Authors:

MOSCOSO DEL PRADO MARTIN, F., HAUK, O. & PULVERMULLER, F.

Reference:

Year of publication:

2006

CBU number:

6714

Abstract:

In this study, we investigated the spatio-temporal patterns of category-specific cortical activation elicited by the visual presentation of words whose meaning relates to a color or to a visual form or shape. We recorded the event-related potentials (ERPs) of ten healthy, ight-handed volunteers while they passively read words presented tachistoscopically. As early as 150 ms after stimulus onset, the ERPs evealed significant neurophysiological differences between words and strings of hash marks. Around 200 ms after stimulus onset, we found significant differences in the ERPs elicited by color- and form-related words. We used minimum norm current estimates to investigate the spatial location of these differences. This revealed that, at the 150 ms peak, the activation advantage of words over sequences of hash arks was located in a left posterior area, proximal to what has previously been called the visual word form area. At the 200 ms peak, the a vantage of words related to colors over words related to forms seemed to reside in temporal cortical areas, whereas the form-related words elicited greater activation in frontal areas than color-related words. These results provide evidence for early access to detailed category-specific representations of word meaning, with subtle differences in meaning being reflected in the activation of different cortical areas, as early as 200 ms after stimulus presentation. In line with previous studies, these differences can be related o the areas involved in the conceptual processing of sensory (visual) and action-related information.