High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <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> BIB001 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> In Speaking, Willem "Pim" Levelt, Director of the Max-Planck-Institut fur Psycholinguistik, accomplishes the formidable task of covering the entire process of speech production, from constraints on conversational appropriateness to articulation and self-monitoring of speech. Speaking is unique in its balanced coverage of all major aspects of the production of speech, in the completeness of its treatment of the entire speech process, and in its strategy of exemplifying rather than formalizing theoretical issues. <s> BIB002 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> Methodological problems have been a longstanding barrier to the systematic exploration of issues in language production. Recently, however, production research has broadened beyond traditional observational approaches to include a diverse set of experimental paradigms. This review surveys the observational and experimental methods that are used to study production, the questions to which the methods have been directed, and the theoretical assumptions that the methods embody. Although tailored to the investigation of language production, most of the methods are closely related to others that are widely employed in cognitive research. The common denominator of these procedures is verbal responding. Because the processing complexities of verbal responses are sometimes overlooked in research on memory, perception, attention, and language comprehension, the methodological assumptions of production research have implications for other experimental procedures that are used to elicit spoken words or sentences. <s> BIB003 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <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> BIB004 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> Preparing words in speech production is normally a fast and accurate process. We generate them two or three per second in fluent conversation; and overtly naming a clear picture of an object can easily be initiated within 600 msec after picture onset. The underlying process, however, is exceedingly complex. The theory reviewed in this target article analyzes this process as staged and feedforward. After a first stage of conceptual preparation, word generation proceeds through lexical selection, morphological and phonological encoding, phonetic encoding, and articulation itself. In addition, the speaker exerts some degree of output control, by monitoring of self-produced internal and overt speech. The core of the theory, ranging from lexical selection to the initiation of phonetic encoding, is captured in a computational model, called weaver ++. Both the theory and the computational model have been developed in interaction with reaction time experiments, particularly in picture naming or related word production paradigms, with the aim of accounting for the real-time processing in normal word production. A comprehensive review of theory, model, and experiments is presented. The model can handle some of the main observations in the domain of speech errors (the major empirical domain for most other theories of lexical access), and the theory opens new ways of approaching the cerebral organization of speech production by way of high-temporal-resolution imaging. <s> BIB005 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <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> BIB006 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <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> BIB007 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> This study examined syntactic changes in the spoken discourse of patients with Huntington's (HD) or Parkinson's disease (PD) and explored possible relationships between their syntactic changes and concomitant cognitive and motoric symptoms. Patient and control groups participated in a conversational discourse activity and completed a battery of standardized speech and cognitive tests. The HD group used shorter and fewer grammatically complete utterances than their healthy, age-matched peers, whereas there were no significant syntactic differences between PD patients and their healthy, age-matched peers or between PD and HD patients. Productive syntax abilities in HD and PD were meaningfully related to both neuropsychological and motor speech changes. These findings indicate that patients with subcortical disease, at least those with HD, may present with language production deficits and that these deficits are most likely the product of not only motor speech limitations (i.e., dysarthria) but also underlying cognitive impairments. <s> BIB008 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> A discussion of modularity in language production processes, with special emphasis on processes for retrieving words and building syntactic structures for a to-be-uttered sentence, is presented. The authors' 1st goal was to assess the extent to which information processing is encapsulated between different processing stages. In particular, they assessed whether the input from one processing stage to the next is minimal and whether the flow of information in the system is strictly unidirectional. On the basis of the reviewed evidence, they conclude that both assumptions have to be revised. Their 2nd goal was to propose an alternative framework that does not