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Baqué L, Machuca MJ. Dysfluency in primary progressive aphasia: Temporal speech parameters. CLINICAL LINGUISTICS & PHONETICS 2024:1-34. [PMID: 39104133 DOI: 10.1080/02699206.2024.2378345] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Subscribe] [Scholar Register] [Received: 10/05/2023] [Revised: 06/28/2024] [Accepted: 07/05/2024] [Indexed: 08/07/2024]
Abstract
Analysing spontaneous speech in individuals experiencing fluency difficulties holds potential for diagnosing speech and language disorders, including Primary Progressive Aphasia (PPA). Dysfluency in the spontaneous speech of patients with PPA has mostly been described in terms of abnormal pausing behaviour, but the temporal features related to speech have drawn little attention. This study compares speech-related fluency parameters in the three main variants of PPA and in typical speech. Forty-three adults participated in this research, thirteen with the logopenic variant of PPA (lvPPA), ten with the non-fluent variant (nfvPPA), nine with the semantic variant (svPPA), and eleven who were healthy age-matched adults. Participants' fluency was assessed through a picture description task from which 42 parameters were computed including syllable duration, speaking pace, the duration of speech chunks (i.e. interpausal units, IPU), and the number of linguistic units per IPU and per second. The results showed that each PPA variant exhibited abnormal speech characteristics reflecting various underlying factors, from motor speech deficits to higher-level issues. Out of the 42 parameters considered, 37 proved useful for characterising dysfluency in the three main PPA variants and 35 in distinguishing among them. Therefore, taking into account not only pausing behaviour but also temporal speech parameters can provide a fuller understanding of dysfluency in PPA. However, no single parameter by itself sufficed to distinguish one PPA group from the other two, further evidence that dysfluency is not dichotomous but rather multidimensional, and that complementary multiparametric analyses are needed.
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Affiliation(s)
- Lorraine Baqué
- Departament de Filologia Francesa i Romànica, Universitat Autònoma de Barcelona, Bellaterra, Spain
| | - María-Jesús Machuca
- Departament de Filologia Espanyola, Universitat Autònoma de Barcelona, Bellaterra, Spain
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Cordella C, Di Filippo L, Kolachalama VB, Kiran S. Connected Speech Fluency in Poststroke and Progressive Aphasia: A Scoping Review of Quantitative Approaches and Features. AMERICAN JOURNAL OF SPEECH-LANGUAGE PATHOLOGY 2024; 33:2091-2128. [PMID: 38652820 PMCID: PMC11253646 DOI: 10.1044/2024_ajslp-23-00208] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/09/2023] [Revised: 10/09/2023] [Accepted: 01/08/2024] [Indexed: 04/25/2024]
Abstract
PURPOSE Speech fluency has important diagnostic implications for individuals with poststroke aphasia (PSA) as well as primary progressive aphasia (PPA), and quantitative assessment of connected speech has emerged as a widely used approach across both etiologies. The purpose of this review was to provide a clearer picture on the range, nature, and utility of individual quantitative speech/language measures and methods used to assess connected speech fluency in PSA and PPA, and to compare approaches across etiologies. METHOD We conducted a scoping review of literature published between 2012 and 2022 following the Preferred Reporting Items for Systematic Reviews and Meta-Analyses Extension for Scoping Reviews guidelines. Forty-five studies were included in the review. Literature was charted and summarized by etiology and characteristics of included patient populations and method(s) used for derivation and analysis of speech/language features. For a subset of included articles, we also charted the individual quantitative speech/language features reported and the level of significance of reported results. RESULTS Results showed that similar methodological approaches have been used to quantify connected speech fluency in both PSA and PPA. Two hundred nine individual speech-language features were analyzed in total, with low levels of convergence across etiology on specific features but greater agreement on the most salient features. The most useful features for differentiating fluent from nonfluent aphasia in both PSA and PPA were features related to overall speech quantity, speech rate, or grammatical competence. CONCLUSIONS Data from this review demonstrate the feasibility and utility of quantitative approaches to index connected speech fluency in PSA and PPA. We identified emergent trends toward automated analysis methods and data-driven approaches, which offer promising avenues for clinical translation of quantitative approaches. There is a further need for improved consensus on which subset of individual features might be most clinically useful for assessment and monitoring of fluency. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.25537237.
