Constituent order and semantic parallelism in online comprehension: Eye-tracking evidence from German

Reading times for the second conjunct of and-coordinated clauses are faster when the second conjunct parallels the first conjunct in its syntactic or semantic (animacy) structure than when its structure differs (Frazier, Munn, & Clifton, 2000; Frazier, Taft, Roeper, & Clifton, 1984). What remains unclear, however, is the time course of parallelism effects, their scope, and the kinds of linguistic information to which they are sensitive. Findings from the first two eye-tracking experiments revealed incremental constituent order parallelism across the board—both during structural disambiguation (Experiment 1) and in sentences with unambiguously case-marked constituent order (Experiment 2), as well as for both marked and unmarked constituent orders (Experiments 1 and 2). Findings from Experiment 3 revealed effects of both constituent order and subtle semantic (noun phrase similarity) parallelism. Together our findings provide evidence for an across-the-board account of parallelism for processing and-coordinated clauses, in which both constituent order and semantic aspects of representations contribute towards incremental parallelism effects. We discuss our findings in the context of existing findings on parallelism and priming, as well as mechanisms of sentence processing.     

On the temporal course of gap-filling during comprehension of verbal passives

The work presented in this paper examines the time course of antecedent reactivation following movement gaps found in passive sentences. Using a cross-modal lexical priming technique, (re) activation of the subject noun phrase (NP) was examined at various critical points following the verb (near the posited gap) for verbal passive sentences and for active (control) sentences. Subjects made lexical decisions to visual targets that were presented at three locations during auditory sentence comprehension: immediately after the matrix verb, 500 msec after the verb, or 1000 msec after the verb. Responses to targets related to the subject NP were faster than those to controls during passive sentences (gap sentences), but not during active sentences (no-gap sentences), thus indicating that reactivation of the matrix subject did occur in the passive cases. Furthermore, the magnitude of the priming increased with distance and time from the verb, going from a nonsignificant trend at the verb to a highly significant effect at 1000 msec following the verb. These results are discussed in terms of both formal and processing models of language.The authors wish to thank Janet Nicol for her contributions to the materials and design of this experiment. This work was supported in part by NIDCD Grant DC01947 and by a University of Washington grant to the first author and an AFOSR grant (AFOSR 91-0225) to the second author.     

The role of the anterior left hemisphere in real-time sentence comprehension: evidence from split intransitivity

We investigate Broca's sentence comprehension as an impairment on normal syntactic composition: the slow-syntax hypothesis (SSH). Experiment 1 examines comprehension of object-relative clauses (Wh-movement). Experiment 2 examines comprehension of sentences with unaccusative verbs (NP-movement), which like passives, base-generate their theme-argument in object position. Guided by the SSH, both experiments test the prediction that syntax-dependent effects such as "gap-filling" are observable but in a delayed fashion. Results show that whereas no priming was obtained at the point of the trace, antecedent reactivation emerged 650 and 800 ms after the verb (for Wh- and NP-movement respectively). This shows, contrary to dependency-based generalizations, that Broca's patients are able to successfully implement dependencies, albeit in a protracted manner. Given the localization value provided by Broca's aphasia, this supports the notion that the temporal implementation of syntactic structure formation (i.e., the requirement that it be fast and automatic) depends on the integrity of the anterior left hemisphere.     

Can we distinguish an “I” and “ME” during listening?—an event-related EEG study on the processing of first and second person personal and possessive pronouns

Theoretically, stimuli can be related to the self as subject (“I”) or object (“ME”) of experience. This event-related brain potential (ERP) study investigated whether listening to personal and possessive pronouns elicits different modes of self-processing regarding time-course and neural sources. Going beyond previous research, first (1PP) and second person (2PP) pronouns were included to determine the specificity of self-processing. Participants listened passively to German pronouns while the electroencephalogram was recorded. Modulation of ERPs revealed a processing advantage for the 2PP personal pronoun “du” (“you”) already in early time windows. Regarding possessive pronouns, N1 amplitudes indicated increased attention orientation to the 1PP pronoun “mein” (“my”), whereas during later time windows, processing of 1PP and 2PP possessive pronouns did not differ but differed from the third person pronoun “sein” (“his”). ERP source imaging suggests that primary sensory brain regions (auditory cortex), the insula and cortical midline structures are differentially involved into these two processing modes. The results support the idea of distinct self-processing modes (“I” and “ME”) and confirm their dynamic nature. Moreover, they demonstrate that on a neural level neither “I” or “ME” are invariantly tied to the first person, in line with the hypothesis that self-processing is relational and context-dependent.     

