Focus Attracts Attachment.

There is growing evidence that pitch accents as well as prosodic boundaries can affect syntactic attachment. But is this an effect of their perceptual salience (the Salience Hypothesis), or is it because accents mark the position of focus (the Focus Attraction Hypothesis)? A pair of auditory comprehension experiments shows that focus position, as indicated by preceding wh-questions instead of by pitch accents, affects attachment by drawing the ambiguous phrase to the focus. This supports the Focus Attraction Hypothesis (or a pragmatic version of salience) for both these results and previous results of accents on attachment. These experiments show that information structure, as indicated with prosody or other means, influences sentence interpretation, and suggests a view on which modifiers are drawn to the most important information in a sentence.

Processing gapping: Parallelism and grammatical constraints.

This study aims to test two hypotheses about the online processing of Gapping: whether the parser inserts an ellipsis site in an incremental fashion in certain coordinated structures (the Incremental Ellipsis Hypothesis), or whether ellipsis is a late and dispreferred option (the Ellipsis as a Last Resort Hypothesis). We employ two offline acceptability rating experiments and a sentence fragment completion experiment to investigate to what extent the distribution of Gapping is controlled by grammatical and extra-grammatical constraints. Furthermore, an eye-tracking while reading experiment demonstrated that the parser inserts an ellipsis site incrementally but only when grammatical and extra-grammatical constraints allow for the insertion of the ellipsis site. This study shows that incremental building of the Gapping structure follows from the parser's general preference to keep the structure of the two conjuncts maximally parallel in a coordination structure as well as from grammatical restrictions on the distribution of Gapping such as the Coordination Constraint.

Correlate not optional: PP sprouting and parallelism in "much less" ellipsis.

Clauses that are parallel in form and meaning show processing advantages in ellipsis and coordination structures (Frazier et al. 1984; Kehler 2000; Carlson 2002). However, the constructions that have been used to show a parallelism advantage do not always require a strong semantic relationship between clauses. We present two eye tracking while reading studies on focus-sensitive coordination structures, an understudied form of ellipsis which requires the generation of a contextually salient semantic relation or scale between conjuncts. However, when the remnant of ellipsis lacks an overt correlate in the matrix clause and must be "sprouted" in the ellipsis site, the relation between clauses is simplified to entailment. Instead of facilitation for sentences with an entailment relation between clauses, our online processing results suggest that violating Parallelism is costly, even when doing so could ease the semantic relations required for interpretation.

Zero-Adjective Contrast in Much-less Ellipsis: The Advantage for Parallel Syntax.

This paper explores the processing of sentences with a much less coordinator (I don't own a pink hat, much less a red one). This understudied ellipsis sentence, one of several focus-sensitive coordination structures, imposes syntactic and semantic conditions on the relationship between the correlate (a pink hat) and remnant (a red one). We present the case of zero-adjective contrast, in which an NP remnant introduces an adjective without an overt counterpart in the correlate (I don't own a hat, much less a red one). Although zero-adjective contrast could in principle ease comprehension by limiting the possible relationships between the remnant and correlate to entailment, we find that zero-adjective contrast is avoided in production and taxing in online processing. Results from several studies support a processing model in which syntactic parallelism is the primary guide for determining contrast in ellipsis structures, even when violating parallelism would assist in computing semantic relationships.

Accents, Not Just Prosodic Boundaries, Influence Syntactic Attachment.

Traditionally, pitch accents are understood to relate to the information structure of a sentence and its discourse connections, while prosodic boundaries indicate groupings of words and affect how constituents attach into a syntactic structure. Here, we show that accents also affect syntactic attachment in multiple different syntactic structures. Three auditory questionnaires on ambiguous attachment sentences (such as Tom reported that Bill was bribed [last May]) find that accenting the higher or lower verb ( reported or bribed) increases the attachment of the final adverbial phrase as a modifier of the accented verb. A fourth experiment shows that accents on verbs or object nouns (in sentences like Jenny sketched a child [with crayons]) also increase the attachment of the final prepositional phrase to the accented head (sketched with crayons versus a child with crayons). Accent effects were small but consistent across sentences with different levels of bias and did not depend on prosodic boundaries. The results suggest that focused elements are important to the main assertion of the sentence and therefore draw the attachment of upcoming material (though the salience of attachment sites may also be important). The results also demonstrate that both prosodic phrasing and pitch accents can affect basic syntactic structure.

