Multidimensional scaling and order asymmetry of the acoustic change complex to voiceless fricatives in Polish, English, and Finnish listeners
Emma Brint, Paul Iverson, Anita E. Wagner · The Journal of the Acoustical Society of America · 2014
The acoustic change complex (ACC) is a P1-N1-P2 onset response to changes between sounds measured using EEG, which when measured at a central location, is not thought to be affected by the language experience of the listener. Recent research has shown that with a pair of stimuli, there is an asymmetry between the ACC recorded when they are presented in one order compared to the other. This study used eight voiceless fricatives to measure the ACC to all possible pairs from EEG recordings of 15 English, Finnish, and Polish listeners. The ACC magnitude was used to perform multidimensional scaling to create a two dimensional perceptual space for each language that is driven by the spectral characteristics of the stimuli. Asymmetry occurred in all three languages depending on how peaky the first and second stimuli were. This asymmetry effect was greater for the Polish group, indicating that the Polish listeners' language experience increases their sensitivity to the spectral peakiness of fricatives. These results show that the ACC is in fact susceptible to native language effects, enhancing its application as a test for auditory speech processing.