Sentence Comprehension Difficulty Research Articles

Inference and sentence comprehension in children with specific or pragmatic language impairments

Children with language impairments have difficulty in reporting verbal inferences, but it is unclear whether the source of this problem lies in limitations of language comprehension, an inability to access world knowledge, or the integration of information in discourse. Children with pragmatic language impairments (CwPLI) are often described as having disproportionate difficulty with verbal inference, although there is little empirical support for this view. To examine the performance of children with specific language impairment (CwSLI), CwPLI and a control group with typical language development (CwTLD) on a verbal inferential comprehension task; to explore whether CwPLI's verbal inferential comprehension performance are disproportionate to their sentence comprehension difficulties; and to analyse inferential error types made by the three groups. Sixty-four children with language impairments (CwLI), aged between 6 and 11 years, participated in an inference comprehension task (IC) and a task of sentence comprehension (SC). For the purpose of analysis, the LI group was then split into two subgroups: CwPLI and CwSLI, using a checklist of pragmatic features. A group of CwTLD were matched to LI children on SC ability and gender; a separate group of CwTLD (CA) was matched to CwLI by age and gender. CwLI had lower raw scores on the IC task than CA-matched CwTLD, but similar scores to SC-matched CwTLD. CwPLI produced lower raw IC scores than CwSLI, and this was the same when age and SC performance were controlled for. CwSLI performed similarly to their SC-matched and CA-matched control subjects on the IC task. CwPLI scored significantly less on the IC task than both their SC-matched and CA-matched control subjects. A regression analysis showed that age and SC ability account for 36% of the variance on the IC task, but group (SLI versus PLI) status accounts for just 5%. A detailed analysis of error types and item performance on the IC task showed a trend for CwPLI to perform more poorly on developmentally more complex inference items, but there was no evidence for a unique pattern of inference errors in CwPLI. Children with language impairments tend to perform like younger children with matched level of sentence comprehension ability on a verbal inference comprehension task. CwPLI have more difficulty with this task than CwSLI, but the distribution of scores shows considerable overlap exists between clinical groups. Sentence comprehension ability, age and, to a lesser extent, group status contribute to verbal inferencing ability in children with language impairments, but other factors may be important. The implications for assessment and intervention are discussed.

Parsing costs as predictors of reading difficulty: An evaluation using the Potsdam Sentence Corpus

The surprisal of a word on a probabilistic grammar constitutes a promising complexity metric for human sentence comprehension difficulty. Using two different grammar types, surprisal is shown to have an effect on fixation durations and regression probabilities in a sample of German readers’ eye movements, the Potsdam Sentence Corpus. A linear mixed-effects model was used to quantify the effect of surprisal while taking into account unigram frequency and bigram frequency (transitional probability), word length, and empirically-derived word predictability; the socalled “early” and “late” measures of processing difficulty both showed an effect of surprisal. Surprisal is also shown to have a small but statistically non-significant effect on empirically-derived predictability itself. This work thus demonstrates the importance of including parsing costs as a predictor of comprehension difficulty in models of reading, and suggests that a simple identification of syntactic parsing costs with early measures and late measures with durations of post-syntactic events may be difficult to uphold.

Sentence comprehensionin Parkinson's disease.

Parkinson’s disease (PD) patients with dementia have impairment of syntactic comprehension. Non-demented PD patients also experience difficulties in sentence comprehension and can be particularly impaired in the processing of grammatical characteristics of syntactically complex sentences.ObjectiveThe aim of this study was to verify the performance of PD patients without dementia in a syntactic comprehension task compared with normal elderly.MethodsWe studied oral sentence comprehension in fourteen patients with idiopathic PD together with fourteen controls matched for age and education, using the Token Test and Schmitt’s Syntactic Comprehension Test (developed in Brazilian Portuguese).ResultsFor the Token Test, there was no statistically significant difference between the PD group and the control group, whereas on the Syntactic Comprehension Test there was a slight statistically significant difference between the groups only for relatives in subject clauses (p=0.0407).ConclusionsPD patients differed from controls in the oral comprehension for relatives subject sentences alone. These results did not strictly reproduce those previously reported in the literature, and therefore point to the need for creating tests with diverse syntactic constructions in Portuguese able to produce consistent data regarding language behavior of Brazilian subjects with PD in comprehension tasks.

