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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.
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Notes Approved no
Call Number Serial 70
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Author Ezrati, O.; Friedman, J.; Dar, R.
Title Attenuation of access to internal states in high obsessive-compulsive individuals might increase susceptibility to false feedback: Evidence from a visuo-motor hand-reaching task Type Journal Article
Year 2019 Publication Journal of Behavior Therapy and Experimental Psychiatry Abbreviated Journal Journal of Behavior Therapy and Experimental Psychiatry
Volume 65 Issue Pages 101445
Keywords Obsessive-compulsive disorder; Movement; Agency; Proprioception; Proxies
Abstract Background and objectives

The Seeking Proxies for Internal States (SPIS) model of obsessive-compulsive disorder (OCD) posits that obsessive-compulsive (OC) individuals have attenuated access to their internal states. Hence, they seek and rely on proxies, or discernible substitutes for these internal states. In previous studies, participants with high OC tendencies and OCD patients, compared to controls, showed increased reliance on external proxies and were more influenced by false feedback when judging their internal states. This study is the first to examine the effects of false feedback on performance of hand movements in participants with high and low OC tendencies.

Method

Thirty-four participants with high OC tendencies and 34 participants with low OC tendencies were asked to perform accurate hand reaches without visual feedback in two separate sessions of a computerized hand-reaching task: once after valid feedback training of their hand location and once with false-rotated feedback. We assessed the accuracy and directional adaptation of participants' reaches.

Results

As predicted, high OC participants evidenced a larger decrease in their hand positioning accuracy after training with false feedback compared to low OC participants.

Limitations

The generalization of our findings to OCD requires replication with a clinical sample.

