Biomedical subjects

Jeffrey B Wagman

Publications and source records attributed to Jeffrey B Wagman.

4 recordsLinked to original sources

PubMed2004

Chosen striking location and the user-tool-environment system.

Controlling a hand-held tool requires that the tool user bring the tool into contact with an environmental surface in a task-appropriate manner. This, in turn, requires applying muscular forces so as to overcome how the object resists being moved about its various axes. Perceived properties of hand-held objects tend to be constrained by inertial variables that describe such resistance to movement. In 3 experiments, the authors investigated whether participants choose different striking locations on striking implements when using that implement under different constraints. The results suggest that the constraints of the striking task and the grasp position on the striking implement together contribute to the chosen striking location. Furthermore, such choices are constrained by inertial variables that reflect combinations of these constraints.

Environment↗

PubMed2003

Nested reciprocities: the organism-environment system in perception-action and development.

The ecological approach to studying perception and action is one in which researchers view the structure in ambient energy arrays surrounding a given organism as being sufficient to specify meaningful environmental properties to that organism. Thus, from this perspective, perception is viewed not as a cognitive achievement but as a lawful state of affairs that exists in an organism-environment system. The approach to studying development known as transactionalism is one in which researchers view the developmental process as the expression of a complex web of endogenous and exogenous factors. Thus, from this perspective, development is not an unfolding of a genetic program, but rather an ongoing exchange among levels of the organism-environment system that continues throughout the life span of the organism. Despite their independent development, these two meta-theoretical approaches have much in common. In each approach, the organism-environment system is the fundamental unit of analysis, and the development of perception and behavior is spread across the multiple levels of this system.

Animals↗

PubMed2003

Haptically creating affordances: the user-tool interface.

Successful use of a hand-held tool requires overcoming the rotational inertia of the hand-plus-tool system. Where an object is grasped affects this rotational inertia. Appropriate choice of grip position may be crucial in the safe, effective, and efficient control of a hand-held tool. In 3 experiments, the authors investigated how choice of grip position on a tool was constrained by task demands. The results suggest that choice of grasp position serves to establish relationships among 3 variables derived from the inertial ellipsoid of the hand-object system (volume, symmetry, and eigenvector angle) in a way that specifically reflected the power or precision constraints of the given task. These variables have previously been shown to play a role in haptic perception of tool function. Changing grasp position on a tool is a way to exert control over the nuances of the user-tool interface.

Choice Behavior↗

PubMed2002

Perceptual behavior: recurrence analysis of a haptic exploratory procedure.

Various object properties are perceptible by wielding. We asked whether the dynamics of wielding differed as a function of the to-be-perceived property. Wielding motions were analyzed to determine if they differed under the intention to perceive or not perceive rod length (experiment 1), to perceive object height versus object width (experiment 2), and to perceive the length forward of where the rod was grasped versus the position of the grasp (experiment 3). Perceiving these different properties is known to depend on different components of the object's inertia tensor. Analyses of the subtle recurrent patterns in the phase space of the hand motions revealed differences in wielding across the different perceptual intentions. Haptic exploratory procedures may exhibit distinct exploratory dynamics.

Adult↗