The speed of lexical activation is altered in Parkinson's disease

Disturbed comprehension of complex noncanonical sentences in Parkinson's disease (PD) has been linked to dopamine depletion and delayed lexical retrieval. The aim of the present study was to replicate findings of delayed lexical activation in PD patients with noncanonical sentence processing difficulties, and investigate the influence of dopamine depletion on these changes to lexical access. In the first experiment, 20 patients with PD (tested whilst ‘on’ dopaminergic medication) and 23 controls participated in a list priming experiment. In this paradigm, stimuli are presented as a continuous list of words/nonwords, and semantic priming effects were measured across inter-stimulus intervals (ISIs) of 500 ms, 1000 ms and 1500 ms, with data analyzed using multivariate analyses of variance. The results revealed longer delays in lexical activation for PD patients with poor comprehension of noncanonical sentences, suggesting that the speed of lexical access may be compromised in PD, and that this feature may contribute to certain sentencecomprehension difficulties. In the second experiment, 7 patients with PD who participated in the first experiment, performed the same lexical decision task while ‘off’ their dopaminergic medication. Semantic priming effects were measured across ISIs of 500 ms and 1500 ms. Within group comparisons revealed a different pattern of semantic priming for the PD patients when ‘on’ compared to ‘off’ medication, providing further support for a dopaminergic influence on the speed of information processing and lexical activation.

Sentence comprehension and general working memory

Although the role of working memory in sentence comprehension has received substantial attention, the nature of this relationship remains unclear. The purpose of this study was to examine the interaction between general, nonverbal working memory (WM) and sentence parsing (SP) in normal English‐speaking adults. Accuracy and reaction times were recorded for thirty‐one young adults during three on‐line tasks: nonverbal WM, SP plausibility, and lexical decision (LD). A significant positive correlation was observed between reaction times for WM and SP, but not between LD and SP. These results suggest that SP may be supported by a general WM capacity, and therefore, some sentence comprehension difficulties observed in the clinical population may potentially be related to impairment in general WM.

Summation of semantic priming and complex sentence comprehension in Parkinson's disease

Research has suggested that the integrity of semantic processing may be compromised in Parkinson's disease (PD), which may account for difficulties in complex sentence comprehension. In order to investigate the time course and integrity of semantic activation in PD, 20 patients with PD and 23 healthy controls performed a lexical decision task based on the multi-priming paradigm. Semantic priming effects were measured across stimulus onset asynchronies of 250 ms, 600 ms, and 1200 ms. Further, PD participants performed an auditory comprehension task. The results revealed significantly different patterns of semantic priming for the PD group at the 250-ms and 1200-ms SOAs. In addition, a delayed time course of semantic activation was evident for PD patients with poor comprehension of complex sentences. These results provide further support to suggest that both automatic and controlled aspects of semantic activation may be compromised in PD. Furthermore, the results also suggest that some sentence comprehension deficits in PD may be related to a reduction in information processing speed.

A longitudinal study of sentence comprehension difficulty in primary progressive aphasia

Context: Patients with primary progressive aphasia have sentence comprehension difficulty, but the longitudinal course of this deficit has not been investigated. Objective: To determine how grammatical, single word meaning, and...

