Sharon Ash

The Atlas of North American English: Phonetics, Phonology and Sound Change

The Atlas of North American English provides the first overall view of the pronunciation and vowel systems of the dialects of the U.S. and Canada. The Atlas re-defines the regional dialects of American English on the basis of sound changes active in the 1990s and draws new boundaries reflecting those changes. It is based on a telephone survey of 762 local speakers, representing all the urbanized areas of North America. It has been developed by Bill Labov, one of the leading sociolinguists of the world, together with his colleagues Sharon Ash and Charles Boberg. The Atlas consists of a printed volume accompanied by an interactive CD-ROM. The print and multimedia content is alsoavailable online. Combined Edition: Book and Multimedia CD-ROM The printed volume contains 23 chapters that re-define the geographic boundaries of North American dialects and trace the influence of gender, age, education, and city size on the progress of sound change; findings that show a dramatic and increasing divergence of English in North America; 139 four color maps that illustrate the regional distribution of phonological and phonetic variables across the North American continent; 120 four color vowel charts of individual speakers. The interactive multimedia CD-ROM supplements the printed articles and maps by providing a data base with measurements of more than 100,000 vowels and mean values for 439 speakers; the Plotnik program for mapping each of the individual vowel systems; extended sound samples of all North American dialects; interactive applications to enhance classroom presentations. Online only Version: Print and Multimedia Content The online only version offers simultaneous access to the print and multimedia content to all users in the university/library network; presents a wider selection of interactive data, maps, and audio samples that will be recurrently updated; provides students with concurrent access to research material for classroom assignments. Key Features: a multimedia reference tool, overthrows previously heldhypothesesin North American dialectology, sound samples on CD-ROM easily accessible through clearly designedinteractive maps. System Requirements for CD-ROM and Online only version: Windows PC: Pentium PC, Windows 9x, NT, or XP, at least 16MB RAM, CD-ROM Drive, 16 Bit Soundcard, SVGA (600 x 800 resolution). Apple MAC: OS 6 or higher, 16 Bit Soundcard, at least 16MB RAM. Supported Browsers: Internet Explorer, 5.5 or 6 (Mac OS: Internet Explorer 5.1)/Netscape 7.x or higher/Mozilla 1.0 or higher/Mozilla Firefox 1.0 or higher. PlugIns: Macromedia Flash Player 6/Acrobat Reader.

Primary Progressive Aphasia: A Review

This review summarizes clinical and imaging features associated with primary progressive aphasia (PPA). We investigate the hypothesis that these patients can be divided into subgroups of progressive non-fluent aphasia (PNFA) and semantic dementia (SD), based on their linguistic profiles and related imaging studies, and examine whether each of these major subgroups can be further subdivided. We focus on several critical features within each progressive aphasic subgroup. In PNFA, we examine agrammatism, phonologic disorder, and impaired verb processing to determine whether this syndrome is related to a modality-specific impairment in word formation and articulation, or a conceptual deficit that interferes with grammatical processing. In SD, we examine impaired semantic memory, limited remote memory, and anomia to assess whether this syndrome is due to a modality-neutral interruption of semantic memory, or the degradation of various material-specific representations of object features and words. We conclude that there is sufficiently consistent and converging evidence from clinical and imaging studies to support the claim that PNFA and SD are distinct subgroups of PPA. However, there does not appear to be sufficient evidence at this point to support further discrimination within these progressive aphasic subgroups. Testing hypotheses about finer-grained syndromes such as progressive dysarthria or progressive anomia has important consequences for improving our understanding of language organization and the neural basis for language.

Trying to tell a tale Discourse impairments in progressive aphasia and frontotemporal dementia

Objective: To assess discourse in patients with frontotemporal dementia (FTD). Methods: The authors asked patients with progressive nonfluent aphasia (PNFA), patients with semantic dementia (SemD), and nonaphasic patients with a disorder of social comportment and executive functioning (SOC/EXEC) to narrate the story of a wordless childrens picture book. Results: The authors found significant discourse impairments in all three groups of patients. Moreover, there were qualitatively important differences between the groups. Patients with PNFA had the sparsest output, producing narratives with the fewest words per minute. Patients with SemD had difficulty retrieving words needed to tell their narratives. Though not aphasic, patients with SOC/EXEC had profound difficulty organizing their narratives, and they could not effectively express the point of the story. This deficit correlated with poor performance on a measure of executive resources requiring an organized mental search. In addition, a correlation of narrative organization with cortical atrophy in patients with SOC/EXEC was significant in right frontal and anterior temporal brain regions. Conclusions: Impaired day-to-day communication in nonaphasic frontotemporal dementia patients with a disorder of social comportment and executive functioning is due in part to a striking deficit in discourse organization associated with right frontotemporal disease. Difficulty with discourse in progressive aphasia is due largely to the language impairments of these patients.

