Brain, Vol. 119, No. 2, 627-649, 1996
© 1996 Oxford University Press
research-article |
Lexical—semantic event–related potential effects in patients with left hemisphere lesions and aphasia, and patients with right hemisphere lesions without aphasia
Max Planck Institute for Psycholinguistics Nijmegen, The Netherlands
Correspondence to:
Correspondence to: Peter Hagoort/Colin Brown, Max Planck Institute for Psycholinguistics, Wundtlaan 1, NL-6525 XD Nijmegen, The Netherlands
Lexical—semantic processing impairments in aphasic patients with left hemisphere lesions and non-aphasic patients with right hemisphere lesions were investigated by recording event-related brain potentials (ERPs) while subjects listened to auditorily presented word pairs. The word pairs consisted of unrelated words, or words that were related in meaning. The related words were either associatively related, e.g. ‘bread-butter’, or were members of the same semantic category without being associatively related, e.g. ‘churchvilla’. The latter relationships are assumed to be more distant than the former ones. The most relevant ERP component in this study is the N400. In elderly control subjects, the N400 amplitude to associatively and semantically related word targets is reduced relative to the N400 elicited by unrelated targets. Compared with this normal N400 effect, the different patient groups showed the following pattern of results: aphasic patients with only minor comprehension deficits (high comprehenders) showed N400 effects of a similar size as the control subjects. In aphasic patients with more severe comprehension deficits (low comprehenders) a clear reduction in the N400 effects was obtained, both for the associative and the semantic word pairs. The patients with right hemisphere lesions showed a normal N400 effect for the associatively related targets, but a trend towards a reduced N400 effect for the semantically related word pairs. A dissociation between the N400 results in the word pair paradigm and P300 results in a classical tone oddball task indicated that the N400 effects were not an aspecific consequence of brain lesion, but were related to the nature of the language comprehension impairment. The conclusions drawn from the ERP results are that comprehension deficits in the aphasic patients are due to an impairment in integrating individual word meanings into an overall meaning representation. Right hemisphere patients are more specifically impaired in the processing of semantically more distant relationships, suggesting the involvement of the right hemisphere in semantically coarse coding.
aphasia; lexical–semantic processing; right hemisphere semantics; event–related brain potentials; N400
.
* Present address: Center for Neuroscience, University of California, Davis, USA
CiteULike 
Connotea 
Del.icio.us What's this?
This article has been cited by other articles:
|
|
 |
|
  C. Dobel, L. Lagemann, and P. Zwitserlood Non-native phonemes in adult word learning: evidence from the N400m Phil Trans R Soc B, December 27, 2009; 364(1536): 3697 - 3709. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 J. Vartiainen, T. Parviainen, and R. Salmelin Spatiotemporal Convergence of Semantic Processing in Reading and Speech Perception J. Neurosci., July 22, 2009; 29(29): 9271 - 9280. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 K. Ledoux, C. C. Camblin, T. Y. Swaab, and P. C. Gordon Reading words in discourse: the modulation of lexical priming effects by message-level context. Behav Cogn Neurosci Rev, September 1, 2006; 5(3): 107 - 127. [Abstract] [PDF]
|
|
|
|
 |
|
 P. Hagoort, M. Wassenaar, and C. Brown Real-time semantic compensation in patients with agrammatic comprehension: Electrophysiological evidence for multiple-route plasticity PNAS, April 1, 2003; 100(7): 4340 - 4345. [Abstract] [Full Text] [PDF]
|
|
|
|
 |
|
 M. St George, M. Kutas, A. Martinez, and M. I. Sereno Semantic integration in reading: engagement of the right hemisphere during discourse processing Brain, July 1, 1999; 122(7): 1317 - 1325. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
A. D. Friederici, D. Y. von Cramon, and S. A. Kotz Language related brain potentials in patients with cortical and subcortical left hemisphere lesions Brain, June 1, 1999; 122(6): 1033 - 1047. [Abstract] [Full Text] [PDF]
|
|
|
|
|
|
M. ter Keurs, C. M. Brown, P. Hagoort, and D. F. Stegeman Electrophysiological manifestations of open- and closed-class words in patients with Broca's aphasia with agrammatic comprehension: An event-related brain potential study Brain, May 1, 1999; 122(5): 839 - 854. [Abstract] [Full Text] [PDF]
|
|