RIC research Seminars 2016 - Rehabilitation Institute of Chicago

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RIC research Seminars 2016

To schedule a seminar at SMPP, please contact the seminar coordinators at seminar-coordinator@ricres.org

  ***All seminars are in RIC, Room 1301 (map) at 12pm - 1pm unless otherwise noted.

Thur, Feb 18

Speaker: Megan O’Brien, PhD

Title: The neuroeconomics of error and effort in movement

Abstract: Consider that the goal of a voluntary movement is to put the body in a more valuable state, so that our movement decisions are based on maximizing rewards and minimizing any costs incurred while pursuing those rewards. Neuroeconomic principles are well-suited for describing movement behavior and control in this way, allowing us to quantify the utility of movement as a summation of the movement’s rewards and costs. The reward of a movement depends on the value of the object attained as well as the probability of obtaining it. The cost of a movement can be naturalistically represented as the effort spent in executing the motor commands. Then, the utility of a movement is determined by getting as much reward as possible while expending as little effort as possible. Importantly, these rewards and costs are susceptible to subjective valuation (wherein individuals may assign more or less value to them than their objective worth), which in turn affects movement behavior. Formalizing movement as a decision-making process allows us to compare the subjective valuation of these rewards and costs between tasks, domains, and populations.
In this talk, I will describe human movement using a neuroeconomic framework. I will present several novel studies that contribute to a broader question: how do subjective interpretations of movement rewards and costs manifest in our behavior? Specifically, I will discuss how implicit threat affects our weighting of the probability of movement error, and how a well-known cognitive bias affects our valuation of movement effort.

Tue, Feb 16

Speaker: Majed Samad

Title: Models of own-body perception and applications to the clinic

Abstract: The body is a fundamental anchor in every individual's perceptual reality, possessing privileged processing status and underlying much of what may be called the sense of selfhood. We have investigated the computational rules governing the integration of information that relates to one's own body using useful illusions such as the rubber hand illusion and a novel visual-tactile variant of the ventriloquist illusion, and shown that an extension of the causal inference model that has previously been shown to account for audiovisual integration can also account for the rubber hand illusion, with two experiments confirming the model's predictions. In addition to modeling, we have also attempted to utilize psychophysical paradigms to improve diagnosis of focal hand dystonia and cervical dystonia, as well as attempt to improve outcomes through the use of proprioceptive perceptual learning. Finally, we are currently conducting an EEG study to uncover the oscillatory markers of multisensory integration through the use of a novel feature selection algorithm and multivariate classification methods with the aim of diagnosing abnormalities of integration in disease populations and devising interventions for their treatment. Overall, these results demonstrate the utility of 1) computational methods for improving our understanding of neural information processing, and 2) psychophysical approaches to improving medical outcomes for patients with challenging clinical disorders.

Fri, Jan 22

Speaker: Keith Gordon, PhD

Title: Robotic Interventions to Enhance Locomotor Stability

Abstract: All mechanisms for stabilizing human walking are not equal. Often individuals with neurologic impairments choose stabilization strategies that inherently sacrifice critical components of community ambulation including speed and energetic efficiency. This is in contrast to neurologically intact individuals who utilize locomotor strategies that are concurrently stable, agile and efficient. I will present a unique perspective on how training environments can be structured to encourage individuals with neurologic impairments to actively practice “higher level” stabilization strategies that this population would typically avoid. Specifically, I will discuss a simple robotic tool we have developed to modulate the requirements for stabilization during walking and demonstrate how we are leveraging this device to drive individuals to adapt varying mechanisms for stabilizing gait.

Fri, Jan 15

Speaker: Thomas Howard, PhD

Title: Learning Models for Robot Decision Making

Abstract: The efficiency and optimality of robot decision making is often dictated by the fidelity and complexity of models for how a robot can interact with its environment. It is common for researchers to engineer these models a priori to achieve particular levels of performance for specific tasks in a restricted set of environments and initial conditions. As we progress towards more intelligent systems that perform a wider range of objectives in a greater variety of domains, the models for how robots make decisions must adapt to achieve, if not exceed, engineered levels of performance. In this talk I will discuss progress towards model adaptation for robot intelligence, including recent efforts in natural language understanding for human-robot interaction.
This presentation will introduce a framework for integrating mechanical characterization of passive prostheses, human subject testing, and numerical simulation to study these relationships and accurately classify prosthesis function in an effort to optimize clinical prescription guidelines and prosthesis designs. Methods of prosthesis mechanical characterization to inform research, clinical prescription and cost justification will be presented, as well as studies that use systematic approaches to explore the effects of isolated prosthesis properties on user performance.

Fri, Jan 8

Speaker: Matthew Major, PhD

Title: Exploring the relationships between lower-limb prosthesis mechanical properties and user performance for clinical prescription and prosthesis design optimization.

Abstract: Prosthetists are confronted with the universal challenge to select from a wide variety of commercially-available lower-limb prostheses to best help patients reach their functional and health-related goals. With more prosthetic components being developed each year, this challenge becomes increasingly difficult, particularly as the fundamental relationship between prosthesis mechanical properties (i.e., stiffness, damping, and roll-over geometry) and user performance (e.g., walking dynamics, muscle activation patterns, and metabolic cost) are still poorly understood. This lack of understanding hinders the development of future prostheses that are designed to maximize walking efficiency. Furthermore, there is no standardized method for the mechanical testing of prostheses for accurate and reliable classification based on functional characteristics (e.g., energy storage-and-return, multi-axial, etc.). Without such standardized methods, clinical prescription, recommendation, and cost justification suffer from ambiguity and may result in suboptimal patient rehabilitation outcomes. Characterization of prosthesis mechanical properties provides a critical means for systematic exploration of the effects of these properties on the biomechanical and physiological performance of lower-limb prosthesis users, and allows for accurate and reliable prosthesis functional classification. Ultimately, improved understanding of this paradigm will inform clinical prescription guidelines and facilitate development of optimal prosthesis designs to enhance the mobility and health of lower-limb prosthesis users.

This presentation will introduce a framework for integrating mechanical characterization of passive prostheses, human subject testing, and numerical simulation to study these relationships and accurately classify prosthesis function in an effort to optimize clinical prescription guidelines and prosthesis designs. Methods of prosthesis mechanical characterization to inform research, clinical prescription and cost justification will be presented, as well as studies that use systematic approaches to explore the effects of isolated prosthesis properties on user performance.