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Affiliation(s)
- Claire Cordella
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Lauren Di Filippo
- Department of Speech, Language and Hearing Sciences, Boston University, MA
| | - Vijaya B. Kolachalama
- Department of Medicine, Boston University Chobanian & Avedisian School of Medicine, MA
- Department of Computer Science and Faculty of Computing & Data Sciences, Boston University, MA
| | - Swathi Kiran
- Department of Speech, Language and Hearing Sciences, Boston University, MA
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Faroqi-Shah Y. A reconceptualization of sentence production in post-stroke agrammatic aphasia: the synergistic processing bottleneck model. FRONTIERS IN LANGUAGE SCIENCES 2023; 2:1118739. [PMID: 39175803 PMCID: PMC11340809 DOI: 10.3389/flang.2023.1118739] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 08/24/2024]
Abstract
The language production deficit in post-stroke agrammatic aphasia (PSA-G) tends to result from lesions to the left inferior frontal gyrus (LIFG) and is characterized by a triad of symptoms: fragmented sentences, errors in functional morphology, and a dearth of verbs. Despite decades of research, the mechanisms underlying production patterns in PSA-G have been difficult to characterize. Two major impediments to progress may have been the view that it is a purely morphosyntactic disorder and the (sometimes overzealous) application of linguistic theory without interceding psycholinguistic evidence. In this paper, empirical evidence is examined to present an integrated portrait of language production in PSA-G and to evaluate the assumption of a syntax-specific syndrome. In light of extant evidence, it is proposed that agrammatic language production results from a combination of morphosyntactic, phonomotor, and processing capacity limitations that cause a cumulative processing bottleneck at the point of articulatory planning. This proposed Synergistic Processing Bottleneck model of PSA-G presents a testable framework for future research. The paper ends with recommendations for future research on PSA-G.
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Affiliation(s)
- Yasmeen Faroqi-Shah
- Department of Hearing and Speech Sciences, University of Maryland, College Park, MD, USA
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Shekari E, Nozari N. A narrative review of the anatomy and function of the white matter tracts in language production and comprehension. Front Hum Neurosci 2023; 17:1139292. [PMID: 37051488 PMCID: PMC10083342 DOI: 10.3389/fnhum.2023.1139292] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/06/2023] [Accepted: 02/24/2023] [Indexed: 03/28/2023] Open
Abstract
Much is known about the role of cortical areas in language processing. The shift towards network approaches in recent years has highlighted the importance of uncovering the role of white matter in connecting these areas. However, despite a large body of research, many of these tracts’ functions are not well-understood. We present a comprehensive review of the empirical evidence on the role of eight major tracts that are hypothesized to be involved in language processing (inferior longitudinal fasciculus, inferior fronto-occipital fasciculus, uncinate fasciculus, extreme capsule, middle longitudinal fasciculus, superior longitudinal fasciculus, arcuate fasciculus, and frontal aslant tract). For each tract, we hypothesize its role based on the function of the cortical regions it connects. We then evaluate these hypotheses with data from three sources: studies in neurotypical individuals, neuropsychological data, and intraoperative stimulation studies. Finally, we summarize the conclusions supported by the data and highlight the areas needing further investigation.