Conclusions

These results suggest that in addition to self-perceptions, motor performance of OC individuals is prone to be overly influenced by false feedback, possibly due to attenuated access to proprioceptive cues. These findings may be particularly relevant to understanding the distorted sense of agency in OCD.
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Language Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN (up) 0005-7916 ISBN Medium
Area Expedition Conference
Notes Approved no
Call Number Serial 95
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Author Liebermann, D.G.; Biess, A.; Friedman, J.; Gielen, C.C.A.M.; Flash, T.
Title Intrinsic joint kinematic planning. I: reassessing the Listing's law constraint in the control of three-dimensional arm movements Type Journal Article
Year 2006 Publication Experimental Brain Research Abbreviated Journal Exp Brain Res
Volume 171 Issue 2 Pages 139-154
Keywords Adolescent; Adult; Analysis of Variance; *Arm; Biomechanics; Eye Movements/*physiology; Humans; Joints/*physiology; Male; Movement/*physiology; *Musculoskeletal System; Orientation/*physiology; Posture
Abstract This study tested the validity of the assumption that intrinsic kinematic constraints, such as Listing's law, can account for the geometric features of three-dimensional arm movements. In principle, if the arm joints follow a Listing's constraint, the hand paths may be predicted. Four individuals performed 'extended arm', 'radial', 'frontal plane', and 'random mixed' movements to visual targets to test Listing's law assumption. Three-dimensional rotation vectors of the upper arm and forearm were calculated from three-dimensional marker data. Data fitting techniques were used to test Donders' and Listing's laws. The coefficient values obtained from fitting rotation vectors to the surfaces described by a second-order equation were analyzed. The results showed that the coefficients that represent curvature and twist of the surfaces were often not significantly different from zero, particularly not during randomly mixed and extended arm movements. These coefficients for forearm rotations were larger compared to those for the upper arm segment rotations. The mean thickness of the rotation surfaces ranged between approximately 1.7 degrees and 4.7 degrees for the rotation vectors of the upper arm segment and approximately 2.6 degrees and 7.5 degrees for those of the forearm. During frontal plane movements, forearm rotations showed large twist scores while upper arm segment rotations showed large curvatures, although the thickness of the surfaces remained low. The curvatures, but not the thicknesses of the surfaces, were larger for large versus small amplitude radial movements. In conclusion, when examining the surfaces obtained for the different movement types, the rotation vectors may lie within manifolds that are anywhere between curved or twisted manifolds. However, a two-dimensional thick surface may roughly represent a global arm constraint. Our findings suggest that Listing's law is implemented for some types of arm movement, such as pointing to targets with the extended arm and during radial reaching movements.
Address Department of Physical Therapy, Sackler Faculty of Medicine, Tel-Aviv University, 69978, Ramat Aviv, Israel. dlieberm@post.tau.ac.il
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
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ISSN (up) 0014-4819 ISBN Medium
Area Expedition Conference
Notes PMID:16341526 Approved no
Call Number Penn State @ write.to.jason @ Serial 18
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Author Liebermann, D.G.; Krasovsky, T.; Berman, S.
Title Planning maximally smooth hand movements constrained to nonplanar workspaces Type Journal Article
Year 2008 Publication Journal of Motor Behavior Abbreviated Journal J Mot Behav
Volume 40 Issue 6 Pages 516-531
Keywords Adaptation, Physiological; Adult; Algorithms; Female; Hand/*physiology; Humans; *Intention; Kinesthesis/*physiology; Male; Models, Statistical; Movement/*physiology; Psychomotor Performance/*physiology; Reference Values; Writing
Abstract The article characterizes hand paths and speed profiles for movements performed in a nonplanar, 2-dimensional workspace (a hemisphere of constant curvature). The authors assessed endpoint kinematics (i.e., paths and speeds) under the minimum-jerk model assumptions and calculated minimal amplitude paths (geodesics) and the corresponding speed profiles. The authors also calculated hand speeds using the 2/3 power law. They then compared modeled results with the empirical observations. In all, 10 participants moved their hands forward and backward from a common starting position toward 3 targets located within a hemispheric workspace of small or large curvature. Comparisons of modeled observed differences using 2-way RM-ANOVAs showed that movement direction had no clear influence on hand kinetics (p < .05). Workspace curvature affected the hand paths, which seldom followed geodesic lines. Constraining the paths to different curvatures did not affect the hand speed profiles. Minimum-jerk speed profiles closely matched the observations and were superior to those predicted by 2/3 power law (p < .001). The authors conclude that speed and path cannot be unambiguously linked under the minimum-jerk assumption when individuals move the hand in a nonplanar 2-dimensional workspace. In such a case, the hands do not follow geodesic paths, but they preserve the speed profile, regardless of the geometric features of the workspace.
Address Department of Physical Therapy, The Stanley Steyer School of Health Professions, Sackler Faculty of Medicine, Tel Aviv University, Israel. dlieberm@post.tau.ac.il
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Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0022-2895 ISBN Medium
Area Expedition Conference
Notes PMID:18980905 Approved no
Call Number Serial 33
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Author Liebermann, D.G.; Buchman, A.S.; Franks, I.M.
Title Enhancement of motor rehabilitation through the use of information technologies Type Journal Article
Year 2006 Publication Clinical Biomechanics (Bristol, Avon) Abbreviated Journal Clin Biomech (Bristol, Avon)
Volume 21 Issue 1 Pages 8-20
Keywords Biotechnology/*methods; Humans; Medical Informatics/*methods; Motion Therapy, Continuous Passive/*methods; Movement Disorders/*rehabilitation; Musculoskeletal Manipulations/methods; Rehabilitation/*methods; Robotics/*methods; Therapy, Computer-Assisted/*methods
Abstract The recent development of information technologies has dramatically increased the tools available for facilitating motor rehabilitation. This review focuses on technologies which can be used to augment movement-related information both to patients as well as to their therapists. A brief outline of the motor system emphasizes the role of spinal motor neurons in the control of voluntary movement and rehabilitative efforts. Technologies which induce passive motion to stimulate spinal motor output as well as technologies that stimulate active voluntary movements are discussed. Finally, we review technologies and notational methods that can be used to quantify and assess the quality of movement for evaluating the efficacy of motor rehabilitation efforts. We conclude that stronger evidence is necessary to determine the applicability of the wide range of technologies now available to clinical rehabilitation efforts.
Address Department of Physical Therapy, Sackler Faculty of Medicine, University of Tel Aviv, Israel. dlieberm@post.tau.ac.il
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Publisher Place of Publication Editor
Language English Summary Language Original Title
Series Editor Series Title Abbreviated Series Title
Series Volume Series Issue Edition
ISSN (up) 0268-0033 ISBN Medium
Area Expedition Conference
Notes PMID:16198463 Approved no
Call Number Serial 49
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