Johan Sandberg, presenterar sitt examensarbete

Detecting MMN in Infants EEG with Bootstrap and SVD



Abstract:

Mismatch Negativity (MMN) is an EEG voltage fluctuation caused by the
brain's automatic reaction to unexpected changes in a repetitive
stimulation. In an experiment Associate Professor Magnus Lindgren
studied 68 infants of which 2/3 were born preterm. Due to noise of
large amplitude, MMN is difficult to detect in infants' EEG. In this
thesis a few noise reduction methods are used, including low rank
modelling with the Karhunen Loéve transform. Two different methods of
evaluating the performance of the signal processing methods are
discussed. The first evaluation method uses the stability of the MMN
latency and the second uses the latency difference between MMNs caused
by two different changes in stimuli. Unfortunately the noise reducing
effect could not be confirmed. Provided that most of the participating
subjects were able to elicit MMN of a detectable amplitude, the
conclusion is that either the noise reduction or the evaluation fails.