Authors:

SHTYROV, Y., HAUK, O. & PULVERMULLER, F.

Reference:

Year of publication:

2004

CBU number:

5868

Abstract:

Mismatch negativity (MMN), an index of experience-dependent memory traces, was used to investigate the processing of action-related words in the human brain. Responses to auditorily presented movement-related English words were recorded in non-attend odd-ball paradigm using a high-density EEG set-up. MMN was calculated using responses to the same words presented as standard and deviant stimuli in different sessions to avoid contamination from phonetic-acoustic differences. The topography of the mismatch negativity to action words showed unusual centro-posterior distribution of the responses suggesting that activity was at least in part generated posterior to usually observed frontal MMNs. Moreover, responses to hand-related word stimulus (pick) had a more spread-out lateral distribution, whereas leg-related stimulus (kick) elicited a more focal dorsal negativity. These differences, remarkably reminiscent of sensorimotor cortex topography, were further assessed using distributed source analysis of the EEG signal (L2 minimum-norm current estimates). The source analysis also confirmed differentially distributed activation for the two stimuli. We suggest that these results indicate activation of distributed neuronal assemblies that function as category-specific memory traces for words and may involve sensorimotor cortical structures for encoding action words.(Title changed to correct one 2/2/05 was: Distributed neuronal networks encoding category-specific semantic information as shown by the mismatch negativity to action words )