| Records |
| Author |
Zopf, Regine; Truong, Sandra; Finkbeiner, Matthew; Friedman, Jason; Williams, Mark A |
| Title |
Viewing and feeling touch modulates hand position for reaching |
Type |
Journal Article |
| Year |
2011 |
Publication |
Neuropsychologia |
Abbreviated Journal |
|
| Volume |
49 |
Issue  |
5 |
Pages |
1287–1293 |
| Keywords |
|
| Abstract |
Action requires knowledge of our body location in space. Here we asked if interactions with the external world prior to a reaching action influence how visual location information is used. We investigated if the temporal synchrony between viewing and feeling touch modulates the integration of visual and proprioceptive body location information for action. We manipulated the synchrony between viewing and feeling touch in the Rubber Hand Illusion paradigm prior to participants performing a ballistic reaching task to a visually specified target. When synchronous touch was given, reaching trajectories were significantly shifted compared to asynchronous touch. The direction of this shift suggests that touch influences the encoding of hand position for action. On the basis of this data and previous findings, we propose that the brain uses correlated cues from passive touch and vision to update its own position for action and experience of self-location. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Penn State @ write.to.jason @ |
Serial |
23 |
| Permanent link to this record |
| |
|
| |
| Author |
Friedman, Jason; Flash, Tamar |
| Title |
Trajectory of the index finger during grasping |
Type |
Journal Article |
| Year |
2009 |
Publication |
Experimental Brain Research |
Abbreviated Journal |
Exp Brain Res |
| Volume |
196 |
Issue |
4 |
Pages |
497-509 |
| Keywords |
|
| Abstract |
The trajectory of the index finger during grasping movements was compared to the trajectories predicted by three optimization-based models. The three models consisted of minimizing the integral of the weighted squared joint derivatives along the path (inertia-like cost), minimizing torque change, and minimizing angular jerk. Of the three models, it was observed that the path of the fingertip and the joint trajectories, were best described by the minimum angular jerk model. This model, which does not take into account the dynamics of the finger, performed equally well when the inertia of the finger was altered by adding a 20 g weight to the medial phalange. Thus, for the finger, it appears that trajectories are planned based primarily on kinematic considerations at a joint level. |
| Address |
Department of Computer Science and Applied Mathematics, Weizmann Institute of Science, Rehovot, Israel, write.to.jason@gmail.com |
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
1432-1106 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:19521692 |
Approved |
no |
| Call Number |
Penn State @ write.to.jason @ |
Serial |
17 |
| Permanent link to this record |
| |
|
| |
| Author |
Noy, L.; Alon, U.; Friedman, J. |
| Title |
Corrective jitter motion shows similar individual frequencies for the arm and the finger |
Type |
Journal Article |
| Year |
2015 |
Publication |
Experimental Brain Research |
Abbreviated Journal |
Exp Brain Res |
| Volume |
233 |
Issue |
4 |
Pages |
1307-1320 |
| Keywords |
|
| Abstract |
A characteristic of visuomotor tracking of non-regular oscillating stimuli are high-frequency jittery corrective motions, oscillating around the tracked stimuli. However, the properties of these corrective jitter responses are not well understood. For example, does the jitter response show an idiosyncratic signature? What is the relationship between stimuli properties and jitter properties? Is the jitter response similar across effectors with different inertial properties? To answer these questions, we measured participants' jitter frequencies in two tracking tasks in the arm and the finger. Thirty participants tracked the same set of eleven non-regular oscillating stimuli, vertically moving on a screen, once with forward-backward arm movements (holding a tablet stylus) and once with upward-downward index finger movements (with a motion tracker attached). Participants' jitter frequencies and tracking errors varied systematically as a function of stimuli frequency and amplitude. Additionally, there were clear individual differences in average jitter frequencies between participants, ranging from 0.7 to 1.15 Hz, similar to values reported previously. A comparison of individual jitter frequencies in the two tasks showed a strong correlation between participants' jitter frequencies in the finger and the arm, despite the very different inertial properties of the two effectors. This result suggests that the corrective jitter response stems from common neural processes. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
English |
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
0014-4819 |
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
PMID:25630905 |
Approved |
no |
| Call Number |
|
Serial |
76 |
| Permanent link to this record |
| |
|
| |
| Author |
Friedman, Jason; Brown, Scott; Finkbeiner, Matthew |
| Title |
Linking cognitive and reaching trajectories via intermittent movement control |
Type |
Journal Article |
| Year |
2013 |
Publication |
Journal of Mathematical Psychology |
Abbreviated Journal |
|
| Volume |
57 |
Issue |
3-4 |
Pages |
140-151 |
| Keywords |
Decision making; Diffusion model; Reaction times; Arm movements; Submovements |
| Abstract |
Theories of decision-making have traditionally been constrained by reaction time data. A limitation of reaction time data, particularly for studying the temporal dynamics of cognitive processing, is that they index only the endpoint of the decision making process. Recently, physical reaching trajectories have been used as proxies for underlying mental trajectories through decision space. We suggest that this approach has been oversimplified: while it is possible for the motor control system to access the current state of the evidence accumulation process, this access is intermittent. Instead, we demonstrate how a model of arm movements that assumes intermittent, not continuous, access to the decision process is sufficient to describe the effects of stimulus quality and viewing time in curved reaching movements. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
|
Serial |
70 |
| Permanent link to this record |
| |
|
| |
| Author |
Friedman, Jason; Flash, Tamar |
| Title |
Task-dependent selection of grasp kinematics and stiffness in human object manipulation |
Type |
Journal Article |
| Year |
2007 |
Publication |
Cortex |
Abbreviated Journal |
|
| Volume |
43 |
Issue |
3 |
Pages |
444-460 |
| Keywords |
|
| Abstract |
Object manipulation with the hand is a complex task. The task has redundancies at many levels, allowing many possibilities for the selection of grasp points, the orientation and posture of the hand, the forces to be applied at each fingertip and the impedance properties of the hand. Despite this inherent complexity, humans perform object manipulation nearly effortlessly. This article presents experimental findings of how humans grasp and manipulate objects, and examines the compatibility of grasps selected for specific tasks. This is accomplished by looking at the velocity transmission and force transmission ellipsoids, which represent the transmission ratios of the corresponding quantity from the joints to the object, as well as the stiffness ellipsoid which represents the directional stiffness of the grasp. These ellipsoids allow visualization of the grasp Jacobian and grasp stiffness matrices. The results show that the orientation of the ellipsoids can be related to salient task requirements. |
| Address |
|
| Corporate Author |
|
Thesis |
|
| Publisher |
|
Place of Publication |
|
Editor |
|
| Language |
|
Summary Language |
|
Original Title |
|
| Series Editor |
|
Series Title |
|
Abbreviated Series Title |
|
| Series Volume |
|
Series Issue |
|
Edition |
|
| ISSN |
|
ISBN |
|
Medium |
|
| Area |
|
Expedition |
|
Conference |
|
| Notes |
|
Approved |
no |
| Call Number |
Penn State @ write.to.jason @ |
Serial |
14 |
| Permanent link to this record |
