About Entrez

Text Version

Entrez PubMed
Help | FAQ

PubMed Services
Journals Database
MeSH Database
Single Citation Matcher
Batch Citation Matcher
Clinical Queries
Special Queries

Related Resources
Order Documents
NLM Mobile
NLM Catalog
NLM Gateway
Consumer Health
Clinical Alerts
PubMed Central
 Display  Show 
All: 1 
Review: 0 
1: J Physiol Paris. 2005 Nov 23; [Epub ahead of print] Related Articles, Links

Comparing information about arm movement direction in single channels of local and epicortical field potentials from monkey and human motor cortex.

Mehring C, Nawrot MP, de Oliveira SC, Vaadia E, Schulze-Bonhage A, Aertsen A, Ball T.

Institute for Biology I, Hauptstr. 1, Albert-Ludwigs-University, 79104 Freiburg, Germany; Berstein Center for Computational Neuroscience, Albert-Ludwigs-University, 79104 Freiburg, Germany.

Cortical field potentials have been used for decades in neurophysiological studies to probe spatio-temporal activity patterns of local populations of neurons. Recently, however, interest in these signals was spurred as they were proposed as potential control signals for neuronal motor prostheses, i.e., for devices fit to record and decode brain activity to restore motor functions in paralyzed patients. Little is known, however, about the functional significance of these cortical field potentials. Here we compared information about arm movement direction in two types of movement related cortical field potentials, obtained during a four direction center-out arm reaching paradigm: local field potentials (LFPs) recorded with intracortical micro-electrodes from monkey motor cortex, and epicortical field potentials (EFPs) recorded with macro-electrode arrays subdurally implanted on the surface of the human cerebral cortex. While monkey LFPs showed a typical sequence of positive and negative potential peaks, an initial negative peak was the most salient feature of human EFPs. Individual contralateral LFPs from the monkey motor cortex carried approximately twice as much decoded information (DI) about arm movement direction (median 0.27bit) as did individual EFPs from the contralateral hand/arm area of primary motor cortex in humans (median 0.12bit). This relation was similar to the relation between median peak signal-to-noise ratios for directional modulation of movement related potentials (MRPs) of both types of signals. We discuss possible reasons for the observed differences, amongst them epi- vs. intracortical recording and the different electrode dimensions used to measure EFPs and LFPs.

PMID: 16310349 [PubMed - as supplied by publisher]

 Display  Show