Authors:

WHITING, C., SHTYROV, Y. MARSLEN-WILSON, W.

Reference:

Year of publication:

2010

CBU number:

7235

Abstract:

Recent studies suggest that the presence of a potential stem and affix within a word (corn-er) is sufficient to trigger attempts at its decomposition, regardless of semantic compositionality. Using combined magneto- and electroencephalography, we investigated how the processing of spoken words is modulated by such morpho-phonological cues. The mismatch negativity (MMN), a well-known index of long-term linguistic memory traces, was recorded to examine the spatiotemporal neural dynamics elicited by words of varied complexity: transparent derivational affixation (baker), pseudo-affixation (beaker), inflectional affixation (bakes, beaks) and non-affixed forms, in the absence of focused attention. Matched pseudowords were used as acoustic and phonological controls. A critical variable was semantic transparency within the derivational set, where the embedded stem is related or unrelated to the meaning of the whole form (baker vs. beaker). Results revealed an initial peak approximately 150-200ms after the deviation point with a major source in left supratemporal cortex. This early component was sensitive not only to lexicality - showing a larger response to real words than pseudowords - but also to morphological structure, with a significant increase for a potential but invalid segmentation (beak-er). A later component at 250-300ms following the deviation point showed differential processing for word conditions containing a suffix, but not for the non-affixed endings. Finally, the N400-like component indicated increased activation for pseudowords, but showed no morphological sensitivity. These results support recent theories pointing to early and automatic processing based on the presence of phonological cues to morphological structure.