutant huntingtin (mHtt) toxicity involves disruption of the ER-associated degradation pathway and loss of the ER protein homeostasis leading to neuronal dysfunction and degeneration. Besides the role of the UPR in regulating cell survival and death, studies that demonstrate the contribution of sustained UPR activation, particularly of PERK signaling, in memory disturbances and synaptic plasticity deficiencies are emerging. Given the contribution of hippocampal dysfunction to emotional and cognitive deficits seen in HD, we have analyzed the involvement of ER stress in HD memory alterations. We have demonstrated that at early disease stages, ER stress activation manifested as an increase in GRP78 and CHOP is observed in the hippocampus of R6/1 mice. Genetic reduction of GRP78 expression resulted in preventing hippocampal-dependent memory alterations but no motor deficits. Accordingly, hippocampal neuropathology namely, dendritic spine loss and accumulation of mHtt aggregates was ameliorated by GRP78 reduction. To elucidate the signaling pathways, we found that the inactivation of PERK by GSK2606414 restored spatial and recognition memories in R6/1 mice and rescued dendritic spine density in CA1 pyramidal neurons and protein levels of some specific immediate early genes. Our study unveils the critical role of the GRP78/PERK axis in memory impairment in HD mice and suggests the modulation of PERK activation as a novel therapeutic target for HD intervention.

The effects of manipulating the visual environment on thermal perception: A structured narrative review.

When exposed to ambient temperatures that cause thermal discomfort, a human's behavioral responses are more effective than autonomic ones at compensating for thermal imbalance. These behavioral thermal responses are typically directed by an individual's perception of the thermal environment. Perception of the environment is a holistic amalgamation of human senses, and in some circumstances, humans prioritize visual information. Existing research has considered this in the specific case of thermal perception, and this review investigates the state of the literature examining this effect. We identify the frameworks, research rationales, and potential mechanisms that underpin the evidence base in this area. Our review identified 31 experiments, comprising 1392 participants that met the inclusion criteria. Methodological heterogeneity was observed in the assessment of thermal perception, and a variety of methods were employed to manipulate the visual environment. However, the majority of the included experiments (80%) reported a difference in thermal perception after the visual environment was manipulated. There was limited research exploring any effects on physiological variables (e.g. skin and core temperature). This review has wide-ranging implications for the broad discipline of (thermo)physiology, psychology, psychophysiology, neuroscience, ergonomics, and behavior.

Parkinson's disease affects gaze behaviour and performance of drivers.

The aim of this study was to investigate the effects of PD and ageing on gaze behaviour and performance of drivers in a simulated task. Ten drivers with PD, ten neurologically healthy older drivers, and ten neurologically healthy younger adult drivers were asked to drive in a car simulator for three minutes, maintaining car speed between 100 and 120 km/h and avoiding collisions. Driver's eye movements were recorded. Drivers with PD had more collisions and spent less time driving within the speed zone than the younger-drivers. Drivers with PD performed an increased number of fixations towards task-irrelevant areas of the visual scene and higher visual entropy, indicating a more random gaze behaviour. Older drivers restricted their visual search to the lane area in order to detect threat-related stimuli. PD led to drops in performance of drivers in the car simulator. Practitioner summary: Parkinson's disease (PD) and ageing process caused a drop in driving performance. Drivers with PD made fewer fixations on task-relevant information and showed higher visual entropy than young adults. Older drivers restricted their visual search to the lane than other areas of interest.