Non-fluent speech in frontotemporal lobar degeneration

We investigated the cognitive and neural bases of impaired speech fluency, a central feature of primary progressive aphasia. Speech fluency was assessed in 35 patients with frontotemporal lobar degeneration (FTLD) who presented with progressive non-fluent aphasia (PNFA, n=11), semantic dementia (SemD, n=12), or a social and executive disorder without aphasia (SOC/EXEC, n=12). Fluency was quantified as the number of words per minute in an extended, semi-structured speech sample. This was related to language characteristics of the speech sample and to neuropsychological measures. PNFA patients were significantly less fluent than controls and other FTLD patients. Fluency correlated with grammatical expression but not with speech errors or executive difficulty. SemD and SOC/EXEC patients were also less fluent than controls. In SemD, fluency was associated with semantically limited content. In SOC/EXEC, fluency was associated with executive limitations. Voxel-based morphometry analyses of high-resolution MRI related fluency to gray matter volume in left inferior frontal, insula, and superior temporal regions for the entire cohort of FTLD patients. This region overlapped partially distinct atrophic areas in each FTLD subgroup. It thus appears to play a crucial role in speech fluency, which can be interrupted in different ways in different FTLD subgroups.

SPEECH ERRORS IN PROGRESSIVE NON-FLUENT APHASIA

The nature and frequency of speech production errors in neurodegenerative disease have not previously been precisely quantified. In the present study, 16 patients with a progressive form of non-fluent aphasia (PNFA) were asked to tell a story from a wordless childrens picture book. Errors in production were classified as either phonemic, involving language-based deformations that nevertheless result in possible sequences of English speech segments; or phonetic, involving a motor planning deficit and resulting in non-English speech segments. The distribution of cortical atrophy as revealed by structural MRI scans was examined quantitatively in a subset of PNFA patients (N=7). The few errors made by healthy seniors were only phonemic in type. PNFA patients made more than four times as many errors as controls. This included both phonemic and phonetic errors, with a preponderance of errors (82%) classified as phonemic. The majority of phonemic errors were substitutions that shared most distinctive features with the target phoneme. The systematic nature of these substitutions is not consistent with a motor planning deficit. Cortical atrophy was found in prefrontal regions bilaterally and peri-Sylvian regions of the left hemisphere. We conclude that the speech errors produced by PNFA patients are mainly errors at the phonemic level of language processing and are not caused by a motor planning impairment.

Differentiating primary progressive aphasias in a brief sample of connected speech

Objective: A brief speech expression protocol that can be administered and scored without special training would aid in the differential diagnosis of the 3 principal forms of primary progressive aphasia (PPA): nonfluent/agrammatic PPA, logopenic variant PPA, and semantic variant PPA. Methods: We used a picture-description task to elicit a short speech sample, and we evaluated impairments in speech-sound production, speech rate, lexical retrieval, and grammaticality. We compared the results with those obtained by a longer, previously validated protocol and further validated performance with multimodal imaging to assess the neuroanatomical basis of the deficits. Results: We found different patterns of impaired grammar in each PPA variant, and additional language production features were impaired in each: nonfluent/agrammatic PPA was characterized by speech-sound errors; logopenic variant PPA by dysfluencies (false starts and hesitations); and semantic variant PPA by poor retrieval of nouns. Strong correlations were found between this brief speech sample and a lengthier narrative speech sample. A composite measure of grammaticality and other measures of speech production were correlated with distinct regions of gray matter atrophy and reduced white matter fractional anisotropy in each PPA variant. Conclusions: These findings provide evidence that large-scale networks are required for fluent, grammatical expression; that these networks can be selectively disrupted in PPA syndromes; and that quantitative analysis of a brief speech sample can reveal the corresponding distinct speech characteristics.

