Higher order affordances.

Affordances are opportunities for action for a given animal (or animals) in a given environment or situation. The concept of affordance has been widely adopted in the behavioral sciences, but important questions remain. We propose a new way of understanding the nature of affordances; in particular, how affordances are related to one another.

The Complexity of Center of Pressure Positions During Quiet Stance and Its Relationship to Cognition, Aging, and Falls.

Background: In a secondary analysis of data taken from a publicly available database, we examined cognitive performance, postural sway, and relations between them for 4 groups: younger and older individuals with versus without a recent history of falls. Our objective was to compare linear versus nonlinear measures of postural activity as post hoc predictors of cognitive performance and falling.

Methods: We evaluated standing body sway in 147 participants (18-85-years old) over 60 seconds, separately with eyes-open and with eyes-closed.

The Complexity of Head Movement is Correlated with Learning about Affordances for Walking.

We asked whether the quantitative kinematics of standing postural activity might be related to short-term learning of affordances. Standing participants viewed a narrow path for 15 s, and then gave perceptual reports about the distance that they could walk along the path while wearing a weighted vest (novel affordance) or while not wearing the vest (familiar affordance). In a control condition, participants gave perceptual reports about egocentric distance along the path.

Perception of Affordances in Female Volleyball Players: Serving Short versus Serving to the Sideline.

: We investigated youth volleyball players' perception of affordances for different types of serves. : Participants were separated into Less Experienced ( = 13, maximum of 3 years of competitive volleyball experience) and More Experienced ( = 11, minimum of 4 years of competitive volleyball experience) groups. In the Sideline Condition, participants were asked to report the narrowest gap, relative to either the left or right sideline, into which they could serve the ball.

Perception of higher-order affordances for kicking in soccer.

We investigated the perception of higher-order interpersonal affordances for kicking that emerged from lower-order personal and interpersonal affordances in the context of soccer. Youth soccer players reported the minimum gap width between two confederates through which they could kick a ball. In Experiment 1, we independently manipulated the egocentric distance of gaps from participants, and the nominal role of the confederates, either as teammates or opponents.

Against free energy, for direct perception.

We question the free energy principle (FEP) as it is used in contemporary physics. If the FEP is incorrect in physics, then it cannot ground the authors' arguments. We also question the assumption that perception requires inference.

Control of a virtual vehicle influences postural activity and motion sickness in pre-adolescent children.

Among adults, persons in control of a vehicle (i.e., drivers) are less likely to experience motion sickness compared to persons in the same vehicle who do not control it (i.

Structure of variability in scanning movement predicts braille reading performance in children.

Among children learning to read braille, we asked whether the quantitative kinematics of scanning movements of the reading finger would be related to the proficiency of braille reading. Over a period of 12 months, we recorded the position and orientation of the reading fingers of eight congenitally or early blind children. We found that the strength of long-range power-law temporal correlations in the velocity fluctuations increased with performance in braille reading.

Effects of physical driving experience on body movement and motion sickness among passengers in a virtual vehicle.

Virtual vehicles (e.g., driving video games) can give rise to visually induced motion sickness.

Perception of Affordances in Soccer: Kicking for Power Versus Kicking for Precision.

: We investigated youth soccer players' perception of affordances for different types of kicks. : In the Power task, players judged the maximum distance they could kick the ball. In the Precision task, players judged how close to a designated target line they could kick the ball.

Perception of Affordances for Vertical and Horizontal Jumping in Children: Gymnasts Versus Non-Athletes.

: We investigated the perception of affordances for vertical jumping-and-reaching and horizontal jumping by children. : In the horizontal task, children were asked to judge their ability in the standing long jump. In the vertical task, children were asked to judge the height of a ball that they could run to, jump up, and reach with their fingertips.

It doesn't add up: Nested affordances for reaching are perceived as a complex particular.

In the Ecological Approach to Perception and Action, affordances are emergent, higher-order relationships in an animal-environment system. In addition, perceivers should perceive such relationships directly, rather than by combining lower-order constituents of the affordance, such as non-affordance properties of the animal or the environment. In the present study, we investigated whether this latter claim applied to perception of superordinate affordances - affordances that emerge from relations between lower-order affordances.

Postural precursors of motion sickness in head-mounted displays: drivers and passengers, women and men.

