• Open Access

Measurement of mismatch negativity in individuals: A study using single-trial analysis

Authors


  • This work was supported by a Programme Grant from the Wellcome Trust. The first author is supported by a Wellcome Trust Principal Research Fellowship. We thank Genevieve McArthur for comments on an earlier draft of this manuscript.

  • Re-use of this article is permitted in accordance with the Terms and Conditions set out at http://www3.interscience.wiley.com/authorresources/onlineopen.html.

Address reprint requests to: Prof. Dorothy Bishop, Department of Experimental Psychology, University of Oxford, South Parks Road, Oxford, UK OX1 3UD. E-mail: dorothy.bishop@psy.ox.ac.uk

Abstract

Mismatch negativity (MMN) is measured by subtracting the averaged response to a set of standard stimuli from the averaged response to rarer deviant stimuli, and taking the amplitude of this difference wave in a given time window. This method is problematic when used to evaluate individuals, because there is no estimate of variance. We describe a new approach, in which independent components with high trial-by-trial variance are first removed. Next, each deviant response has the preceding standard response subtracted, giving a set of single trial difference waves. We illustrate this approach in analysis of MMN to brief tones in 17 adults. The best criterion for MMN combined t-test with an index of inter-trial coherence, giving significant MMN in 14 (82%) of individuals. Single-trial methods can indicate which people show MMN. However, in some clinically normal individuals there was no MMN, despite good behavioral discrimination of stimuli.

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