Spatial and physical frames of reference in positioning a limb

Garrett, Steven R.; Pagano, Christopher C.; Austin, Gary R.; Turvey, M. T.

doi:10.3758/bf03206170

Cited by 25 publications

(41 citation statements)

References 36 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Taking such an approach, Pagano and colleagues (e.g., Pagano and Turvey 1995; Pagano et al 1996; Garrett et al 1998) hypothesized that the perception of a limb’s spatial orientation depends on its inertial eigenvectors ( e i ), which represent a characteristic of a limb’s mass distribution related to the direction in which it resists rotation (see the appendix for a more detailed explanation of the physical meaning of inertial eigenvectors). Relative to a given point in space, any rigid object has three orthogonal eigenvectors: e 1 , e 2 , and e 3 .…”

Section: Introductionmentioning

confidence: 99%

Perception of limb orientation in the vertical plane depends on center of mass rather than inertial eigenvectors

2007

View full text Add to dashboard Cite

We performed two experiments to test the hypothesis that the perception of limb orientation depends on inertial eigenvectors (e i ) against the alternative hypothesis that it depends on the center of mass vector (CM). Whereas e i constrains the dynamic torques involved in angular rotation, CM constrains the static torque necessary to keep the limb aloft in the gravitational field. Hence, possible effects of e i and CM on kinesthetic judgments must be related to the dynamic and static torques, respectively, involved in moving and positioning a limb. In the first experiment, blindfolded participants matched, with upper arms supported, the orientation of their forearms while the forearms' e i and CM were manipulated relative to the elbow. The manipulation of the vector CM alone induced a matching bias, as did the combined manipulation of e i and CM, whereas the manipulation of e i alone did not. In the second experiment, participants positioned their unseen and unsupported right arm at an indicated spatial configuration while e i and CM of the right forearm were manipulated as in Experiment 1. As in the first experiment, forearm positioning was affected by the independent manipulation of CM and the combined manipulation of e i and CM, but not by the independent variation of e i .Moreover, none of the manipulations affected upper arm positioning. These results refute the claim that the perception of limb orientation (in the vertical plane) is based on e i and demonstrate, for the first time, the implication of a limb segment's CM in the perception of its orientation.

show abstract

Section: Introductionmentioning

confidence: 99%

Perception of limb orientation in the vertical plane depends on center of mass rather than inertial eigenvectors

2007

View full text Add to dashboard Cite

show abstract

“…The parameter could be manipulated using the deflating ball paradigm (e.g., Savelsbergh et al 1991), and X h could be manipulated by changing the perceived direction or location of the arm through the manipulation of eigenvectors of its inertia tensors (e.g., Garrett et al 1998;Pagano & Turvey 1995;Riley & Turvey, in press;Turvey 1996). The crucial manipulation would be to combine a later (perceived) arrival of the ball (by deflating the ball during its approach) with a closer (perceived) location of the hand.…”

Section: R12 Research Methodologymentioning

confidence: 99%

“…In such cases, once the player has left the ground, the ball may be the sole referent for both perception and control. Recent research on prehension suggests that reaching and grasping are organized directly with reference to the object, rather than by defining the object's position and motion relative to other referents (Garrett et al 1998;Zaal et al 1998). …”

Section: No Privileged Referentmentioning

confidence: 99%

Energy, information, detection, and action

Michaels

Oudejans

2001

Behav Brain Sci

View full text Add to dashboard Cite

show abstract

“…Similarly, other investigators manipulated the orientation of the arm to change the relationship between joint angles and torques at the elbow. [35][36][37][38][39] However, in all these studies, humeral orientation was different between the positioning and matching motions (regardless of whether a bilateral or unilateral experiment was performed). To our knowledge, only Gooey et al 40 manipulated the arm angle between trials, and they found a decrease in the magnitude, but an increase in the variability of errors when the arm was elevated.…”

mentioning

confidence: 99%

Unconstrained shoulder joint position sense does not change with body orientation

Chapman

Suprak

Karduna

2008

Journal Orthopaedic Research

View full text Add to dashboard Cite

Our knowledge of the role of muscle activation on proprioception is incomplete. Previous work has either focused on comparing active and passive motions or manipulated both muscle activation and joint angles simultaneously. We conducted an experiment at the shoulder in which subjects' trunks were tilted backwards to decouple joint angle from joint torque. Twenty three healthy subjects underwent testing in an unconstrained joint position sense task. Kinematics were measured with a magnetic tracking device. The joint position sense task consisted of subjects moving their arms to a predetermined orientation in space with the help of visual feedback from the magnetic tracking device presented to the subjects through a head-mounted display. Subjects were then asked to reproduce the presented joint position in the absence of visual feedback. The protocol was performed under two tilts: upright and trunk tilted back 458. This allowed for a comparison of joint position sense at different joint angles (at the same resistive torque) and at different resistive torques (at the same joint angles). When comparing these two tilts, we found that matching based on elevation angle demonstrated no significant difference, while matching based on torques did find differences. These results implicate elevation angle at the shoulder as playing a more important role in modulating joint position sense than joint torque. ß

show abstract

Spatial and physical frames of reference in positioning a limb

Cited by 25 publications

References 36 publications

Perception of limb orientation in the vertical plane depends on center of mass rather than inertial eigenvectors

Perception of limb orientation in the vertical plane depends on center of mass rather than inertial eigenvectors

Energy, information, detection, and action

Unconstrained shoulder joint position sense does not change with body orientation

Contact Info

Product

Resources

About