Motion sickness is preceded by distinctive patterns of postural activity that differ between the sexes. We asked whether such postural precursors of motion sickness might exist before participants were exposed to a virtual driving game presented via a head-mounted display. Men and women either controlled a virtual vehicle (drivers), or viewed a recording of virtual vehicle motion (passengers).

Social interaction in the emergence of toddler's mealtime spoon use.

The use of a spoon for eating is among the important daily skills in early development. The article provides an analysis of how caregiver-toddler interactions guides the attention of toddlers who were first learning how to use a spoon to spoon-related action opportunities that were relevant to the mealtime context. Our analysis revealed several related results.

Sensitivity to changes in dynamic affordances for walking on land and at sea.

We investigated the perception of affordances for walking along a narrow path. We asked whether participants could perceive changes in affordances brought about by manipulation of properties of the body, or of the environment, without direct practice of the to-be-perceived affordance, and without external feedback about the accuracy of perception. In Experiment 1, participants made a series of 8 judgments of how far they could walk along a narrow path either, 1) without added weight, 2) while wearing a weighted vest, or 3) while wearing weights on their ankles.

The Role of Visual Feedback about Motion of the Ground on Postural Sway.

We asked whether body sway would be influenced by visual information about motion of the ground surface. On a ship at sea, standing participants performed a demanding visual search task or a simple visual inspection task. Display content was stationary relative to the ship or relative to the Earth.

Unstable coupling of body sway with imposed motion precedes visually induced motion sickness.

Motion sickness is preceded by differences in the quantitative kinematics of body sway between individuals who (later) become sick and those who do not. In existing research, this effect has been demonstrated only in measures of body sway, relative to the earth. However, body sway can become coupled with imposed oscillatory motion of the illuminated environment, and the nature of this coupling may differ between individuals who become sick and those who do not.

Adaptive perception of changes in affordances for walking on a ship at sea.

Ocean waves cause oscillatory motion of ships. Oscillatory ship motion typically is greater in roll (i.e.

Real-time visual feedback about postural activity increases postural instability and visually induced motion sickness.

Background: Several studies have shown that the kinematics of standing body sway can be influenced by the provision of real time feedback about postural activity through visual displays.

Research Question: We asked whether real time visual feedback about the position of the body's center of pressure (COP) might affect body sway and the occurrence of visually induced motion sickness.

Methods: Standing participants (women) were exposed to complex visual oscillation in a moving room, a device that nearly filled the field of view.

Higher order affordances for reaching: Perception and performance.

Affordances are available behaviours emerging from relations between properties of animals and their environment. In any situation, multiple behaviours are available, that is, multiple affordances exist. We asked whether participants could detect means-ends relations among affordances (i.

Postural time-to-contact as a precursor of visually induced motion sickness.

The postural instability theory of motion sickness predicts that subjective symptoms of motion sickness will be preceded by unstable control of posture. In previous studies, this prediction has been confirmed with measures of the spatial magnitude and the temporal dynamics of postural activity. In the present study, we examine whether precursors of visually induced motion sickness might exist in postural time-to-contact, a measure of postural activity that is related to the risk of falling.

Effects of decades of physical driving on body movement and motion sickness during virtual driving.

We investigated relations between experience driving physical automobiles and motion sickness during the driving of virtual automobiles. Middle-aged individuals drove a virtual automobile in a driving video game. Drivers were individuals who had possessed a driver's license for approximately 30 years, and who drove regularly, while non-drivers were individuals who had never held a driver's license, or who had not driven for more than 15 years.

Effects of Physical Driving Experience on Body Movement and Motion Sickness During Virtual Driving.

Background: In previous research on motion sickness in simulated and virtual vehicles, subjects' experience controlling the corresponding physical vehicles has been confounded with their age. During driving of virtual automobiles in a video game, we separated chronological age from experience driving physical automobiles.

Methods: Subjects drove a virtual automobile in a driving video game.

Passive restraint reduces visually induced motion sickness in older adults.

Virtual environments such as those used in video games and driving/flight simulators are used for entertainment and training, but are often associated with visually induced motion sickness (VIMS). In this study, we asked whether passive restraint of the head and torso could reduce VIMS in younger and older adults. Twenty-one younger (18-35 years) and 16 older (65 + years) healthy adults engaged in a simulated driving task using a console video game while seated.