We investigated contingent frequency effects in syntactic ambiguity resolution in three self-paced reading experiments. Experiment 1 demonstrated that the frequency with which that occurs as a determiner or a complementizer in different syntactic environments predicts readers initial parsing preferences. Experiments 2 and 3 demonstrated frequencyand regularity effects for reading the and that after different types of verbs that are similar to effects that have been well-documented in word recognition.

Linguistic devices that mark confidence (uncertainty) havebeen well documented (e.g., choice of modals, hedges, etc),yet there has been surprisingly little empirical work thatexplicitly measures how uncertainty is signaled andinterpreted. We present an initial report on a project designedto investigate how interlocutors communicate uncertainty anduse that information in acquiring new information andintegrating interlocutor based input with their prior beliefs.Experiment 1 establishes that speakers and listeners agree onthe relative degree of uncertainty for a set of phrases.Experiment 2 manipulated how likely it was that a participantwould recognize an object using images that varied inrecoverability, finding that recoverability mapped ontocertainty. Experiment 3 used a word-learning paradigm toestablish that learners take into account the certainty withwhich a speaker labels uses a novel word to label a novelshape.

We monitored readers' eye-movements to examine the time-course of discourse and semantic influences in syntactic ambiguity resolution. Our results indicate immediate and simultaneous influences of referential context and local semantic fit in the reading of reduced relative clauses (i.e.. The horse raced past the bam fell.). These results support a model of sentence processing in which alternatives of a syntactic ambiguity are differentially activated by the bottom-up input, and syntactically-relevant contextual constraints simultaneously add activation to their supported alternatives. Competition between comparably active alternatives may then cause slowed reading times in regions of ambiguity.

An important aspect of language processing is the comprehender's ability to determine temporal relations between an event denoted by a verb and events already established in the discourse. This often requires the tense of a verb to be evaluated in relation to specific temporal discourse properties. W e investigate the time course of this process by examining how the temporal properties of a discourse influence the initial processing of temporarily ambiguous reduced relative clauses. M u c h of tfie empirical work on the reading of reduced relative clauses has revealed that readers experience a large mis-analysis effect (or *gardenpatfi') in reduced relatives like "The student spotted bv the proctor received a warning" because the reader has initially interpreted the verb "spotted" as a past tense verb in a main clause. Recent results from an eye movement study are provided which irnlicate that this mis-analysis of relative clauses can be eliminated when the temporal constraints of a discourse do not easily permit a main clause past tense interpretation. Such a flnding strongly suggests that readers process tense in relation to the temporal properties of the discourse, and that constraints from these properties can n^ndly influence processing at a stnKtural level.

Seidenberg and Tanenhaus (1979) demonstrated that orthographic information is obligatorily activated during auditory word recognition by showing that rhyme decisions to orthographically similar rhymes pie-tie were quicker than rhyme decisions to orthographically dissimilar rhymes ryetie. This effect could be due to the fact that orthographic and phonological codes axe closely inter-related in lexical memory and the two dimensions are highly correlated. However, it could also be a example of a more general similarity bias in making rhyme decisions, in which subjects cannot ignore irrelevant information from other dimensions. W e explored this later possibility by having subjects make rhyme decisions to words that vary in orthographic similarity and also to words that vary in semantic similarity {good-kind, cruel-kind). This possibility is ruled out in two experiments in which we fail to find an interference effect with semantically related trials, while replicating the basic orthographic interference and facilitation results.