High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> Previous research has shown that subjects can make up sentences faster from related noun pairs than from unrelated pairs. Two experiments tested the proposal that for the related pairs a subject simply has to access stored information but must make up an appropriate relation for unrelated pairs. In both studies the subjects were asked on some trials to remember a digit preload while they made up their sentences. Contrary to an initial prediction, the latencies were faster rather than slower with a preload. Furthermore, a surprise recall test at the end of Experiment 2 showed that there was no difference in the recall of related and unrelated pairs. The results were interpreted as evidence that semantic work was necessary for both types of noun pairs, and that the subjects did less semantic work with a digit preload. This interpretation was further supported by the finding that with the preload the subjects produced a narrower range of semantic relations between the noun pairs. <s> BIB001 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> Speech and language alterations were assessed in 51 patients with Parkinson9s disease (PD) and 10 patients with dementia of the Alzheimer type (DAT). Thirty-five of the PD patients had no evidence of intellectual impairment on a conventional mental status questionnaire and 16 of the PD patients had dementia syndromes of comparable severity to the DAT patients. DAT produced significantly greater language disturbances, including anomia, decreased information content of spontaneous speech, and diminished word list generation. PD patients had significantly decreased phrase length, impaired speech melody, dysarthria, and agraphia. The results suggest that the dementia of PD is distinguishable from that of DAT: PD patients have prominent motor speech abnormalities, whereas DAT patients exhibit more profound language alterations. <s> BIB002 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> Abstract The hypokinetic dysarthria of Parkinson's disease (PD) has been described extensively. In contrast, patterns of hesitation and the language structure in spontaneous speech of the PD patient have not been investigated, although several studies have shown language-related abnormalities in word naming, word generation, and verbal recall. In the present study, 10 male Parkinson's patients and 10 normal male speakers were compared in a reading and spontaneous speaking paradigm for acoustic and linguistic features. Among acoustic measures, fundamental frequency and relative intensity differentiated PD from control subjects, consistent with reported features of hypokinetic dysarthria. The striking observations among linguistic measures differentiating PD from control subjects were an increase in the number of (a) silent hesitations per minute, (b) abnormally long silent hesitations, (c) words per silent hesitation, (d) open class phrases, and (e) optional open phrases per speech sample, and a decrease in the number of modalizations and interjections. An increase in the number of filled hesitations occurring per minute, as well as a decrease in syntactic complexity separated moderate from mild Parkinson's patients. Our interpretation of the data favors the hypothesis that changes in the structure of spontaneous language production with increasing severity of dysarthria reflect PD patients' adaptation to their disease. <s> BIB003 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> Abstract An analysis of the temporal (prospective) form (silent and filled hesitations, repetitions, incomplete phrases, context-related comments, interjections), syntactic form, and lexical (retrospective) form (verbal deviations, open and closed class phrases) of spontaneous language production of early and middle stage Alzheimer's, Huntington's, and Parkinson's patients was made. Results showed that the language structure was disrupted in each disease, but in different ways. Temporal interruptions of varying types were frequent in the language of Alzheimer's and Huntington's Disease patients; only long-duration silent hesitations were frequent in Parkinson's language samples. Syntactic complexity was reduced in Huntington's Disease. Verbal paraphasias were found in both the language of Alzheimer's patients, as well as moderately advanced Huntington's patients. Closed class phrases were predominant in the language of Alzheimer's patients and Huntington's patients, and open class phrases in the language of Parkinson's patients. Taken together, the results suggest that (1) there is a unique neurolinguistic profile for spontaneous language production for each neurodegenerative disease, (2) pathology of the neostriatum disrupts syntactic organization, (3) adaptive strategies are used to cope with verbal and speech-motor difficulties, and (4) adaptive strategies fail to be effective with increasing disease severity. <s> BIB004 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> Previously published reports of deficits in linguistically oriented tasks were reviewed for both demented and nondemented Parkinson disease (PD) patients in a discussion of the question of whether PD affects language. Additionally, to illustrate the methodological problems inherent in evaluating linguistic competence, the performance on four linguistically oriented tasks of 12 PD patients who scored 8 or better