Alumni of the Laboratory for Computational Motor Control

 

Jun Izawa

 

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Jun Izawa, August 2005

 

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Reza Shadmehr, Vincent Huang, Tushar Rane, Jun Izawa, Christine Lee, and Minnan Xu-Wilson, Niagara Falls, 2006

 

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Reza Shadmehr and Jun Izawa, San Diego, 2007.

 

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Sarah Hemminger, Vincent Ethier, Jun Izawa, Minnan Xu-Wilson, Courtney Haswell, and Vincent Huang.  San Diego, 2007.

 

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Reza Shadmehr, Jun Izawa, John Krakauer, Andy Barto, Minnan Xu-Wilson, and JJ Orban de Xivry, Germany 2009.

 

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Adrian Haith, Reza Shadmehr, and Jun Izawa, 2009.

 

Jun joined the lab as a postdoc in 2005 after completing his PhD from University of Tokyo.  Jun played a leading role in a number of new directions for the lab.  He demonstrated that adaptation was not merely a process of canceling a perturbation, but rather re-optimization, i.e., finding a new way to maximize probability of acquiring reward.  This implied that there could not be a ‘desired trajectory’ in the brain, but rather that all learning was ultimately a search for reward.  He discovered that in cerebellar disease, there was intact learning from reward prediction errors, but a specific impairment in learning from sensory prediction errors.  In this way, it was possible to improve performance of cerebellar patients, something that had been very difficult to do before Jun’s work.  He discovered that in autism, children exhibited an abnormally strong sensitivity proprioception during learning.  Perhaps the most important of his many contributions is the idea that the brain maintains multiple learning systems, and that during motor learning, two systems cooperate: a reward based learning system, and a sensory prediction based learning system.  The former is spared in people with cerebellar damage.  He discovered a way to behaviorally examine the consequence of learning with each system.  He is currently Associate Professor in the Faculty of Engineering, Information, and Systems, University of Tsukuba, Japan.

 

The results of his research were published in the following papers:

 

Cerebellar contributions to reach adaptation and learning sensory consequences of action. J Izawa, SE Criscimagna-Hemminger, and R Shadmehr (2012) Journal of Neuroscience 32:4230-4239. Abstract

 

Motor learning relies on integrated sensory inputs in ADHD, but over-selectively on proprioception in Autism spectrum conditions. J Izawa, SE Pekny, MK Marko, C Haswell, R Shadmehr, and SH Mostofsky (2012) Autism Research in press. Abstract

 

Cerebellar contributions to reach adaptation and learning sensory consequences of action. J Izawa, SE Criscimagna-Hemminger, and R Shadmehr (2012) Journal of Neuroscience 32:4230-4239. Abstract

 

Stimulation of the human motor cortex alters generalization patterns of motor learning. JJ Orban de Xivry, M Marko, S Pekny, D Pastor, J Izawa, P Celnik, and R Shadmehr (2011)Journal of Neuroscience 31:7102-7110Abstract

 

Learning from sensory and reward prediction errors during motor adaptation. J Izawa and R Shadmehr (2011) PLoS Computational Biology 7:e1002012. Abstract

 

Representation of internal models of action in the autistic brain. C Haswell, J Izawa, L Dowell, SH Mostofsky, and R Shadmehr (2009) Nature Neuroscience 12:970-972. Abstract Citations

 

Online processing of uncertain information in visuomotor control. J Izawa and R Shadmehr (2008) Journal of Neuroscience 28:11360-11368. Abstract Supplementary-material Matlab-Code 

 

Motor adaptation as a process of reoptimization.  J Izawa, T Rane, O Donchin, and R Shadmehr (2008) Journal of Neuroscience 28:2883-2891.  Abstract Supplementary-material