Effects of age, speed of processing, and working memory on comprehension of sentences with relative clauses

Two hundred participants, 50 in each of four age ranges (19-29, 30-49, 50-69, 70-90) were tested for working memory, speed of processing, and the processing of sentences with relative clauses. In Experiment 1, participants read four sentence types (cleft subject, cleft object, subject-subject, subject-object) in a word-by-word, non-cumulative, self-paced reading task and made speeded plausibility judgments about them. In Experiment 2, participants read two types of sentences, one of which contained a doubly center embedded relative clause. Older participants' comprehension was less accurate and there was age-related slowing of online processing times in all but the simplest sentences, which increased in syntactically complex sentences in Experiment 1. This pattern suggests an age-related decrease in the efficiency of parsing and interpretation. Slower speed of processing and lower working memory were associated with longer online processing times only in Experiment 2, suggesting that task-related operations are related to general speed of processing and working memory. Lower working memory was not associated with longer reading times in more complex sentences, consistent with the view that general working memory is not critically involved in online syntactic processing. Longer online processing at the most demanding point in the most demanding sentence was associated with better comprehension, indicating that it reflects effective processing under some certain circumstances. However, the poorer comprehension performance of older individuals indicates that their slower online processing reflects inefficient processing even at these points.     

Effects of Local and Global Context on Processing Sentences with Subject and Object Relative Clauses

An eye tracking study investigated the effects of local and global discourse context on the processing of subject and object relative clauses, whereby the contexts favored either a subject relative clause interpretation or an object relative clause interpretation. The fixation data replicated previous studies showing that object relative clause sentences were more difficult to process than subject relative sentences. Crucially, however, the reading difficulty asymmetry between subject and object relative clause sentences disappeared when the sentences were presented with a local or a global discourse context that favored the objects in the object relative clauses. These findings demonstrate that the evidence for a syntax-based account of sentence processing is found when sentences are presented in isolation. However, if sentences are placed more naturally, in context, discourse factors outweigh the initial structural assignment.     

Speech Rate and Syntactic Complexity as Multiplicative Factors in Speech Comprehension by Young and Older Adults

An experiment is reported in which young and older adults heard short English sentences that differed in syntactic complexity and speech rate. The syntactic contrast pitted center-embedded sentences with a subject-relative clause against sentences with center-embedded object-relative clauses. Speech rate was varied using computer time-compression of the speech signal. Both young and older adults showed poorer comprehension accuracy for the more complex object-relative clause sentences than subject-relative sentences, with an age difference appearing only when sentences were presented at a very rapid rate. By contrast to accuracy scores, older adults took longer than the young adults to give their comprehension responses at all speech rates tested, with this age difference amplified by both speech rate and syntactic complexity.     

Processing Italian Relative Clauses: Working Memory Span and Word Order Effects on RTs

In this study, the authors aim to clarify whether the subject–object asymmetry in relative clause comprehension is due to the use of parsing strategies (Active Filler Theory) or to a greater memory load generated by object sentences. Two experiments investigate how individual differences in working memory span may influence the reading times of relative sentences in Italian, a language characterized by a flexible structure. The results of Experiment 1 indicate that object extraction is more complex than subject extraction when sentences have a canonical structure. Furthermore, low-span participants have particular difficulties with object relative sentence comprehension. The results of Experiment 2 show that subject-relative clauses with uncanonical structures are more complex to understand than object-relative clauses, and low-span participants have more difficulties than high-span participants in elaborating both subject and object relative clauses. These data seem to be coherent with the Active Filler Theory.     

Effects of concurrent arithmetical and syntactic complexity on self-paced reaction times and eye fixations

Two dual-task experiments (replications of Experiments 1 and 2 in Fedorenko, Gibson, & Rohde, Journal of Memory and Language, 56, 246–269 2007) were conducted to determine whether syntactic and arithmetical operations share working memory resources. Subjects read object- or subject-extracted relative clause sentences phrase by phrase in a self-paced task while simultaneously adding or subtracting numbers. Experiment 2 measured eye fixations as well as self-paced reaction times. In both experiments, there were main effects of syntax and of mathematical operation on self-paced reading times, but no interaction of the two. In the Experiment 2 eye-tracking results, there were main effects of syntax on first-pass reading time and total reading time and an interaction between syntax and math in total reading time on the noun phrase within the relative clause. The findings point to differences in the ways individuals process sentences under these dual-task conditions, as compared with viewing sentences during “normal” reading conditions, and do not support the view that arithmetical and syntactic integration operations share a working memory system.     

