JN AJP: Lung Cellular and Molecular Physiology
HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
 QUICK SEARCH:   [advanced]


     


J Neurophysiol (January 3, 2007). doi:10.1152/jn.00405.2006
This Article
Right arrow Full Text (PDF)
Right arrow Supplemental Figure
Right arrow All Versions of this Article:
97/3/2107    most recent
00405.2006v1
Right arrow Alert me when this article is cited
Right arrow Alert me if a correction is posted
Services
Right arrow Email this article to a friend
Right arrow Similar articles in this journal
Right arrow Similar articles in PubMed
Right arrow Alert me to new issues of the journal
Right arrow Download to citation manager
Citing Articles
Right arrow Citing Articles via HighWire
Right arrow Citing Articles via Google Scholar
Google Scholar
Right arrow Articles by Tunik, E.
Right arrow Articles by Grafton, S. T.
Right arrow Search for Related Content
PubMed
Right arrow PubMed Citation
Right arrow Articles by Tunik, E.
Right arrow Articles by Grafton, S. T.
Submitted on April 17, 2006
Accepted on December 15, 2006

BOLD coherence reveals segregated functional neural interactions when adapting to distinct torque perturbations

Eugene Tunik1, Paul Schmitt1, and Scott T. Grafton2*

1 Psychological and Brain Science, Dartmouth College, Hanover, New Hampshire, United States
2 Psychological & Brain Science, Dartmouth College, Hanover, New Hampshire, United States

* To whom correspondence should be addressed. E-mail: grafton{at}psych.ucsb.edu.

In the natural world, we experience and adapt to multiple extrinsic perturbations. This poses a challenge to neural circuits in discriminating between different context-appropriate responses. Using event-related fMRI, we characterized the neural dynamics involved in this process by randomly delivering a position- or velocity-dependent torque perturbation to subjects arms during a target capture task. Each perturbation was color-cued during movement preparation to provide contextual information. Though trajectories differed between perturbations, subjects significantly reduced error under both conditions. This was paralleled by reduced BOLD signal in the right dentate nucleus, the left sensorimotor cortex, and the left intraparietal sulcus. Trials included NoGo conditions to dissociate activity related to preparation from execution and adaptation. Subsequent analysis identified perturbation-specific neural processes underlying preparation (NoGo) and adaptation (Go) early and late into learning. Between-perturbation comparisons of BOLD magnitude revealed negligible differences for both preparation and adaptation trials. However, a network-level analysis of BOLD coherence revealed that by late learning, response preparation (NoGo) was attributed to a relative focusing of coherence within cortical and basal ganglia networks in both perturbation conditions, demonstrating a common network interaction for establishing arbitrary visuomotor associations. Conversely, late-learning adaptation (Go) was attributed to a focusing of BOLD coherence between a cortical-basal ganglia network in the viscous condition and between a cortical-cerebellar network in the positional condition. Our findings demonstrate that trial-to-trial acquisition of two distinct adaptive responses is attributed not to anatomically segregated regions, but to differential functional interactions within common sensorimotor circuits.




This article has been cited by other articles:


Home page
J. Neurophysiol.Home page
W. M. Joiner and M. A. Smith
Long-Term Retention Explained by a Model of Short-Term Learning in the Adaptive Control of Reaching
J Neurophysiol, November 1, 2008; 100(5): 2948 - 2955.
[Abstract] [Full Text] [PDF]


Home page
NeuroscientistHome page
L. Shmuelof and E. Zohary
Watching Others' Actions: Mirror Representations in the Parietal Cortex
Neuroscientist, December 1, 2007; 13(6): 667 - 672.
[Abstract] [PDF]




HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH
Visit Other APS Journals Online
Copyright © 2007 by the The American Physiological Society.