[ACT-R-users] paper on ACT-R model of sentence processing

[Richard L. Lewis]

Dear colleagues,

Shravan Vasishth and I are happy to provide a downloadable version of  
our recent paper on an ACT-R model of sentence processing (link below).

Even if you are not a sentence processing geek (and you probably would  
have to be to enjoy some parts of this paper),  you may appreciate that  
this is a single model that accounts quantitatively for reading time  
contrasts across about a half dozen experiments (from different labs)  
--- with no parameter variation and fitting only the single scaling  
parameter.

(This is but one of the papers in the recent special issue of Cognitive  
Science celebrating John's Rumelhart Award, but not everyone may have  
access to the electronic form of the journal).

Abstract, link and citation below.

cheers,
Rick


Lewis, R. L. and Vasishth, S.  (2005) An activation-based model of  
sentence processing as skilled memory retrieval.  Cognitive Science,  
29(3) 375-419.

http://www.ling.uni-potsdam.de/~vasishth/Papers/ 
cogsci05lewisvasishth.pdf


An activation-based model of sentence processing as skilled memory  
retrieval

We present a detailed process theory of the moment-by-moment working  
memory retrievals
and associated control structure that subserve sentence comprehension.  
The theory is derived
from the application of independently motivated principles of memory  
and cognitive skill to
the specialized task of sentence parsing. The resulting theory  
construes sentence processing
as a series of skilled associative memory retrievals modulated by  
similarity-based interference
and fluctuating activation. The cognitive principles we appeal to are  
formalized in computational
form in the ACT-R architecture, and our process model is realized in  
ACT-R.  We present
the results of six sets of simulations: five simulation sets provide  
quantitative accounts of the
effects of length and structural interference on both unambiguous and  
garden path structures.
A final simulation set provides a graded taxonomy of double  
center-embeddings ranging from
relatively easy to extremely difficult. The explanation of  
center-embedding difficulty is a novel
one that derives from the model’s complete reliance on discriminating  
retrieval cues in the
absence of an explicit representation of serial order information. All  
fits were obtained with
only one free scaling parameter fixed across the simulations; all other  
parameters were ACT-R
defaults. The modeling results support the hypothesis that fluctuating  
activation and similarity-based
interference are the key factors shaping working memory in sentence  
processing. We
contrast the theory and empirical predictions with several related  
accounts of sentence processing
complexity.


--------------------------
Richard L. Lewis			rickl at umich.edu
Associate Professor		http://www-personal.umich.edu/~rickl/
Department of Psychology	Voice:  (734) 763-1466
University of Michigan		Fax:    (734) 763-7480
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Ann Arbor, MI  48109-1043