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Affiliation(s)
- Ehsan Shekari
- Department of Neuroscience, Iran University of Medical Sciences, Tehran, Iran
| | - Nazbanou Nozari
- Department of Psychology, Carnegie Mellon University, Pittsburgh, PA, United States
- Center for the Neural Basis of Cognition (CNBC), Pittsburgh, PA, United States
- *Correspondence: Nazbanou Nozari
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Zevgolatakou E, Thye M, Mirman D. Behavioural and neural structure of fluent speech production deficits in aphasia. Brain Commun 2022; 5:fcac327. [PMID: 36601623 PMCID: PMC9798301 DOI: 10.1093/braincomms/fcac327] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/10/2021] [Revised: 09/03/2022] [Accepted: 12/12/2022] [Indexed: 12/15/2022] Open
Abstract
Deficits in fluent speech production following left hemisphere stroke are a central concern because of their impact on patients' lives and the insight they provide about the neural organization of language processing. Fluent speech production requires the rapid coordination of phonological, semantic, and syntactic processing, so this study examined how deficits in connected speech relate to these language sub-systems. Behavioural data (N = 69 participants with aphasia following left hemisphere stroke) consisted of a diverse and comprehensive set of narrative speech production measures and measures of overall severity, semantic deficits, and phonological deficits. These measures were entered into a principal component analysis with bifactor rotation-a latent structure model where each item loads on a general factor that reflects what is common among the items, and orthogonal factors that explain variance not accounted for by the general factor. Lesion data were available for 58 of the participants, and each factor score was analysed with multivariate lesion-symptom mapping. Effects of connectivity disruption were evaluated using robust regression with tract disconnection or graph theoretic measures of connectivity as predictors. The principal component analysis produced a four-factor solution that accounted for 70.6% of the variance in the data, with a general factor corresponding to the overall severity and length and complexity of speech output (complexity factor), a lexical syntax factor, and independent factors for Semantics and Phonology. Deficits in the complexity of speech output were associated with a large temporo-parietal region, similar to overall aphasia severity. The lexical syntax factor was associated with damage in a relatively small set of fronto-parietal regions which may reflect the recruitment of control systems to support retrieval and correct usage of lexical items that primarily serve a syntactic rather than semantic function. Tract-based measures of connectivity disruption were not statistically associated with the deficit scores after controlling for overall lesion volume. Language network efficiency and average clustering coefficient within the language network were significantly associated with deficit scores after controlling for overall lesion volume. These results highlight overall severity as the critical contributor to fluent speech in post-stroke aphasia, with a dissociable factor corresponding to lexical syntax.
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Affiliation(s)
- Eleni Zevgolatakou
- Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK
| | - Melissa Thye
- Department of Psychology, University of Edinburgh, 7 George Square, Edinburgh EH8 9JZ, UK
| | - Daniel Mirman
- Correspondence to: Daniel Mirman Department of Psychology, 7 George Square Edinburgh EH8 9JZ, UK E-mail:
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Ding J, Schnur TT. Anterior connectivity critical for recovery of connected speech after stroke. Brain Commun 2022; 4:fcac266. [PMID: 36382224 PMCID: PMC9651028 DOI: 10.1093/braincomms/fcac266] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/29/2022] [Revised: 07/20/2022] [Accepted: 10/17/2022] [Indexed: 01/11/2023] Open
Abstract
Connected speech recovers to different degrees across people after left hemisphere stroke, but white matter predictors of differential recovery from the acute stage of stroke are unknown. We assessed changes in lexical-syntactic aspects of connected speech in a longitudinal analysis of 40 individuals (18 females) from the acute stage of left hemisphere stroke (within an average of 4 days post-stroke) to subacute (within 2 months) and chronic stages (early: 6 months, late: 1 year) while measuring the extent of acute lesions on white matter tracts to identify tracts predictive of recovery. We found that acute damage to the frontal aslant tract led to a decreased recovery of the fluency and structural complexity of connected speech during the year following left hemisphere stroke. The results were independent of baseline performance, overall lesion volume and the proportion of damage to tract-adjacent grey matter. This longitudinal analysis from acute to chronic stroke provides the first evidence that recovery of fluent and structurally complex spontaneous connected speech requires intact left frontal connectivity via the frontal aslant tract. That the frontal aslant tract was critical for recovery at early as well as later stages of stroke demonstrates that anterior connectivity plays a lasting and important role for the reorganization of function related to the successful production of connected speech.
