The cortical processing of rising-intensity tonal and speech stimuli in young adults: Effects of spectral complexity

Using magnetoencephalography (MEG), we studied nine healthy young subjects and presented them with auditory sinusoidal stimuli or spectrally complex speech sounds rising in intensity over a duration of 750 ms. The speech sounds elicited more prominent transient brain activity than their frequency-matched sinusoidal counterparts. Attentional engagement further enhanced the amplitude of the responses for both stimulus types. The findings hold promise for both basic and applied research.