Geração de dados sintéticos para classificação de disléxicos por meio de aprendizado de máquina / Synthetic data generation for classification of dyslexics by machine learning / Generación de datos sintéticos para clasificación de disléxicos mediante aprendizaje automático

Objetivo: Este estudo pretende aplicar a técnica de geração de dados sintéticos com auxílio de técnicas de limpeza de dados para a classificação de disléxicos e não - disléxicos. Método: Os outliers foram selecionados por especialista. Foi feito uma geração sintética de dados. para cada um de cinco algoritmos foram selecionados características com busca exaustiva. Cada algoritmo foi executado com as características selecionadas e então suas curvas de calibração foram comparadas. Resultados: A regressão logística se destacou como o melhor algoritmo, apresentando o resultado de 99% de acurácia e área sob a curva ROC de 0,999, além de ter obtido a melhor curva de calibração Conclusão: O uso da geração sintética de dados e seleção de características foram capazes de fazer todos os algoritmos avaliados obterem ótimos resultados na classificação de disléxicos e não disléxicos. A regressão logística foi selecionado como melhor algoritmo para classificação de disléxicos.

Objective: This study aims to apply the synthetic data generation technique with the aid of data cleaning techniques for the classification of dyslexics and non - dyslexics. Method: Outliers were selected by specialist. Synthetic of data Generated. For each of five algorithms, characteristics were selected with exhaustive search. Each algorithm was executed with the selected characteristics and then their calibration curves were compared. Results: Logistic regression presented the best results with 99% accuracy and area under the ROC curve of 0.999, besides obtaining the best calibration curve. Conclusion: The use of synthetic data generation and feature selection were able to make all algorithms achieve excellent results in the classification of dyslexic and non - dyslexic. Logistic regression was selected as the best algorithm for dyslexic classification.

Objetivo: Este estudio tiene como objetivo aplicar la técnica de generación de datos sintéticos con la ayuda de técnicas de limpieza de datos para la clasificación de disléxicos y no disléxicos. Método: los valores atípicos fueron seleccionados por especialistas. Se realizó una generación sintética de datos. Para cada uno de los cinco algoritmos, se seleccionaron características con búsqueda exhaustiva. Cada algoritmo se ejecutó con las características seleccionadas y luego se compararon sus curvas de calibración. Resultados: La regresión logística se destacó como el mejor algoritmo, presentando el resultado del 99% de precisión y área bajo la curva ROC de 0.999, además de obtener la mejor curva de calibración. Conclusión: El uso de la generación de datos sintéticos y la selección de Estas características lograron que todos los algoritmos evaluados obtuvieron excelentes resultados en la clasificación de disléxicos y no disléxicos. Se seleccionó la regresión logística como el mejor algoritmo para la clasificación disléxica.

Combining experiences of race gaming and natural driving affects gaze location strategy in simulated context.

The aims of the study were to investigate the effects of race gaming experience in playing racing video games on gaze behaviour and performance of drivers and the effects of natural driving experience on gaze behaviour and performance of gamers. Thirty participants, divided into drivers-gamers, drivers-non-gamers and non-drivers-gamers, were asked to drive in a race circuit as fast as possible while their eye movements were recorded. Drivers-gamers spent more time looking at the lane than non-drivers-gamers. Furthermore, drivers-gamers performed greater number of fixations towards the speedometer and showed faster performance in the racing task than the drivers-non-gamers. Combining natural driving and race gaming experiences changed the gaze location strategy of drivers. Practitioner summary: Racing video games practitioners have high propensity to exhibit attitudes and intentions of risky driving behaviour. Combining natural driving and race gaming experiences affects gaze behaviour strategy of drivers. Abbreviations: DG: Drivers-gamers; DNG: Drivers-non-gamers; NDG: Non-drivers-gamers; AOIs: Areas of Interest; r-NUMFIX: Relative number of fixations; r-DURFIX: Relative fixations duration.

Adverse effects of anxiety on attentional control differ as a function of experience: A simulated driving study.

This study tested whether adverse effects of state anxiety on attention and performance may be modulated by experience. Sixteen experienced and eleven inexperienced drivers drove in a simulator under low- and high-stress conditions. Anxiety was manipulated by competition, the presence of an evaluator, external video camera, and traffic noise. Most drivers showed greater anxiety scores and higher mean heart rates following manipulation. In both groups increased state anxiety decreased car speed control and caused more collisions, accompanied by fewer fixations of longer duration towards the driving lane across a horizontally narrower region. Inexperienced drivers increased the number of short fixations towards cars, while experienced drivers increased the number of short fixations on the speedometer. Although anxiety impairs processing efficiency and performance effectiveness for both groups, attentional changes differ as a function of experience. Inexperienced drivers tended to shift attention to threatening stimuli, while experienced drives were more likely to consciously monitor task goal.

