Do Event-Related Potentials (ERPs) Reflect Right Hemisphere's Processing of Semantics?

To test the right hemisphere's functional difference in relation to semantically related vs. semantically unrelated linguistic tasks we investigated 25 young right-handed healthy adults. A S1-S2 design was used. At S1 one word was presented binaurally, at S2 two words dichotically. S1-S2 was composed of sentence-like (syntagmatic) and nonsentence-like (paradigmatic) word sequences with and without semantic relations. As control trials we used pure tones and modulated noise. The EEG was recorded over frontal, central and temporoparietal areas of both hemispheres. Referring to semantics it could be shown only that semantic relations between words increased the amount of recalled words. Additionally, ERPs reflected: (1) modes of presentation (binaural vs. dichotic) (2) processing of different linguistic categories (e.g., syntagmatic vs. paradigmatic) and (3) fronto-centrally focused neuronal processes of both hemispheres before language production.