assume strict encapsulation but that maintains multiple levels of integration for production. <s> BIB009 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> Young and older adults provided language samples in response to elicitation questions while concurrently performing different tasks including walking, , finger tapping, and ignoring speech or noise. The language samples were scored on three dimensions: fluency, grammatical complexity, and content. The hypothesis that working memory limitations affect speech production by older adults was tested by comparing language samples collected during a baseline condition with those produced while the participants were performing the concurrent tasks. There were baseline differences: older adults’ speech was less fluent and less complex than young adults’ speech. Young adults adopted a different strategy in response to the dual task demands than older adults; they reduced sentence length and grammatical complexity while performing the concurrent tasks. In contrast, older adults shifted to a reduced speech rate in the dual task conditions. <s> BIB010 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> Twenty-six subjects with idiopathic Parkinson's disease (PD) and normal cognitive status (as measured by the Mini-Mental State Examination) were examined with a battery of tests selected to reveal subtle and/or high-level language impairments. The test battery included 'repetition of long sentences', 'recreating sentences', 'making inferences', 'comprehension of logico-grammatical sentences', 'comprehension of ambiguous sentences' and 'comprehension of metaphors', 'word definitions', 'word fluency', 'naming', 'sentence analysis' and 'morphological completion'. Comparisons were made between the PD subjects and 26 control subjects matched for age, gender and level of education. Significant differences in performance between the PD subjects and the control subjects were found in the ability to make inferences and to analyse sentences (state the correct number of words in a read sentence). An additional four subjects with different degrees of cognitive dysfunction were also investigated and were found to have... <s> BIB011 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> The current study examines whether young and older adults have similar preferences for animate-subject and active sentences, and for using the order of activation of a verb's arguments to determine sentence structure. Ninetysix participants produced sentences in response to three-word stimuli that included a verb and two nouns differing in animacy. Dependent variables included accuracy, sentence structure produced, and production times for active vs. passive sentences. Neither group shows a strict preference for active sentences, but the two groups are differentially sensitive to animacy and the order of noun activation. Results suggest that sentence structure choice is a probabilistic, constraint-satisfaction process during which these factors interact. <s> BIB012 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> In order to study the role of working memory in sentence formulation, we elicited errors of subject-verb agreement in spoken sentence completion, while speakers did or did not maintain an extrinsic memory load (a word list). We compared participants with low and high speaking spans (a measure of verbal working memory for sentence production). As in previous studies, agreement errors occurred more frequently for sentence fragments with a singular subject noun and a plural noun than for corresponding fragments in which both nouns were singular. Agreement errors also occurred more frequently when the fragment had a distributive interpretation, so that the conceptual number of the subject mismatched its grammatical number, than when the fragment was not distributive. Importantly, there were effects of memory span and of memory load, and these variables interacted: Load affected only low-span speakers. Distributivity did not interact with either load or span. These data establish that a pivotal syntactic planning process is affected by verbal working memory limitations. As such, they constrain existing proposals about the role of working memory in language production. <s> BIB013 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> ABSTRACT The costs of doing two things were assessed for a group of healthy older adults and older adults who were tested at least 6 months after a stroke. A baseline language sample was compared to language samples collected while the participants were performing concurrent motor tasks or selective ignoring tasks. Whereas the healthy older adults showed few costs due to the concurrent task demands, the language samples from the stroke survivors were disrupted by the demands of doing two things at once. The dual task measures reveal long-lasting effects of strokes that were not evident when stroke survivors were assessed using standard clinical tools. <s> BIB014 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <s> Nine early non-demented bilingual (L1 – Friulian, L2 – Italian) patients with Parkinson’s disease and nine normal controls matched for age, sex and years of education were studied on a spontaneous language production task. All subjects had acquired L1 from birth in a home environment and L2 at the age of six at school formally. Patients with PD evidenced more phonological, morphological and syntactic errors in L1 than in L2. The opposite pattern was observed in normal controls as far as grammar was concerned. These findings suggest that implicit language processing is more impaired than explicit language processing in Parkinson’s disease. <s> BIB015 </s> High-Level Language Production in Parkinson's Disease: A Review <s> The Functional Level of Processing. <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> BIB016