Information Structure Preferences in Focus-Sensitive Ellipsis: How Defaults Persist.

We compare the roles of overt accent and default focus marking in processing ellipsis structures headed by focus-sensitive coordinators (such as Danielle couldn't pass the quiz, let alone the final/Kayla). In a small auditory corpus study of radio transcripts, we establish that such structures overwhelmingly occur with contrastive pitch accents on the correlate and remnant ( the quiz and the final, or Danielle and Kayla), and that there is a strong bias to pair the remnant with the most local plausible correlate in production. In two auditory naturalness ratings experiments, we observe that marking a non-local correlate with contrastive pitch accent moderates, but does not fully overturn, the bias for local correlates in comprehension. We propose that the locality preference is due to a sentence-final default position for sentence accent, and that auditory processing is subject to "enduring focus," in which default positions for focus continue to influence the focus structure of the sentence even in the presence of overt accents. The importance of these results for models of auditory processing and of the processing of remnants in ellipsis structures is discussed.

Form and function: Optional complementizers reduce causal inferences.

Many factors are known to influence the inference of the discourse coherence relationship between two sentences. Here, we examine the relationship between two conjoined embedded clauses in sentences like The professor noted that the student teacher did not look confident and (that) the students were poorly behaved. In two studies, we find that the presence of that before the second embedded clause in such sentences reduces the possibility of a forward causal relationship between the clauses, i.e., the inference that the student teacher's confidence was what affected student behavior. Three further studies tested the possibility of a backward causal relationship between clauses in the same structure, and found that the complementizer's presence aids that relationship, especially in a forced-choice paradigm. The empirical finding that a complementizer, a linguistic element associated primarily with structure rather than event-level semantics, can affect discourse coherence is novel and illustrates an interdependence between syntactic parsing and discourse parsing.

Keep it local (and final): Remnant preferences in "let alone" ellipsis.

The let alone construction (John can't run a mile, let alone a marathon) differs from standard coordination structures (with and or but) by requiring ellipsis of the second conjunct--for example, a marathon is the remnant of an elided clause [[see text] a marathon]. In support of an ellipsis account, a corpus study of British and American English finds that let alone exhibits a Locality bias, as the second conjunct preferentially contrasts with the nearest lexical item of the same syntactic type. Two self-paced reading studies show that the Locality bias is active during online processing, but must be reconciled with indicators of semantic contrast and discourse information. Further, a sentence-rating study shows that the Locality bias interacts with a Finality bias that favours placing the let alone phrase at the end of a clause, which sometimes necessitates a nonlocal contrast. Together, the results show how a general bias in ellipsis for local contrasts is affected by discourse demands, such as the need for scalar contrast imposed by let alone, thereby offering a window into how possibly divergent syntactic and discourse constraints impact sentence processing.

Predicting contrast in sentences with and without focus marking.

How do we know when a contrast is coming? This study explores the prediction of parallel contrastive phrases, especially NPs, in sentences with and without overt focus marking. A written sentence-completion questionnaire with clauses followed by the conjunction "but" compared unmarked initial clauses to ones with the focus marker "only" on the subject or object. Both conditions with "only" elicited more contrasts overall than the condition without focus marking, and many of the contrasts were with the focus-marked NP. While the baseline (no-only) condition had full clauses for half of the completions, subject focus increased clausal completions and object focus increased negative ellipsis completions ("not"+NP structures), both changes in syntax which make a contrast with the marked NP easy. The production of negative ellipsis sentences primarily in the object-focus condition suggests that the object bias of these sentences in comprehension could relate to their being used more frequently with this meaning. Finally, the overall pattern of results shows that overt marking of contrastive focus increases continuations with contrasts, and the conjunction "but" does not reliably predict explicitly-stated contrasts within a sentence without overt focus marking.

Standing alone with prosodic help.

