Subcortical Involvement in Formulaic Language: Studies on Bilingual Individuals With Parkinson's Disease.

Purpose An impoverished production of routinized expressions, namely, formulaic language, has been reported for monolingual speakers with Parkinson's disease (PD). Little is known regarding how formulaic expressions might be manifested in individuals with neurological damage who speak more than one language. This study investigated the processing of formulaic language across first language (L1) and second language (L2) in bilingual individuals with PD. Method Eleven Korean-English bilingual speakers with PD, who acquired Korean as L1 and English as L2, were recruited for this study. Two matched control groups composed of 11 healthy Korean-English bilingual individuals and 11 healthy native English speakers were included for comparison. Their performance on three structured tasks (comprehension, completion, and judgment-correction) and conversational speech was measured and compared across groups for analyses. Results The bilingual speakers with PD had significantly impaired comprehension of formulaic language in L1 and had lower proportions of formulaic expressions in their L1 conversational speech compared with the bilingual controls. Regarding L2, both bilingual groups with and without PD were comparable in their English performance across all tasks. Both groups performed significantly poorer in L2 structured tasks than the native English speakers. Spontaneous production of formulaic language in English (L2 for bilingual individuals) was similar across all three groups. Conclusions The results of this study contribute to the growing body of literature on impoverishment of formulaic language production following subcortical dysfunction. Additionally, findings here demonstrate a selective impairment of formulaic language performance in L1 but not L2 for bilinguals with PD, further supporting the role of the basal ganglia in native language.

Emotionally expressed voices are retained in memory following a single exposure.

Studies of voice recognition in biology suggest that long exposure may not satisfactorily represent the voice acquisition process. The current study proposes that humans can acquire a newly familiar voice from brief exposure to spontaneous speech, given a personally engaging context. Studies have shown that arousing and emotionally engaging experiences are more likely to be recorded and consolidated in memory. Yet it remains undemonstrated whether this advantage holds for voices. The present study examined the role of emotionally expressive context in the acquisition of voices following a single, 1-minute exposure by comparing recognition of voices experienced in engaging and neutral contexts at two retention intervals. Listeners were exposed to a series of emotionally nuanced and neutral videotaped narratives produced by performers, and tested on the recognition of excerpted voice samples, by indicating whether they had heard the voice before, immediately and after a one-week delay. Excerpts were voices from exposed videotaped narratives, but utilized verbal material taken from a second (nonexposed) narrative provided by the same performer. Overall, participants were consistently able to distinguish between voices that were exposed during the video session and voices that were not exposed. Voices experienced in emotional, engaging contexts were significantly better recognized than those in neutral ones both immediately and after a one-week delay. Our findings provide the first evidence that new voices can be acquired rapidly from one-time exposure and that nuanced context facilitates initially inducting new voices into a repertory of personally familiar voices in long-term memory. The results converge with neurological evidence to suggest that cerebral processes differ for familiar and unfamiliar voices.

Performance and Function Meet Structure: A White Matter Connection Tuned for Vocal Production.

Contemporary imaging techniques have increased the potential for establishing how brain regions interact during spoken language. Some imaging methods report bilateral changes in brain activity during speech, whereas another approach finds that the relationship between individual variability in speech measures and individual variability in brain activity more closely resembles clinical observations. This approach has repeatedly demonstrated that speaking rate for phonological and lexical items can be predicted by an inverse relationship between cerebral blood flow in the left inferior frontal region and the right caudate nucleus. To determine whether morphology contributes to this relationship, we examined ipsilateral and contralateral white matter connections between these structures using diffusion tensor imaging, and we further assessed possible relationships between morphology and selected acoustic measures of participants' vocal productions. The ipsilateral connections between the inferior frontal regions and the caudate nuclei had higher average fractional anisotropy and mean diffusivity values than the contralateral connections. Neither contralateral connection between inferior frontal and caudate regions showed a significant advantage on any of the average morphology measures. However, individual differences in white matter morphology were significantly correlated with individual differences in vocal amplitude and frequency stability in the left frontal-right caudate connection. This cortical-striatal connection may be "tuned" for a role in the coordination of cortical and subcortical activity during speech. The structure-function relationship in this cortical-subcortical pathway supports the previous observation of a predictive pattern of cerebral blood flow during speech and may reflect a mechanism that ensures left-hemisphere control of the vocal expression of propositional language.

Cortical-subcortical production of formulaic language: A review of linguistic, brain disorder, and functional imaging studies leading to a production model.

