Attractive Stepping Stones Landscapes:Preference for Stone Height Variation Appears to Be Age Independent

An earlier study on the attractiveness of stepping stones configurations revealed that children like variation in stone height better than variation in stone size or gap width. In the present study, we conducted two experiments to examine whether this preference is found also in young and older adults. In Experiment 1, participants stepped freely in a standardized configuration, and three configurations with either height, size or gap width variation. Most interestingly, adults judged playgrounds with variation in stone height as most fun and beautiful, suggesting that the preference for variation in height is indeed age independent. In Experiment 2, we compared the configuration with only height variation with three configurations in which variation in height was combined with variation in stone size or gap width, or both. Although we found no significant differences among the configurations in the older adults, young adults judged the combination of height with size and gap width variation as more fun and esthetically appealing than the configuration with only height variation. The implications of our findings for playground research and designers are discussed.</p

Attractive Stepping Stones Landscapes:Preference for Stone Height Variation Appears to Be Age Independent

An earlier study on the attractiveness of stepping stones configurations revealed that children like variation in stone height better than variation in stone size or gap width. In the present study, we conducted two experiments to examine whether this preference is found also in young and older adults. In Experiment 1, participants stepped freely in a standardized configuration, and three configurations with either height, size or gap width variation. Most interestingly, adults judged playgrounds with variation in stone height as most fun and beautiful, suggesting that the preference for variation in height is indeed age independent. In Experiment 2, we compared the configuration with only height variation with three configurations in which variation in height was combined with variation in stone size or gap width, or both. Although we found no significant differences among the configurations in the older adults, young adults judged the combination of height with size and gap width variation as more fun and esthetically appealing than the configuration with only height variation. The implications of our findings for playground research and designers are discussed.</p

Attractive Stepping Stones Landscapes:Preference for Stone Height Variation Appears to Be Age Independent

An earlier study on the attractiveness of stepping stones configurations revealed that children like variation in stone height better than variation in stone size or gap width. In the present study, we conducted two experiments to examine whether this preference is found also in young and older adults. In Experiment 1, participants stepped freely in a standardized configuration, and three configurations with either height, size or gap width variation. Most interestingly, adults judged playgrounds with variation in stone height as most fun and beautiful, suggesting that the preference for variation in height is indeed age independent. In Experiment 2, we compared the configuration with only height variation with three configurations in which variation in height was combined with variation in stone size or gap width, or both. Although we found no significant differences among the configurations in the older adults, young adults judged the combination of height with size and gap width variation as more fun and esthetically appealing than the configuration with only height variation. The implications of our findings for playground research and designers are discussed.</p

Predicting volleyball serve-reception at group level

In a group-serve-reception task, how does serve-reception become effective? We addressed "who" receives/passes the ball, what task-related variables predict action mode selection and whether the action mode selected was associated with reception efficacy. In 182 serve-receptions we tracked the ball and the receivers' heads with two video-cameras to generate 3D world-coordinates reconstructions. We defined receivers' reception-areas based on Voronoi diagrams (VD). Our analyses of the data showed that this approach was accurate in describing "who" receives the serve in 95.05% of the times. To predict action mode selection, we used variables related to: serve kinematics, receiver's movement and on-court positioning, the relation between receiver and his closest partner, and interactions between receiver-ball and receiver-target. Serve's higher initial velocities together with higher maximum height, as well as smaller longitudinal distances between receiver and target increased the chances for the use of the overhand pass. Conversely, decreasing alignment of the receiver with the ball and the target increased the chances of using the underhand-lateral pass. Finally, the use of the underhand-lateral pass was associated with lower quality receptions. Behavioural variability's relevance for serve-reception training is discussed