During the functional level of processing, the conceptual message activates the abstract representations of the word or words that have the greatest meaning overlap with the message BIB003 . Activation of these abstract word representations, often called lemmas BIB002 BIB005 BIB009 , leads to the concomitant activation of grammatical information about the word, such as the argument structure of a verb BIB012 or grammatical gender in French or Italian BIB009 . Sentence generation differs fundamentally from single word production in that at the functional level, the meanings and grammatical requirements of several words must be activated simultaneously and, importantly, integrated into a structure that conserves all the meaningrelevant information in the message (e.g., tense, aspect, definiteness of nouns, thematic roles of nouns, and perhaps even focus). This logic suggests that executive function resources may be required for computation of grammaticality. Impairments at the functional level of processing that affect lemma selection could lead to semantic paraphasias (i.e., off-target word choices), disfluency, or incoherence. Impairments in the selection of verbs, however, would have a more pervasive impact on sentence and discourse production than impairments of noun selection, because of the importance of verbs to sentence structure BIB012  BIB002 . As discussed briefly above, the verb is the primary determinant of the structure of a sentence in English and many other languages, because verbs place specific constraints on what types of nouns can act as their subjects and objects. Verbs also serve as constraints on how the resulting sentences are interpreted BIB012 BIB002 . For example, when using the verb to bore, native speakers know that it is ungrammatical for an active sentence to include an inanimate object ( * Jerry bored the movie). Similarly, English speakers know that Jerry bored Joe means that Joe is the person who lost interest and Jerry caused it. Therefore, because of its importance in determining sentence structure and the positions of the nouns in the sentence, slow or impaired access to verb lemmas and their associated grammatical constraints could potentially disrupt the grammaticality of the sentences produced as well as fluency of production (i.e., lead to more sentence-medial pauses, lexical and nonlexical fillers, and abandoned utterances). Another potential effect of impairments at the functional level might be simplified syntax. Complex sentences with embedded clauses, especially center-embedded relative clauses (e.g., that man who won the race was born in Jamaica), require that the messages and lemmas for both clauses are available simultaneously. Thus, limitations in the ability to activate the full set of items could lead to the production of less complex conjoined or consecutive sentences (e.g., that man won the race. He was born in Jamaica.). Limitations in syntactic complexity during language production have been associated with working memory limitations in healthy adults (e.g., BIB007 ). Evidence from the psycholinguistic literature suggests that grammaticality (e.g., verb agreement) may be particularly vulnerable in individuals with low working memory BIB013 . Furthermore, grammaticality has been found to be vulnerable in dual task settings in older adults with BIB014 and without stroke  BIB010 when the dual task becomes particularly difficult, suggesting that limiting available executive function resources can impair grammaticality. Grammaticality of oral language production is impaired in PD, particularly in more difficult tasks BIB006 BIB016 BIB015  . Consistent with the above findings, grammatical language production has been associated with executive function in individuals with PD BIB016 BIB015 . These difficulties could be traceable to either functional level impairments or to impaired transfer of information from the functional level stage of processing to the positional stage of processing, based on findings that unusual amounts of grammatical errors were only found when language was generated, not repeated BIB016 BIB011 . In contrast, findings regarding the simplification of syntax in PD have been mixed. Two studies examining oral language production, Cummings et al. BIB001 and Murray BIB006 , report impaired syntactic complexity in individuals with PD. Moreover, Murray also reported that sentence complexity correlated with measures of attention and short-term memory, which is consistent with findings from the healthy adult literature (e.g., BIB007 ). In contrast, Small et al. BIB004 found reduced syntactic complexity only in more severely impaired individuals with PD, examining single written sentences. This variability in findings across studies may be attributable to differences in the demands of the elicitation tasks used BIB008 . Based on this analysis, it appears that functional level processing in PD is impaired. Furthermore, the evidence suggests that individual differences in executive function and/or working memory can account for these impairments to a large extent though not completely.