Implicit learning increases shot accuracy of football players when making strategic decisions during penalty kicking.

Implicit learning has been proposed to improve athletes' performance in dual-task situations. Yet, only a few studies tested this with a sports-relevant dual-task. Hence, the current study aimed to compare the effects of implicit and explicit training methods on penalty kicking performance. Twenty skilled football players were divided in two training groups and took part in a practice phase to improve kicking accuracy (i.e., without a goalkeeper) and in a post-test in order to check penalty kick performance (i.e., accuracy including a decision to kick to the side opposite the goalkeeper's dive). Results found that the implicit and explicit training method resulted in similar levels of decision-making, but after implicit training this was achieved with higher kicking accuracy. Additionally, applications for football players and coaches are discussed.

Kicking Performance in Young U9 to U20 Soccer Players: Assessment of Velocity and Accuracy Simultaneously.

PURPOSE: The purpose of this study was to compare the kicking performance of young soccer players in the U9 to U20 age groups. METHOD: Three hundred and sixty-six Brazilian players were evaluated on an official pitch using three-dimensional kinematics to measure (300 Hz) ball velocity (Vball), foot velocity (Vfoot), Vball/Vfoot ratio, last stride length, and distance between the support foot and the ball. Simultaneously, a two-dimensional procedure was also conducted to compute (60 Hz) the mean radial error, bivariate variable error, and accuracy. Possible age-related differences were assessed through one-way analysis of variance and magnitude-based inferences. RESULTS: Ball velocity increased by 103% (p < .001, η2 = .39) from the U11 age group (48.54 ± 8.31 km/hr) to the U20 age group (98.74 ± 16.35 km/hr). Foot velocity presented a 59% increase (p < .001, η2 = .32) from the U11 age group (49.08 ± 5.16 km/hr) to U20 (78.24 ± 9.49 km/hr). This finding was due to improvement in the quality of foot-ball impact (Vball/Vfoot ratio) from U11 (0.99 ± 0.13 a.u.) to U20 (1.26 ± 0.11 a.u.; p < .001, η2 = .25). Parameters such as mean radial error and accuracy appeared to be impaired during the growth spurt (U13-U15). Last stride length was correlated, low to moderately high, with Vball in all age groups (r = .36-.79). CONCLUSIONS: In summary, we concluded that simple biomechanical parameters of kicking performance presented distinct development. These results suggest that different training strategies specific for each age group could be applied. We provide predictive equations to aid coaches in the long-term monitoring process to develop the kick in soccer or search for talented young players.

Oscillation of plantar pressure center in athletes and non-athletes with and without ankle sprains.

OBJECTIVE: To assess whether there is any difference in the oscillation of the plantar pressure center in single-leg stance between athletes and non-athletes with and without ankle sprains. METHODS: 54 volunteers performed four static assessments and one dynamic assessment while standing on one foot on a baropodometer, barefoot, for 10 s in each test. The variables of area (cm(2)), distance (cm), anteroposterior oscillation (cm), mediolateral oscillation (cm) and mean velocity (cm/s) were analyzed. The items "other symptoms" and "sports and recreation" of the subjective Foot and Ankle Outcome Score (FAOS) questionnaire were applied. For the statistical analysis, repeated-measurement ANOVA (ANOVA-MR), multivariate ANOVA (MANOVA), Tukey's post hoc test and partial eta squared were used. RESULTS: ANOVA-MR revealed differences regarding distance, with major effects for eyes (p < 0.001), knees (p < 0.001), group (p < 0.05) and the interaction between eyes and knees (p < 0.05); and regarding mean velocity with major effects for eyes (p < 0.001), knees (p < 0.001) (p < 0.05), group (p < 0.05) and the interaction between eyes and knees (p < 0.05). MANOVA revealed main group effects for distance (p < 0.05), anteroposterior oscillation (p < 0.05) and mean velocity (p < 0.05). In the FAOS questionnaire, there were no differences: "other symptoms", p > 0.05; and "sport and recreation", p > 0.05. CONCLUSION: Athletes present higher mean velocity of oscillation of plantar pressure center and generally do not have differences in oscillation amplitude in the sagittal and coronal planes, in comparison with non-athletes.