Formulaic language forms about one-fourth of everyday talk. Formulaic (fixed expressions) and novel (grammatical language) differ in important characteristics. The features of idioms, slang, expletives, proverbs, aphorisms, conversational speech formulas, and other fixed expressions include ranges of length, flexible cohesion, memory storage, nonliteral and situation meaning, and affective content. Neurolinguistic observations in persons with focal brain damage or progressive neurological disease suggest that producing formulaic expressions can be achieved by interactions between the right hemisphere and subcortical structures. The known functional characteristics of these structures form a compatible substrate for production of formulaic expressions. Functional imaging using a performance-based analysis supported a right hemisphere involvement in producing conversational speech formulas, while indicating that the pause fillers, uh and um, engage the left hemisphere and function like lexical items. Together these findings support a dual-process model of language, whereby formulaic and grammatical language are modulated by different cerebral structures.

Switching Language Modes: Complementary Brain Patterns for Formulaic and Propositional Language.

Language has been modeled as a rule governed behavior for generating an unlimited number of novel utterances using phonological, syntactic, and lexical processes. This view of language as essentially propositional is expanding as a contributory role of formulaic expressions (e.g., you know, have a nice day, how are you?) is increasingly recognized. The basic features of the functional anatomy of this language system have been described by studies of brain damage: left lateralization for propositional language and greater right lateralization and basal ganglia involvement for formulaic expressions. Positron emission tomography (PET) studies of cerebral blood flow (CBF) have established a cortical-subcortical pattern of brain activity predictive of syllable rate during phonological/lexical repetition. The same analytic approach was applied to analyzing brain images obtained during spontaneous monologues. Sixteen normal, right-handed, native English speakers underwent PET scanning during several language tasks. Speech rate for the repetition of phonological/lexical items was predicted by increased CBF in the left inferior frontal region and decreased CBF in the head of the right caudate nucleus, replicating previous results. A complementary cortical-subcortical pattern (CBF increased in the right inferior frontal region and decreased in the left caudate) was predictive of the use of speech formulas during monologue speech. The use of propositional language during the monologues was associated with strong left lateralization (increased CBF at the left inferior frontal region and decreased CBF at the right inferior frontal region). Normal communication involves the integration of two language modes, formulaic and novel, that have different neural substrates.

Perception of formulaic and novel expressions under acoustic degradation.

BACKGROUND: Formulaic expressions, including idioms and other fixed expressions, comprise a significant proportion of discourse. Although much has been written about this topic, controversy remains about their psychological status. An important claim about formulaic expressions, that they are known to native speakers, has seldom been directly demonstrated. This study tested the hypothesis that formulaic expressions are known and stored as whole unit mental representations by performing three perceptual experiments. METHOD: Listeners transcribed two kinds of spectrally-degraded spoken sentences, half formulaic, and half novel, newly created expressions, matched for grammar and length. Two familiarity ratings, usage and exposure, were obtained from listeners for each expression. Text frequency data for the stimuli and their constituent words were obtained using a spoken corpus. RESULTS: Participants transcribed formulaic more successfully than literal utterances. Usage and familiarity ratings correlated with accuracy, but formulaic utterances with low ratings were also transcribed correctly. Phrase types differed significantly in text frequency, but word frequency counts did not differentiate the two kinds of expressions. DISCUSSION: These studies provide new converging evidence that formulaic expressions are encoded and processed as whole units, supporting a dual-process model of language processing, which assumes that grammatical and formulaic expressions are differentially processed.

Evaluation, treatment, and analysis of a rare case of motor speech systems dyscoordination syndrome.

This report describes an unusual presentation of a voice disorder arising from inability to coordinate the three components of motor speech: respiration, phonation, and articulation. These systems were individually intact, as demonstrated by laryngoscopy, motor speech examination, and treatment methods achieving success under controlled conditions. Following initial programming of his deep brain stimulation (DBS) device, a 62-year-old male, diagnosed with Parkinson's disease (PD) 14 years previously, abruptly experienced a vocal disorder characterized by pressed, very low frequency creaky voice produced on held breath. Evaluation and therapy sessions revealed intact respiration, phonation, and articulation as component systems of motor speech, while indicating a severe deficit in coordinating these systems for articulated speech. Performance varied with mode of vocal production. Vowel prolongation and singing were normal in contrast to severe impairment when respiration and phonation were integrated with articulated speech. A listening study utilizing speech samples from five spoken modes-conversation, repetition, formulaic expressions, continuously phonated material and singing, yielded higher intelligibility on sung and continuously phonated phrases, confirming clinical impressions. Acoustic measures of fundamental frequency, vowel quality (harmonic-to-noise ratios) and duration supported the intelligibility results. Repetition and conversation were similarly impaired, suggesting that the disability was not attributable to the basal ganglia. This case reveals the role of higher order management of respiration, articulation, and voice for speech and describes a successful treatment utilizing breath control.

