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Schlagwörter:
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Zusammenfassung:
Morphology is the aspect of language concerned with
the internal structure of words. In the past decades,
a large body of masked priming (behavioral and
neuroimaging) data has suggested that the visual
word recognition system automatically decomposes
any morphologically complex word into a stem and
its constituent morphemes. Yet, it remains equivocal
whether this morphemic decomposition relies primarily
on orthography or on semantics. Here, we approached
the issue straightforwardly by applying a task of
morphological unification, that is, by assembling internal
(morphemic) units into a whole-word. Morphemic units
were sequentially presented while participants were
requested to judge whether their assemblage represented
real- or pseudo-words. Trials representing real words
were divided into words with a transparent (true) or a
non-transparent (pseudo) morphological relationship.
Morphological unification of truly suffixed words
occurred in a more straightforward way (shorter RT and
higher accuracy). Additionally, oscillatory brain activity
was monitored with magnetoencephalography and
revealed that real, compared to pseudo morphological unification enhanced narrow gamma band oscillations
(60-85 Hz, 300-450 ms) in the left posterior occipitotemporal
junction, which is known as a cerebral hub for
visual word processing. This neural signature could not
be explained by a mere automatic lexical processing (i.e.
stem perception), but more likely it related to a semantic
access step during the morphological unification process.
These findings highlight a plausible retrieval of lexical
semantic associations for enabling true morphological
unification, and further instantiate the pivotal role of
the left occipito-temporal junction in visual word form
processing.
