A Uniied Process Model of Syntactic and Semantic Error Recovery in Sentence Understanding

The development of models of human sentence processing has traditionally followed one of two paths. Either the model posited a sequence of processing modules, each with its own task-speciic knowledge (e.g., syntax and semantics), or it posited a single processor utilizing diierent types of knowledge inextricably integrated into a monolithic knowledge base. Our previous work in modeling the sentence processor resulted in a model in which diierent processing modules used separate knowledge sources but operated in parallel to arrive at the interpretation of a sentence. One highlight of this model is that it ooered an explanation of how the sentence processor might recover from an error in choosing the meaning of an ambiguous word: the semantic processor brieey pursued the diierent interpretations associated with the diierent meanings of the word in question until additional text connrmed one of them, or until processing limitations were exceeded. Errors in syntactic ambiguity resolution were assumed to be handled in some other way by a separate syntactic module. Recent experimental work by Laurie Stowe strongly suggests that the human sentence processor deals with syntactic error recovery using a mechanism very much like that proposed by our model of semantic error recovery. Another way to interpret Stowe's nding that two signii-cantly diierent kinds of errors are handled in the same way is this: the human sentence processor consists of a single uniied processing module utilizing multiple independent knowledge sources in parallel. A sentence processor built upon this architecture should at times exhibit behavior associated with modular approaches, and at other times act like an integrated system. In this paper we explore some of these ideas via a prototype computational model of sentence processing called COMPERE, and propose a set of psychological experiments for testing our theories. Overview Most models of human language processing enforce a separation of language levels either through an assumption of individual modules each devoted to a diierent level of language or, de facto, by focusing on only one aspect of language processing (e.g., lexical disambiguation, theta-role assignment, or syntactic structure building). In contrast, our ongoing research has focused on nding ways to integrate language processing using as few assumptions of separate processes as possible. However, we have always been cog-nizant of the fact that theories of modular processes have support in the literature, and we have found it convenient in our own work to focus on lexical and pragmatic disambiguation during …