Understanding of action-related and abstract verbs in comparison: a behavioral and TMS study

Does the comprehension of both action-related and abstract verbs rely on motor simulation? In a behavioral experiment, in which a semantic task was used, response times to hand-action-related verbs were briefer than those to abstract verbs and both decreased with repetition of presentation. In a transcranial magnetic stimulation (TMS) experiment, single-pulse stimulation was randomly delivered over hand motor area of the left primary motor cortex to measure cortical-spinal excitability at 300 or 500 ms after verb presentation. Two blocks of trials were run. In each block, the same verbs were randomly presented. In the first block, stimulation induced an increase in motor evoked potentials only when TMS was applied 300 ms after action-related verb presentation. In the second block, no modulation of motor cortex was found according to type of verb and stimulation-delay. These results confirm that motor simulation can be used to understand action rather than abstract verbs. Moreover, they suggest that with repetition, the semantic processing for action verbs does not require activation of primary motor cortex anymore.     

动词隐含因果性和重读对代词加工的影响

采用听觉动窗法和跨通道探测技术,设计3个实验考察了汉语口语句子理解中,动词隐含因果性和重读对代词加工的影响及其时间进程。其中的自变量为动词类型和韵律特征;探测实验中增加探测词类型变量。结果发现：动词隐含因果性影响代词的指认方向;当代词不重读时,动词隐含因果关系在遇到代词后立即影响代词可能先行词的激活水平。代词重读影响“因为”分句的阅读时间,且在代词后立即影响主语型动词语句中代词的加工     

Relative Clause Effects at the Matrix Verb Depend on Type of Intervening Material

Although a large literature demonstrates that object-extracted relative clauses (ORCs) are harder to process than subject-extracted relative clauses (SRCs), there is less agreement regarding where during processing this difficulty emerges, as well as how best to explain these effects. An eye-tracking study by Staub, Dillon, and Clifton (2017) demonstrated that readers experience more processing difficulty at the matrix verb for ORCs than for SRCs when the matrix verb immediately follows the relative clause (RC), but the difficulty is eliminated if a prepositional phrase (PP) intervenes. A careful examination of Staub et al.’s materials reveals that the types of PPs used in the experiment were a mixture of locative and temporal PPs. This is important in that locative PPs can modify either a noun phrase or a verb phrase (VP), whereas temporal PPs typically modify VPs, resulting in systematic differences in PP attachment across ORCs versus SRCs. In the current eye-tracking experiment, we systematically manipulated RC type and PP type in the same sentences used by Staub et al. The manipulation of PP type resulted in a crossover pattern at the matrix verb such that there was a trend for reading times to be longer for ORCs than SRCs when the PP was locative, but reading times were longer for SRCs than ORCs when the PP was temporal. These results provide important information regarding the locus of RC-processing effects and highlight the importance of carefully considering how intervening material might unintentionally alter the structure or the meaning of a sentence.     

The role of pragmatic principles in resolving attachment ambiguities: Evidence from eye movements

In an eyetracking experiment, participants read sentences that contained a prepositional phrase (PP) that could be attached to one of two preceding verbs. To understand the sentence, readers had to select which verb would serve as the host for the PP. In some of the sentences, the critical verbs and the PPs were part of a subordinate clause in which lexical and syntactic factors were expected to matter, but discourse factors favoring attachment of the material to positions where it would be relevant to the main assertion of the sentence were not expected to matter. In other sentences, the critical material was tested in main clause contexts in which the main assertion principle was predicted to apply. Hierarchical linear modeling showed that online attachment preferences were affected by clause type (main vs. subordinate). Specifically, the preference for a local verb over a distant verb was greater when the critical material appeared within a subordinate clause than when it appeared within a main clause. This pattern of results can be explained by the operation of the relativized relevance or main assertion principle, which in our sentences meant that participants favored attachment of the PP to the first verb over the second.     

