Tracking auditory pattern learning with single-trial event related potentials: A group ICA study

Abstract

The aim of the study was to further investigate the dynamics of auditory pattern-learning using a single-trial analysis of event-related EEG (Eichele, 2007 ; Eichele, et al., 2005; Jongsma, et al.,2006). We used an auditory target detection experiment, where the standard was a binaural 500Hz sound (P = 0.8), and the targets were left or right panned (P = 0.1 each), respectively, at varying target-to-target intervals (TTI). Series of eight successive target stimuli were presentedin four conditions with varying levels of predictability: 1. Target side and TTI were random, 2.The target side was fixed while the TTI was random, 3. The side was random and the TTI fixed,and 4. Both side and TTI was fixed. EEG was collected from 64 scalp channels, preprocessed with individual independent component analysis (ICA) for artifact correction and waveletdenoising, and then subjected to group temporal ICA. The resulting temporally independent components (IC) were related to the N1, N2, P2, P3 and SW components of the auditory ERP.The single-trial event related EEG decomposition shows a number of ICs at different peaklatencies that were correlated by the TTI, response times, long term habituation, as well as by varying levels of predictability.