The time course of semantic category processing in the cerebral hemispheres: An electrophysiological study

Asaid Khateb, Christoph M. Michel, Alan J. Pegna, Gregor Thut, Theodor Landis, Jean Marie Annoni

Research output: Contribution to journalArticlepeer-review


Using visual half-field presentations of words to the right (RVF) and to the left visual field (LVF), this study investigated the time course of the hemispheric involvement in the processing of semantic category information. Multi-channel event related brain potentials (ERPs) were recorded from 15 healthy subjects during a categorisation task of sequentially presented word pairs. Subjects had to judge mentally after the appearance of the second word whether the words of a pair were semantically related (SR) or not (SU). ERPs were computed, from 100 ms before the onset of the second word to 600 ms, for SR and SU conditions in the LVF and in the RVF separately. The temporal segmentation of ERP map series into sequences of quasi-stable map configurations revealed a total of seven segments in each visual field of which only the first five (S1-S5, appearing between 70 and 400 ms) showed different map configurations as a function of visual field but presented a similar temporal sequence in both visual fields. By contrast, of the last two segments (S6 and S7) which appeared between ∼400 and ∼600 ms, only S7 differentiated SR and SU conditions in terms of its duration. Source localisation analysis of the segments showed that following the initial activation of posterior brain regions as a function of the visual field of presentation, a common neural network was activated in the left hemisphere (LH) although the dynamics of activation varied as a function of visual field. Concerning the role of the right hemisphere (RH) in lexico-semantic processing, the results presented here appear to be compatible with a 'callosal relay model' and suggest that, in healthy subjects, information is transferred rapidly (∼150 ms) from the RH to the language dominant-LH.

Original languageEnglish
Pages (from-to)251-264
Number of pages14
JournalCognitive Brain Research
Issue number3
StatePublished - 2001
Externally publishedYes

Bibliographical note

Funding Information:
This research was supported by the Swiss National Science Foundation grants No. 31-52923-97 to J.M. Annoni and PNR 38-4038-044081 to C.M. Michel. We thank Denis Brunet for providing us with the computer programs used in this study.


  • Callosal transfer
  • Event-related potential
  • Human brain mapping
  • Language
  • Semantic processing
  • Source localization
  • Temporal segmentation

ASJC Scopus subject areas

  • Experimental and Cognitive Psychology
  • Cognitive Neuroscience
  • Behavioral Neuroscience


Dive into the research topics of 'The time course of semantic category processing in the cerebral hemispheres: An electrophysiological study'. Together they form a unique fingerprint.

Cite this