Target objects defined by a conjunction of colour and shape can be selected independently and in parallel

It is generally assumed that during search for targets defined by a feature conjunction, attention is allocated sequentially to individual objects. We tested this hypothesis by tracking the time course of attentional processing biases with the N2pc component in tasks where observers searched for two targets defined by a colour/shape conjunction. In Experiment 1, two displays presented in rapid succession (100 ms or 10 ms SOA) each contained a target and a colour-matching or shape-matching distractor on opposite sides. Target objects in both displays elicited N2pc components of similar size that overlapped in time when the SOA was 10 ms, suggesting that attention was allocated in parallel to both targets. Analogous results were found in Experiment 2, where targets and partially matching distractors were both accompanied by an object without target-matching features. Colour-matching and shape-matching distractors also elicited N2pc components, and the target N2pc was initially identical to the sum of the two distractor N2pcs, suggesting that the initial phase of attentional object selection was guided independently by feature templates for target colour and shape. Beyond 230 ms after display onset, the target N2pc became superadditive, indicating that attentional selection processes now started to be sensitive to the presence of feature conjunctions. Results show that independent attentional selection processes can be activated in parallel by two target objects in situations where these objects are defined by a feature conjunction.     

Evidence for a response preparation bottleneck during dual-task performance: Effect of a startling acoustic stimulus on the psychological refractory period

The present study was designed to investigate the mechanism associated with dual-task interference in a psychological refractory period (PRP) paradigm. We used a simple reaction time paradigm consisting of a vocal response (R1) and key-lift task (R2) with a stimulus onset asynchrony (SOA) between 100 ms and 1500 ms. On selected trials we implemented a startling acoustic stimulus concurrent with the second stimulus to determine if we could involuntarily trigger the second response. Our results indicated that the PRP delay in the second response was present for both control and startle trials at short SOAs, suggesting the second response was not prepared in advance. These results support a response preparation bottleneck and can be explained via a neural activation model of preparation. In addition, we found that the reflexive startle activation was reduced in the dual-task condition for all SOAs, a result we attribute to prepulse inhibition associated with dual-task processing.     

The On-Line Processing of Verb-Phrase Ellipsis in Aphasia

We investigate the on-line processing of verb-phrase ellipsis (VPE) constructions in two brain injured populations: Broca’s and Anomic aphasics. VPE constructions are built from two simple clauses; the first is the antecedent clause and the second is the ellipsis clause. The ellipsis clause is missing its verb and object (i.e., its verb phrase (VP)), which receives its reference from the fully specified VP in the antecedent clause. VPE constructions are unlike other sentence types that require displacement of an argument NP; these latter constructions (e.g., object-relatives, wh-questions) yield either on-time or delayed antecedent reactivation. Our results demonstrate that Anomics, like unimpaired individuals, evince reactivation of the direct object NP (within the VP) at the elided position. Broca’s patients, on the other hand, do not show reactivation of the antecedent. We consider several interpretations for our data, including explanations focusing on the larger ‘grain size’ of the reconstructed material in the ellipsis clause, the properties of the auxiliary that carries tense and agreement features, and the possibility that the cost-free syntactic copy procedure claimed to underlie VPE may be modulated by the functional deficit in Broca’s aphasia.     

Information Density and Syntactic Repetition

In noun phrase (NP) coordinate constructions (e.g., NP and NP), there is a strong tendency for the syntactic structure of the second conjunct to match that of the first; the second conjunct in such constructions is therefore low in syntactic information. The theory of uniform information density predicts that low‐information syntactic constructions will be counterbalanced by high information in other aspects of that part of the sentence, and high‐information constructions will be counterbalanced by other low‐information components. Three predictions follow: (a) lexical probabilities (measured by N‐gram probabilities and head‐dependent probabilities) will be lower in second conjuncts than first conjuncts; (b) lexical probabilities will be lower in matching second conjuncts (those whose syntactic expansions match the first conjunct) than nonmatching ones; and (c) syntactic repetition should be especially common for low‐frequency NP expansions. Corpus analysis provides support for all three of these predictions.     

