Younger and older adults' on-line processing of syntactically ambiguous sentences.

Off-line studies of younger and older adults' processing of syntactically complex sentences have shown that there is a consistent negative relationship between task performance and working memory for older adults. However, it is not evident from these studies whether working memory affects the immediate syntactic analysis of a sentence, off-line processes, or both. In the current study an on-line reading paradigm was used to examine the working memory capacity-constrained sentence processing model from M. C. MacDonald, M. A. Just, and P. A. Carpenter (1992). Working memory span, type of syntactic ambiguity (ambiguous vs. unambiguous), and type of syntactic ambiguity resolution (main verb vs. relative clause) interacted to influence younger and older adults' on-line reading times and off-line sentence comprehension. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

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. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

Task demands and sentence comprehension in patients with dementia of the Alzheimer's type

Patients with dementia of the Alzheimer's type (DAT) and matched normal controls were given three tests of syntactic comprehension in which nonlinguistic visual and memory task demands were varied. In all tasks, subjects were presented spoken semantically reversible sentences with a variety of syntactic structures and required to match the sentence to a picture. In the first experiment, subjects matched the spoken sentence to one of two pictures that appeared either before or immediately following the presentation of the sentence. The target picture depicted the spoken sentence correctly and the foil depicted the reversed thematic roles to those in the sentence (i.e., it was a syntactic foil). The second experiment employed a sentence video-verification task in which subjects were required to determine if the spoken sentence matched a videotaped depiction of the action in the sentence or a syntactic foil. In the third experiment, in different conditions, subjects were required to determine whether the spoken sentence matched a single picture or to choose the picture that matched the sentence from an array of two or three pictures. In this experiment, both lexical and syntactic foils were used. In all tasks, DAT patients were affected by the number of propositions in the presented sentence, but not by the syntactic complexity of the sentence. Control subjects also were unaffected by the syntactic complexity of the sentence; the number-of-proposition effect was present in some experiments in the control population. Comparison of performance across the one-, two-, and three-picture versions of the task showed that the magnitude of the effect of number of propositions increased as the number of pictures in the array increased. In addition, analysis of the data from each of the tasks separately showed that the effect of number of propositions only occurred when subjects were attempting to match the target to a syntactic foil (one-picture version) or to choose between the target and a syntactic foil (two- and three-picture versions). The results support the view that patients with DAT do not have disturbances affecting syntactic processing. In addition, they suggest that the effect of number of propositions arises at a stage of analysis that is partially separate from assigning sentence meaning, such as in holding a representation of the sentence in memory until the pictures can be analyzed and encoded and/or in comparing the results of the picture analysis with a stored representation of the sentence meaning.     

Age, working memory, and on-line syntactic processing in sentence comprehension.

One hundred twenty-seven individuals who ranged in age from18 to 90 years were tested on a reading span test and on measures of on-line and off-line sentence processing efficiency. Older participants had reduced working-memory spans compared with younger participants. The on-line measures were sensitive to local increases in processing load, and the off-line measures were sensitive to the syntactic complexity of the sentences. Older and younger participants showed similar effects of syntactic complexity on the on-line measures. There was some evidence that older participants were more affected than younger participants by syntactic complexity on the off-line measures. The results support the hypothesis that on-line processes involved in recognizing linguistic forms and determining the literal, preferred, discourse-coherent meaning of sentences constitute a domain of language processing that relies on its own processing resource or working-memory system. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Building syntactic structure in speaking

We investigated how people produce simple and complex phrases in speaking using a newly developed immediate recall task. People read and tried to memorize a target sentence, then read a prime sentence, then did a distractor task involving the prime sentence. Despite the delay and activity between memory and recall, people could still recall the target sentence although the syntactic form of the recalled sentence was influenced by the syntactic form of the prime sentence. This result replicates the syntactic priming effect found with other experimental paradigms. Using this task, we tested how people used abstract syntactic plans to produce simple and complex noun phrases. We found syntactic priming both when targets and prime sentences matched in complexity and when they did not match, suggesting that simple and complex noun phrases are built by the same syntactic routines during speech production.     

Effects of adult age and working memory on reasoning and spatial abilities.