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Affiliation(s)
- Junhua Ding
- Department of Psychology, University of Edinburgh, Edinburgh, UK
| | - Tatiana T Schnur
- Correspondence to: Tatiana T. Schnur Department of Neurosurgery Baylor College of Medicine 1 Baylor Plaza, Houston, TX 77030, USA E-mail:
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Gordon JK, Clough S. How Do Clinicians Judge Fluency in Aphasia? JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2022; 65:1521-1542. [PMID: 35271379 DOI: 10.1044/2021_jslhr-21-00484] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/14/2023]
Abstract
PURPOSE Aphasia fluency is multiply determined by underlying impairments in lexical retrieval, grammatical formulation, and speech production. This poses challenges for establishing a reliable and feasible tool to measure fluency in the clinic. We examine the reliability and validity of perceptual ratings and clinical perspectives on the utility and relevance of methods used to assess fluency. METHOD In an online survey, 112 speech-language pathologists rated spontaneous speech samples from 181 people with aphasia (PwA) on eight perceptual rating scales (overall fluency, speech rate, pausing, effort, melody, phrase length, grammaticality, and lexical retrieval) and answered questions about their current practices for assessing fluency in the clinic. RESULTS Interrater reliability for the eight perceptual rating scales ranged from fair to good. The most reliable scales were speech rate, pausing, and phrase length. Similarly, clinicians' perceived fluency ratings were most strongly correlated to objective measures of speech rate and utterance length but were also related to grammatical complexity, lexical diversity, and phonological errors. Clinicians' ratings reflected expected aphasia subtype patterns: Individuals with Broca's and transcortical motor aphasia were rated below average on fluency, whereas those with anomic, conduction, and Wernicke's aphasia were rated above average. Most respondents reported using multiple methods in the clinic to measure fluency but relying most frequently on subjective judgments. CONCLUSIONS This study lends support for the use of perceptual rating scales as valid assessments of speech-language production but highlights the need for a more reliable method for clinical use. We describe next steps for developing such a tool that is clinically feasible and helps to identify the underlying deficits disrupting fluency to inform treatment targets. SUPPLEMENTAL MATERIAL https://doi.org/10.23641/asha.19326419.
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Affiliation(s)
- Jean K Gordon
- Department of Communication Sciences and Disorders, The University of Iowa, Iowa City
| | - Sharice Clough
- Department of Hearing and Speech Sciences, Vanderbilt University Medical Center, Nashville, TN
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Riello M, Frangakis CE, Ficek B, Webster KT, Desmond JE, Faria AV, Hillis AE, Tsapkini K. Neural Correlates of Letter and Semantic Fluency in Primary Progressive Aphasia. Brain Sci 2021; 12:1. [PMID: 35053745 PMCID: PMC8773895 DOI: 10.3390/brainsci12010001] [Citation(s) in RCA: 9] [Impact Index Per Article: 3.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/22/2021] [Revised: 12/15/2021] [Accepted: 12/16/2021] [Indexed: 11/21/2022] Open
Abstract
Verbal fluency (VF) is an informative cognitive task. Lesion and functional imaging studies implicate distinct cerebral areas that support letter versus semantic fluency and the understanding of neural and cognitive mechanisms underlying task performance. Most lesion studies include chronic stroke patients. People with primary progressive aphasia (PPA) provide complementary evidence for lesion-deficit associations, as different brain areas are affected in stroke versus PPA. In the present study we sought to determine imaging, clinical and demographic correlates of VF in PPA. Thirty-five patients with PPA underwent an assessment with letter and category VF tasks, evaluation of clinical features and an MRI scan for volumetric analysis. We used stepwise regression models to determine which brain areas are associated with VF performance while acknowledging the independent contribution of clinical and demographic factors. Letter fluency was predominantly associated with language severity (R2 = 38%), and correlated with the volume of the left superior temporal regions (R2 = 12%) and the right dorsolateral prefrontal area (R2 = 5%). Semantic fluency was predominantly associated with dementia severity (R2 = 47%) and correlated with the volume of the left inferior temporal gyrus (R2 = 7%). No other variables were significantly associated with performance in the two VF tasks. We concluded that, independently of disease severity, letter fluency is significantly associated with the volume of frontal and temporal areas whereas semantic fluency is associated mainly with the volume of temporal areas. Furthermore, our findings indicated that clinical severity plays a critical role in explaining VF performance in PPA, compared to the other clinical and demographic factors.
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Affiliation(s)
- Marianna Riello
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (M.R.); (B.F.); (K.T.W.); (J.E.D.); (A.E.H.)
| | - Constantine E. Frangakis
- Department of Biostatistics, Johns Hopkins School of Public Health, Baltimore, MD 21227, USA;
- Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD 21227, USA;
- Department of Psychiatry and Behavioral Sciences, Johns Hopkins School of Medicine, Baltimore, MD 21227, USA
| | - Bronte Ficek
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (M.R.); (B.F.); (K.T.W.); (J.E.D.); (A.E.H.)
| | - Kimberly T. Webster
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (M.R.); (B.F.); (K.T.W.); (J.E.D.); (A.E.H.)