The organization of narrative discourse in Lewy body spectrum disorder

Narrative discourse is an essential component of day-to-day communication, but little is known about narrative in Lewy body spectrum disorder (LBSD), including Parkinsons disease (PD), Parkinsons disease with dementia (PDD), and dementia with Lewy bodies (DLB). We performed a detailed analysis of a semi-structured speech sample in 32 non-aphasic patients with LBSD, and we related their narrative impairments to gray matter (GM) atrophy using voxel-based morphometry. We found that patients with PDD and DLB have significant difficulty organizing their narrative speech. This was correlated with deficits on measures of executive functioning and speech fluency. Regression analyses associated this deficit with reduced cortical volume in inferior frontal and anterior cingulate regions. These findings are consistent with a model of narrative discourse that includes executive as well as language components and with an impairment of the organizational component of narrative discourse in patients with PDD and DLB.

Deficits in sentence expression in amyotrophic lateral sclerosis.

Abstract Quantitative examinations of speech production in amyotrophic lateral sclerosis (ALS) are rare. To identify language features minimally confounded by a motor disorder, we investigated linguistic and motor sources of impaired sentence expression in ALS, and we related deficits to gray matter (GM) and white matter (WM) MRI abnormalities. We analyzed a semi-structured speech sample in 26 ALS patients and 19 healthy seniors for motor- and language-related deficits. Regression analyses related grammaticality to GM atrophy and reduced WM fractional anisotropy (FA). Results demonstrated that ALS patients were impaired relative to controls on quantity of speech, speech rate, speech articulation errors, and grammaticality. Speech rate and articulation errors were related to the patients’ motor impairment, while grammatical difficulty was independent of motor difficulty. This was confirmed in subgroups without dysarthria and without executive deficits. Regressions related grammatical expression to GM atrophy in left inferior frontal and anterior temporal regions and to reduced FA in superior longitudinal and inferior frontal-occipital fasciculi. In conclusion, patients with ALS exhibit multifactorial deficits in sentence expression. They demonstrate a deficit in grammatical expression that is independent of their motor disorder. Impaired grammatical expression is related to disease in a network of brain regions associated with syntactic processing.

Narrative discourse deficits in amyotrophic lateral sclerosis

Objective: We examined narrative discourse in amyotrophic lateral sclerosis (ALS) to assess the role of executive functioning in support of language and the neuroanatomical basis for such support. Methods: We analyzed a semistructured speech sample in 26 patients with ALS and 19 healthy seniors for narrative discourse features of coherence. Regression analyses related a measure of discourse coherence (“local connectedness”) to gray matter atrophy and reduced white matter fractional anisotropy. Results: Patients with ALS were impaired relative to controls on measures of discourse adequacy, including local connectedness and maintenance of the theme. These discourse measures were related to measures of executive functioning but not to motor functioning. Regressions related local connectedness to gray matter atrophy in ventral and dorsal prefrontal regions and to reduced fractional anisotropy in white matter tracts mediating projections between prefrontal regions. Conclusion: Patients with ALS exhibit deficits in their ability to organize narrative discourse. These deficits appear to be related in part to executive limitations. Consistent with the hypothesis that ALS is a multisystem disorder, this deficit is related to disease in prefrontal regions.

Grammatical comprehension deficits in non-fluent/agrammatic primary progressive aphasia

Importance Grammatical comprehension difficulty is an essential supporting feature of the non-fluent/agrammatic variant of primary progressive aphasia (naPPA), but well-controlled clinical measures of grammatical comprehension are unavailable. Objective To develop a measure of grammatical comprehension and examine this comparatively in PPA variants and behavioural-variant frontotemporal degeneration (bvFTD) and to assess the neuroanatomic basis for these deficits with volumetric grey matter atrophy and whole-brain fractional anisotropy (FA) in white matter tracts. Design Case–control study. Setting Academic medical centre. Participants 39 patients with variants of PPA (naPPA=12, lvPPA=15 and svPPA=12), 27 bvFTD patients without aphasia and 12 healthy controls. Main outcome measure Grammatical comprehension accuracy. Results Patients with naPPA had selective difficulty understanding cleft sentence structures, while all PPA variants and patients with bvFTD were impaired with sentences containing a centre-embedded subordinate clause. Patients with bvFTD were also impaired understanding sentences involving short-term memory. Linear regressions related grammatical comprehension difficulty in naPPA to left anterior-superior temporal atrophy and reduced FA in corpus callosum and inferior frontal-occipital fasciculus. Difficulty with centre-embedded sentences in other PPA variants was related to other brain regions. Conclusions and relevance These findings emphasise a distinct grammatical comprehension deficit in naPPA and associate this with interruption of a frontal-temporal neural network.