Three predictions were derived from the hypothesis that adult age differences in certain measures of cognitive functioning are attributable to age-related reductions in a processing resource such as working-memory capacity. Each prediction received at least some degree of empirical support in a study involving 120 males ranging between 20 and 79 years of age. First, older adults exhibited greater impairments of performance than did young adults when task complexity increased and more demands were placed on the limited processing resources: second, the magnitudes of these complexity effects were highly correlated across verbal (reasoning) and spatial (paper folding) tasks. Finally, statistical control of an index of a working-memory processing resource attenuated the effects of age on the measures of cognitive performance. It was concluded that further progress in understanding the mechanisms of the relation between age and cognitive functioning will require improved conceptualizations of the nature of working memory or other hypothesized mediating constructs. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The sentence-composition effect: Processing of complex sentences depends on the configuration of common noun phrases versus unusual noun phrases.

In 2 experiments, the authors used an eye tracking while reading methodology to examine how different configurations of common noun phrases versus unusual noun phrases (NPs) influenced the difference in processing difficulty between sentences containing object- and subject-extracted relative clauses. Results showed that processing difficulty was reduced when the head NP was unusual relative to the embedded NP, as manipulated by lexical frequency. When both NPs were common or both were unusual, results showed strong effects of both commonness and sentence structure, but no interaction. In contrast, when 1 NP was common and the other was unusual, results showed the critical interaction. These results provide evidence for a sentence-composition effect analogous to the list-composition effect that has been well documented in memory research, in which the pattern of recall for common versus unusual items is different, depending on whether items are studied in a pure or mixed list context. This work represents an important step in integrating the list-memory and sentence-processing literatures and provides additional support for the usefulness of studying complex sentence processing from the perspective of memory-based models. (PsycINFO Database Record (c) 2011 APA, all rights reserved)     

The Relationship Between Age, Verbal Working Memory, and Language Comprehension.

A structural modeling approach was used to examine the relationships between age, verbal working memory (vWM), and 3 types of language measures: online syntactic processing, sentence comprehension, and text comprehension. The best-fit model for the online-processing measure revealed a direct effect of age on online sentence processing, but no effect mediated through vWM. The best-fit models for sentence and text comprehension included an effect of age mediated through vWM and no direct effect of age. These results indicate that the relationship among age, vWM, and comprehension differs depending on the measure of language processing and support the view that individual differences in vWM do not affect individuals' online syntactic processing. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Conjoint and dissociable effects of syntactic and semantic context

Manipulating the semantic relatedness of noun and verb targets in contexts where they are grammatically appropriate or inappropriate allows for simultaneous examination of syntactic and semantic context effects. A lexical-decision experiment showed both a syntactic context effect and a semantic relatedness effect that was stronger in syntactically appropriate conditions. Thus, latencies appeared to be conjointly determined by syntactic and semantic context. In contrast, naming experiments also showed both semantic and syntactic effects, but the syntactic context effect was independent of semantic relatedness and was observed in the virtual absence of sensitivity to semantic anomaly. Thus, syntactic and semantic processing are largely dissociable in the naming task. In conjunction with other findings in the literature, this suggests the existence of an isolable level of syntactic assignment that precedes semantic integration of content words in sentence comprehension.     

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. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Making sense of sentences in schizophrenia: Electrophysiological evidence for abnormal interactions between semantic and syntactic processing.

Event-related potentials to critical verbs were measured as patients with schizophrenia and healthy controls read sentences word by word. Relative to their preceding context, critical verbs were (a) congruous, (b) incongruous and semantically unrelated to individual preceding words (pragmatic-semantic violations), (c) incongruous but semantically related to individual preceding words (animacy-semantic violations), or (d) syntactically anomalous. The N400 was modulated normally in patients, suggesting that semantic integration between individual words within sentences was normal in schizophrenia. The amplitude of the P600 to both syntactic and animacy-semantic violations was reduced in patients relative to controls. The authors suggest that, in schizophrenia, an abnormality in combining semantic and syntactic information online to build up propositional meaning leaves sentence processing to be primarily driven by semantic relationships between individual words. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

The effects of syntactic expectations during reading.