Effects of Age and Location in Chinese Relative Clauses Processing

Three experiments investigated Chinese relative clause processing with children, youths and elders using sentence-picture matching and self-paced reading methods. In Experiment 1, we found that object-extracted clause were easier to comprehend than subject-extracted clause , and object-modified relative clause (i.e., object-modified subject-extracted clause\(\backslash \)object-modified object-extracted clause) were difficult to comprehend than subject modified relative clause (subject-modified subject-extracted clause\(\backslash \)subject-modified object-extracted clause). Importantly, this paper also found 5–6.5 ages may be critical for children to comprehend RCs in Chinese. Experiment 2 also showed that S-ORCs were easier to comprehend than S-SRCs for youths and elders. Further, elders have more difficulty comprehending RCs than youths. Experiment 3 indicated that there were no significant differences in difficulty between O-SRCs and O-ORCs, and no differences were found between youths and elders. In general, our findings gave support to predictions of working memory-based theory, and also indicated that RCs processing has an intricate course. Many factors such as syntactic, language specificity, experience, personality, must all be considered in sentence processing.     

The effect of noun animacy on the processing of unambiguous sentences: evidence from French relative clauses

Two experiments, one using self-paced reading and one using eye tracking, investigated the influence of noun animacy on the processing of subject relative (SR) clauses, object relative (OR) clauses, and object relative clauses with stylistic inversion (OR-SI) in French. Each sentence type was presented in two versions: either with an animate relative clause (RC) subject and an inanimate object (AS/IO), or with an inanimate RC subject and an animate object (IS/AO). There was an interaction between the RC structure and noun animacy. The advantage of SR sentences over OR and OR-SI sentences disappeared in AS/IO sentences. The interaction between animacy and structure occurred in self-paced reading times and in total fixation times on the RCs, but not in first-pass reading times. The results are consistent with a late interaction between animacy and structural processing during parsing and provide data relevant to several models of parsing.     

Structure and limited capacity in verbal working memory: a study with event-related potentials

In order to test recent claims about the structure of verbal working memory, two ERP experiments with Dutch speaking participants were carried out. We compared the ERP effects of syntactic and semantic mid-sentence anomalies in subject and object relative sentences. In Experiment 1, the participants made acceptability judgments, while in Experiment 2 they read for comprehension. Syntactic anomalies concerned subject-verb disagreement, while semantic anomalies were related to implausible events (e.g., *The cat that fled from the mice ran through the room). Semantic anomalies did not elicit an N400 effect. The semantic as well as syntactic anomalies elicited P600 effects, with similar centro-parietal scalp distributions. For both kinds of anomaly, the P600 effects were modulated by syntactic complexity: they were either relatively small (Experiment 1) or absent (Experiment 2) in object relative sentences. Taken together, our results suggest that: (a) verbal working memory is a limited capacity system; (b) it is not subdivided into an interpretative and a post-interpretative component (); (c) the P600 can reflect the presence of a semantic bias in syntactically unambiguous sentences; (d) the P600 is related to language monitoring: its function is to check upon the veridicality of an unexpected (linguistic) event; (e) if such a check is made, there is no integration of the event and hence no N400 effect.     

The Role of Animacy in Children's Interpretation of Relative Clauses in English: Evidence From Sentence–Picture Matching and Eye Movements

Subject relative clauses (SRCs) are typically processed more easily than object relative clauses (ORCs), but this difference is diminished by an inanimate head-noun in semantically non-reversible ORCs (“The book that the boy is reading”). In two eye-tracking experiments, we investigated the influence of animacy on online processing of semantically reversible SRCs and ORCs using lexically inanimate items that were perceptually animate due to motion (e.g., “Where is the tractor that the cow is chasing”). In Experiment 1, 48 children (aged 4;5–6;4) and 32 adults listened to sentences that varied in the lexical animacy of the NP1 head-noun (Animate/Inanimate) and relative clause (RC) type (SRC/ORC) with an animate NP2 while viewing two images depicting opposite actions. As expected, inanimate head-nouns facilitated the correct interpretation of ORCs in children; however, online data revealed children were more likely to anticipate an SRC as the RC unfolded when an inanimate head-noun was used, suggesting processing was sensitive to perceptual animacy. In Experiment 2, we repeated our design with inanimate (rather than animate) NP2s (e.g., “where is the tractor that the car is following”) to investigate whether our online findings were due to increased visual surprisal at an inanimate as agent, or to similarity-based interference. We again found greater anticipation for an SRC in the inanimate condition, supporting our surprisal hypothesis. Across the experiments, offline measures show that lexical animacy influenced children's interpretation of ORCs, whereas online measures reveal that as RCs unfolded, children were sensitive to the perceptual animacy of lexically inanimate NPs, which was not reflected in the offline data. Overall measures of syntactic comprehension, inhibitory control, and verbal short-term memory and working memory were not predictive of children's accuracy in RC interpretation, with the exception of a positive correlation with a standardized measure of syntactic comprehension in Experiment 1.     