Sentence Processing in Frontotemporal Dementia

Patients with frontotemporal dementia (FTD) have sentence comprehension difficulty. We examined the hypothesis that both grammatical and resource factors contribute to their impaired sentence comprehension with a traditional, off-line sentence comprehension task, and an on-line sentence processing procedure that minimizes task-related resources. This was investigated in subgroups of FTD patients with Progressive Non-fluent Aphasia (PNFA; n = 5) who have effortful speech; non-aphasic patients with an executive deficit (EXEC; n = 8); and Semantic Dementia (SD; n = 3) patients with poor single word comprehension. The results were correlated with measures of executive resources. We found that PNFA patients are significantly impaired in their off-line sentence comprehension, and that their performance correlated with auditory-verbal short-term memory. PNFA patients also demonstrated a pattern of slowed processing for the on-line sentence measure. This is consistent with the hypothesis that information relevant for constructing sentence representations during comprehension degrades in working memory as it is activated over an abnormally slowed time course. EXEC patients had modest off-line sentence comprehension difficulty, and this correlated with performance on measures of working memory, planning, and inhibitory control. On-line processing in EXEC patients demonstrated their insensitivity to sentence-based information. This raises the possibility that a limitation in material-neutral executive resources not dedicated to grammatical processing may play a role in their sentence comprehension deficit. SD patients' pattern of on-line sentence comprehension paralleled control subjects' performance. We conclude that grammatical and executive components both contribute to sentence comprehension, and that the profile of sentence comprehension difficulty varies across FTD subgroups depending on the sentence processing component that is impaired.

Expression of syntactic complexity in sentence comprehension: A comparison between dyslexic and regular readers

The present study was designed to investigate the influence of syntactic complexity on sentence comprehension in Hebrew. Participants were 40 native Hebrew-speaking 5th grade dyslexic and normally reading children aged 10–11 years. Children’s syntactic abilities were tested by three experimental measures: syntactic judgment, a sentence-picture matching task, and a sentence correction task. Each task consisted of sentences composed of five syntactic constructions varying in the level of syntactic complexity (active, passive, conjoined, object-subject relative, and subject-object relative). The length of sentences and the number of propositions in the sentences were controlled. In addition, a wide range of the children’s reading and general abilities (e.g., reading comprehension, phonological awareness, and working memory) was examined. The results indicated that dyslexic readers were less accurate and slower than good readers in all reading tasks and in the tasks on sentence comprehension. The findings suggest that the factor of syntactic complexity seems to be a relatively independent aspect of sentence comprehension. This aspect of sentence comprehension is probably not affected in dyslexic readers. Rather, processing deficit related to phonological and memory impairments of dyslexic children and their ability to process syntactic information is responsible for the difficulties in sentence comprehension.

Sentence comprehension in children with specific language impairment: effects of input rate and phonological working memory.

Many children with specific language impairment (SLI) exhibit sentence comprehension difficulties. In some instances, these difficulties appear to be related to poor linguistic knowledge and, in other instances, to inferior general processing abilities. Two processing deficiencies evidenced by these children include reduced linguistic processing speed and diminished phonological working memory (PWM) capacity. While providing children with SLI a slower input rate appears to facilitate their immediate (real-time) processing of language; it is not known whether such a manipulation might also promote better offline (conventional) sentence comprehension. Complicating the potential benefits of a slower input rate on these children's offline comprehension is that a slower input rate might negatively interact with their PWM deficit. That is, a slower presentation rate may have the unintended consequence of placing too great a temporal burden on these children's vulnerable PWM system, thereby leading to even poorer comprehension. That is, a slower input rate presumably requires the listener to store previously processed information for a longer period while new, incoming material is being processed. To investigate the interaction of input rate and PWM capacity on the sentence comprehension of children with SLI. It was hypothesized that if a slower input rate negatively affects the PWM functioning of children with SLI, these children would comprehend significantly fewer sentences presented at a slower rate versus sentences presented at a normal rate. It was also hypothesized that input rate should have no differential effect on the typically developing control children. A group of 12 school-age children with SLI, a group of 12 age-matched children (CA), and a group of 12 receptive syntax-matched (RS) children (all with normal-range non-verbal IQ and hearing) completed a conventional picture-pointing sentence comprehension task. Sentences were presented at a normal speaking rate and a slower rate (25% time expanded). Children also completed a non-word repetition task, which served as an index of PWM capacity. Results of the PWM task revealed that the children with SLI repeated fewer three- and four-syllable non-words than both the CA and RS children, suggesting they had reduced PWM capacity. On the sentence comprehension task, a significant group by input rate interaction emerged. The children with SLI yielded significantly poorer comprehension of normal-rate sentences compared with both the CA and RS children. Whereas input rate had no differential effect on CA and RS children's comprehension, the comprehension of the children with SLI improved to the level of RS children in the slow-rate condition. Correlational analyses showed no significant association between PWM and sentence comprehension in either rate condition for any of the groups. Together, these findings suggest that the simple manipulation of altering speaking rate to children with SLI indeed can facilitate sentence comprehension, with no apparent detrimental effect on the operations of their PWM system.

