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.     

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.     

In search of referents for nouns and pronouns

In comprehending a sentence, people normally try to identify the objects, events, and states referred to by its definite noun phrases. In Experiment 1, subjects took less time comprehending a sentence when the referents of such noun phrases were mentioned one sentence back than when they were mentioned two or three sentences back. There appeared to be a discontinuity between the first and second sentences back. Experiments 2 and 3 showed that it was most likely the first clause back, not the first sentence back, that was critical. These findings suggest that, independent of other factors, the last clause processed grants the entities it mentions a privileged place in working memory. They are readily available to be referred to by nouns and pronouns.     

Another word on parsing relative clauses: Eyetracking evidence from Spanish and English

Ambiguity as to what the relative clause modifies in phrases such as Someone shot the maid of the actress who was divorced/Alguien disparó contra la criada de la actriz que estaba divorciada tends to be resolved differently in different languages (and in different forms of complex noun phrases). In English, there is a weak but seldom significant tendency for the relative clause to be taken as modifying the second noun phrase, the actress, but in Spanish, several researchers have found a significant preference for the relative clause's modifying the first noun phrase, la criada. The present experiments compare Spanish and English readers' eye movements while reading exactly comparable sentences in their native languages and find a significant reading time advantage in Spanish when it is forced to modify the first noun phrase, but in English when the relative clause is forced to modify the second noun phrase. Theoretical implications of the findings for previous explanations of the phenomenon are discussed.     

Effects of punctuation on the processing of temporarily ambiguous sentences in Japanese

This study explored the effects of comma insertion on the processing of garden path sentences in Japanese. In two experiments, participants read relative clause sentences containing two ambiguities: single versus relative clause and early‐opening (EO) versus late‐opening (LO) left clause boundaries. EO sentences were presented with or without a comma compatible with an EO boundary in Experiment 1 and, in Experiment 2, with an LO boundary. The results showed that the comma, whether compatible or incompatible with the correct clause boundary, decreased reading time for the relative clause's head noun, indicating that a comma helps readers avoid or recover from garden paths caused by relative clause structures. Conversely, a comma incompatible with a clause boundary increased processing costs of second ambiguity resolution (EO vs. LO). We concluded that punctuation affects processing of temporary ambiguity in Japanese as in languages with stricter punctuation rules; furthermore, readers depend strongly on punctuation for online processing of whole sentence structures. We also discuss the relationship between punctuation and (implicit) prosody.     

韵律对指代歧义的解歧作用及其机制

研究了韵律特征对指代歧义的解歧作用及其机制。所选的指代歧义句先由 33名被试确定其主要意思和次要意思。歧义句由 8名发音人朗读 ,经专家和普通听者评定后选出 1人的语料为实验材料。各有 12名在校大学生参加了重音听辨实验和名词互换语义判断实验。实验 1请被试比较歧义句中切分出来的所指名词与非所指名词的重读程度。实验 2中将不同的名词组合嵌入到主要意思与次要意思的句子框架中 ,请被试判断合成句表达的是主要意思还是次要意思。实验 3对 4名发音人的语料进行了声学分析 ,测量并比较了歧义句中的所指名词和非所指名词的音高、时长和音强。结果表明 ,韵律信息对于指代歧义有较好的解歧效果 ,消解指代歧义的基本手段是在所指名词上设置重音 ,其主要的声学表现是所指名词时长的延长。     

Underspecification of syntactic ambiguities: Evidence from self-paced reading

Syntactically ambiguous sentences are sometimes read faster than disambiguated strings. Models of parsing have explained this tendency by appealing either to a race in the construction of alternative structures or to reanalysis. However, it is also possible that readers of ambiguous sentences save time by strategically underspecifying interpretations of ambiguous attachments. In a self-paced reading study, participants viewed sentences with relative clauses that could attach to one of two sites. Type of question was also manipulated between participants in order to test whether goals can influence reading/parsing strategies. The experiment revealed an ambiguity advantage in reading times, but only when participants expected superficial comprehension questions. When participants expected queries about relative clause interpretation, disambiguating regions were inspected with more care, and the ambiguity advantage was attenuated. However, even when participants expected relative clause queries, question-answering times suggested underspecified representations of ambiguous relative clause attachments. The results support the construal and "good-enough" models of parsing.     

Plausibility and subcategorization preference in children's processing of temporarily ambiguous sentences: Evidence from self-paced reading

Three self-paced reading experiments investigated children's processing of temporarily ambiguous sentences. Across the three experiments, subcategorization preference of a verb in a subordinate clause and the semantic plausibility of the misanalysis were manipulated. Reading times in the temporarily ambiguous region and following syntactic disambiguation indicated that children in the age range tested (8 years, 11 months to 12 years, 11 months) routinely misanalyse sentences of the type tested, and their tendency to misanalyse the sentences does not depend on the subcategorization preferences of the initial verb. Additional correlational analyses suggested that subcategory information did affect the degree of difficulty that readers experienced processing the critical noun and matrix verb.     