Visual arguments

Three experiments investigated the use of verb argument structure by tracking participants' eye movements across a set of related pictures as they listened to sentences. The assumption was that listeners would naturally look at relevant pictures as they were mentioned or implied. The primary hypothesis was that a verb would implicitly introduce relevant entities (linguistic arguments) that had not yet been mentioned, and thus a picture corresponding to such an entity would draw anticipatory looks. For example, upon hearing ...mother suggested..., participants would look at a potential recipient of the suggestion. The only explicit task was responding to comprehension questions. Experiments 1 and 2 manipulated both the argument structure of the verb and the typicality/co-occurrence frequency of the target argument/adjunct, in order to distinguish between anticipatory looks to arguments specifically and anticipatory looks to pictures that were strongly associated with the verb, but did not have the linguistic status of argument. Experiment 3 manipulated argument status alone. In Experiments 1 and 3, there were more anticipatory looks to potential arguments than to potential adjuncts, beginning about 500 ms after the acoustic onset of the verb. Experiment 2 revealed a main effect of typicality. These findings indicate that both real world knowledge and argument structure guide visual attention within this paradigm, but that argument structure has a privileged status in focusing listener attention on relevant aspects of a visual scene.     

Inhibition of return in visual marking? The importance of the interstimulus interval and the type of search task

Four experiments are presented that examine the possibility that inhibition of return (IOR) may occur in visual marking. Previously, Watson and Humphreys (1997), using a cue duration of 750 ms and an interstimulus interval (ISI) of 250 ms, concluded that IOR was not present in visual marking. In the present study, the first experiment examined three ISIs (250 ms, 500 ms, and 750 ms) with a constant stimulus onset asynchrony (SOA, 1000 ms) in a typical cueing paradigm and failed to find IOR with the short ISI. Based on these findings, the second (feature search) and third (conjunction search) experiments tested for IOR by using a visual marking paradigm with a 500 ms ISI. Evidence for IOR was found in the feature search (preview condition similar to half-elements baseline condition) and not in the conjunction search (preview condition similar to the all-elements baseline). The typical preview effect was found in Experiment 4 with a cue duration 1000 ms and no ISI. Overall, these findings indicate that IOR may play a role in visual marking, but only with feature search tasks and long ISIs between displays.     

Irrelevant conjunction and the ratio measure or historical skepticism

It is widely believed that one should not become more confident that all swans are white and all lions are brave simply by observing white swans. Irrelevant conjunction or “tacking” of a theory onto another is often thought problematic for Bayesianism, especially given the ratio measure of confirmation considered here. It is recalled that the irrelevant conjunct is not confirmed at all. Using the ratio measure, the irrelevant conjunction is confirmed to the same degree as the relevant conjunct, which, it is argued, is ideal: the irrelevant conjunct is irrelevant. Because the past’s really having been as it now appears to have been is an irrelevant conjunct, present evidence confirms theories about past events only insofar as irrelevant conjunctions are confirmed. Hence the ideal of not confirming irrelevant conjunctions would imply that historical claims are not confirmed. Confirmation measures partially realizing that ideal make the confirmation of historical claims by present evidence depend strongly on the (presumably subjective) degree of belief in the irrelevant conjunct. The unusually good behavior of the ratio measure has a bearing on the problem of measure sensitivity. For non-statistical hypotheses, Bayes’ theorem yields a fractional linear transformation in the prior probability, not a linear rescaling, so even the ratio measure arguably does not aptly measure confirmation in such cases.     

Parieto-occipital areas involved in efficient filtering in search: A time course analysis of visual marking using behavioural and functional imaging procedures

Search for a colour-form conjunction target can be facilitated by presenting one set of distractors prior to the second set of distractors and the target: the preview benefit (Watson & Humphreys, 1997). The early presentation of one set of distractors enables them to be efficiently filtered from search. We report two studies investigating the time course of the preview benefit. In Experiment 1 we use a standard reaction time analysis to show that the benefit has a relatively slow time course; old items need to precede the new set by 600 ms or more in order to be fully filtered from search. Furthermore, the reductions in reaction time across time in the preview condition varied nonlinearly with the display size, suggesting that old items were discounted from search in parallel. In Experiment 2 we examined the neural locus of this filtering effect over time, using positron emission tomography (PET). We show that regions of parieto-occipital cortex are selectively activated in a preview search condition relative to a detection baseline. These regions also increase in activation as the preview interval increases (and search then becomes easier), consistent with them modulating the parallel filtering of distractors from targets in spatial search. Interestingly, the same areas as those activated in preview search were also active in conjunction search relative to its own detection baseline. Thus these regions either modulate parallel filtering in conjunction search too, or they modulate different behavioural functions according to task constraints.     