Attentional resource and processing speed limitations during sentence processing in Parkinson’s disease

Several studies have suggested that patients with Parkinson’s disease (PD) have sentence comprehension difficulty in part because of their limited executive resources. However, these assessments confound the executive resources contributing to sentence comprehension with the resources needed for task performance. In the present study, we used a word detection technique that minimizes task demands in order to evaluate attentional and processing speed resources during the comprehension of simple sentences without subordinate clauses and sentences containing subject-relative and object-relative center-embedded subordinate clauses. We found that PD patients have poor sensitivity to phonetic errors embedded in unbound grammatical morphemes, regardless of the clausal structure of the sentence, suggesting difficulty attending to grammatical morphemes. We also found that PD patients are significantly slowed in their sensitivity to phonetic errors in content words embedded in object-relative center-embedded sentences. Slowed sensitivity to content words in object-relative sentences was correlated with timed executive measures of planning. On a traditional measure of comprehension, these PD patients were impaired for sentences containing object-relative center-embedded clauses compared to sentences with subject-relative center-embedded clauses, and comprehension of object-relative sentences was correlated with executive measures. Our findings are consistent with the claim that limited executive resources for strategic attention and processing speed contribute to the sentence comprehension difficulties of PD patients.

Grammatical and resource components of sentence processing in Parkinson’s disease

Sentence comprehension requires linguistic processing as well as cognitive resources such as working memory (WM) and information-processing speed (IPS). The authors hypothesize that sentence comprehension difficulty in patients with mild PD is due to degradation of the large-scale neural network that supports cognitive resources during sentence processing. To understand the neural basis for sentence comprehension difficulty in PD. Regional brain activity with blood oxygenation level-dependent fMRI was monitored while seven PD patients and nine healthy seniors answered a simple probe about written sentences that vary in their grammatical and cognitive resource properties. Healthy seniors recruited posterolateral temporal and ventral inferior frontal regions of the left hemisphere, brain regions associated with grammatical processing that were also activated by PD patients. Healthy seniors also recruited left dorsal inferior frontal, right posterolateral temporal, and striatal regions that are associated with cognitive resources during sentence processing. Direct contrasts showed that striatal, anteromedial prefrontal, and right temporal regions are recruited to a significantly lesser degree in PD, but these patients have increased activation of right inferior frontal and left posterolateral temporal-parietal areas during sentence comprehension. These findings associate impaired sentence comprehension in PD with interruption of a large-scale network important for cognitive resources during sentence processing. These results also imply compensatory up-regulation of cortical activity that allows patients with mild PD to maintain sentence comprehension accuracy.

