M. Jobert et al., PROCESSING VISUAL-EVOKED POTENTIALS BASED ON MATCHED FILTERING OF SINGLE TRIAL RESPONSES, Neuropsychobiology, 34(3), 1996, pp. 166-174
Physiological signals recorded after presentation of a stimulus can be
considered as the sum of an evoked sensory response and uncorrelated
noise corresponding to the spontaneous neural background activity. In
case of low signal-to-noise ratio, the sensory signal is estimated by
averaging a large number of single trial records sampled under the sam
e experimental conditions. The averaging technique, however, is inappr
opriate for displaying trial-to-trial variations that may occur during
a recording session. A method based on matched filtering was develope
d for processing single visual evoked potentials (VEPs). To illustrate
the performance of this method, a set of VEPs for grating patches of
8 different contrasts (including 0) was evaluated. The VEPs were subje
cted to signal detection analysis by computing for each contrast simil
arity indices between the single trial records and the averaged respon
se used as a Signal processing template. The signals were analysed in
terms of probability density distributions, expressing the goodness of
fit between template and each single waveform.