Memory reactivation in the second year of life

Memory reactivation has not been systematically studied with infants older than 1 year. Currently, three experiments examined the effects of a reactivation treatment (priming) on retention throughout the second postnatal year. Fifteen- and 18-month-olds learned an operant train task, forgot it, received a 2-min or 10-s prime, and later were tested for retention. Although the longer prime was effective for 15-month-olds, 18-month-olds required the shorter prime (Experiment 1). The memory was reactivated after delays two (18 months) and three (15 months) times longer than infants originally remembered it (Experiment 2). The reactivated memory was forgotten as fast as the original memory after the 2-min prime and twice as fast after the 10-s prime (Experiment 3). The fact that reactivation changes quantitatively but not qualitatively throughout infancy suggests that the same mechanism mediates it at all ages. These findings have major implications for the impact of early experience on cognitive development.     

Parallel parsing: Evidence from reactivation in garden-path sentences

An all-visual, on-line, lexical priming technique was used to investigate whether the human sentence processor computes syntactic representations serially or in parallel. Structurally ambiguous garden-path sentences such as the following were studied: “The psychologist told the wife that the man bumpedthat her car was stolen.” Despite the strong preference for the sentential-complement reading of the ambiguous region (italicized), a reactivation effect for the head of the relative clause (wife) was observed immediately following the presentation of the embedded verb (bumped), suggesting that the relative clause analysis is also computed. This finding is taken as evidence for parallel parsing since both possible analyses were shown to have a processing reflection simultaneously: Computation of the sentential-complement analysis was demonstrated by the fact that readers garden-path when that analysis turns out to be incorrect, and computation of the relative clause analysis was demonstrated by the reactivation effect.     

Native language influence on the distributive effect in producing second language subject–verb agreement

Three experiments were conducted to investigate the distributive effect when producing subject–verb agreement in English as a second language (L2) when the participant's first language either does or does not require subject–verb agreement. Both Chinese–English and Uygur–English bilinguals were included in Experiment 1. Chinese has no required subject–verb agreement, whereas Uygur does. Results showed that the distributive effect was observed in Uygur–English bilinguals but not in Chinese–English bilinguals, indicating that this particular first language (L1) syntactic feature is one significant factor affecting the distributive effect in the production of subject–verb agreement in L2. Experiment 2 further investigated the matter by choosing Chinese–English participants with higher L2 proficiency. Still, no distributive effect was observed, suggesting that the absence of distributive effect in Chinese–English bilinguals in Experiment 1 was not due to low proficiency in the target language. Experiment 3 changed the way the stimuli were presented, highlighting the singular or distributive nature of the subject noun phrases, and the distributive effect was observed in Chinese–English bilinguals. Altogether, the results show that the L1 syntactic feature of subject–verb agreement is one significant factor affecting the distributive effect in the production of subject–verb agreement in L2. More specifically, distributive effects rarely occur in L2 when L1 has no requirement on subject–verb agreement, whereas distributive effects are more likely to occur in L2 when the L1 also has required subject–verb agreement.     

Gapping: Electrophysiological evidence for immediate processing of "missing" verbs in sentence comprehension

In the present study we use event related potentials (ERPs) to explore the time course of identification and resolution of verb gaps. ERPs were recorded while participants read sentences that contained a verb gap like Ron took/sanded the planks, and Bill ? the hammer... Plausibility of the critical words (hammer) that followed the verb gap was manipulated. Relative to the plausible control (preceded by took), ERPs to the critical word in the implausible condition (preceded by sanded) showed an N400, followed by a positivity (P600). ERPs to determiners following gapped verbs showed a negativity between 100 and 300 ms, and a positivity between 300 and 500 ms compared to determiners in non-gapping constructions. These results suggest that the sentence processor recognizes a verb gap and reconstructs the verb information at the earliest possible occasion, and that this reconstruction process is different from the reconstruction of antecedents in other filler-gap constructions (e.g., WH gaps).