Improved detection of amnestic MCI by means of discriminative vector quantization of single-trial cognitive ERP responses

Laskaris, N. A.; Tarnanas, I.; Tsolaki, M. N.; Vlaikidis, N.; Karlovasitou, A. K. (2013). Improved detection of amnestic MCI by means of discriminative vector quantization of single-trial cognitive ERP responses. Journal of neuroscience methods, 212(2), pp. 344-354. Elsevier 10.1016/j.jneumeth.2012.10.014

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Cognitive event-related potentials (ERPs) are widely employed in the study of dementive disorders. The morphology of averaged response is known to be under the influence of neurodegenerative processes and exploited for diagnostic purposes. This work is built over the idea that there is additional information in the dynamics of single-trial responses. We introduce a novel way to detect mild cognitive impairment (MCI) from the recordings of auditory ERP responses. Using single trial responses from a cohort of 25 amnestic MCI patients and a group of age-matched controls, we suggest a descriptor capable of encapsulating single-trial (ST) response dynamics for the benefit of early diagnosis. A customized vector quantization (VQ) scheme is first employed to summarize the overall set of ST-responses by means of a small-sized codebook of brain waves that is semantically organized. Each ST-response is then treated as a trajectory that can be encoded as a sequence of code vectors. A subject's set of responses is consequently represented as a histogram of activated code vectors. Discriminating MCI patients from healthy controls is based on the deduced response profiles and carried out by means of a standard machine learning procedure. The novel response representation was found to improve significantly MCI detection with respect to the standard alternative representation obtained via ensemble averaging (13% in terms of sensitivity and 6% in terms of specificity). Hence, the role of cognitive ERPs as biomarker for MCI can be enhanced by adopting the delicate description of our VQ scheme.

Item Type:	Journal Article (Original Article)
Division/Institute:	10 Strategic Research Centers > ARTORG Center for Biomedical Engineering Research > ARTORG Center - Gerontechnology and Rehabilitation
UniBE Contributor:	Tarnanas, Ioannis
Subjects:	500 Science > 570 Life sciences; biology 600 Technology > 610 Medicine & health
ISSN:	0165-0270
Publisher:	Elsevier
Language:	English
Submitter:	Ioannis Tarnanas
Date Deposited:	15 Apr 2014 08:36
Last Modified:	05 Dec 2022 14:31
Publisher DOI:	10.1016/j.jneumeth.2012.10.014
PubMed ID:	23147007
Uncontrolled Keywords:	Mild cognitive impairment, Event-related potentials, Single-trial analysis,Vector quantization
URI:	https://boris.unibe.ch/id/eprint/47651