The grand-averaged latency of the left- and right-hemispheric N1m for the vowels /a/ and /u/ with three different types of phonation (periodic, aperiodic & tonal). In both hemispheres, the N1m for the vowel /a/ was elicited, on the average, 10 ms earlier than that for /u/. The latency behavior of the N1m was asymmetric across the two hemispheres: In the right hemisphere, N1m latency was determined by articulation (vowel category), whereas the latency of the left-hemispheric N1m depends on both phonation and articulation. Notably, in the left hemisphere, there were no significant latency differences between the N1m responses elicited by the periodic vowels /a/per and /u/per. Bars indicate standard error of the mean.
Tiitinen et al. BMC Neuroscience 2005 6:62 doi:10.1186/1471-2202-6-62