Subthalamic Stimulation Reduces Vowel Space at the Initiation of Sustained Production: Implications for Articulatory Motor Control in Parkinson's Disease.

BACKGROUND: Stimulation of the subthalamic nuclei (STN) is an effective treatment for Parkinson's disease, but complaints of speech difficulties after surgery have been difficult to quantify. Speech measures do not convincingly account for such reports. OBJECTIVE: This study examined STN stimulation effects on vowel production, in order to probe whether DBS affects articulatory posturing. The objective was to compare positioning during the initiation phase with the steady prolongation phase by measuring vowel spaces for three "corner" vowels at these two time frames. METHODS: Vowel space was measured over the initial 0.25 sec of sustained productions of high front (/i/), high back (/u/) and low vowels (/a/), and again during a 2 sec segment at the midpoint. Eight right-handed male subjects with bilateral STN stimulation and seven age-matched male controls were studied based on their participation in a larger study that included functional imaging. Mean values: age = 57±4.6 yrs; PD duration = 12.3±2.7 yrs; duration of DBS = 25.6±21.2 mos, and UPDRS III speech score = 1.6±0.7. STN subjects were studied off medication at their therapeutic DBS settings and again with their stimulators off, counter-balanced order. RESULTS: Vowel space was larger in the initiation phase compared to the midpoint for both the control and the STN subjects off stimulation. With stimulation on, however, the initial vowel space was significantly reduced to the area measured at the mid-point. For the three vowels, the acoustics were differentially affected, in accordance with expected effects of front versus back position in the vocal tract. CONCLUSIONS: STN stimulation appears to constrain initial articulatory gestures for vowel production, raising the possibility that articulatory positions normally used in speech are similarly constrained.

Production of Korean Idiomatic Utterances Following Left- and Right-Hemisphere Damage: Acoustic Studies.

PURPOSE: This study investigates the effects of left- and right-hemisphere damage (LHD and RHD) on the production of idiomatic or literal expressions utilizing acoustic analyses. METHOD: Twenty-one native speakers of Korean with LHD or RHD and in a healthy control (HC) group produced 6 ditropically ambiguous (idiomatic or literal) sentences in 2 different speech tasks: elicitation and repetition. Utterances were analyzed using durational and fundamental-frequency (F0) measures. Listeners' goodness ratings (how well each utterance represented its category: idiomatic or literal) were correlated with acoustic measures. RESULTS: During the elicitation tasks, the LHD group differed significantly from the HC group in durational measures. Significant differences between the RHD and HC groups were seen in F0 measures. However, for the repetition tasks, the LHD and RHD groups produced utterances comparable to the HC group's performance. Using regression analysis, selected F0 cues were found to be significant predictors for goodness ratings by listeners. CONCLUSIONS: Using elicitation, speakers in the LHD group were deficient in producing durational cues, whereas RHD negatively affected the production of F0 cues. Performance differed for elicitation and repetition, indicating a task effect. Listeners' goodness ratings were highly correlated with the production of certain acoustic cues. Both the acoustic and functional hypotheses of hemispheric specialization were supported for idiom production.

The formulaic schema in the minds of two generations of native speakers.

Schemata are expressions that are fixed except for slots available for novel words (I'm not a ______ person). Our goals were to quantify speakers' knowledge, examine semantic flexibility in open slots, and compare performance data in two generations of speakers using cloze procedures in formulaic expressions, schemata open slots, fixed portions of schemata, and novel sentences. Fewer unique words appeared for the schemata-fixed and formulaic exemplars, reflecting speakers' knowledge of these utterances; the most semantic categories appeared for schemata-open responses. Age groups did not differ. Schemata exemplify creative interplay between novel lexical retrieval and fixed formulaic expression.

Formulaic Language in Parkinson's Disease and Alzheimer's Disease: Complementary Effects of Subcortical and Cortical Dysfunction.

