title: Long term, stable brain machine interface performance using local field potentials and multiunit spikes.
abstract: OBJECTIVE
  Brain machine interfaces (BMIs) have the potential to restore movement to people with paralysis. However, a clinically-viable BMI must enable consistently accurate control over time spans ranging from years to decades, which has not yet been demonstrated. Most BMIs that use single-unit spikes as inputs will experience degraded performance over time without frequent decoder re-training. Two other signals, local field potentials (LFPs) and multi-unit spikes (MSPs), may offer greater reliability over long periods and better performance stability than single-unit spikes. Here, we demonstrate that LFPs can be used in a biomimetic BMI to control a computer cursor.
  
  
  METHODS
  We implanted two rhesus macaques with intracortical microelectrodes in primary motor cortex. We recorded LFP and MSP signals from the monkeys while they performed a continuous reaching task, moving a cursor to randomly-placed targets on a computer screen. We then used the LFP and MSP signals to construct biomimetic decoders for control of the cursor.
  
  
  RESULTS
  Both monkeys achieved high-performance, continuous control that remained stable or improved over nearly 12 months using an LFP decoder that was not retrained or adapted. In parallel, the monkeys used MSPs to control a BMI without retraining or adaptation and had similar or better performance, and that predominantly remained stable over more than six months. In contrast to their stable online control, both LFP and MSP signals showed substantial variability when used offline to predict hand movements.
  