Neural basis for sentence comprehension deficits in frontotemporal dementia

Many patients with frontotemporal dementia (FTD) have impaired sentence comprehension. However, the pattern of comprehension difficulty appears to vary depending on the clinical subgroup. The purpose of this study was to elucidate the neural basis for these deficits in FTD. We studied patients with two different presentations: Three patients with Progressive Non-Fluent Ahasia (PNFA), and five non-aphasic patients with a dysexecutive and social impairment (EXEC). The FTD patient subgroups were compared to a cohort of 11 healthy seniors with intact sentence comprehension. We monitored regional cerebral activity with blood oxygen level dependent (BOLD) functional magnetic resonance imaging (fMRI) while subjects read sentences featuring both a grammatically complex object-relative center-embedded clause and a long linkage between the head noun phrase (NP) and the gap where the NP is interpreted in the center-embedded clause. Subjects decided whether the agent of the action is a male or a female. Healthy seniors activated both ventral portions of inferior frontal cortex (vIFC) and dorsal portions of IFC (dIFC) in the left hemisphere, often associated with grammatical and working memory components of these sentences, respectively. PNFA patients differed from healthy controls since they have reduced activation of left vIFC, while EXEC patients have less recruitment of left dIFC. We conclude that FTD subgroups have distinct patterns of sentence comprehension difficulty in part because of selective interruptions of a large-scale neural network for sentence processing.

Assessing Resource Demands during Sentence Processing in Parkinson's Disease

Patients with Parkinson's disease (PD) have sentence comprehension difficulty, but it is unclear whether this is due to a deficit in grammatical processing or to an executive resource limitation. To assess grammatical processing in PD while minimizing task-related demands, PD patients and healthy control subjects performed a word detection procedure that assesses sensitivity to grammatical agreements in sentences in an “on-line” fashion. With this technique, we found that control subjects and PD patients are equally sensitive to grammatical agreement violations in sentences. A traditional, resource-demanding measure of sentence comprehension was also administered to the same PD patients. In comparison to healthy controls, PD patients were significantly impaired in their relative comprehension of sentences containing object-gap subordinate clauses compared to subject-gap subordinate clauses. Performance on several executive resource measures was also impaired in PD, and this correlated with their comprehension performance. Sensitivity to grammatical agreements with the word detection procedure, in the context of sentence comprehension difficulty on a traditional measure, suggests that PD patients' executive resource limitations contribute to their sentence comprehension difficulty.

Information processing speed and sentence comprehension in Parkinson's disease.

This study tests the hypothesis that sentence comprehension difficulty in Parkinson's disease (PD) is related in part to altered information processing speed that plays a crucial role in grammatical processing. The authors measured information processing speed in 32 PD patients without dementia using a lexical list-priming paradigm in which the interstimulus interval (ISI) between the prime and the target varied. Sentence comprehension accuracy was also assessed in 22 of these patients. Sentence comprehension accuracy for object-relative center-embedded sentences was impaired in a subgroup of PD patients. This subgroup of PD patients primed at an abnormally long ISI. Similarly, only PD patients who primed at a long ISI had greater difficulty understanding sentences with an object-relative clause than a subject-relative clause. Findings suggest that slowed information processing speed contributes to sentence comprehension difficulty in PD.

Cognitive Resource Limitations during Sentence Comprehension in Parkinson's Disease

Patients with idiopathic Parkinson's disease (PD) were asked to identify the agent of the action in orally presented sentences with subject-relative or object-relative center-embedded clauses while simultaneously performing a secondary task that was less resource-demanding (finger tapping) or more resource-demanding (recognition span). We found that a subgroup of PD patients with impaired sentence comprehension at baseline (no secondary task) did not differ from random in their accuracy understanding all types of sentences during the more demanding (recognition span) condition and also had difficulty understanding the most complex sentences during the less demanding (finger tapping) condition. Control subjects and PD patients without baseline sentence comprehension difficulty were random only in their comprehension of the most complex sentences under the more demanding (recognition span) secondary task condition. Examination of response latencies for accurately understood sentences revealed only an effect for the type of sentence, and this was equally evident across all groups of subjects and regardless of the condition under which the sentences were administered. The sensitivity of PD patients' sentence comprehension accuracy to secondary task resource demands is most consistent with the hypothesis that limited cognitive resources contribute to sentence comprehension difficulty in PD.