PURPOSE: The production of formulaic expressions (conversational speech formulas, pause fillers, idioms, and other fixed expressions) is excessive in the left hemisphere and deficient in the right hemisphere and in subcortical stroke. Speakers with Alzheimer's disease (AD), having functional basal ganglia, reveal abnormally high proportions of formulaic language. Persons with Parkinson's disease (PD), having dysfunctional basal ganglia, were predicted to show impoverished formulaic expressions in contrast to speakers with AD. This study compared participants with PD, participants with AD, and healthy control (HC) participants on protocols probing production and comprehension of formulaic expressions. METHOD: Spontaneous speech samples were recorded from 16 individuals with PD, 12 individuals with AD, and 18 HC speakers. Structured tests were then administered as probes of comprehension. RESULTS: The PD group had lower proportions of formulaic expressions compared with the AD and HC groups. Comprehension testing yielded opposite contrasts: participants with PD showed significantly higher performance compared with participants with AD and did not differ from HC participants. CONCLUSIONS: The finding that PD produced lower proportions of formulaic expressions compared with AD and HC supports the view that subcortical nuclei modulate the production of formulaic expressions. Contrasting results on formal testing of comprehension, whereby participants with AD performed significantly worse than participants with PD and HC participants, indicate differential effects on procedural and declarative knowledge associated with these neurological conditions.

Cerebral processing of proper and common nouns: Perception and production following left hemisphere damage.

The goal of this study was to further investigate hemispheric specialization for proper and common nouns by examining the ability of individuals with left hemisphere damage (LHD) to perceive and verbally reproduce famous names and matched common names compared with the performance of matched healthy controls (HC). Ten individuals with LHD due to stroke and 16 age- and education-matched HC completed recognition and production tasks of famous proper and common nouns. All tasks were designed as split-visual field experiments, modelled after the study done by Ohnesorge and Van Lancker. Results contribute to a better understanding of hemispheric roles in perception and production of famous proper nouns, suggesting that (1) both hemispheres can recognize famous proper nouns, possibly due to a right hemisphere role in personal relevance and (2) production of proper nouns as well as common nouns is associated with left hemisphere.

Effects of Deep Brain Stimulation on Pausing During Spontaneous Speech in Parkinson's Disease.

The present study examined pausing patterns in spontaneous speech as a measure of the effect of deep brain stimulation (DBS) of the subthalamic nucleus (STN) on parkinsonian speech. Pauses reflect various aspects of speech and language processes, including motor initiation and linguistic planning. Relatively little attention has been given to pauses in determining the effect of STN-DBS. An examination of pausing may be helpful to understanding how this form of therapy affects these behaviors. Seven individuals with Parkinson's disease who received surgery for bilateral STN-DBS participated. Spontaneous speech samples were elicited in both the ON and OFF STN-DBS condition. Findings indicated that long pauses (250-3000 ms) in spontaneous speech were significantly shorter and more frequent in the STN-DBS ON condition. Furthermore, the proportion of nonlinguistic boundary pauses was significantly greater with stimulation. The findings support previous studies suggesting that speech motor control and lexical retrieval may be affected by STN-DBS.

Formulaic Language in Alzheimer's Disease.

BACKGROUND: Studies of productive language in Alzheimer's disease (AD) have focused on formal testing of syntax and semantics but have directed less attention to naturalistic discourse and formulaic language. Clinical observations suggest that individuals with AD retain the ability to produce formulaic language long after other cognitive abilities have deteriorated. AIMS: This study quantifies production of formulaic expressions in the spontaneous speech of individuals with AD. Persons with early- and late-onset forms of the disease were compared. METHODS & PROCEDURES: Conversational language samples of individuals with early- (n = 5) and late-onset (n = 6) AD and healthy controls (n = 5) were analyzed to determine whether formulaic language, as measured by the number of words in formulaic expressions, differs between groups. OUTCOMES & RESULTS: Results indicate that individuals with AD, regardless of age of onset, used significantly more formulaic expressions than healthy controls. The early- and late-onset AD groups did not differ on formulaic language measures. CONCLUSIONS: These findings contribute to a dual process model of cerebral function, which proposes differing processing principles for formulaic and novel expressions. In this model, subcortical areas, which remain intact into late in the progression of Alzheimer's disease, play an important role in the production of formulaic language. Applications to clinical practice include identifying preserved formulaic language and providing informed counseling to patient and family.

The role of subcortical structures in recited speech: Studies in Parkinson's disease.

The role of subcortical structures in language function is complex and dependent on language task, with studies increasingly showing subcortical involvement for the production of formulaic language, including recited speech. Individuals with Parkinson's disease (PD), with (n = 6) and without (n = 7) surgical treatment, deep brain stimulation (DBS), were compared to healthy adults (n = 14) to determine whether individuals with subcortical dysfunction produce more errors during a recitation speech task. Participants were asked to recite poems, prayers, and rhymes familiar to them in order to determine the effects of subcortical disease on recited speech ability. When compared with healthy controls, the DBS-OFF group produced significantly more error words, suggesting that deficits in recitation arise with severe states of subcortical dysfunction. Individuals with DBS in the ON or OFF conditions did not differ significantly during the recited speech task. Results support a model of language where large units of overlearned language are at least partially modulated by subcortical structures.