On possibilities for action: The past, present and future of affordance research

We give a historical overview of the development of almost 50 years of empirical research on the affordances in the past and in the present. Defined by James Jerome Gibson in the early development of the Ecological Approach to Perception and Action as the prime of perception and action, affordances have become a rich topic of investigation in the fields of human movement science and experimental psychology. The methodological origins of the empirical research performed on affordances can be traced back to the mid 1980's and the works of Warren (1984, 1988) and Michaels (1988). Most of the research in Ecological Psychology performed since has focused on the actualization of discretely defined actions, the perception of action boundaries, the calculation of pi-numbers, and the measurement of response times. The research efforts have resulted in advancements in the understanding of the dynamic nature of affordances, affordances in a social context and the importance of calibration for perception of affordances. Although affordances are seen as an instrumental part of the control of action most studies investigating affordances do not pay attention to the control of the action. We conclude that affordances are still primarily treated as a utility to select behaviour, which creates a conceptual barrier that hinders deeper understanding of affordances. A focus on action-boundaries has largely prevented advancement in other aspects of affordances, most notably an integrative understanding of the role of affordances in the control of action

Distance over Time in a Maximal Sprint: Understanding Athletes’ Action Boundaries in Sprinting

The present study examined the kinematics of maximal effort sprint running, mapping the relations among a person’s maximal running speed, maximum running acceleration and the distance coverable in a certain amount of time by this person. Thirty-three participants were recruited to perform a simple sprint task. Both forward and backward running were considered. Participants’ position, velocity and acceleration data were obtained using a Local Positioning Measurement system. Participants’ speed-acceleration profiles turned out to be markedly non-linear. To account for these non-linear patterns, we propose a new macroscopic model on the kinematics of sprint running. Second, we examined whether target distance was of influence on the evolution of participants’ running speeds over time. Overall, no such effect on running velocity was present, except for a ‘finish-line effect’. Finally, we studied how variation in individuals’ maximum running velocities and accelerations related to differences in their action boundaries. The findings are discussed in the context of affordance-based control in running to catch fly balls

Timing of steering actions in locomotor interception of targets following curving trajectories

Recent work on the visual guidance of locomotor interception of nonuniformly moving targets argued for an early reliance on first-order (velocity-based) changes in the target's bearing angle that was complemented approximately 1 second later with reliance on second-order (acceleration-based) changes. Here we provide further support for this hypothesis in a virtual driving task, in which 19 participants steered a vehicle to intercept targets moving along receding circular trajectories. Adopting a set of carefully designed target trajectories, we tested discriminating predictions with respect to the timing and direction of the first steering action. Analyses of temporal and directional characteristics of first steering events revealed a pattern of results that was fully compatible with our predictions. Moreover, application of the recently developed QuID method, focusing on the temporal co-evolution of steering behavior and the potential information sources driving it, confirmed the operative progression from early reliance on first-order changes to subsequent (after approximately 1 second) reliance on a combination of first- and second-order changes in the target's bearing angle over the course of action at the individual-trial level. The finding of an evolution over time toward higher-order informational variables, potentially captured by a fractional-order time derivative, may have consequences for other locomotor interception tasks such as running to catch a fly ball

Characterisation of visual guidance of steering to intercept targets following curving trajectories using Qualitative Inconsistency Detection

This study explored the informational variables guiding steering behaviour in a locomotor interception task with targets moving along circular trajectories. Using a new method of analysis focussing on the temporal co-evolution of steering behaviour and the potential information sources driving it, we set out to invalidate reliance on plausible informational candidates. Applied to individual trials rather than ensemble averages, this Qualitative Inconsistency Detection (QuID) method revealed that steering behaviour was not compatible with reliance on information grounded in any type of change in the agent-centred target-heading angle. First-order changes in the environment-centred target’s bearing angle could also not adequately account for the variations in behaviour observed under the different experimental conditions. Capturing the observed timing of unfolding steering behaviour ultimately required a combination of (velocity-based) first-order and (acceleration-based) second-order changes in bearing angle. While this result may point to reliance on fractional-order based changes in bearing angle, the overall importance of the present findings resides in the demonstration of the necessity to break away from the existing practice of trying to fit behaviour into a priori postulated functional strategies based on categorical differences between operative heuristic rules or control laws