Electrophysiological correlates of direct versus indirect semantic priming in normal volunteers.
The N400 component of event related potentials (ERP) was studied in 27 right-handed healthy subjects in a speeded lexical decision task. The semantic distance between primes (always words) and targets (50% words, 50% non-words) was systematically varied. Prime-target relations included directly related words (hen-egg), indirectly related words (lemon-sweet), and non-related words (sofa-wing). ERPs were recorded from 20 scalp electrodes positioned according to the international 10-20 system. The N400 reflected semantic distance with the most negative and latest N400 peak in the non-related condition, the least negative and earliest N400 peak in the direct condition and the peak in the indirect condition in-between. Hence, N400 priming effect in the indirect condition was obtained in the absence of strong sentential constraints and even though the mediating word was physically not present.
Weisbrod
M
M
Psychiatric Department, University of Heidelberg, Voss-Str. 4, 69115, Heidelberg, Germany. matthias_weisbrod@med.uni-heidelberg.de
Kiefer
M
M
Winkler
S
S
Maier
S
S
Hill
H
H
Roesch-Ely
D
D
Spitzer
M
M
D000328:Adult; D005072:Evoked Potentials, Auditory / Q000502:physiology*; D005260:Female; D006801:Humans; D008297:Male; D011930:Reaction Time / Q000502:physiology; D012016:Reference Values; D012660:Semantics