Overt reanalysis strategies and eye movements during the reading of mild garden path sentences

In an eye movement experiment, we examined the use of reanalysis strategies during the reading of locally ambiguous but globally unambiguous Spanish sentences. Among other measures, we examined regressive eye movements made while readers were recovering in reading mild garden path sentences. The sentences had an adverbial clause that, depending on the mood (indicative vs. subjunctive) of the subordinate clause verb, could attach high (to the main verb of the sentence) or low (to the verb in the subordinate clause). Although Spanish speakers favor low attachment, the high attachment version was quite easy to understand. Readers predominately used two alternative strategies to recover from the mild garden path in our sentences. In the more common reanalysis strategy, their eyes regressed from the last region (disambiguation+ 1) directly to the main verb in the sentence. Following this, they reread the rest of the sentence, fixating the next region and the adverb (the beginning of the ambiguous part of the sentence). Less frequently, readers regressed from the last region (disambiguation+1) directly to the adverb. We argue that both types of strategies are consistent with a selective reanalysis process as described by Frazier and Rayner (1982).     

Aging and individual differences in binding during sentence understanding: Evidence from temporary and global syntactic attachment ambiguities

We report an investigation of aging and individual differences in binding information during sentence understanding. An age-continuous sample of adults (N = 91), ranging from 18 to 81 years of age, read sentences in which a relative clause could be attached high to a head noun NP1, attached low to its modifying prepositional phrase NP2 (e.g., The son of the princess who scratched himself/herself in public was humiliated), or in which the attachment site of the relative clause was ultimately indeterminate (e.g., The maid of the princess who scratched herself in public was humiliated). Word-by-word reading times and comprehension (e.g., who scratched?) were measured. A series of mixed-effects models were fit to the data, revealing: (1) that, on average, NP1-attached sentences were harder to process and comprehend than NP2-attached sentences; (2) that these average effects were independently moderated by verbal working memory capacity and reading experience, with effects that were most pronounced in the oldest participants and; (3) that readers on average did not allocate extra time to resolve global ambiguities, though older adults with higher working memory span did. Findings are discussed in relation to current models of lifespan cognitive development, working memory, language experience, and the role of prosodic segmentation strategies in reading. Collectively, these data suggest that aging brings differences in sentence understanding, and these differences may depend on independent influences of verbal working memory capacity and reading experience.     

Semantic context influences memory for verbs more than memory for nouns

Three experiments revealed that memory for verbs is more dependent on semantic context than is memory for nouns. The participants in Experiment 1 were asked to remember either nouns or verbs from intransitive sentences. A recognition test included verbatim sentences, sentences with an old noun and a new verb, sentences with an old verb and a new noun, and entirely new sentences. Memory for verbs was significantly better when the verb was presented with the same noun at encoding and at retrieval. This contextual effect was much smaller for nouns. Experiments 2 and 3 replicated this effect and provided evidence that context effects reflect facilitation from bringing to mind the same meaning of a verb at encoding and at retrieval. Memory for verbs may be more dependent on semantic context because the meanings of verbs are more variable across semantic contexts than are the meanings of nouns.     

The importance of knowledge in vivid text memory: An individual-differences investigation of recollection and familiarity

The goal of this study was to examine how individual variation in readers’ skills and, in particular, their background knowledge about a text are related to text memory. Recollection and familiarity estimates were obtained from remember and know judgments to text ideas. Recollection estimates to old items were predicted by readers’ background knowledge, but not by other comprehension-related factors, such as word-decoding skill and working memory capacity. False alarms involving recollection of new items (inferences) were diminished as a function of verbal ability, working memory capacity, and reasoning but increased as a function of background knowledge. The results suggest that recollection indexes the reader’s ability to construct a text representation in which text ideas are integrated with relevant domain knowledge. Moreover, these results highlight the importance of background knowledge in explaining individual variation in comprehension and memory for text.     

Eye movements of young and older adults during reading

The eye movements of young and older adults were tracked as they read sentences varying in syntactic complexity. In Experiment 1, cleft object and object relative clause sentences were more difficult to process than cleft subject and subject relative clause sentences; however, older adults made many more regressions, resulting in increased regression path fixation times and total fixation times, than young adults while processing cleft object and object relative clause sentences. In Experiment 2, older adults experienced more difficulty than young adults while reading cleft and relative clause sentences with temporary syntactic ambiguities created by deleting the that complementizers. Regression analyses indicated that readers with smaller working memories need more regressions and longer fixation times to process cleft object and object relative clause sentences. These results suggest that age-associated declines in working memory do affect syntactic processing.     