OBJETIVO: Avaliar se há diferença quanto à oscilação do centro de pressão plantar em apoio unipodal entre atletas e não atletas com e sem entorse de tornozelo. MÉTODO: Fizeram quatro avaliações estáticas e uma dinâmica em apoio unipodal descalço sobre o baropodômetro 54 voluntarios, com duração de 10 segundos cada teste. Foram analisadas as variáveis área (cm2), distância (cm), oscilação anteroposterior (cm), oscilação mediolateral (cm) e velocidade média (cm/s). Foram aplicados os itens "Outros sintomas" e "Esporte e recreação" do questionário subjetivo Foot and Ankle Outcome Score (FAOS). Para a análise estatística foram usadas a ANOVA de médias repetidas (ANOVA-MR), a ANOVA multivariada (MANOVA), o post hoc de Tukey e o partial eta square. RESULTADOS: A ANOVA-MR revelou diferenças para distância, com efeitos principais para olhos (p < 0,001), joelho (p < 0,001), grupo (p < 0,05) e interação olhos e joelho (p < 0,05) e para a velocidade média com efeitos principais para olhos (p < 0,001), joelho (p < 0,001), grupo (p < 0,05) e interação olhos e joelho (p < 0,05). A MANOVA revelou efeitos principais de grupo para distância (p < 0,05), oscilação anteroposterior (p < 0,05) e velocidade média (p < 0,05). No questionário FAOS não houve diferenças ("Outros sintomas" [p > 0,05], "Esporte e eecreação" [p > 0,05]). CONCLUSÃO: Atletas apresentam maior velocidade média de oscilação do centro de pressão plantar e não apresentam, de modo geral, diferenças quanto à amplitude de oscilação nos planos sagital e coronal quando comparados com não atletas.

Oscillation of plantar pressure center in athletes and non-athletes with and without ankle sprains / Oscilação do centro de pressão plantar de atletas e não atletas com e sem entorse de tornozelo

ABSTRACT OBJECTIVE: To assess whether there is any difference in the oscillation of the plantar pressure center in single-leg stance between athletes and non-athletes with and without ankle sprains. METHODS: 54 volunteers performed four static assessments and one dynamic assessment while standing on one foot on a baropodometer, barefoot, for 10 s in each test. The variables of area (cm2), distance (cm), anteroposterior oscillation (cm), mediolateral oscillation (cm) and mean velocity (cm/s) were analyzed. The items "other symptoms" and "sports and recreation" of the subjective Foot and Ankle Outcome Score (FAOS) questionnaire were applied. For the statistical analysis, repeated-measurement ANOVA (ANOVA-MR), multivariate ANOVA (MANOVA), Tukey's post hoc test and partial eta squared were used. RESULTS: ANOVA-MR revealed differences regarding distance, with major effects for eyes (p < 0.001), knees (p < 0.001), group (p < 0.05) and the interaction between eyes and knees (p < 0.05); and regarding mean velocity with major effects for eyes (p < 0.001), knees (p < 0.001) (p < 0.05), group (p < 0.05) and the interaction between eyes and knees (p < 0.05). MANOVA revealed main group effects for distance (p < 0.05), anteroposterior oscillation (p < 0.05) and mean velocity (p < 0.05). In the FAOS questionnaire, there were no differences: "other symptoms", p > 0.05; and "sport and recreation", p > 0.05. CONCLUSION: Athletes present higher mean velocity of oscillation of plantar pressure center and generally do not have differences in oscillation amplitude in the sagittal and coronal planes, in comparison with non-athletes.