Two partially independent issues are addressed in two auditory rating studies: under what circumstances is a sub-string of a sentence identified as a stand-alone sentence, and under what circumstances do globally ill-formed but 'locally coherent' analyses (Tabor, Galantucci, & Richardson., 2004) emerge? A new type of locally coherent structure is established in Experiment 1, where a that-less complement clause is at least temporarily analyzed as a stand-alone sentence when it corresponds to a prosodic phrase. In Experiment 2, reduced relative clause structures like those in Tabor et al. were investigated. As in Experiment 1, the root sentence (mis-)analyses emerged most frequently when the locally coherent clause corresponded to a prosodic phrase. However, a substantial number of locally coherent analyses emerged even without prosodic help, especially in examples with for-datives (which do not grammatically permit a reduced relative clause structure for some speakers). Overall, the results suggest that prosodic grouping of constituents encourages analysis of a sub-string as a root sentence, and raise the question of whether all local coherence structures involve analysis of an utterance-final sub-string as a root sentence.

The Role of Only in Contrasts in and out of Context.

Three self-paced reading experiments explored the processing of "only" and its interaction with context. In isolated sentences, the focus particle "only" predicts an upcoming contrast. Ambiguous replacive sentences (e.g., "The curator embarrassed the gallery owner in public, not the artist") with "only" on the subject or object showed faster reading of the contrast phrase ("not the artist") than without it. The position of "only" also influenced the phrase's meaning; despite a bias toward object contrasts, subject "only" increased subject interpretations. If preceding context provides another reason for the focus particle, it no longer predicts an upcoming contrast. In biasing contexts including indirect questions, there was no facilitation when "only" marked the argument which answered the question, while "only" on the other argument slowed processing. Both "only" and context influenced interpretation. The results show that focus particles and questions can each influence processing of an upcoming contrast on- and off-line.

Syntactic structure guides prosody in temporarily ambiguous sentences.

A pair of speaking and listening studies investigated the prosody of sentences with temporary Object/Clause and Late/Early Closure ambiguities. Speakers reliably produced prosodic cues that allowed listeners to disambiguate Late/Early Closure sentences, but only infrequently produced prosody that disambiguated Object/Clause sentences, as shown by the results of listening studies.The two continuations for Object/Clause sentences were not pronounced with identical prosody, but the differences in their productions were not helpful to listeners. Speakers' different performance on the two sentence types is traced to their different syntactic structures. These results illustrate the importance of the syntax-prosody mapping in production and test the prosodic predictions of syntax-prosody models like that ofWatson and Gibson (2004).

Nonlocal effects of prosodic boundaries.

Placing a prosodic boundary before a phrase may influence its syntactic analysis. However, the boundary's effect depends on the presence, size, and position of other, earlier, prosodic boundaries. In three experiments, we extend previous results about the effect of the position of the early boundary. In sentences in which a final phrase may modify either a local verb or an earlier verb, a boundary immediately after the first verb leads to more first-verb attachments than when the earlier boundary appears in another position between the two verbs (Experiments 1 and 2). This effect cannot be attributed to weaker effects of more distant boundaries (Experiment 2), but is likely due to the first verb being more prominent when a boundary immediately follows it, since similar effects are observed when the verb is accented (Experiment 3). The results support the informative boundary hypothesis and show that the impact of earlier, nonlocal boundaries is not fully uniform.

Information structure expectations in sentence comprehension.

In English, new information typically appears late in the sentence, as does primary accent. Because of this tendency, perceivers might expect the final constituent or constituents of a sentence to contain informational focus. This expectation should in turn affect how they comprehend focus-sensitive constructions such as ellipsis sentences. Results from four experiments on sluicing sentences (e.g., The mobster implicated the thug, but we can't find out who else) suggest that perceivers do prefer to place focus late in the sentence, though that preference can be mitigated by prosodic information (pitch accents, Experiment 2) or syntactic information (clefted sentences, Experiment 3) indicating that focus is located elsewhere. Furthermore, it is not necessarily the direct object, but the informationally focused constituent that is the preferred antecedent (Experiment 4). Expectations regarding the information structure of a sentence, which are only partly cancellable by means of overt focus markers, may explain persistent biases in ellipsis resolution.