- Department of Otolaryngology, Head and Neck Surgery, Johns Hopkins School of Medicine, Baltimore, MD 21227, USA
| | - John E. Desmond
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (M.R.); (B.F.); (K.T.W.); (J.E.D.); (A.E.H.)
| | - Andreia V. Faria
- Department of Radiology, Johns Hopkins School of Medicine, Baltimore, MD 21227, USA;
| | - Argye E. Hillis
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (M.R.); (B.F.); (K.T.W.); (J.E.D.); (A.E.H.)
- Department of Cognitive Science, Johns Hopkins University, Baltimore, MD 21218, USA
- Department of Physical Medicine and Rehabilitation, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA
| | - Kyrana Tsapkini
- Department of Neurology, Johns Hopkins School of Medicine, Baltimore, MD 21205, USA; (M.R.); (B.F.); (K.T.W.); (J.E.D.); (A.E.H.)
- Department of Cognitive Science, Johns Hopkins University, Baltimore, MD 21218, USA
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Kim H, Kintz S, Wright HH. Development of a measure of function word use in narrative discourse: core lexicon analysis in aphasia. INTERNATIONAL JOURNAL OF LANGUAGE & COMMUNICATION DISORDERS 2021; 56:6-19. [PMID: 32909656 PMCID: PMC7902380 DOI: 10.1111/1460-6984.12567] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.3] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Subscribe] [Scholar Register] [Received: 06/30/2019] [Revised: 07/09/2020] [Accepted: 07/27/2020] [Indexed: 05/31/2023]
Abstract
BACKGROUND Although discourse-level assessments contribute to predicting real-world performance in persons with aphasia (PWA), the use of discourse measures is uncommon in clinical settings due to resource-heavy procedures. Moreover, assessing function word use in discourse requires the arduous procedure of defining grammatical categories for each word in language transcripts. AIMS The purpose of this exploratory study was twofold: (1) to develop core function word lists as a clinician-friendly means of evaluating function word use in discourse; and (2) to examine the ability of the core function word measure to differentiate PWA from cognitively healthy adults and persons with fluent aphasia from non-fluent aphasia. METHODS & PROCEDURES The 25 most commonly used function words (core function words) were extracted from narrative language samples from 470 cognitively healthy adults, which were divided into seven age groups (20s, 30s, 40s, 50s, 60s, 70s and 80s). The percent agreement of core function words for 11 PWA (fluent aphasia = 5; non-fluent aphasia = 6) and 11 age- and education-matched controls were then calculated. Percent agreement for the core function words produced was compared between the controls and the PWA group, and between participants with fluent aphasia and non-fluent aphasia. OUTCOMES & RESULTS The results indicated that PWA produced fewer core function words from the lists than the control group, and that core function word use was strongly correlated with aphasia severity. Persons with non-fluent aphasia produced fewer core function words than those with fluent aphasia, although this could be a confound of aphasia classification from the use of the Western Aphasia Battery (WAB)-Revised. CONCLUSIONS & IMPLICATIONS Core function word lists consisting of a limited number of items for quantifying function word use in discourse remain in a nascent stage of development. However, the findings are consistent with previous studies analysing the total production of function words in language samples produced by PWA. Therefore, core function words may potentially serve as a clinician-friendly manner of quantifying function words produced in discourse. What this paper adds What is already known on the subject Function word analysis in discourse requires arduous processes of identifying the error production and grammatical category of function words in discourse. Previous studies have demonstrated that core lexicon measures are an efficient, simple means of quantifying discourse in PWA. However, function words have never been considered for generating an independent core lexicon list. What this paper adds to existing knowledge As an exploratory study, we focused primarily on developing a clinician-friendly measure to evaluate function word production in discourse, motivated by the idea of an adaptation strategy within the core lexicon framework. Our findings demonstrated that by using a simple scoring system that the core lexicon measure provides, we differentiated the control group from the PWA group, and persons with fluent aphasia from persons with non-fluent aphasia. Additionally, we found significant correlations between function word production and aphasia severity determined by WAB Aphasia Quotient (AQ). What are the potential or actual clinical implications of this work? The results add empirical evidence for the utility of core function word lists for quantifying function word usage in discourse in PWA. Counting the presence and absence of function words in discourse will allow clinicians to avoid labour-intensive preparatory work, and to obtain useful diagnostic information in a less time-consuming way.
