343 research outputs found
Is implicit motor imagery a reliable strategy for a brain computer interface?
Explicit motor imagery (eMI) is a widely used brain computer interface (BCI) paradigm, but not everybody can accomplish this task. Here we propose a BCI based on implicit motor imagery (iMI). We compared classification accuracy between eMI and iMI of hands. Fifteen able bodied people were asked to judge the laterality of hand images presented on a computer screen in a lateral or medial orientation. This judgement task is known to require mental rotation of a person’s own hands which in turn is thought to involve iMI. The subjects were also asked to perform eMI of the hands. Their electroencephalography (EEG) was recorded. Linear classifiers were designed based on common spatial patterns. For discrimination between left and right hand the classifier achieved maximum of 81 ± 8% accuracy for eMI and 83 ± 3% for iMI. These results show that iMI can be used to achieve similar classification accuracy as eMI. Additional classification was performed between iMI in medial and lateral orientations of a single hand; the classifier achieved 81 ± 7% for the left and 78 ± 7% for the right hand which indicate distinctive spatial patterns of cortical activity for iMI of a single hand in different directions. These results suggest that a special brain computer interface based on iMI may be constructed, for people who cannot perform explicit imagination, for rehabilitation of movement or for treatment of bodily spatial neglect
06401 Abstracts Collection -- Complexity of Constraints
From 01.10.06 to 06.10.06, the Dagstuhl Seminar 06401 ``Complexity of Constraints\u27\u27 was held in the International Conference and Research Center (IBFI),
Schloss Dagstuhl.
During the seminar, several participants presented their current
research, and ongoing work and open problems were discussed. Abstracts of
the presentations given during the seminar as well as abstracts of
seminar results and ideas are put together in this paper. The first section
describes the seminar topics and goals in general.
Links to extended abstracts or full papers are provided, if available
Range and Roots: Two Common Patterns for Specifying and Propagating Counting and Occurrence Constraints
We propose Range and Roots which are two common patterns useful for
specifying a wide range of counting and occurrence constraints. We design
specialised propagation algorithms for these two patterns. Counting and
occurrence constraints specified using these patterns thus directly inherit a
propagation algorithm. To illustrate the capabilities of the Range and Roots
constraints, we specify a number of global constraints taken from the
literature. Preliminary experiments demonstrate that propagating counting and
occurrence constraints using these two patterns leads to a small loss in
performance when compared to specialised global constraints and is competitive
with alternative decompositions using elementary constraints.Comment: 41 pages, 7 figure
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