Word-specific cortical activity as revealed by the mismatch negativity


  • We are grateful to Sampo Antila, Steve Hackley, Olaf Hauk, Anne Lehtokoski, Teemu Rinne, Elisabeth Service, Jaana Simola, Mari Tervaniemi, and the anonymous referees for their help, comments, and suggestions at different stages of this work. This work was supported by the Medical Research Council (UK), the Deutsche Forschungsgemeinschaft, the Academy of Finland, and the European Community, under the “Information Society Technologies Programme” (IST-2001-35282).

Address reprint requests to: Friedemann Pulvermüller, Ph.D., Cognition and Brain Sciences Unit, Medical Research Council, 15 Chaucer Road, Cambridge CB2 2EF, England. E-mail: friedemann.pulvermuller@mrc-cbu.cam.ac.uk


Neurophysiological brain activity evoked by individual spoken words and pseudowords was recorded and the mismatch negativity (MMN), an automatic index of experience-dependent auditory memory traces, was calculated. Consistent with earlier reported results, the MMN response to word-final syllables was enhanced compared with that elicited by the same syllables placed in a pseudoword context. Here we now demonstrate that the enhancement of the MMN elicited by two individual words showed different scalp topographies. The early word-specific brain activity is consistent with the assumption that the memory traces activated by individual words are carried by large neuronal ensembles that differ in their distributions over the cortex. Current source estimates localized the between-word differences in the right hemisphere and in parieto-occipital left-hemispheric areas. The differential brain responses to individual words appeared as early as ∼100 ms after the recognition points of the words, suggesting that their specific memory traces become active almost immediately after the information in the acoustic input is sufficient for word identification.