Instruct: Identify the main and secondary category of Arxiv papers based on the titles and abstracts
Query: Operation of a Brain-Computer Interface Walking Simulator by Users with
  Spinal Cord Injury   Background: Spinal cord injury (SCI) can leave the affected individuals
unable to ambulate. Since there are no restorative treatments for SCI, novel
approaches such as brain-controlled prostheses have been sought. Our recent
studies show that a brain-computer interface (BCI) can be used to control
ambulation within a virtual reality environment (VRE), suggesting that a
BCI-controlled lower extremity prosthesis for ambulation may be feasible.
However, the operability of our BCI has not been tested in a SCI population.
  Methods: Five subjects with paraplegia or tetraplegia due to SCI underwent a
10-min training session in which they alternated between kinesthetic motor
imagery (KMI) of idling and walking while their electroencephalogram (EEG) were
recorded. Subjects then performed a goal-oriented online task, where they
utilized KMI to control the linear ambulation of an avatar and make 10
sequential stops at designated points within the VRE. Multiple online trials
were performed over 5 experimental days.
  Results: Classification accuracy of idling and walking was estimated offline
and ranged from 60.5% (p=0.0176) to 92.3% (p=1.36*10^-20) across subjects and
days. In the online task, all subjects achieved purposeful control with an
average performance of 7.4 +/- 2.3 successful stops in 273 +/- 51 sec (p<0.01).
All subjects maintained purposeful control throughout the study, and their
online performances improved over time.
  Conclusions: The results demonstrate that SCI subjects can purposefully
operate a self-paced BCI walking simulator to complete a goal-oriented
ambulation task. The operation of this BCI system requires short training, is
intuitive, and robust against subject-to-subject and day-to-day
neurophysiological variations. These findings indicate that BCI-controlled
lower extremity prostheses for gait rehabilitation or restoration after SCI may
be feasible in the future.

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The categories of this paper are: hep-th
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The categories of this paper are: supr-con
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The categories of this paper are: stat
32
The categories of this paper are: atom-ph
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The categories of this paper are: eess
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The categories of this paper are: adap-org
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The categories of this paper are: chem-ph
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The categories of this paper are: mtrl-th
18
The categories of this paper are: econ
30
The categories of this paper are: q-alg
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The categories of this paper are: solv-int
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The categories of this paper are: astro-ph
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The categories of this paper are: hep-lat
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The categories of this paper are: q-fin
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The categories of this paper are: nucl-th
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The categories of this paper are: alg-geom