Adult age differences in working memory

Two experiments were conducted to determine whether adult age differences in working memory should be attributed to less efficient processing, a smaller working memory storage capacity, or both. In Experiment 1, young, middle-age, and older adults solved three addition problems before giving the answers to any. Older adults added as well as young and middle-age adults but showed a more pronounced serial position curve across the three problem positions. In Experiment 2, young and older adults constructed linear orderings (e.g., ABCD) from pairwise information presented in sentences (e.g., BC). Manipulations involving processing (e.g., type of sentence) did not interact with age differences, but those involving storage capacity (e.g., ordering length) did. All main effects and interactions support the hypothesis of a smaller storage capacity but do not rule out some processing deficit in older adults.     

The processing of subject and object relative clauses in Spanish: An eye-tracking study

A normative study and an eye-tracking experiment investigated the influence of animacy on the processing of subject and object relative clauses in Spanish. The results showed that object relative clauses caused more difficulty than subject relative clauses, but that animacy modulated this preference. The overall pattern was similar to findings in other languages. However, because of the syntactic characteristics of Spanish relative clauses, the results give novel insights into the processing mechanisms that underlie relative clause processing.     

Syntactic presupposition in sentence comprehension

Two experiments investigated the role of syntactic presupposition in sentence comprehension. In Experiment I subjects verified cleft, pseudocleft and factive complement sentences with respect to preceding context paragraphs, which contradicted either the assertion or the presupposition of the target sentence. Subjects took significantly longer to verify sentences with false presuppositions than sentences with false assertions. In Experiment II subjects verified cleft and pseudocleft sentences with respect to subsequently presented pictures. Once again, verification times for sentences with false presuppositions were significantly longer than verification times for sentences with false assertions. It was argued that these findings are more adequately explained by a “structural” hypothesis, than in terms of strategies designed to locate given and new information.     

句法预测对句子理解影响的眼动实验

实验采用眼动技术实时考察了句子阅读理解过程中的句法预测效应和并列句的结构表征特点。眼动数据分析发现：(1)有无句法预测没有明显影响名词短语区域的加工, 不同眼动指标差异不显著; (2)有无句法预测显著影响被试对包含暂时局部歧义的关键区和具有解歧作用的关键后区域的阅读理解, 首次注视时间、第一遍阅读时间、回视路径时间和第一遍回视率明显减少。眼动研究表明, 暂时局部歧义句子阅读理解过程中表现出明显的句法预测效应, 有句法预测降低了局部歧义区域和解歧区域早期和晚期加工的难度; 和英语的短语并列优先法则不同, 汉语并列句子的结构表征出现分离现象, 即短语并列和句子并列。     

The on-line resolution of the sentence complement/relative clause ambiguity: evidence from Spanish

Two self-paced reading experiments investigated syntactic ambiguity resolution in Spanish. The experiments examined the way in which Spanish subjects initially interpret sentences that are temporarily ambiguous between a sentence complement and a relative clause interpretation. Experiment 1 examined whether the sentence complement preference found in English is observed in Spanish speaking subjects. In Experiment 2, verbal mood was manipulated in order to study the influence of verb-specific information on sentence processing. Since subcategorization for a subjunctive complement clause is generally assumed to be a lexical property of some verbs, the manipulation of the mood of the embedded verb affords us an interesting and novel way to examine the influence of lexical information on syntactic ambiguity resolution. Experiment 1 showed that Spanish speakers initially interpret the ambiguous that-clause as a sentence complement. Experiment 2 showed that verb-specific information, in particular, the information that specificies that a verb subcategorizes for a subjunctive complement, is accessed and used rapidly and affects the ambiguity resolution process. The results are discussed in relation to current models of sentence processing.     

Eye movements of young and older adults while reading with distraction

The authors used eye-tracking technology to examine young and older adults' online performance in the reading in distraction paradigm. Participants read target sentences and answered comprehension questions following each sentence. In some sentences, single-word distracters were presented in either italic or red font. Distracters could be related or unrelated to the target text. Online measures, including probability of fixation, fixation duration, and number of fixations to distracting text, revealed no age differences in text processing. However, young adults did have an advantage over older adults in overall reading time and text comprehension. These results provide no support for an inhibition deficit account of age differences in the reading in distraction paradigm, but are consistent with J. Dywan and W. E. Murphy's (1996) suggestion that older adults are less able than the young to distinguish target and distracter information held in working memory.     

