Sarah E. Criscimagna-Hemminger

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Accurate performance of reaching movements depends on adaptable neural circuitry that learns to predict forces and compensate for limb dynamics. In earlier experiments, we quantified generalization from training at one arm position to another position. The generalization patterns suggested that neural elements learning to predict forces coded a limb's state(More)
When we use a novel tool, the motor commands may not produce the expected outcome. In healthy individuals, with practice the brain learns to alter the motor commands. This change depends critically on the cerebellum as damage to this structure impairs adaptation. However, it is unclear precisely what the cerebellum contributes to the process of adaptation(More)
Small errors may affect the process of learning in a fundamentally different way than large errors. For example, adapting reaching movements in response to a small perturbation produces generalization patterns that are different from large perturbations. Are distinct neural mechanisms engaged in response to large versus small errors? Here, we examined the(More)
Can memories be unlearned, or is unlearning a form of acquiring a new memory that competes with the old, effectively masking it? We considered motor memories that were acquired when people learned to use a novel tool. We trained people to reach with tool A and quantified recall in error-clamp trials, i.e., trials in which the memory was reactivated but(More)
The function of the cerebellum in motor control is a long-standing puzzle because cerebellar damage is associated with both timing and coordination deficits. Timing is the ability to produce consistent intervals between movements based on an internal representation of time. Coordination, in contrast, is a state-dependent control process in which motor(More)
When we adapt our movements to a perturbation, and then adapt to another perturbation, is the initial memory destroyed, or is it protected? Despite decades of experiments, this question remains unresolved. The confusion, in our view, is due to the fact that in every instance the approach has been to assay contents of motor memory by retesting with the same(More)
Cerebellar damage impairs the control of complex dynamics during reaching movements. It also impairs learning of predictable dynamic perturbations through an error-based process. Prior work suggests that there are distinct neural mechanisms involved in error-based learning that depend on the size of error experienced. This is based, in part, on the(More)
During adaptation, motor commands tend to repeat as performance plateaus. It has been hypothesized that this repetition produces plasticity in the motor cortex (M1). Here, we considered a force field reaching paradigm, varied the perturbation schedule to potentially alter the amount of repetition, and quantified the interaction between disruption of M1(More)
Alkis M. Hadjiosif, Sarah E. Criscimagna-Hemminger, Tricia L. Gibo, Allison M. Okamura, Reza Shadmehr, Amy J. Bastian and Maurice A. Smith A number of studies have shown that motor adaptation is impaired following cerebellar damage. However, the degree of impairment varies considerably from one study to another, with widely ranging results reported even(More)
[PDF] [Full Text] [Abstract] , July 15, 2013; 110 (2): 322-333. J Neurophysiol Tricia L. Gibo, Sarah E. Criscimagna-Hemminger, Allison M. Okamura and Amy J. Bastian Cerebellar motor learning: are environment dynamics more important than error size? [PDF] [Full Text] [Abstract] , August 15, 2013; 110 (4): 916-925. J Neurophysiol Sara J. Hussain, Angela(More)
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