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Affiliation(s)
- Hana Kim
- Department of Communication Sciences and Disorders, East Carolina University, Greenville, NC, USA
| | - Stephen Kintz
- Department of Audiology and Speech Pathology, University of Arkansas, Little Rock, AK, USA
| | - Heather Harris Wright
- Department of Communication Sciences and Disorders, East Carolina University, Greenville, NC, USA
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Gordon JK. Factor Analysis of Spontaneous Speech in Aphasia. JOURNAL OF SPEECH, LANGUAGE, AND HEARING RESEARCH : JSLHR 2020; 63:4127-4147. [PMID: 33197361 DOI: 10.1044/2020_jslhr-20-00340] [Citation(s) in RCA: 2] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [MESH Headings] [Track Full Text] [Subscribe] [Scholar Register] [Indexed: 06/11/2023]
Abstract
Purpose Spontaneous speech tasks are critically important for characterizing spoken language production deficits in aphasia and for assessing the impact of therapy. The utility of such tasks arises from the complex interaction of linguistic demands (word retrieval, sentence formulation, articulation). However, this complexity also makes spontaneous speech hugely variable and difficult to assess. The current study aimed to simplify the problem by identifying latent factors underlying performance in spontaneous speech in aphasia. The ecological validity of the factors was examined by examining how well the factor structures corresponded to traditionally defined aphasia subtypes. Method A factor analysis was conducted on 17 microlinguistic measures of narratives from 274 individuals with aphasia in AphasiaBank. The resulting factor scores were compared across aphasia subtypes. Supervised (linear discriminant analysis) and unsupervised (latent profile analysis) classification techniques were then conducted on the factor scores and the solutions compared to traditional aphasia subtypes. Results Six factors were identified. Two reflected aspects of fluency, one at the phrase level (Phrase Building) and one at the narrative level (Narrative Productivity). Two other factors reflected the accuracy of productions, one at the word level (Semantic Anomaly) and one at the utterance level (Grammatical Error). The other two factors reflected the complexity of sentence structures (Grammatical Complexity) and the use of repair behaviors (Repair), respectively. Linear discriminant analyses showed that only about two thirds of speakers were classified correctly and that misclassifications were similar to disagreements between clinical diagnoses. The most accurately diagnosed syndromes were the largest groups-Broca's and anomic aphasia. The latent profile analysis also generated profiles similar to Broca's and anomic aphasia but separated some subtypes according to severity. Conclusions The factor solution and the classification analyses reflected broad patterns of spontaneous speech performance in a large and representative sample of individuals with aphasia. However, such data-driven approaches present a simplified picture of aphasia patterns, much as traditional syndrome categories do. To ensure ecological validity, a hybrid approach is recommended, balancing population-level analyses with examination of performance at the level of theoretically specified subgroups or individuals. Supplemental Material https://doi.org/10.23641/asha.13232354.
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Affiliation(s)
- Jean K Gordon
- Department of Communication Sciences and Disorders, University of Iowa, Iowa City
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Ding J, Martin RC, Hamilton AC, Schnur TT. Dissociation between frontal and temporal-parietal contributions to connected speech in acute stroke. Brain 2020; 143:862-876. [PMID: 32155246 PMCID: PMC7089660 DOI: 10.1093/brain/awaa027] [Citation(s) in RCA: 18] [Impact Index Per Article: 4.5] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 10/29/2019] [Revised: 12/03/2019] [Accepted: 12/17/2019] [Indexed: 02/04/2023] Open
Abstract
Humans are uniquely able to retrieve and combine words into syntactic structure to produce connected speech. Previous identification of focal brain regions necessary for production focused primarily on associations with the content produced by speakers with chronic stroke, where function may have shifted to other regions after reorganization occurred. Here, we relate patterns of brain damage with deficits to the content and structure of spontaneous connected speech in 52 speakers during the acute stage of a left hemisphere stroke. Multivariate lesion behaviour mapping demonstrated that damage to temporal-parietal regions impacted the ability to retrieve words and produce them within increasingly complex combinations. Damage primarily to inferior frontal cortex affected the production of syntactically accurate structure. In contrast to previous work, functional-anatomical dissociations did not depend on lesion size likely because acute lesions were smaller than typically found in chronic stroke. These results are consistent with predictions from theoretical models based primarily on evidence from language comprehension and highlight the importance of investigating individual differences in brain-language relationships in speakers with acute stroke.