Two experiments examined the effects of knowing the syntactic structure of a sentence before reading it. In Exp I, 24 college students were required to remember a sequence of numbers before reading a sentence displayed at a constant rate. When the syntactic structure was known beforehand, Ss were able to devote more effort to rehearsing the numbers while reading the sentence. Consequently, their recall of the number sequence was superior. In Exp II, 8 undergraduates were timed while reading individual sentences. When the syntactic structure was known beforehand, reading times decreased. Results are explained in terms of linguistic decisions, memory storage during reading, and reading as an interactive process. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Aging, memory load, and resource allocation during reading.

To test the notion that aging brings an inability to self-initiate processing, the authors investigated the effects of memory load on online sentence understanding. Younger and older adults read a series of short passages with or without a simultaneous updating task, which would be expected to deplete resources by consuming memory capacity. Regression analyses of word-by-word reading times onto text variables within each condition were used to decompose reading times into resources allocated to the array of word-level and textbase-level processes needed for comprehension. Among neither the young nor the old were word-level processes disrupted by a simultaneous memory load. However, older readers showed relatively greater levels of resource allocation to conceptual integration than the younger adults when under load, regardless of working-memory span or task priority. These results suggest that the ability to self-initiate the allocation of processing resources during reading is preserved among older readers. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Verbal working memory and sentence comprehension: A multiple-components view.

Semantic and syntactic aspects of sentence comprehension were investigated for 3 patients (aged 61, 65, and 72 yrs) who showed different patterns of performance on short-term memory tasks. On a sentence anomaly judgment task assessing the retention of semantic information, only patient A. B. showed a detrimental effect on comprehension with increases in the number of words to be held in an unintegrated fashion. On judgments of grammatical acceptability, only patient M. W. demonstrated a detrimental effect of increasing the number of words intervening between the words signaling that a sentence was ungrammatical. The results suggest that semantic and syntactic components must be postulated in addition to the phonological and articulatory components of A. D. Baddeley's (1986, 1990) working memory model. Although the phonological, semantic, and syntactic components may be differentially affected by brain damage, the components interact and support each other in normal comprehension. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Experimentally disentangling what's beneficial about elderspeak from what's not.

Three studies evaluated different varieties of elderspeak using a referential communication task. Experiment 1 compared the effects of syntactic simplifications and semantic elaborations. Experiment 2 contrasted syntactic simplifications and prosodic exaggerations. Experiment 3 contrasted 2 different syntactic simplification strategies and 2 different prosodic exaggerations. Providing semantic elaborations and reducing the use of subordinate and embedded clauses benefit older adults and improve their performance on the referential communication task, whereas reducing sentence length, slowing speaking rate, and using high pitch do not. The use of short sentences, a slow rate of speaking, and high pitch resulted in older adults' reporting more communication problems. These experiments validate a version of elderspeak that benefits older adults without sounding patronizing and insulting. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Syntactic prediction in language comprehension: Evidence from either...or.

Readers' eye movements were monitored as they read sentences in which two noun phrases or two independent clauses were connected by the word or (NP-coordination and S-coordination, respectively). The word either could be present or absent earlier in the sentence. When either was present, the material immediately following or was read more quickly, across both sentence types. In addition, there was evidence that readers misanalyzed the S-coordination structure as an NP-coordination structure only when either was absent. The authors interpret the results as indicating that the word either enabled readers to predict the arrival of a coordination structure; this predictive activation facilitated processing of this structure when it ultimately arrived, and in the case of S-coordination sentences, enabled readers to avoid the incorrect NP-coordination analysis. The authors argue that these results support parsing theories according to which the parser can build predictable syntactic structure before encountering the corresponding lexical input. (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Context effects in syntactic ambiguity resolution: Discourse and semantic influences in parsing reduced relative clauses.

Examined how certain types of semantic and discourse context affect the processing of relative clauses that are temporarily ambiguous between a relative clause and a main clause. Three experiments with 104 undergraduates explored whether referential contexts can influence parsing decisions under conditions in which (1) norms are used to establish that the contexts provide constraint at the point of ambiguity and (2) the 2-word format facilitates the availability of the less frequent relative clause structure. Results demonstrate that all types of context can have early effects on syntactic ambiguity resolution during on-line reading comprehension. Results are discussed within a constraint-based framework for ambiguity resolution. (French abstract) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

关系代词That和Which引导的定语从句比较

英语定语从句可以由关系代词that和which引导。一般情况下，两种从句可以通用，但有时只能由that引导，有时只能由which引导。两种从句在句法分布和语义解释上存在着一定的差异。