Objectives: Event-related potential correlates of phonological encoding - a
s compared with lexical access and semantic categorization were measured in
two studies involving two groups of 14 German and 14 Italian subjects.
Methods: A two stimulus reaction time paradigm was used. Stimulus pairs pre
sented one-by-one with 2 s inter-stimulus intervals (ISI) had to be matched
with respect to lexical identity (word-picture) in a word comprehension ta
sk or with respect: to the phonological representative of objects in a rhym
ing task. A semantic categorization task was added for the Italian sample.
In both studies, the EEG was recorded from 26 scalp electrodes according to
the 10-20 system. The slow negative potential during the ISI (CNV) was det
ermined as the electrocortical correlate of preparation for and activation
of the specific language-related task.
Results: In both samples phonological encoding (rhyming) evoked a more pron
ounced CNV over the left- compared with the right-frontal area, while less
lateralized central dominance of the CNV was found in the word comprehensio
n task. Semantic categorization was accompanied by the least asymmetry of a
ctivity.
Conclusions: Results indicate that the different degree of asymmetry induce
d by phonological and semantic processing may be determined from the scalp
distribution of slow cortical potentials with cross-lingual reliability. (C
) 2000 Elsevier Science Ireland Ltd. All rights reserved.