Working memory contributions to relative clause attachment processing: A hierarchical linear modeling analysis

An eye-movement-monitoring experiment tested readers' responses to sentences containing relative clauses that could be attached to one or both of two preceding nouns. Previous experiments with such sentences have indicated that globally ambiguous relative clauses are processed more quickly than are determinately attached relative clauses. Central to the present research, a recent study (Swets, Desmet, Hambrick, & Ferreira, 2007) showed that offline preferences for such sentences differ as a function of working memory capacity. Specifically, both English and Dutch participants' preference for the second of two nouns as the host for the relative clause increased as their working memory capacity increased. In the present study, readers' working memory capacity was measured, and eye movements were monitored. Hierarchical linear modeling was used to determine whether working memory capacity moderated readers' online processing performance. The modeling indicated that determinately attached sentences were harder to process than globally ambiguous sentences, that working memory did not affect processing of the relative clause itself, but that working memory did moderate how easy it was to integrate the relative clause with the preceding sentence context. Specifically, in contrast with the offline results from Swets and colleagues' study, readers with higher working memory capacity were more likely to prefer the first noun over the second noun as the host for the relative clause.     

Processing controlled PROs in Spanish

Two experiments were carried out to investigate the processing of the empty category PRO and the time-course of this in Spanish. Eye movements were recorded while participants read sentences in which a matrix clause was followed by a subordinate infinitival clause, so that the subject or the object of the main clause could act as controller of PRO, and therefore as implicit grammatical subject of the infinitive. In Experiment 1, verb control information was manipulated: The matrix clause contained either subject-control verbs like prometer ('promise') or object-control verbs like forzar ('force'). In Experiment 2, the preposition that headed adverbial subordinate clauses was manipulated: Two different kinds of infinitival adverbial clauses were used, expressing purpose (preposition para) and reason (preposition por) and in which control information is primarily induced by the prepositions (para tends to trigger subject-control; por object-control). Experiment 1 showed that readers make immediate use of verb control information to recover the antecedent of the empty category PRO in Spanish obligatory control constructions. The data obtained in Experiment 2 suggest that during the processing of the empty category PRO in purpose vs. reason adverbial subordinate infinitival clauses the control information induced by the prepositions por vs. para is not initially used as a constraint to guide the selection of the nominal antecedent of PRO. In addition, both experiments showed that PRO antecedent selection is a very fast process and that, together with verb control information, recency played an important role. The results are discussed in terms of current psycholinguistic hypotheses about empty categories and in relation to formal linguistic hypotheses about PRO control. We argue that obligatory control ties (which are co-referential ties) are processed fast because they are launched from the same lexical platform that launches all fast syntactic connections (complements, as opposed to modifiers). In short, that such lexically-specified co-referential ties are regulated by linguistic form.     

Constraints on semantic priming in reading: A fixation time analysis

In Experiment 1, subjects read sentences containing a category name or a neutral prime that was followed by a target exemplar that varied in typicality. Fixation time on the target exemplar was the measure of processing difficulty. The category name facilitated processing for both high- and low-typicality exemplars. Unexpectedly, high-typicality exemplars were processed more quickly than low-typicality exemplars in both primed and unprimed conditions. Experiment 2 extended the priming effect to primary associates. Most importantly, the priming effect was influenced by the syntactic structure of the stimulus sentence. When both the prime and the associated target word were in the same clause, semantic priming occurred, but when the prime and target were in different clauses, no associative facilitation was observed. These results were interpreted as supporting a clausal processing hypothesis based on an autonomous modular view of the language processing system. Furthermore, the results were consistent with direct control models of eye movements, which claim that fixation duration reflects the timing of processing related to the word currently under fixation.     

Converging evidence that visuospatial cognition is more age-sensitive than verbal cognition

In 3 separate experiments, the same samples of young and older adults were tested on verbal and visuospatial processing speed tasks, verbal and visuospatial working memory tasks, and verbal and visuospatial paired-associates learning tasks. In Experiment 1, older adults were generally slower than young adults on all speeded tasks, but age-related slowing was much more pronounced on visuospatial tasks than on verbal tasks. In Experiment 2, older adults showed smaller memory spans than young adults in general, but memory for locations showed a greater age difference than memory for letters. In Experiment 3, older adults had greater difficulty learning novel information than young adults overall, but older adults showed greater deficits learning visuospatial than verbal information. Taken together, the differential deficits observed on both speeded and unspeeded tasks strongly suggest that visuospatial cognition is generally more affected by aging than verbal cognition.