RESUMO OBJETIVO: Avaliar se há diferença quanto à oscilação do centro de pressão plantar em apoio unipodal entre atletas e não atletas com e sem entorse de tornozelo. MÉTODO: Fizeram quatro avaliações estáticas e uma dinâmica em apoio unipodal descalço sobre o baropodômetro 54 voluntarios, com duração de 10 segundos cada teste. Foram analisadas as variáveis área (cm2), distância (cm), oscilação anteroposterior (cm), oscilação mediolateral (cm) e velocidade média (cm/s). Foram aplicados os itens "Outros sintomas" e "Esporte e recreação" do questionário subjetivo Foot and Ankle Outcome Score (FAOS). Para a análise estatística foram usadas a ANOVA de médias repetidas (ANOVA-MR), a ANOVA multivariada (MANOVA), o post hoc de Tukey e o partial eta square. RESULTADOS: A ANOVA-MR revelou diferenças para distância, com efeitos principais para olhos (p < 0,001), joelho (p < 0,001), grupo (p < 0,05) e interação olhos e joelho (p < 0,05) e para a velocidade média com efeitos principais para olhos (p < 0,001), joelho (p < 0,001), grupo (p < 0,05) e interação olhos e joelho (p < 0,05). A MANOVA revelou efeitos principais de grupo para distância (p < 0,05), oscilação anteroposterior (p < 0,05) e velocidade média (p < 0,05). No questionário FAOS não houve diferenças ("Outros sintomas" [p > 0,05], "Esporte e eecreação" [p > 0,05]). CONCLUSÃO: Atletas apresentam maior velocidade média de oscilação do centro de pressão plantar e não apresentam, de modo geral, diferenças quanto à amplitude de oscilação nos planos sagital e coronal quando comparados com não atletas.

The mere presence of a goalkeeper affects the accuracy of penalty kicks.

The keeper-independent strategy, in which a football penalty kicker selects a target location in advance and ignores the goalkeeper's actions during the run-up, has been suggested to be the preferable strategy for taking a penalty kick. The current in-field experiment investigated the question of whether the goalkeeper can indeed be ignored. Ten intermediate-level football players were instructed to adopt a goalkeeper-independent strategy and to perform penalty kicks directed at one of two targets located in the upper corners of the goal under three conditions: without a goalkeeper, in the presence of a goalkeeper (who tried to save the ball), and in the presence of a goalkeeper who was informed by the penalty kickers where they intended to direct the ball. The mere presence of a goalkeeper impaired shot accuracy. The shots were more centralised, that is, biased toward the goalkeeper. The effects were enhanced for the condition in which the penalty kicker knew the goalkeeper was knowledgeable about ball direction. The findings were consistent with the response activation model that holds that aiming at a target can be biased toward salient visual non-targets. The implications for adopting and practising goalkeeper-independent strategies are discussed.

The effects of high pressure on the point of no return in simulated penalty kicks.

We investigated the effects of high pressure on the point of no return or the minimum time required for a kicker to respond to the goalkeeper's dive in a simulated penalty kick task. The goalkeeper moved to one side with different times available for the participants to direct the ball to the opposite side in low-pressure (acoustically isolated laboratory) and high-pressure situations (with a participative audience). One group of participants showed a significant lengthening of the point of no return under high pressure. With less time available, performance was at chance level. Unexpectedly, in a second group of participants, high pressure caused a qualitative change in which for short times available participants were inclined to aim in the direction of the goalkeeper's move. The distinct effects of high pressure are discussed within attentional control theory to reflect a decreasing efficiency of the goal-driven attentional system, slowing down performance, and a decreasing effectiveness in inhibiting stimulus-driven behavior.