  
  CONCLUSIONS
  Our results suggest that the monkeys were able to stabilize the relationship between neural activity and cursor movement during online BMI control, despite variability in the relationship between neural activity and hand movements.
authors.affiliation: Department of Neurology, Northwestern University, Chicago, IL 60611, USA.
authors.forename: Robert D
authors.initials: RD
authors.lastname: Flint
authors.forename: Zachary A
authors.initials: ZA
authors.lastname: Wright
authors.forename: Michael R
authors.initials: MR
authors.lastname: Scheid
authors.forename: Marc W
authors.initials: MW
authors.lastname: Slutzky
mesh_terms: D000465:Algorithms; D000818:Animals; D062207:Brain-Computer Interfaces; D003627:Data Interpretation, Statistical; D005071:Evoked Potentials / Q000502:physiology*; D005260:Female; D006225:Hand / Q000502:physiology; D008253:Macaca mulatta; D008297:Male; D008839:Microelectrodes; D009044:Motor Cortex; D058117:Neural Prostheses; D011474:Prosthesis Design; D011597:Psychomotor Performance / Q000502:physiology; D015203:Reproducibility of Results; D012201:Reward
references.citation: IEEE Trans Neural Syst Rehabil Eng. 2012 Jul;20(4):468-77
references.pmid: 22772374
references.citation: J Neurosci. 2005 Nov 16;25(46):10712-6
references.pmid: 16291944
references.citation: J Neurosci. 2003 May 15;23(10):3963-71
references.pmid: 12764080
references.citation: J Neural Eng. 2004 Jun;1(2):63-71
references.pmid: 15876624
references.citation: J Neurosci. 2009 Nov 11;29(45):14363-70
references.pmid: 19906983
references.citation: J Neural Eng. 2008 Mar;5(1):75-84
references.pmid: 18310813
references.citation: Nature. 2012 May 17;485(7398):368-71
references.pmid: 22522928
references.citation: Nature. 2002 Mar 14;416(6877):141-2
references.pmid: 11894084
references.citation: IEEE Trans Biomed Eng. 2010 Jul;57(7):1774-84
references.pmid: 20403782
references.citation: Neural Comput. 2006 Feb;18(2):329-55
references.pmid: 16378517
references.citation: Nat Neurosci. 2002 Aug;5(8):805-11
references.pmid: 12134152
references.citation: Neurosurg Focus. 2009 Jul;27(1):E13
references.pmid: 19569888
references.citation: J Neural Eng. 2011 Aug;8(4):045005
references.pmid: 21775782
references.citation: J Neurosurg. 2007 Mar;106(3):495-500
references.pmid: 17367076
references.citation: Nature. 2006 Jul 13;442(7099):164-71
references.pmid: 16838014
references.citation: J Neural Eng. 2009 Oct;6(5):056002
references.pmid: 19700814
references.citation: IEEE Trans Biomed Eng. 2009 May;56(5):1502-11
references.pmid: 19203886
references.citation: J Neural Eng. 2012 Aug;9(4):046006
references.pmid: 22733013
references.citation: J Mot Behav. 1989 Sep;21(3):323-30
references.pmid: 15136269
references.citation: Neuron. 2007 May 24;54(4):653-66
references.pmid: 17521576
references.citation: PLoS One. 2012;7(12):e52173
references.pmid: 23300606
references.citation: IEEE Trans Neural Syst Rehabil Eng. 2006 Jun;14(2):194-8
references.pmid: 16792292
references.citation: J Neural Eng. 2009 Oct;6(5):055004
references.pmid: 19721186
references.citation: Lancet. 2013 Feb 16;381(9866):557-64
references.pmid: 23253623
references.citation: PLoS Biol. 2003 Nov;1(2):E42
references.pmid: 14624244
references.citation: Nat Neurosci. 2003 Dec;6(12):1253-4
references.pmid: 14634657
references.citation: Biol Cybern. 1986;55(2-3):135-44
references.pmid: 3801534
references.citation: Nat Neurosci. 2012 Dec;15(12):1752-7
references.pmid: 23160043
references.citation: J Neurophysiol. 2011 Apr;105(4):1603-19
references.pmid: 21273313
references.citation: Front Neuroeng. 2010 Mar 30;3:3
references.pmid: 20407639
references.citation: J Neurosci. 2007 Oct 3;27(40):10742-50
references.pmid: 17913908
references.citation: Nature. 2008 Jun 19;453(7198):1098-101
references.pmid: 18509337
references.citation: Science. 2002 Jun 7;296(5574):1829-32
references.pmid: 12052948
references.citation: PLoS One. 2009 Jun 15;4(6):e5924
references.pmid: 19526055
references.citation: J Neurophysiol. 2009 Aug;102(2):1331-9
references.pmid: 19535480
references.citation: J Neural Eng. 2011 Apr;8(2):025027
references.pmid: 21436513
references.citation: J Neurophysiol. 2012 Jul;108(1):18-24
references.pmid: 22496527
references.citation: J Neural Eng. 2007 Sep;4(3):264-75
references.pmid: 17873429
references.citation: IEEE Trans Biomed Eng. 2006 Aug;53(8):1678-87
references.pmid: 16916103
references.citation: J Neural Eng. 2008 Dec;5(4):455-76
references.pmid: 19015583
references.citation: J Neural Eng. 2007 Dec;4(4):369-79
references.pmid: 18057504
references.citation: Nature. 2012 May 16;485(7398):372-5
references.pmid: 22596161
references.citation: J Neurosci. 2010 Dec 15;30(50):16777-87
references.pmid: 21159949
references.citation: J Neurophysiol. 2011 Aug;106(2):764-74
references.pmid: 21613593
references.citation: J Physiol Paris. 2004 Jul-Nov;98(4-6):498-506
references.pmid: 16310349
references.citation: J Neurosci. 2011 Dec 14;31(50):18412-22
references.pmid: 22171043
references.citation: J Neurosci. 2005 Sep 28;25(39):8815-24
references.pmid: 16192371
references.citation: Med Biol Eng Comput. 1997 Mar;35(2):83-90
references.pmid: 9136198
references.citation: J Exp Psychol. 1954 Jun;47(6):381-91
references.pmid: 13174710
references.citation: J Neurosci. 2007 Aug 1;27(31):8387-94
references.pmid: 17670985
references.citation: Curr Opin Neurobiol. 2004 Dec;14(6):720-6
references.pmid: 15582374
references.citation: IEEE Trans Neural Syst Rehabil Eng. 2011 Oct;19(5):534-41
references.pmid: 21659037
references.citation: Nature. 2008 Dec 4;456(7222):639-42
references.pmid: 18923392
references.citation: Proc Natl Acad Sci U S A. 2010 Mar 2;107(9):4430-5
references.pmid: 20160084
references.citation: Neuron. 2009 Jan 15;61(1):35-41
references.pmid: 19146811
references.citation: IEEE Trans Neural Syst Rehabil Eng. 2004 Sep;12(3):339-44
references.pmid: 15473196
references.citation: PLoS Biol. 2009 Jul;7(7):e1000153
references.pmid: 19621062
references.citation: Physiol Rev. 1985 Jan;65(1):37-100
references.pmid: 3880898