Limitations on the use of verb information during sentence comprehension

An eye tracking experiment was conducted in order to investigate the role of verb information in resolving structural ambiguity during sentence comprehension. Reading time was measured on sentences containing temporarily ambiguous noun phrases (e.g., “The athlete revealed the problem⊙) that were continued as tensed sentence (S) complements or noun phrase (NP) complements. Ambiguous noun phrases were preceded either by verbs occurring most frequently with NP complements (NPbiased) or verbs occurring most frequently with S complements (S-biased). Reading time was also measured on sentences containing unambiguous S complements preceded by either NP-biased or S-biased verbs. The results showed that contrary to predictions made by verb guidance theories (e.g., constraint satisfaction; MacDonald, Pearlmutter, & Seidenberg, 1994a, 1994b; Trueswell & Tanenhaus, 1994), for both NP- and S-biased verb conditions, sentences containing temporarily ambiguous noun phrase complements were read most quickly, and sentences containing temporarily ambiguous S complements were read more slowly than those containing unambiguous S complements.     

The effects of emotional arousal and gender on the associative memory deficit of older adults

In this study we assessed the potential moderating roles of stimulus type (emotionally arousing) and participants’ characteristics (gender) in older adults’ associative memory deficit. In two experiments, young and older participants studied lists that included neutral and emotionally arousing word pairs (positive and negative) and completed recognition tests for the words and their associations. In Experiment 1, the majority of the word pairs were composed of two nouns, whereas in Experiment 2 they were composed of adjective–noun pairs. The results extend evidence for older adults’ associative deficit and suggest that older and younger adults’ item memory is improved for emotionally arousing words. However, associative memory for the word pairs did not benefit (and even showed a slight decline) from emotionally arousing words, which was the case for both younger and older adults. In addition, in these experiments, gender appeared to moderate the associative deficit of older adults, with older males but not females demonstrating this deficit.     

汉语主、宾关系从句加工难度及其核心名词生命性效应

采用眼动追踪实验技术,考查了核心名词生命性取向对汉语主、宾关系从句加工难度调节效应。结果显示:(1)核心名词生命性格局对汉语主、宾关系从句的加工难度有着显著调节作用,具体表现为:当主、从句中的核心名词为"生命性-非生命性"格局时,在主句核心名词、核心动词位置,宾语关系从句加工较为容易;当主、从句中的核心名词为"非生命性-生命性"格局时,在上述位置,两种关系从句加工难度差异不显著;(2)汉语主、宾关系从句加工中核心名词生命性效应主要发生在语义信息提取、论元关系建构阶段,体现出汉语语言的特异性。上述结果支持了题元切适性理论。     

Episodic Memory in Adult Age and Effects of Sibship Size and Birth Order: Longitudinal Data

This study examined the effects of sibship size and birth order on episodic memory performance in adulthood and old age. Participants were 1,141 healthy individuals aged 35–80 years, who took part in a longitudinal project on age, health, and memory. Episodic memory measurements over a 5-year interval included tests of recognition (recognition of faces, family names, first names, and nouns) and tests of recall (free recall of sentences, free recall and cued recall of nouns, and recall of activities). Results showed significant effects for both recall and recognition, that is, the smaller the sibship size is for an individual and the earlier born, the better memory performance. These results demonstrate that the effects of sibship size and birth order previously shown in children and adolescents (Belmont and Marolla, Science 182:1096–1101, 1973; Zajonc and Markus, Psych Rev 82:74–88, 1975; Zajonc, Am Psychol 56:490–496, 2001) are robust over time and hold over a large adult range.     

Sentence contexts as facilitators of noun pair learning in children

Fifth graders were asked to learn noun pairs embedded in sentence contexts varied in terms of verb voice and grammatical relations. Also, their ability to reproduce sentence contexts for nouns was examined. Recall was prompted with both first- and final-position nouns. Results indicated that variations in deep structure grammatical relations but not surface structure complexity influenced noun pair retrieval. Subjects' incidental memory for the deep structure of sentences was substantial, suggesting that learners were noticing and making use of the meaningful relations aroused between nouns by the contexts. Various sentence generative strategies involving verb voice and noun prompt position were noted.     

Argument Status and PP-Attachment

Prepositional phrase attachment was investigated in temporarily ambiguous sentences. Both attachment site (noun phrase or verb phrase) and argument status (argument or adjunct) were manipulated to test the hypothesis that arguments are processed differently than adjuncts. Contrary to this hypothesis, some previous research suggested that arguments and adjuncts are initially processed in the same manner, following a general bias to attach prepositional phrases to the verb phrase whenever possible [Clifton, Speer, & Abney (1991) Journal of Memory and Language, 30, 251–271]. The current study supports the hypothesis for differential processing, even during the initial stages of syntactic analysis. In an eye movement experiment, readers spent less first-pass time on argument prepositional phrases (PPs) than adjunct PPs. The results support a view in which a noun’s or verb’s argument structure can facilitate the analysis of its arguments.This research was supported by NSF grants SBR-9729056 and SBR-9720473 to the first author. We gratefully thank Gerry Altmann, Rick Lewis, Brian McElree, Don Mitchell, Neal Pearlmutter, Shari Speer, and Suzanne Stevenson for useful discussions and helpful comments. We would also like to acknowledge the Rutgers University Center for Cognitive Science, where the eye movement data were collected and an initial draft of the paper was written.