Words and pseudowords elicit distinct patterns of 30-Hz EEG responses in humans.
Meaningful words, such as moon, and physically similar but meaningless pseudowords, such as noom, were presented visually in a lexical decision task. The EEG was recorded from 17 scalp electrodes. Significant differences between both stimulus classes were observed in evoked spectral responses of the 'gamma-band' approximately 30 Hz. A hemisphere by wordness interaction demonstrated that 30-Hz spectral power over the left hemisphere was reduced after pseudowords only. These results indicate that gamma-band responses reflect the different cognitive processes induced by words and pseudowords. A possible explanation is the following. Synchronous activation of large cortical cell assemblies takes place after word presentation but not after presentation of pseudowords.
Institut für Medizinische Psychologie und Verhaltensneurobiologie, Universität Tübingen, Germany.
W
W
Lutzenberger
F
F
Pulvermüller
N
N
Birbaumer
D001921:Brain / Q000502:physiology*; D003071:Cognition / Q000502:physiology*; D004569:Electroencephalography; D007839:Functional Laterality; D006801:Humans; D013016:Sound; D013060:Speech