Stefan Frisch, Matthias Schlesewsky, Douglas Saddy, and Annegret Alpermann
frisch@rz.uni-potsdam.de, schlesel@rz.uni-potsdam.de, saddy@ling.uni-potsdam.de
alperm@rz.uni-potsdam.de
Institute of Linguistics, University of Potsdam, Potsdam, Germany
One of the core issues in psycholinguistic research is the question of
how our parser deals with syntactic ambiguity. The processing of the
ambiguity itself can tell us whether the presence of syntactic
alternatives induces processing cost or not, which would allow us to
distinguish between serial and parallel approaches to parsing (cf.
Mitchell, 1994). On the other hand, the point of disambiguation is of
interest since it is crucial for deciding whether our parser prefers
one alternative over others or whether it considers all continuations
to be equally likely (cf. Mitchell, 1994). German provides an
excellent testing ground for both questions, seeing that in German,
arguments can be either ambiguous with respect to their grammatical
function or they can be unambiguously case marked. We addressed the
question of how syntactic ambiguity is processed by using transitive
German declarative structures in which either the first (1) or the
second argument (2) was ambiguous with respect to its grammatical
function and in which either the first (a) or the second argument (b)
was the subject.
- (1)
- a.
- Die Detektivin sah den Kommissar ...
--[the detective]FEM.AMB saw [the cop]MASC.ACC
- b.
- Die Detektivin sah der Kommissar ...
--[the detective]FEM.AMB saw [the cop]MASC.NOM
- (2)
- a.
- Der Kommissar sah die Detektivin ...
--[the cop]MASC.NOM saw [the detective]FEM.AMB
- b.
- Den Kommissar sah die Detektivin ...
--[the cop]MASC.ACC saw [the detective]FEM.AMB
In two experiments using different on-line techniques (self-paced
reading and event-related potentials/ERPs), we presented the above
sentences with a phrase-by-phrase segmentation. Results for the
sentence initial NP showed that syntactic ambiguity induces enhanced
processing cost which is reflected in higher reading times as well as
in a late positive ERP component (P600). On the second NP, the
initially ambiguous sentences being disambiguated in the dispreferred
way (object-before-subject, 1b) elicited higher reading times as well
as a P600 ERP effect compared to all other conditions. In sum, both
techniques revealed a higher cost of processing for a syntactic
ambiguity as well as for a dispreferred disambiguation. Results speak
in favour of a parsing architecture according to which the parser is
sensitive to syntactic ambiguity but then makes a decision for one of
the alternatives (local parallelism).
References
Mitchell, D.C. (1994). Sentence parsing. In M. A. Gernsbacher (ed.):
Handbook of Psycholinguistics (pp. 375-409). San Diego: Academic
Press.
AMLaP Conference, Saarbrücken, September 2001