on the Mental Status Questionnaire was compared to that of 32 age- and education-matched control subjects. These tasks, from which a composite variable representing performance was formed, were oral object description, story retelling, the Peabody Picture Vocabulary Test, and the Similarities subtest of the Wechsler Adult Intelligence Scale (WAIS), a test of verbal associative reasoning. After controlling for the effects of disease severity, a significant effect was observed for the presence of PD. However, when the additional effects of performance on the Block Design subtest of the WAIS were controlled, the PD effect was of borderline significance. These results typify those in the literature, that is, whereas nondemented PD patients can be demonstrated to perform significantly more poorly on linguistically oriented tasks, the performance deficit cannot be conclusively demonstrated to result from a language deficit per se. <s> BIB005 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> Abstract This study examined the grammatical content of written sentences elicited from 96 Parkinson's patients, 30 Parkinson's with dementia patients and 167 control subjects. Parkinson's patients without dementia or with mild dementia presented no impairments in sentence length, syntactic complexity or amount of information content. Moderately demented Parkinson's patients showed reduced sentence length and information content but normal syntactic complexity. This pattern of results provides evidence that lexical-semantic content is more susceptible to decline than syntactic structure with the progression of dementia in Parkinson's disease. <s> BIB006 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> The purpose of this study was to investigate the presence and nature of spoken language deficits in Huntington's (HD) and Parkinson's (PD) diseases. Specifically, the study examined whether (a) the... <s> BIB007 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> Four language sample measures as well as measures of vocabulary, verbal fluency, and memory span were obtained from a sample of young adults and a sample of older adults. Factor analysis was used to analyze the structure of the vocabulary, fluency, and span measures for each age group. Then an extension analysis was performed by using structural modeling techniques to determine how the language sample measures were related to the other measures. The measure of grammatical complexity was associated with measures of working memory including reading span and digit span. Two measures, sentence length in words and a measure of lexical diversity, were associated with the vocabulary measures. The fourth measure, propositional density, was associated with the fluency measures as a measure of processing efficiency. The structure of verbal abilities in young and older adults is somewhat different, suggesting age differences in processing efficiency. <s> BIB008 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Message Level. <s> Experimental studies of sentence production in Parkinson disease (PD) are rare. This study examined the relationship between cognitive abilities and performance on two sentence production tasks, sentence repetition, and sentence generation, in which complexity was manipulated. Thirty-eight older adults aged 60 to 85, half with PD, completed the two language tasks plus a cognitive battery. Participants with PD performed more poorly in the repetition task overall, especially in fluency, but differences were no longer significant once cognitive ability was controlled. In contrast, on the sentence generation task the PD group was significantly impaired on all language dimensions and overall performance. Although cognitive ability accounted for significant variance in all measures of sentence generation, the PD group remained significantly impaired when these factors were controlled. These findings suggest that, although language production is influenced by cognitive abilities, it can be significantly impaired in PD over and above the effects of differences in cognitive abilities. <s> BIB009
In general, the production of any intentional utterance begins with the activation of an idea or message to be communicated. Deficits at this stage of the production process would lead to reductions in information content, shorter sentences, and/or empty speech. In previous studies in healthy populations, information content has been statistically associated with working memory BIB001 and processing speed BIB008 . In the studies described above, there seems to be general agreement that information content is reduced in PD across various language tasks, including conversational discourse, picture description tasks, and written sentences BIB002 BIB007 BIB006 BIB005 . These deficits likely represent limitations in activation at the message level of sentence production BIB009 BIB004 BIB003 . Small et al. BIB006 and Murray BIB007 reported decreases in content associated with increasing dementia. Our study BIB009 reported that education, working memory and executive function all contributed significantly to information content in nondemented individuals with PD; furthermore, the groups differed even when these cognitive differences were accounted for. Therefore, limitations in information production may represent a primary characteristic of PD, occurring even in the absence of cognitive impairment.