Towards Communication in the Completely Locked-In State: Neuroelectric Semantic Conditioning BCI
We introduced a Pavlovian semantic conditioning paradigm to enable basic communication in completely locked-in state (CLIS). Patients in CLIS have no means of communication and they have represented the target population for brain–computer interface (BCI) research in the last 15 years. Although different paradigms have been tested as well as different physiological signals have been used, to date no documented CLIS patient was able to control a BCI over an extended time period. We designed a novel paradigm based on semantic conditioning for online classification of neuroelectric or any other physiological signals to discriminate between covert (cognitive) ‘yes’ and ‘no’ responses. The paradigm comprised the presentation of affirmative and negative statements used as conditioned stimuli and only affirmative statements were paired with electrical stimulation. A CLIS patient diagnosed with amyotrophic lateral sclerosis (ALS) participated in the study and underwent 37 daily sessions. The online classification accuracies of the slow cortical potentials, identified as the electroencephalographic (EEG) signature differentiating between covert ‘yes’ and ‘no’ responses, were around chance level on average, with peaks of high communication accuracy in some sessions.
KeywordsAmyotrophic Lateral Sclerosis Conditioned Stimulus Unconditioned Stimulus Functional Electrical Stimulation Slow Cortical Potential
Supported by the European Commission Framework Programme 7 (FP7), Marie Curie Networks for Initial Training: ITN-LAN and the Deutsche Forschungsgemeinschaft (DFG).
- B. Blankertz, M. Tangermann, C. Vidaurre, S. Fazli, C. Sannelli, S. Haufe, C. Maeder, L. Ramsey, I. Sturm, G. Curio et al, The Berlin brain-computer interface: non-medical uses of BCI technology. Frontiers Neurosci. 4, 198 (2010). http://www.pubmedcentral.nih.gov/articlerender.fcgi?artid=3002462&tool=pmcentrez&rendertype=abstract
- L. Cohen, U. Ziemann, R. Chen, J. Classen, M. Hallet, C. Gerloff, C. Butefisch, Studies of neuroplasticity with transcranial magnetic stimulation. J. Clin. Neurophysiol: Off. Publ. Am. Electroencephalogr. Soc. 15, 305–324 (1998). http://journals.lww.com/clinicalneurophys/Abstract/1998/07000/Studies_of_Neuroplasticity_With_Transcranial.3.aspx Google Scholar
- B.R. Dworkin, N.E. Miller, Failure to replicate visceral learning in the acute curarized rat preparation. Behav. Neurosci. 100, 299–314 (1986). http://www.ncbi.nlm.nih.gov/pubmed/3730136
- E.R. Hilgard, D.G. Marquis, Conditioning and Learning, 6th edn. (Appleton-Century, Oxford, England, 1940)Google Scholar
- B. Kotchoubey, S. Lang, V. Bostanov, N. Birbaumer, Is there a mind? Electrophysiology of unconscious patients. News Physiol. Sci.: Int. J. Physiol. Prod. Jt. Int. Un. Physiol. Sci. Am. Physiol. Soc. 17, 38–42 (2002)Google Scholar
- B. Kotchoubey, S. Lang, S. Winter, N. Birbaumer, Cognitive processing in completely paralyzed patients with amyotrophic lateral sclerosis. Eur. J. Neurol.: Off J. Eur. Fed. Neurol. Soc. 10, 551–558 (2003)Google Scholar
- J. Moore (ed.), A neuroscientist’s guide to classical conditionin (Springer, New York, 2002). http://www.lavoisier.fr/livre/notice.asp?id=O2SWL6ASLSLOWF
- M.T. Motley, Verbal conditioning-generalization in encoding: a hint at the structure of the lexicon. Commun. Monogr. 4, 151–162 (1974). http://www.tandfonline.com/doi/abs/10.1080/03637757409375830
- A.R. Murguialday, J. Hill, M. Bensch, S. Martens, S. Halder, F. Nijboer, B. Schoelkopf, N. Birbaumer, A. Gharabaghi, Transition from the locked into the completely locked-in state: a physiological analysis. Clin. Neurophysiol.: Off. J. Int. Fed. Clin. Neurophysiol. 122, 925–933 (2011)CrossRefGoogle Scholar
- N. Neumann, B. Kotchoubey, Assessment of cognitive functions in severely paralysed and severely brain-damaged patients: neuropsychological and electrophysiological methods. Brain Res. Brain Res. Protoc. 14, 25–36 (2004). http://www.ncbi.nlm.nih.gov/pubmed/15519949
- I. Pavlov, in Conditioned Reflexes: an Investigation of the Physiological Activity of the Cerebral Cortex (1927), ed. by G.V. Anrep. New York: Boyer . http://scholar.google.it/scholar?hl=it&q=Conditioned+reflexes%3A+An+investigation+of+the+physiological+activity+of+the+cerebral+cortex&btnG=&lr=#6 (1960)