The goal of the proposal is to explore the strategies used by the central nervous system when manipulating hand- held objects. Recently we developed a new mathematical method of inverse optimization - the 'Analytic Inverse Optimization'(ANIO) method -that allows for reconstructing unknown cost functions (CF) from experimental recordings (Terekhov et al. 2010). The first line of research will deal with the further development of the method and its application to human prehension. Experiment 1-A will explore whether all performers use CFs of the same class. Experiment 1-B will test whether the ANIO method yields estimates of the CFs that are reproducible over protracted periods of time. Experiment 1-C will explore the dependence of the CF class of functions on the number of fingers involved in the task. Experiment 1-D will address interaction between the optimization and variability in multi-finger prehension. The second line of research is based on previous results obtained in our lab and is intended to test the following hypotheses: Experiment 2-A will test the additivity hypothesis: suppose that the digit forces are affected by factors A, B, C, etc. The hypothesis assumes that the effects of the neural commands associated with the above factors are additive. In statistical terms it means that the effects of the factors are significant while their interactions are not. Experiment 2B extends the additivity hypothesis to the complex dynamic tasks. We expect to find that the pattern of grasping force changes as a sum of the effects of two commands associated with the movements along and normal to grasp direction, respectively. Experiment 2C will deal with testing a template control hypothesis according to which for every given combination of the object geometry and local friction the performers select a digit force pattern ('template') and then scale the digit forces with the load force. Experiment 2- D will consist of two parts in which effects of one finger fatigue or fatigue of all fingers will be explored. The goal is to test whether the fatigued finger exerts the same %% of its current maximal force as it did prior to fatigue. Essentially, the experiment will explore the 'robustness'of prehension control, using local fatigue as a perturbation tool. Under 'robustness'we understand ability to perform a task when performance potential of one of the contributing elements is diminished.

Public Health Relevance

The research has three potential fields of applications: clinics, prosthetics, and robotics. In clinics, the research will have implications for improving diagnostic tools and rehabilitation procedures. In prosthetics and robotics, it will lead to construction of efficient hand prostheses and 'artificial hands'.

National Institute of Health (NIH)
National Institute of Arthritis and Musculoskeletal and Skin Diseases (NIAMS)
Research Project (R01)
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Special Emphasis Panel (ZRG1-MOSS-C (02))
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Panagis, James S
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Pennsylvania State University
Schools of Allied Health Profes
University Park
United States
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Jo, Hang Jin; Ambike, Satyajit; Lewis, Mechelle M et al. (2016) Finger force changes in the absence of visual feedback in patients with Parkinson's disease. Clin Neurophysiol 127:684-92
Ambike, Satyajit; Mattos, Daniela; Zatsiorsky, Vladimir M et al. (2016) Unsteady steady-states: central causes of unintentional force drift. Exp Brain Res 234:3597-3611
Latash, Mark L (2016) Towards physics of neural processes and behavior. Neurosci Biobehav Rev 69:136-46
Ambike, S; Mattos, D; Zatsiorsky, V M et al. (2016) Synergies in the space of control variables within the equilibrium-point hypothesis. Neuroscience 315:150-61
Parsa, Behnoosh; Ambike, Satyajit; Terekhov, Alexander et al. (2016) Analytical Inverse Optimization in Two-Hand Prehensile Tasks. J Mot Behav 48:424-34
Solnik, Stanislaw; Reschechtko, Sasha; Wu, Yen-Hsun et al. (2016) Interpersonal synergies: static prehension tasks performed by two actors. Exp Brain Res 234:2267-82
Parsa, Behnoosh; Zatsiorsky, Vladimir M; Latash, Mark L (2016) Optimality and stability of intentional and unintentional actions: II. Motor equivalence and structure of variance. Exp Brain Res :
Ambike, Satyajit; Mattos, Daniela; Zatsiorsky, Vladimir M et al. (2016) The nature of constant and cyclic force production: unintentional force-drift characteristics. Exp Brain Res 234:197-208
Zhou, Tao; Falaki, Ali; Latash, Mark L (2016) Unintentional movements induced by sequential transient perturbations in a multi-joint positional task. Hum Mov Sci 46:1-9
Parsa, Behnoosh; Terekhov, Alexander; Zatsiorsky, Vladimir M et al. (2016) Optimality and stability of intentional and unintentional actions: I. Origins of drifts in performance. Exp Brain Res :

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