Hybrid model of the context dependent vestibulo-ocular reflex: implications for vergence-version interactions

Ranjbaran, Mina; Galiana, Henrietta L.

doi:10.3389/fncom.2015.00006

Cited by 10 publications

(5 citation statements)

References 37 publications

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“…17 shows a simplified model of the VOR, where the cerebellum predicts the eye plant output and indirectly compensates the movement command. In the saccadic system, the head movements are sensed by the vestibular system consisting of semicircular canals and otolith organs [38]. For simplicity, only the horizontal head velocity sensed by the horizontal canal is considered as the input.…”

Section: Cerebellar Model Evaluationmentioning

confidence: 99%

“…For simplicity, only the horizontal head velocity sensed by the horizontal canal is considered as the input. The horizontal canal is modeled as a high-pass filter, V (s) = s s+1/T c , where T c = 6 s [38]. The brainstem acts as a control center that receives the sensory information and compensation signals from the cerebellum.…”

Section: Cerebellar Model Evaluationmentioning

confidence: 99%

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A High-Performance and Energy-Efficient FIR Adaptive Filter Using Approximate Distributed Arithmetic Circuits

Jiang

Liu

Jonker

et al. 2019

IEEE Trans. Circuits Syst. I

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In this paper, a fixed-point finite impulse response adaptive filter is proposed using approximate distributed arithmetic (DA) circuits. In this design, the radix-8 Booth algorithm is used to reduce the number of partial products in the DA architecture, although no multiplication is explicitly performed. In addition, the partial products are approximately generated by truncating the input data with an error compensation. To further reduce hardware costs, an approximate Wallace tree is considered for the accumulation of partial products. As a result, the delay, area, and power consumption of the proposed design are significantly reduced. The application of system identification using a 48-tap bandpass filter and a 103tap high-pass filter shows that the approximate design achieves a similar accuracy as its accurate counterpart. Compared with the state-of-the-art adaptive filter using bit-level pruning in the adder tree (referred to as the delayed least mean square (DLMS) design), it has a lower steady-state mean squared error and a smaller normalized misalignment. Synthesis results show that the proposed design attains on average a 55% reduction in energy per operation (EPO) and a 3.2× throughput per area compared with an accurate design. Moreover, the proposed design achieves 45%-61% lower EPO compared with the DLMS design. A saccadic system using the proposed approximate adaptive filterbased cerebellar model achieves a similar retinal slip as using an accurate filter. These results are promising for the large-scale integration of approximate circuits into high-performance and energy-efficient systems for error-resilient applications.

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Section: Cerebellar Model Evaluationmentioning

confidence: 99%

Section: Cerebellar Model Evaluationmentioning

confidence: 99%

A High-Performance and Energy-Efficient FIR Adaptive Filter Using Approximate Distributed Arithmetic Circuits

Jiang

Liu

Jonker

et al. 2019

IEEE Trans. Circuits Syst. I

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“…The participant's head was restrained using a chin/head rest to minimize head movement and influence from the vestibular system (Ranjbaran & Galiana, 2015). A midline adjustment procedure was performed to insure proper positioning within the chin/head rest.…”

Section: Calibrationmentioning

confidence: 99%

Changes in the disparity vergence main sequence after treatment of symptomatic convergence insufficiency in children

Scheiman

Yaramothu²,

Alvarez³

2019

JEMR

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This study investigates the underlying physiological mechanisms that may lead to improved outcomes for symptomatic convergence insufficiency (CI) patients after 12 weeks of office-based vergence/accommodation therapy (OBVAT) by evaluating the change in the main sequence of vergence and saccadic eye movements. In this prospective trial, 12 participants with symptomatic CI were recruited and treated with 12 weeks of OBVAT. Outcome measures included the objective assessment of the following: peak velocity, time to peak velocity, latency, response amplitude, and clinical changes in the near point of convergence (NPC), positive fusional vergence (PFV) and symptoms via the Convergence Insufficiency Symptom Survey (CISS). Ten of the twelve participants (83%) were categorized as “successful” and two were “improved” based on pre-determined published criteria (CISS, NPC, PFV). There were statistically significant changes in peak velocity, time to peak velocity, and response amplitude for both 4° and 6° symmetrical convergence and divergence eye movements. There was a significant change in the main sequence ratio for convergence post-OBVAT compared to baseline measurements (P=0.007) but not for divergence or saccadic responses. Phasic/step vergence movements adjust the underlying neural control of convergence and are critical within a vision therapy program for CI patients.

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“…Therefore, control-theoretic constructs likely apply (e.g., [143,144,145,146,147]). Such an approach is justified by the successes in identifying neural circuits that perform closed-loop feedback control such as homeostasis in physiological control systems [148], muscle stretch reflexes [149], and vestibuloocular reflexes for eye tracking in the presence of head rotation [150,151].…”

Section: Advantages and Limitations Of Control Theoretic Approaches Tmentioning

confidence: 99%

On neuromechanical approaches for the study of biological and robotic grasp and manipulation

Valero-Cuevas

Santello

2017

J NeuroEngineering Rehabil

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Biological and robotic grasp and manipulation are undeniably similar at the level of mechanical task performance. However, their underlying fundamental biological vs. engineering mechanisms are, by definition, dramatically different and can even be antithetical. Even our approach to each is diametrically opposite: inductive science for the study of biological systems vs. engineering synthesis for the design and construction of robotic systems. The past 20 years have seen several conceptual advances in both fields and the quest to unify them. Chief among them is the reluctant recognition that their underlying fundamental mechanisms may actually share limited common ground, while exhibiting many fundamental differences. This recognition is particularly liberating because it allows us to resolve and move beyond multiple paradoxes and contradictions that arose from the initial reasonable assumption of a large common ground. Here, we begin by introducing the perspective of neuromechanics, which emphasizes that real-world behavior emerges from the intimate interactions among the physical structure of the system, the mechanical requirements of a task, the feasible neural control actions to produce it, and the ability of the neuromuscular system to adapt through interactions with the environment. This allows us to articulate a succinct overview of a few salient conceptual paradoxes and contradictions regarding under-determined vs. over-determined mechanics, under- vs. over-actuated control, prescribed vs. emergent function, learning vs. implementation vs. adaptation, prescriptive vs. descriptive synergies, and optimal vs. habitual performance. We conclude by presenting open questions and suggesting directions for future research. We hope this frank and open-minded assessment of the state-of-the-art will encourage and guide these communities to continue to interact and make progress in these important areas at the interface of neuromechanics, neuroscience, rehabilitation and robotics.

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Hybrid model of the context dependent vestibulo-ocular reflex: implications for vergence-version interactions

Cited by 10 publications

References 37 publications

A High-Performance and Energy-Efficient FIR Adaptive Filter Using Approximate Distributed Arithmetic Circuits

A High-Performance and Energy-Efficient FIR Adaptive Filter Using Approximate Distributed Arithmetic Circuits

Changes in the disparity vergence main sequence after treatment of symptomatic convergence insufficiency in children

On neuromechanical approaches for the study of biological and robotic grasp and manipulation

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