The Effects of Case Marking Information on Korean Sentence Processing

Two experiments were conducted to determine whether a parser's on-line processes are affected by manipulation of case markings in Korean sentence processing, and to evaluate the usefulness of a Ranked Flagged Serial Parser (RFSP) model in predicting Korean ambiguity resolution processes. By using a self-paced word-by-word reading task, in Experiment 1, relative and coordinate sentences of the form NP-ka (nominative), NP-lul (accusative), and Verb were compared to those sentences of the form NP-nun (topic marker), NP-lul, and Verb. In Experiment 2, relative sentences that have NP-ka, NP-ka, and Verb sequence were compared to those sentences of NP-nun, NP-ka, and Verb sequence. In addition, reversed relative clause sentences were compared after changing case markings of the last NP. The topic marker -nun changed overall patterns of word-by-word reading times of the sentences in both experiments. The results clearly showed that local grammatical cues, such as case markings, are used in generating syntactic hypotheses. We also found that the RFSP model successfully predicted local processing loads and reparsing difficulties in Korean sentence comprehension. Suggestions for further studies were made.

Sentence Processing in Parkinson's Disease

Parkinson's disease (PD) is a neurodegenerative condition that is associated with the depletion of dopamine (DA)-containing neurons in specific brain regions. This article reviews one consequence of this defect—sentence comprehension difficulty in nondemented patients with PD. The first section describes the pattern of cognitive deficits seen in patients with PD, focusing specifically on their difficulties with language processing. Subsequent sections relate the profile of cognitive impairments in PD to studies investigating compromised DA metabolism in fronto-striatal brain regions. The findings suggest that the sentence comprehension deficit in PD is due in large part to limitations in the strategic distribution of cognitive resources such as selective attention that contribute to the processing of complex material. The physiological basis for this deficit appears to be associated with the disruption of a fronto-striatal cerebral network that is compromised following degradation of the DA projection system.

Language comprehension profiles in Alzheimer's disease, multi-infarct dementia, and frontotemporal degeneration

We assessed language functioning in 116 age-, education-, and severity-matched patients with the clinical diagnosis of Alzheimer's disease (AD), multi-infarct dementia (MID) due to small-vessel ischemic disease, or a frontotemporal form of degeneration (FD). Assessments of comprehension revealed that patients with AD are significantly impaired in their judgments of single word and picture meaning, whereas patients with FD had sentence comprehension difficulty due to impaired processing of grammatical phrase structure. Patients with MID did not differ from control subjects in their comprehension performance. Traditional aphasiologic measures did not distinguish between AD, MID, and FD. Selective patterns of comprehension difficulty in patients with different forms of dementia emphasize that language deficits cannot be explained entirely by the compromised memory associated with a progressive neurodegenerative illness.

Sentence comprehension in Parkinson's disease: The role of attention and memory

Sentence comprehension is a complex process involving at least attentional, memory, grammatical, and semantic components. We report three experiments designed to evaluate the impairments underlying sentence comprehension difficulties in nondemented patients with Parkinson's disease (PD). In the first experiment, we asked patients to answer simple questions about sentences which varied in terms of grammatical complexity and semantic constraint. We found that PD patients are significantly compromised in their ability to perform this task. Their difficulties became more prominent as grammatical complexity increased, but they were significantly assisted by semantic constraints that limited possible interpretations of a sentence. Analyses of individual patient profiles revealed heterogeneous performance across the group of PD patients and somewhat inconsistent performance for patients across testing sessions. In the second experiment, we tested the possibility that patients' heterogeneous performance on the sentence comprehension task is due to an impairment in memory or attention, cognitive domains known to be compromised in some PD patients. Although PD patients and control subjects differed on one memory measure, there were no significant correlations between attention and memory performance and the results of the sentence comprehension task. In the final experiment, we manipulated the sentences used in the first experiment in a fashion that stressed the need for memory and attention in a sentence. The results indicated that PD patients are significantly compromised in their ability to attend to certain critical grammatical features of a sentence. A regression analysis identified specific grammatical, semantic, and attentional mechanisms as significant contributors to PD patients' overall sentence comprehension, accounting for over 97% of the variance in their performance. We conclude that there are multiple sources of cognitive difficulty underlying PD patients' sentence comprehension impairment.