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Affiliation(s)
- Junhua Ding
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA
| | - Randi C Martin
- Department of Psychological Sciences, Rice University, Houston, Texas, USA
| | - A Cris Hamilton
- Department of Institution Reporting, Research and Information Systems, University of Texas at Austin, Austin, Texas, USA
| | - Tatiana T Schnur
- Department of Neurosurgery, Baylor College of Medicine, Houston, Texas, USA
- Department of Neuroscience, Baylor College of Medicine, Houston, Texas, USA
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Alyahya RSW, Halai AD, Conroy P, Lambon Ralph MA. Mapping psycholinguistic features to the neuropsychological and lesion profiles in aphasia. Cortex 2019; 124:260-273. [PMID: 31958653 DOI: 10.1016/j.cortex.2019.12.002] [Citation(s) in RCA: 19] [Impact Index Per Article: 3.8] [Reference Citation Analysis] [Abstract] [Key Words] [MESH Headings] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/18/2019] [Revised: 06/04/2019] [Accepted: 12/04/2019] [Indexed: 11/17/2022]
Abstract
Naming and word retrieval deficits are two of the most persistent symptoms in chronic post-stroke aphasia. Naming success or failure on specific words can sometimes be predicted by the psycholinguistic properties of the word. Despite a wealth of literature investigating the influence of psycholinguistic properties in neuro-typical and clinical language processing, the underlying structure of these properties and their relation to the fundamental language components and neural correlates are unexplored. In this study, a multivariate data-decomposition approach was used to identify the underlying structure within a collection of psycholinguistic properties (word imageability, frequency, age-of-acquisition, familiarity, length, semantic diversity and phonological neighbourhood density) and their influence on naming accuracy was explored in a cohort of 42 participants with a diverse range of chronic post-stroke aphasia classifications and severities. The results extracted three principal psycholinguistic factors, which were best described as 'lexical usage', 'semantic clarity' and 'phonological complexity'. Furthermore, a novel approach was used to systematically relate the influence of these psycholinguistic properties to participants' neuropsychological and lesion profiles. The findings did not show a one-to-one mapping between psycholinguistic features and core language components. 'Lexical usage' was the only factor that showed a significant difference between fluent versus non-fluent aphasia groups in terms of the influence of this lexical factor on successful naming, and it was the only factor that was related to the pattern of patients' brain lesions. Voxel-wise whole brain lesion-symptom mapping identified left frontal regions, aligning with previous evidence that these regions are related to language production functions, including word retrieval and repetition. The evidence from the current study suggests that the functional locus of psycholinguistic properties is distributed across multiple language components rather than being localised to a single language element.
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Affiliation(s)
- Reem S W Alyahya
- MRC Cognition and Brain Sciences Unit, University of Cambridge, United Kingdom; King Fahad Medical City, Riyadh, Saudi Arabia; Neuroscience and Aphasia Research Unit, Division of Neuroscience & Experimental Psychology, University of Manchester, United Kingdom.
| | - Ajay D Halai
- MRC Cognition and Brain Sciences Unit, University of Cambridge, United Kingdom; Neuroscience and Aphasia Research Unit, Division of Neuroscience & Experimental Psychology, University of Manchester, United Kingdom
| | - Paul Conroy
- Neuroscience and Aphasia Research Unit, Division of Neuroscience & Experimental Psychology, University of Manchester, United Kingdom
| | - Matthew A Lambon Ralph
- MRC Cognition and Brain Sciences Unit, University of Cambridge, United Kingdom; Neuroscience and Aphasia Research Unit, Division of Neuroscience & Experimental Psychology, University of Manchester, United Kingdom.