How prosody constrains comprehension: A limited effect of prosodic packaging.

Prosody has a large impact on language processing. We contrast two views of how prosody and intonation might exert their effects. On a 'prosodic packaging' approach, prosodic boundaries structure the linguistic input into perceptual and memory units, with the consequence that material in earlier packages is less accessible for linguistic processing than material in the current package. This approach claims that such lessened accessibility holds true for the comprehension of all constructions, regardless of the particular kind of linguistic dependency that needs to be established using the earlier constituent. A 'specialized role' approach, by contrast, attributes to prosodic boundaries a role in making grouping decisions when building hierarchical structure, but attributes to pitch accents the major role in determining the accessibility of a constituent. The results of four listening studies with replacive sentences (Diane thought Patrick was entertaining, not Louise) support the predictions of the specialized role hypothesis over the prosodic packaging approach.

Focus and VP ellipsis.

In spoken English, pitch accents can convey the focus associated with new or contrasted constituents. Two listening experiments were conducted to determine whether accenting a subject makes its predicate a more tempting antecedent for an elided verb phrase, presumably because the accent helps focus the subject of the antecedent clause, increasing its likelihood of contrasting with the subject of the elided clause. The results of Experiment 1 supported the predictions of this "Contrasted Remnant hypothesis" but in principle could also be caused by listeners avoiding antecedents containing a focused (F-marked) constituent. Experiment 2 disconfirmed the hypothesis that listeners avoid antecedents containing a focused constituent, although pitch accents within a potential antecedent VP affected ellipsis resolution.

Prosodic phrasing is central to language comprehension.

Words, like musical notes, are grouped together into phrases by their rhythmic and durational properties as well as their tonal pitch. This 'prosodic phrasing' affects the understanding of sentences. Many processing studies of prosody have investigated sentences with a single, grammatically required prosodic boundary, which might be interpreted strictly locally, as a signal to end the current syntactic unit. Recent results suggest, however, that the global pattern of prosodic phrasing is what matters in sentence comprehension, not just the occurrence or size of a single local boundary. In this article we claim that the impact of prosodic boundaries depends on the other prosodic choices a speaker has made. We speculate that prosody serves to hold distinct linguistic representations together in memory.

Tracking the what and why of speakers' choices: prosodic boundaries and the length of constituents.

The rational speaker hypothesis (Clifton, Carlson, & Frazier, 2002) claims that speakers are self-consistent, employing intonation in a manner consistent with their intended message. Preceding a constituent by a prosodic boundary that is not required by the grammar often signals that this constituent is not part of the immediately preceding phrase. However, speakers tend to place prosodic boundaries before and after long constituents. The question is whether prosodic boundaries will have a larger influence on listeners' choice of an analysis when they flank short constituents than when they flank long ones. The results of two listening experiments indicate that they do, suggesting that listeners attend not just to properties of the input signal, but also to the reasons why speakers produce those properties.

Informative prosodic boundaries.

In principle, a prosodic boundary in an utterance might affect its interpretation in a local, context-independent fashion. In a right-branching language like English, the presence of a large prosodic boundary might signal the end of the current constituent, requiring the following constituent to be attached high in the syntactic tree. We present three listening experiments that test an alternative position suggested in Carlson, Clifton, and Frazier (2001) as the "informative boundary" hypothesis. This hypothesis claims that the interpretation of a prosodic boundary is determined not by its absolute size but by its size relative to relevant certain other boundaries. Experiment 1 confirmed the predictions of this hypothesis in phrases like the old men and women with very large houses, manipulating the boundaries before and and with. Experiment 2 investigated the effect in a variety of diverse syntactic structures, varying syntactic category and status (head vs. nonhead) of the ambiguous constituent. It confirmed the predictions of the informative boundary hypothesis in every structure tested except for '-ly' adverbs that are ambiguous between a manner interpretation and a speaker-evaluation interpretation. Experiment 3 demonstrated that sentence interpretation was affected by the size of the late boundary relative to a relevant early boundary, but not relative to an early boundary that was predicted to be irrelevant.