Dramatic effects of speech task on motor and linguistic planning in severely dysfluent parkinsonian speech.

In motor speech disorders, dysarthric features impacting intelligibility, articulation, fluency and voice emerge more saliently in conversation than in repetition, reading or singing. A role of the basal ganglia in these task discrepancies has been identified. Further, more recent studies of naturalistic speech in basal ganglia dysfunction have revealed that formulaic language is more impaired than novel language. This descriptive study extends these observations to a case of severely dysfluent dysarthria due to a parkinsonian syndrome. Dysfluencies were quantified and compared for conversation, two forms of repetition, reading, recited speech and singing. Other measures examined phonetic inventories, word forms and formulaic language. Phonetic, syllabic and lexical dysfluencies were more abundant in conversation than in other task conditions. Formulaic expressions in conversation were reduced compared to normal speakers. A proposed explanation supports the notion that the basal ganglia contribute to formulation of internal models for execution of speech.

Preservation of relational timing in speech of persons with Parkinson's disease with and without deep brain stimulation.

BACKGROUND: Initial shortening of stem vowels in three-word derivational paradigms (e.g., zip, zipper, zippering) was studied in persons with Parkinson's disease (PWPD) with and without deep brain stimulation (DBS), and in normal speakers. METHOD: Seven PWPD without DBS, 7 PWPD with DBS ON (DBSN) or OFF (DBSF), and 6 healthy control (CON) persons were studied. Stimuli were 7 three-word paradigms consisting of a stem word and two derived longer forms created by adding the suffixes er (+1), and er+ing (+2). RESULTS: Vowel durations decreased across word forms of increasing length (initial shortening) for DBSF, DBSN, PWPD, and CON. Vowel shortening did not interact with group. For each word form, CON vowel duration was shorter than those for PWPD, DBSN and DBSF but word duration did not differ between groups. DBS did not have a significant effect on either vowel or word duration. CONCLUSION: These results agree with previous findings for a PWPD with accelerated speech and faster rates of speech in DBS-ON. Observations that vowel duration patterns are maintained in subcortical and cerebellar but not left hemisphere damage suggest that cortical control factors play a primary role in relational timing.

Voice and fluency changes as a function of speech task and deep brain stimulation.

PURPOSE: Speaking, which naturally occurs in different modes or "tasks" such as conversation and repetition, relies on intact basal ganglia nuclei. Recent studies suggest that voice and fluency parameters are differentially affected by speech task. In this study, the authors examine the effects of subcortical functionality on voice and fluency, comparing measures obtained from spontaneous and matched repeated speech samples. METHOD: Subjects with Parkinson's disease who were being treated with bilateral deep brain stimulation (DBS) of the subthalamic nuclei were tested with stimulators ON and OFF. RESULTS: The study found that a voice measure, harmonic to noise ratio, is improved in repetition and in the DBS-ON condition and that dysfluencies are more plentiful in conversation with little or variable influence of DBS condition. CONCLUSIONS: These findings suggest that voice and fluency are differentially affected by DBS treatment and that task conditions, interacting with subcortical functionality, influence motor speech performance.

Prosodic changes in aphasic speech: timing.

Controversy remains about the impairment of prosody in aphasia, particularly with regard to speech timing. This paper addresses this topic through an analysis of timing in four sets of a common morphological paradigm. The paradigm consisted of a basic form (stem) and two longer derived forms (e.g. zip, zipper, zippering). Normally, vowel durations are shorter in longer derived forms (e.g. zippering) than in the stem (e.g. zip), due to a process called 'initial shortening'. Twelve patients with aphasia (four each Broca, Wernicke, and Anomic), and 11 age-matched healthy adults were assessed. Structural (CT) and functional brain imaging (PET) were available for all patients. While all groups showed initial shortening between the stem and the derived forms, the patients with Broca's aphasia presented an inverse pattern between the two derived forms (longer initial vowel in 'zippering' than 'zipper'), and the patients with Wernicke's aphasia produced significantly longer vowel durations overall than the healthy participants. The results are related to radiological information regarding the location of structural and functional brain damage and relative preservation and loss of prosodic features in cerebral damage.