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13
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Chenausky K, Paquette S, Norton A, Schlaug G. Apraxia of speech involves lesions of dorsal arcuate fasciculus and insula in patients with aphasia. Neurol Clin Pract 2019; 10:162-169. [PMID: 32309035 DOI: 10.1212/cpj.0000000000000699] [Citation(s) in RCA: 10] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/21/2019] [Accepted: 05/29/2019] [Indexed: 11/15/2022]
Abstract
Objective To determine the contributions of apraxia of speech (AOS) and anomia to conversational dysfluency. Methods In this observational study of 52 patients with chronic aphasia, 47 with concomitant AOS, fluency was quantified using correct information units per minute (CIUs/min) from propositional speech tasks. Videos of patients performing conversational, how-to and picture-description tasks, word and sentence repetition, and diadochokinetic tasks were used to diagnose AOS using the Apraxia of Speech Rating Scale (ASRS). Anomia was quantified by patients' scores on the 30 even-numbered items from the Boston Naming Test (BNT). Results Together, ASRS and BNT scores accounted for 51.4% of the total variance in CIUs/min; the ASRS score accounted for the majority of that variance. The BNT score was associated with lesions in the left superior temporal gyrus, left inferior frontal gyrus, and large parts of the insula. The global ASRS score was associated with lesions in the left dorsal arcuate fasciculus (AF), pre- and post-central gyri, and both banks of the central sulcus of the insula. The ASRS score for the primary distinguishing features of AOS (no overlap with features of aphasia) was associated with less AF and more insular involvement. Only ∼27% of this apraxia-specific lesion overlapped with lesions associated with the BNT score. Lesions associated with AOS had minimal overlap with the frontal aslant tract (FAT) (<1%) or the extreme capsule fiber tract (1.4%). Finally, ASRS scores correlated significantly with damage to the insula but not to the AF, extreme capsule, or FAT. Conclusions Results are consistent with previous findings identifying lesions of the insula and AF in patients with AOS, damage to both of which may create dysfluency in patients with aphasia.
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Affiliation(s)
- Karen Chenausky
- Sargent College (KC), Boston University; Department of Neurology (KC, SP, GS), Harvard Medical School; and Music, Neuroimaging, and Stroke Recovery Laboratory (KC, SP, AN, GS), Beth Israel Deaconess Medical Center, Boston
| | - Sébastien Paquette
- Sargent College (KC), Boston University; Department of Neurology (KC, SP, GS), Harvard Medical School; and Music, Neuroimaging, and Stroke Recovery Laboratory (KC, SP, AN, GS), Beth Israel Deaconess Medical Center, Boston
| | - Andrea Norton
- Sargent College (KC), Boston University; Department of Neurology (KC, SP, GS), Harvard Medical School; and Music, Neuroimaging, and Stroke Recovery Laboratory (KC, SP, AN, GS), Beth Israel Deaconess Medical Center, Boston
| | - Gottfried Schlaug
- Sargent College (KC), Boston University; Department of Neurology (KC, SP, GS), Harvard Medical School; and Music, Neuroimaging, and Stroke Recovery Laboratory (KC, SP, AN, GS), Beth Israel Deaconess Medical Center, Boston
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Mirman D, Thye M. Uncovering the Neuroanatomy of Core Language Systems Using Lesion-Symptom Mapping. CURRENT DIRECTIONS IN PSYCHOLOGICAL SCIENCE 2018. [DOI: 10.1177/0963721418787486] [Citation(s) in RCA: 13] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/12/2023]
Abstract
Recent studies have integrated noninvasive brain-imaging methods and advanced analysis techniques to study associations between the location of brain damage and cognitive deficits. By applying data-driven analysis methods to large sets of data on language deficits after stroke (aphasia), these studies have identified the cognitive systems that support language processing—phonology, semantics, fluency, and executive functioning—and their neural basis. Phonological processing is supported by dual pathways around the Sylvian fissure, a ventral speech-recognition component and a dorsal speech-production component; fluent sentence-level speech production relies on a more anterior frontal component, and the semantic system relies on a hub in the anterior temporal lobe and frontotemporal white-matter tracts. The executive function system was less consistently localized, possibly because of the kinds of brain damage tested in these studies. This review synthesizes the results of these studies, showing how they converge with contemporary models of primary systems that support perception, action, and conceptual knowledge across domains, and highlights some divergent findings and directions for future research.
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Affiliation(s)
- Daniel Mirman
- Department of Psychology, University of Alabama at Birmingham
| | - Melissa Thye
- Department of Psychology, University of Alabama at Birmingham
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