Connectionist Modeling of Experience-based Effects in Sentence ...

2.3 Predicting RC Extraction Preferences Cross-linguistically
This hierarchy is based on observed preferences for relativized NPs in a number of
languages. The explanation is that subjects are more obligatory for predicates than
objects are, and therefore, are more predictable.
Lin, Fong, and Bever (2005) and Lin and Bever (2006b) suggest that the subject
position is higher up in the syntactic tree structure than the object position. They propose
an incremental minimalist parser (IMP), that performs a top down search through
the tree from the filler to the gap. The search starts at the head noun and proceeds
downward, looking for a c-commanded trace. Since subjects are higher in the tree, this
mechanism makes sure that subject traces are always accessed first, irrespective of fillergap
distances or specific word orders: “This top-down searching mechanism overrides
the effect of NP recency (i.e. linear locality), and passive complexity (i.e. canonicity).”
(Lin et al., 2005; p. 11). Since an Accessibility Theory is independent of word order and
locality, it would predict cross-linguistic preference for subject extractions.
The top-down gap-searching mechanism makes the same predictions for pre- and postnominal
RCs. Consequently a subject preference is also predicted for Mandarin RCs.
The facilitation effect in subject extraction would occur on the head noun where the
gap-searching mechanism is initiated. Supporting evidence for this structural account
provides the PRC experiment by Lin et al. (2005) reported above: the easiest condition
was the one where the gap is in subject position. There was no significant difference on
the head noun between the other two conditions.
Perspective Shift
A more pragmatic explanation provides the theory of perspective shift (MacWhinney and
Pleh, 1988; MacWhinney, 1982; 1977). Somehow the comprehender preferably adopts
the perspective of a sentential subject. Consequently, when the subject changes the
comprehender has to shift his or her perspective. An object relative clause demands a
perspective shift from the main clause subject to the RC’s subject and then back to the
main clause subject after completion of the embedding-structure. In subject relatives
the subject is the same for both clauses and hence no shifting is required. Perspective
shifting demands processing resources. That makes ORCs costlier to process because
here two shifts are necessary and none in SRCs. A slowdown in ORC reading is predicted
on the embedded NP (first shift) and the main verb (second shift).
The perspective shifting account predicts a subject-preference in most languages with
post-nominal RCs. For pre-nominal RCs in a language like Mandarin the pattern would
change. In Mandarin ORCs the subject of the RC is in initial position followed by a
verb. Seeing the head noun, a main clause is predicted. Thus one shift is necessary to
change perspective from the embedded to the head noun, being the subject now. As for
Mandarin SRCs, the locus of perspective is dependent on the predicted structure when
reading the ‘V N’ sequence. Predicting a gapped structure, i.e., being aware of the SRC,
would cause an expectation of a subject head noun. This would not require any shifting.
However, what happens when the gap is not recognized? Could perspective possibly
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